/*
 * Copyright (c) 1995, 2025, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package java.awt;

import java.awt.event.ComponentEvent;
import java.awt.event.FocusEvent;
import java.awt.event.KeyEvent;
import java.awt.event.MouseWheelEvent;
import java.awt.event.WindowEvent;
import java.awt.event.WindowFocusListener;
import java.awt.event.WindowListener;
import java.awt.event.WindowStateListener;
import java.awt.geom.Path2D;
import java.awt.geom.Point2D;
import java.awt.im.InputContext;
import java.awt.image.BufferStrategy;
import java.awt.peer.ComponentPeer;
import java.awt.peer.WindowPeer;
import java.beans.PropertyChangeListener;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.OptionalDataException;
import java.io.Serial;
import java.io.Serializable;
import java.lang.ref.WeakReference;
import java.lang.reflect.InvocationTargetException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.EventListener;
import java.util.Locale;
import java.util.ResourceBundle;
import java.util.Set;
import java.util.Vector;
import java.util.concurrent.atomic.AtomicBoolean;

import javax.accessibility.Accessible;
import javax.accessibility.AccessibleContext;
import javax.accessibility.AccessibleRole;
import javax.accessibility.AccessibleState;
import javax.accessibility.AccessibleStateSet;

import sun.awt.AWTAccessor;
import sun.awt.AppContext;
import sun.awt.DebugSettings;
import sun.awt.SunToolkit;
import sun.awt.util.IdentityArrayList;
import sun.java2d.pipe.Region;
import sun.util.logging.PlatformLogger;

/**
 * A {@code Window} object is a top-level window with no borders and no
 * menubar.
 * The default layout for a window is {@code BorderLayout}.
 * <p>
 * A window must have either a frame, dialog, or another window defined as its
 * owner when it's constructed.
 * <p>
 * In a multi-screen environment, you can create a {@code Window}
 * on a different screen device by constructing the {@code Window}
 * with {@link #Window(Window, GraphicsConfiguration)}.  The
 * {@code GraphicsConfiguration} object is one of the
 * {@code GraphicsConfiguration} objects of the target screen device.
 * <p>
 * In a virtual device multi-screen environment in which the desktop
 * area could span multiple physical screen devices, the bounds of all
 * configurations are relative to the virtual device coordinate system.
 * The origin of the virtual-coordinate system is at the upper left-hand
 * corner of the primary physical screen.  Depending on the location of
 * the primary screen in the virtual device, negative coordinates are
 * possible, as shown in the following figure.
 * <p>
 * <img src="doc-files/MultiScreen.gif"
 * alt="Diagram shows virtual device containing 4 physical screens. Primary
 * physical screen shows coords (0,0), other screen shows (-80,-100)."
 * style="margin: 7px 10px;">
 * <p>
 * In such an environment, when calling {@code setLocation},
 * you must pass a virtual coordinate to this method.  Similarly,
 * calling {@code getLocationOnScreen} on a {@code Window} returns
 * virtual device coordinates.  Call the {@code getBounds} method
 * of a {@code GraphicsConfiguration} to find its origin in the virtual
 * coordinate system.
 * <p>
 * The following code sets the location of a {@code Window}
 * at (10, 10) relative to the origin of the physical screen
 * of the corresponding {@code GraphicsConfiguration}.  If the
 * bounds of the {@code GraphicsConfiguration} is not taken
 * into account, the {@code Window} location would be set
 * at (10, 10) relative to the virtual-coordinate system and would appear
 * on the primary physical screen, which might be different from the
 * physical screen of the specified {@code GraphicsConfiguration}.
 *
 * <pre>
 *      Window w = new Window(Window owner, GraphicsConfiguration gc);
 *      Rectangle bounds = gc.getBounds();
 *      w.setLocation(10 + bounds.x, 10 + bounds.y);
 * </pre>
 *
 * <p>
 * Note: the location and size of top-level windows (including
 * {@code Window}s, {@code Frame}s, and {@code Dialog}s)
 * are under the control of the desktop's window management system.
 * Calls to {@code setLocation}, {@code setSize}, and
 * {@code setBounds} are requests (not directives) which are
 * forwarded to the window management system.  Every effort will be
 * made to honor such requests.  However, in some cases the window
 * management system may ignore such requests, or modify the requested
 * geometry in order to place and size the {@code Window} in a way
 * that more closely matches the desktop settings.
 * <p>
 * Visual effects such as halos, shadows, motion effects and animations may be
 * applied to the window by the desktop window management system. These are
 * outside the knowledge and control of the AWT and so for the purposes of this
 * specification are not considered part of the top-level window.
 * <p>
 * Due to the asynchronous nature of native event handling, the results
 * returned by {@code getBounds}, {@code getLocation},
 * {@code getLocationOnScreen}, and {@code getSize} might not
 * reflect the actual geometry of the Window on screen until the last
 * request has been processed.  During the processing of subsequent
 * requests these values might change accordingly while the window
 * management system fulfills the requests.
 * <p>
 * An application may set the size and location of an invisible
 * {@code Window} arbitrarily, but the window management system may
 * subsequently change its size and/or location when the
 * {@code Window} is made visible. One or more {@code ComponentEvent}s
 * will be generated to indicate the new geometry.
 * <p>
 * Windows are capable of generating the following WindowEvents:
 * WindowOpened, WindowClosed, WindowGainedFocus, WindowLostFocus.
 *
 * @author      Sami Shaio
 * @author      Arthur van Hoff
 * @see WindowEvent
 * @see #addWindowListener
 * @see java.awt.BorderLayout
 * @since       1.0
 */
public class Window extends Container implements Accessible {

    /**
     * Enumeration of available <i>window types</i>.
     *
     * A window type defines the generic visual appearance and behavior of a
     * top-level window. For example, the type may affect the kind of
     * decorations of a decorated {@code Frame} or {@code Dialog} instance.
     * <p>
     * Some platforms may not fully support a certain window type. Depending on
     * the level of support, some properties of the window type may be
     * disobeyed.
     *
     * @see   #getType
     * @see   #setType
     * @since 1.7
     */
    public static enum Type {
        /**
         * Represents a <i>normal</i> window.
         *
         * This is the default type for objects of the {@code Window} class or
         * its descendants. Use this type for regular top-level windows.
         */
        NORMAL,

        /**
         * Represents a <i>utility</i> window.
         *
         * A utility window is usually a small window such as a toolbar or a
         * palette. The native system may render the window with smaller
         * title-bar if the window is either a {@code Frame} or a {@code
         * Dialog} object, and if it has its decorations enabled.
         */
        UTILITY,

        /**
         * Represents a <i>popup</i> window.
         *
         * A popup window is a temporary window such as a drop-down menu or a
         * tooltip. On some platforms, windows of that type may be forcibly
         * made undecorated even if they are instances of the {@code Frame} or
         * {@code Dialog} class, and have decorations enabled.
         */
        POPUP
    }

    /**
     * {@code icons} is the graphical way we can
     * represent the frames and dialogs.
     * {@code Window} can't display icon but it's
     * being inherited by owned {@code Dialog}s.
     *
     * @serial
     * @see #getIconImages
     * @see #setIconImages
     */
    transient java.util.List<Image> icons;

    /**
     * Holds the reference to the component which last had focus in this window
     * before it lost focus.
     */
    private transient Component temporaryLostComponent;

    static boolean systemSyncLWRequests = false;

    /**
     * @serial Focus transfers should be synchronous for lightweight component requests.
     */
    boolean syncLWRequests = false;
    transient boolean beforeFirstShow = true;
    private transient boolean disposing = false;
    transient WindowDisposerRecord disposerRecord = null;

    static final int OPENED = 0x01;

    /**
     * An Integer value representing the Window State.
     *
     * @serial
     * @since 1.2
     * @see #show
     */
    int state;

    /**
     * A boolean value representing Window always-on-top state
     * @since 1.5
     * @serial
     * @see #setAlwaysOnTop
     * @see #isAlwaysOnTop
     */
    private boolean alwaysOnTop;

    /**
     * Contains all the windows that have a peer object associated,
     * i. e. between addNotify() and removeNotify() calls. The list
     * of all Window instances can be obtained from AppContext object.
     *
     * @since 1.6
     */
    private static final IdentityArrayList<Window> allWindows = new IdentityArrayList<Window>();

    /**
     * A vector containing all the windows this
     * window currently owns.
     * @since 1.2
     * @see #getOwnedWindows
     */
    transient Vector<WeakReference<Window>> ownedWindowList =
                                            new Vector<WeakReference<Window>>();

    /*
     * We insert a weak reference into the Vector of all Windows in AppContext
     * instead of 'this' so that garbage collection can still take place
     * correctly.
     */
    private transient WeakReference<Window> weakThis;

    transient boolean showWithParent;

    /**
     * Contains the modal dialog that blocks this window, or null
     * if the window is unblocked.
     *
     * @since 1.6
     */
    transient Dialog modalBlocker;

    /**
     * @serial
     *
     * @see java.awt.Dialog.ModalExclusionType
     * @see #getModalExclusionType
     * @see #setModalExclusionType
     *
     * @since 1.6
     */
    Dialog.ModalExclusionType modalExclusionType;

    transient WindowListener windowListener;
    transient WindowStateListener windowStateListener;
    transient WindowFocusListener windowFocusListener;

    transient InputContext inputContext;
    private transient Object inputContextLock = new Object();

    /**
     * Unused. Maintained for serialization backward-compatibility.
     *
     * @serial
     * @since 1.2
     */
    private FocusManager focusMgr;

    /**
     * Indicates whether this Window can become the focused Window.
     *
     * @serial
     * @see #getFocusableWindowState
     * @see #setFocusableWindowState
     * @since 1.4
     */
    private boolean focusableWindowState = true;

    /**
     * Indicates whether this window should receive focus on
     * subsequently being shown (with a call to {@code setVisible(true)}), or
     * being moved to the front (with a call to {@code toFront()}).
     *
     * @serial
     * @see #setAutoRequestFocus
     * @see #isAutoRequestFocus
     * @since 1.7
     */
    private volatile boolean autoRequestFocus = true;

    /*
     * Indicates that this window is being shown. This flag is set to true at
     * the beginning of show() and to false at the end of show().
     *
     * @see #show()
     * @see Dialog#shouldBlock
     */
    transient boolean isInShow = false;

    /**
     * The opacity level of the window
     *
     * @serial
     * @see #setOpacity(float)
     * @see #getOpacity()
     * @since 1.7
     */
    private volatile float opacity = 1.0f;

    /**
     * The shape assigned to this window. This field is set to {@code null} if
     * no shape is set (rectangular window).
     *
     * @serial
     * @see #getShape()
     * @see #setShape(Shape)
     * @since 1.7
     */
    @SuppressWarnings("serial") // Not statically typed as Serializable
    private Shape shape = null;

    private static final String base = "win";
    private static int nameCounter = 0;

    /**
     * Use serialVersionUID from JDK 1.1 for interoperability.
     */
    @Serial
    private static final long serialVersionUID = 4497834738069338734L;

    private static final PlatformLogger log = PlatformLogger.getLogger("java.awt.Window");

    private static final boolean locationByPlatformProp;

    transient boolean isTrayIconWindow = false;

    static {
        /* ensure that the necessary native libraries are loaded */
        Toolkit.loadLibraries();
        if (!GraphicsEnvironment.isHeadless()) {
            initIDs();
        }

        String s = System.getProperty("java.awt.syncLWRequests");
        systemSyncLWRequests = "true".equals(s);
        String s2 = System.getProperty("java.awt.Window.locationByPlatform");
        locationByPlatformProp = "true".equals(s2);
    }

    /**
     * Initialize JNI field and method IDs for fields that may be
       accessed from C.
     */
    private static native void initIDs();

    /**
     * Constructs a new, initially invisible window in default size with the
     * specified {@code GraphicsConfiguration}.
     * <p>
     *
     * @param gc the {@code GraphicsConfiguration} of the target screen
     *     device. If {@code gc} is {@code null}, the system default
     *     {@code GraphicsConfiguration} is assumed
     * @throws IllegalArgumentException if {@code gc}
     *    is not from a screen device
     * @throws HeadlessException when
     *     {@code GraphicsEnvironment.isHeadless()} returns {@code true}
     *
     * @see java.awt.GraphicsEnvironment#isHeadless
     */
    Window(GraphicsConfiguration gc) {
        init(gc);
    }

    transient Object anchor = new Object();
    static class WindowDisposerRecord implements sun.java2d.DisposerRecord {
        WeakReference<Window> owner;
        final WeakReference<Window> weakThis;
        final WeakReference<AppContext> context;

        WindowDisposerRecord(AppContext context, Window victim) {
            weakThis = victim.weakThis;
            this.context = new WeakReference<AppContext>(context);
        }

        public void updateOwner() {
            Window victim = weakThis.get();
            owner = (victim == null)
                    ? null
                    : new WeakReference<Window>(victim.getOwner());
        }

        public void dispose() {
            if (owner != null) {
                Window parent = owner.get();
                if (parent != null) {
                    parent.removeOwnedWindow(weakThis);
                }
            }
            AppContext ac = context.get();
            if (null != ac) {
                Window.removeFromWindowList(ac, weakThis);
            }
        }
    }

    private GraphicsConfiguration initGC(GraphicsConfiguration gc) {
        GraphicsEnvironment.checkHeadless();

        if (gc == null) {
            gc = GraphicsEnvironment.getLocalGraphicsEnvironment().
                getDefaultScreenDevice().getDefaultConfiguration();
        }
        setGraphicsConfiguration(gc);

        return gc;
    }

    private void init(GraphicsConfiguration gc) {
        GraphicsEnvironment.checkHeadless();

        syncLWRequests = systemSyncLWRequests;

        weakThis = new WeakReference<Window>(this);
        addToWindowList();

        this.cursor = Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR);
        this.visible = false;

        gc = initGC(gc);

        if (gc.getDevice().getType() !=
            GraphicsDevice.TYPE_RASTER_SCREEN) {
            throw new IllegalArgumentException("not a screen device");
        }
        setLayout(new BorderLayout());

        /* offset the initial location with the original of the screen */
        /* and any insets                                              */
        Rectangle screenBounds = gc.getBounds();
        Insets screenInsets = getToolkit().getScreenInsets(gc);
        int x = getX() + screenBounds.x + screenInsets.left;
        int y = getY() + screenBounds.y + screenInsets.top;
        if (x != this.x || y != this.y) {
            setLocation(x, y);
            /* reset after setLocation */
            setLocationByPlatform(locationByPlatformProp);
        }

        modalExclusionType = Dialog.ModalExclusionType.NO_EXCLUDE;
        disposerRecord = new WindowDisposerRecord(appContext, this);
        sun.java2d.Disposer.addRecord(anchor, disposerRecord);

        SunToolkit.checkAndSetPolicy(this);
    }

    /**
     * Constructs a new, initially invisible window in the default size.
     * <p>
     *
     * @throws HeadlessException when
     *     {@code GraphicsEnvironment.isHeadless()} returns {@code true}
     *
     * @see java.awt.GraphicsEnvironment#isHeadless
     */
    Window() throws HeadlessException {
        GraphicsEnvironment.checkHeadless();
        init((GraphicsConfiguration)null);
    }

    /**
     * Constructs a new, initially invisible window with the specified
     * {@code Frame} as its owner. The window will not be focusable
     * unless its owner is showing on the screen.
     *
     * @param owner the {@code Frame} to act as owner or {@code null}
     *    if this window has no owner
     * @throws IllegalArgumentException if the {@code owner}'s
     *    {@code GraphicsConfiguration} is not from a screen device
     * @throws HeadlessException when
     *    {@code GraphicsEnvironment.isHeadless} returns {@code true}
     *
     * @see java.awt.GraphicsEnvironment#isHeadless
     * @see #isShowing
     */
    public Window(Frame owner) {
        this(owner == null ? (GraphicsConfiguration)null :
            owner.getGraphicsConfiguration());
        ownedInit(owner);
    }

    /**
     * Constructs a new, initially invisible window with the specified
     * {@code Window} as its owner. This window will not be focusable
     * unless its nearest owning {@code Frame} or {@code Dialog}
     * is showing on the screen.
     *
     * @param owner the {@code Window} to act as owner or
     *     {@code null} if this window has no owner
     * @throws IllegalArgumentException if the {@code owner}'s
     *     {@code GraphicsConfiguration} is not from a screen device
     * @throws HeadlessException when
     *     {@code GraphicsEnvironment.isHeadless()} returns
     *     {@code true}
     *
     * @see       java.awt.GraphicsEnvironment#isHeadless
     * @see       #isShowing
     *
     * @since     1.2
     */
    public Window(Window owner) {
        this(owner == null ? (GraphicsConfiguration)null :
            owner.getGraphicsConfiguration());
        ownedInit(owner);
    }

    /**
     * Constructs a new, initially invisible window with the specified owner
     * {@code Window} and a {@code GraphicsConfiguration}
     * of a screen device. The Window will not be focusable unless
     * its nearest owning {@code Frame} or {@code Dialog}
     * is showing on the screen.
     *
     * @param owner the window to act as owner or {@code null}
     *     if this window has no owner
     * @param gc the {@code GraphicsConfiguration} of the target
     *     screen device; if {@code gc} is {@code null},
     *     the system default {@code GraphicsConfiguration} is assumed
     * @throws IllegalArgumentException if {@code gc}
     *     is not from a screen device
     * @throws HeadlessException when
     *     {@code GraphicsEnvironment.isHeadless()} returns
     *     {@code true}
     *
     * @see       java.awt.GraphicsEnvironment#isHeadless
     * @see       GraphicsConfiguration#getBounds
     * @see       #isShowing
     * @since     1.3
     */
    public Window(Window owner, GraphicsConfiguration gc) {
        this(gc);
        ownedInit(owner);
    }

    private void ownedInit(Window owner) {
        this.parent = owner;
        if (owner != null) {
            owner.addOwnedWindow(weakThis);
            if (owner.isAlwaysOnTop()) {
                setAlwaysOnTop(true);
            }
        }

        // WindowDisposerRecord requires a proper value of parent field.
        disposerRecord.updateOwner();
    }

    /**
     * Construct a name for this component.  Called by getName() when the
     * name is null.
     */
    String constructComponentName() {
        synchronized (Window.class) {
            return base + nameCounter++;
        }
    }

    /**
     * Returns the sequence of images to be displayed as the icon for this window.
     * <p>
     * This method returns a copy of the internally stored list, so all operations
     * on the returned object will not affect the window's behavior.
     *
     * @return    the copy of icon images' list for this window, or
     *            empty list if this window doesn't have icon images.
     * @see       #setIconImages
     * @see       #setIconImage(Image)
     * @since     1.6
     */
    public java.util.List<Image> getIconImages() {
        java.util.List<Image> icons = this.icons;
        if (icons == null || icons.size() == 0) {
            return new ArrayList<Image>();
        }
        return new ArrayList<Image>(icons);
    }

    /**
     * Sets the sequence of images to be displayed as the icon
     * for this window. Subsequent calls to {@code getIconImages} will
     * always return a copy of the {@code icons} list.
     * <p>
     * Depending on the platform capabilities one or several images
     * of different dimensions will be used as the window's icon.
     * <p>
     * The {@code icons} list can contain {@code MultiResolutionImage} images also.
     * Suitable image depending on screen resolution is extracted from
     * base {@code MultiResolutionImage} image and added to the icons list
     * while base resolution image is removed from list.
     * The {@code icons} list is scanned for the images of most
     * appropriate dimensions from the beginning. If the list contains
     * several images of the same size, the first will be used.
     * <p>
     * Ownerless windows with no icon specified use platform-default icon.
     * The icon of an owned window may be inherited from the owner
     * unless explicitly overridden.
     * Setting the icon to {@code null} or empty list restores
     * the default behavior.
     * <p>
     * Note : Native windowing systems may use different images of differing
     * dimensions to represent a window, depending on the context (e.g.
     * window decoration, window list, taskbar, etc.). They could also use
     * just a single image for all contexts or no image at all.
     *
     * @param     icons the list of icon images to be displayed.
     * @see       #getIconImages()
     * @see       #setIconImage(Image)
     * @since     1.6
     */
    public synchronized void setIconImages(java.util.List<? extends Image> icons) {
        this.icons = (icons == null) ? new ArrayList<Image>() :
            new ArrayList<Image>(icons);
        WindowPeer peer = (WindowPeer)this.peer;
        if (peer != null) {
            peer.updateIconImages();
        }
        // Always send a property change event
        firePropertyChange("iconImage", null, null);
    }

    /**
     * Sets the image to be displayed as the icon for this window.
     * <p>
     * This method can be used instead of {@link #setIconImages setIconImages()}
     * to specify a single image as a window's icon.
     * <p>
     * The following statement:
     * <pre>
     *     setIconImage(image);
     * </pre>
     * is equivalent to:
     * <pre>
     *     ArrayList&lt;Image&gt; imageList = new ArrayList&lt;Image&gt;();
     *     imageList.add(image);
     *     setIconImages(imageList);
     * </pre>
     * <p>
     * Note : Native windowing systems may use different images of differing
     * dimensions to represent a window, depending on the context (e.g.
     * window decoration, window list, taskbar, etc.). They could also use
     * just a single image for all contexts or no image at all.
     *
     * @param     image the icon image to be displayed.
     * @see       #setIconImages
     * @see       #getIconImages()
     * @since     1.6
     */
    public void setIconImage(Image image) {
        ArrayList<Image> imageList = new ArrayList<Image>();
        if (image != null) {
            imageList.add(image);
        }
        setIconImages(imageList);
    }

    /**
     * Makes this Window displayable by creating the connection to its
     * native screen resource.
     * This method is called internally by the toolkit and should
     * not be called directly by programs.
     * @see Component#isDisplayable
     * @see Container#removeNotify
     * @since 1.0
     */
    public void addNotify() {
        synchronized (getTreeLock()) {
            Container parent = this.parent;
            if (parent != null && parent.peer == null) {
                parent.addNotify();
            }
            if (peer == null) {
                peer = getComponentFactory().createWindow(this);
            }
            synchronized (allWindows) {
                allWindows.add(this);
            }
            super.addNotify();
        }
    }

    /**
     * {@inheritDoc}
     */
    public void removeNotify() {
        synchronized (getTreeLock()) {
            synchronized (allWindows) {
                allWindows.remove(this);
            }
            super.removeNotify();
        }
    }

    /**
     * Causes this Window to be sized to fit the preferred size
     * and layouts of its subcomponents. The resulting width and
     * height of the window are automatically enlarged if either
     * of dimensions is less than the minimum size as specified
     * by the previous call to the {@code setMinimumSize} method.
     * <p>
     * If the window and/or its owner are not displayable yet,
     * both of them are made displayable before calculating
     * the preferred size. The Window is validated after its
     * size is being calculated.
     *
     * @see Component#isDisplayable
     * @see #setMinimumSize
     */
    public void pack() {
        Container parent = this.parent;
        if (parent != null && parent.peer == null) {
            parent.addNotify();
        }
        if (peer == null) {
            addNotify();
        }
        Dimension newSize = getPreferredSize();
        if (peer != null) {
            setClientSize(newSize.width, newSize.height);
        }

        if(beforeFirstShow) {
            isPacked = true;
        }

        validateUnconditionally();
    }

    /**
     * Sets the minimum size of this window to a constant
     * value.  Subsequent calls to {@code getMinimumSize}
     * will always return this value. If current window's
     * size is less than {@code minimumSize} the size of the
     * window is automatically enlarged to honor the minimum size.
     * <p>
     * If the {@code setSize} or {@code setBounds} methods
     * are called afterwards with a width or height less than
     * that was specified by the {@code setMinimumSize} method
     * the window is automatically enlarged to meet
     * the {@code minimumSize} value. The {@code minimumSize}
     * value also affects the behaviour of the {@code pack} method.
     * <p>
     * The default behavior is restored by setting the minimum size
     * parameter to the {@code null} value.
     * <p>
     * Resizing operation may be restricted if the user tries
     * to resize window below the {@code minimumSize} value.
     * This behaviour is platform-dependent.
     *
     * @param minimumSize the new minimum size of this window
     * @see Component#setMinimumSize
     * @see #getMinimumSize
     * @see #isMinimumSizeSet
     * @see #setSize(Dimension)
     * @see #pack
     * @since 1.6
     */
    public void setMinimumSize(Dimension minimumSize) {
        synchronized (getTreeLock()) {
            super.setMinimumSize(minimumSize);
            Dimension size = getSize();
            if (isMinimumSizeSet()) {
                if (size.width < minimumSize.width || size.height < minimumSize.height) {
                    int nw = Math.max(width, minimumSize.width);
                    int nh = Math.max(height, minimumSize.height);
                    setSize(nw, nh);
                }
            }
            if (peer != null) {
                ((WindowPeer)peer).updateMinimumSize();
            }
        }
    }

    /**
     * {@inheritDoc}
     * <p>
     * The {@code d.width} and {@code d.height} values
     * are automatically enlarged if either is less than
     * the minimum size as specified by previous call to
     * {@code setMinimumSize}.
     * <p>
     * The method changes the geometry-related data. Therefore,
     * the native windowing system may ignore such requests, or it may modify
     * the requested data, so that the {@code Window} object is placed and sized
     * in a way that corresponds closely to the desktop settings.
     *
     * @see #getSize
     * @see #setBounds
     * @see #setMinimumSize
     * @since 1.6
     */
    public void setSize(Dimension d) {
        super.setSize(d);
    }

    /**
     * {@inheritDoc}
     * <p>
     * The {@code width} and {@code height} values
     * are automatically enlarged if either is less than
     * the minimum size as specified by previous call to
     * {@code setMinimumSize}.
     * <p>
     * The method changes the geometry-related data. Therefore,
     * the native windowing system may ignore such requests, or it may modify
     * the requested data, so that the {@code Window} object is placed and sized
     * in a way that corresponds closely to the desktop settings.
     *
     * @see #getSize
     * @see #setBounds
     * @see #setMinimumSize
     * @since 1.6
     */
    public void setSize(int width, int height) {
        super.setSize(width, height);
    }

    /**
     * {@inheritDoc}
     * <p>
     * The method changes the geometry-related data. Therefore,
     * the native windowing system may ignore such requests, or it may modify
     * the requested data, so that the {@code Window} object is placed and sized
     * in a way that corresponds closely to the desktop settings.
     */
    @Override
    public void setLocation(int x, int y) {
        super.setLocation(x, y);
    }

    /**
     * {@inheritDoc}
     * <p>
     * The method changes the geometry-related data. Therefore,
     * the native windowing system may ignore such requests, or it may modify
     * the requested data, so that the {@code Window} object is placed and sized
     * in a way that corresponds closely to the desktop settings.
     */
    @Override
    public void setLocation(Point p) {
        super.setLocation(p);
    }

    /**
     * @deprecated As of JDK version 1.1,
     * replaced by {@code setBounds(int, int, int, int)}.
     */
    @Deprecated
    public void reshape(int x, int y, int width, int height) {
        if (isMinimumSizeSet()) {
            Dimension minSize = getMinimumSize();
            if (width < minSize.width) {
                width = minSize.width;
            }
            if (height < minSize.height) {
                height = minSize.height;
            }
        }
        super.reshape(x, y, width, height);
    }

    void setClientSize(int w, int h) {
        synchronized (getTreeLock()) {
            setBoundsOp(ComponentPeer.SET_CLIENT_SIZE);
            setBounds(x, y, w, h);
        }
    }

    private static final AtomicBoolean
        beforeFirstWindowShown = new AtomicBoolean(true);

    final void closeSplashScreen() {
        if (isTrayIconWindow) {
            return;
        }
        if (beforeFirstWindowShown.getAndSet(false)) {
            // We don't use SplashScreen.getSplashScreen() to avoid instantiating
            // the object if it hasn't been requested by user code explicitly
            SunToolkit.closeSplashScreen();
            SplashScreen.markClosed();
        }
    }

    /**
     * Shows or hides this {@code Window} depending on the value of parameter
     * {@code b}.
     * <p>
     * If the method shows the window then the window is also made
     * focused under the following conditions:
     * <ul>
     * <li> The {@code Window} meets the requirements outlined in the
     *      {@link #isFocusableWindow} method.
     * <li> The {@code Window}'s {@code autoRequestFocus} property is of the {@code true} value.
     * <li> Native windowing system allows the {@code Window} to get focused.
     * </ul>
     * There is an exception for the second condition (the value of the
     * {@code autoRequestFocus} property). The property is not taken into account if the
     * window is a modal dialog, which blocks the currently focused window.
     * <p>
     * Developers must never assume that the window is the focused or active window
     * until it receives a WINDOW_GAINED_FOCUS or WINDOW_ACTIVATED event.
     * @param b  if {@code true}, makes the {@code Window} visible,
     * otherwise hides the {@code Window}.
     * If the {@code Window} and/or its owner
     * are not yet displayable, both are made displayable.  The
     * {@code Window} will be validated prior to being made visible.
     * If the {@code Window} is already visible, this will bring the
     * {@code Window} to the front.<p>
     * If {@code false}, hides this {@code Window}, its subcomponents, and all
     * of its owned children.
     * The {@code Window} and its subcomponents can be made visible again
     * with a call to {@code #setVisible(true)}.
     * @see java.awt.Component#isDisplayable
     * @see java.awt.Component#setVisible
     * @see java.awt.Window#toFront
     * @see java.awt.Window#dispose
     * @see java.awt.Window#setAutoRequestFocus
     * @see java.awt.Window#isFocusableWindow
     */
    public void setVisible(boolean b) {
        super.setVisible(b);
    }

    /**
     * Makes the Window visible. If the Window and/or its owner
     * are not yet displayable, both are made displayable.  The
     * Window will be validated prior to being made visible.
     * If the Window is already visible, this will bring the Window
     * to the front.
     * @see       Component#isDisplayable
     * @see       #toFront
     * @deprecated As of JDK version 1.5, replaced by
     * {@link #setVisible(boolean)}.
     */
    @Deprecated
    public void show() {
        if (peer == null) {
            addNotify();
        }
        validateUnconditionally();

        isInShow = true;
        if (visible) {
            toFront();
        } else {
            beforeFirstShow = false;
            closeSplashScreen();
            Dialog.checkShouldBeBlocked(this);
            super.show();
            locationByPlatform = false;
            for (int i = 0; i < ownedWindowList.size(); i++) {
                Window child = ownedWindowList.elementAt(i).get();
                if ((child != null) && child.showWithParent) {
                    child.show();
                    child.showWithParent = false;
                }       // endif
            }   // endfor
            if (!isModalBlocked()) {
                updateChildrenBlocking();
            } else {
                // fix for 6532736: after this window is shown, its blocker
                // should be raised to front
                modalBlocker.toFront_NoClientCode();
            }
            if (this instanceof Frame || this instanceof Dialog) {
                updateChildFocusableWindowState(this);
            }
        }
        isInShow = false;

        // If first time shown, generate WindowOpened event
        if ((state & OPENED) == 0) {
            postWindowEvent(WindowEvent.WINDOW_OPENED);
            state |= OPENED;
        }
    }

    static void updateChildFocusableWindowState(Window w) {
        if (w.peer != null && w.isShowing()) {
            ((WindowPeer)w.peer).updateFocusableWindowState();
        }
        for (int i = 0; i < w.ownedWindowList.size(); i++) {
            Window child = w.ownedWindowList.elementAt(i).get();
            if (child != null) {
                updateChildFocusableWindowState(child);
            }
        }
    }

    synchronized void postWindowEvent(int id) {
        if (windowListener != null
            || (eventMask & AWTEvent.WINDOW_EVENT_MASK) != 0
            ||  Toolkit.enabledOnToolkit(AWTEvent.WINDOW_EVENT_MASK)) {
            WindowEvent e = new WindowEvent(this, id);
            Toolkit.getEventQueue().postEvent(e);
        }
    }

    /**
     * Hide this Window, its subcomponents, and all of its owned children.
     * The Window and its subcomponents can be made visible again
     * with a call to {@code show}.
     * @see #show
     * @see #dispose
     * @deprecated As of JDK version 1.5, replaced by
     * {@link #setVisible(boolean)}.
     */
    @Deprecated
    public void hide() {
        synchronized(ownedWindowList) {
            for (int i = 0; i < ownedWindowList.size(); i++) {
                Window child = ownedWindowList.elementAt(i).get();
                if ((child != null) && child.visible) {
                    child.hide();
                    child.showWithParent = true;
                }
            }
        }
        if (isModalBlocked()) {
            modalBlocker.unblockWindow(this);
        }
        super.hide();
        locationByPlatform = false;
    }

    final void clearMostRecentFocusOwnerOnHide() {
        /* do nothing */
    }

    /**
     * Releases all of the native screen resources used by this
     * {@code Window}, its subcomponents, and all of its owned
     * children. That is, the resources for these {@code Component}s
     * will be destroyed, any memory they consume will be returned to the
     * OS, and they will be marked as undisplayable.
     * <p>
     * The {@code Window} and its subcomponents can be made displayable
     * again by rebuilding the native resources with a subsequent call to
     * {@code pack} or {@code show}. The states of the recreated
     * {@code Window} and its subcomponents will be identical to the
     * states of these objects at the point where the {@code Window}
     * was disposed (not accounting for additional modifications between
     * those actions).
     * <p>
     * <b>Note</b>: When the last displayable window
     * within the Java virtual machine (VM) is disposed of, the VM may
     * terminate.  See <a href="doc-files/AWTThreadIssues.html#Autoshutdown">
     * AWT Threading Issues</a> for more information.
     * @see Component#isDisplayable
     * @see #pack
     * @see #show
     */
    public void dispose() {
        doDispose();
    }

    /*
     * Fix for 4872170.
     * If dispose() is called on parent then its children have to be disposed as well
     * as reported in javadoc. So we need to implement this functionality even if a
     * child overrides dispose() in a wrong way without calling super.dispose().
     */
    void disposeImpl() {
        dispose();
        if (peer != null) {
            doDispose();
        }
    }

    void doDispose() {
    class DisposeAction implements Runnable {
        public void run() {
            disposing = true;
            try {
                // Check if this window is the fullscreen window for the
                // device. Exit the fullscreen mode prior to disposing
                // of the window if that's the case.
                GraphicsDevice gd = getGraphicsConfiguration().getDevice();
                if (gd.getFullScreenWindow() == Window.this) {
                    gd.setFullScreenWindow(null);
                }

                Object[] ownedWindowArray;
                synchronized(ownedWindowList) {
                    ownedWindowArray = new Object[ownedWindowList.size()];
                    ownedWindowList.copyInto(ownedWindowArray);
                }
                for (int i = 0; i < ownedWindowArray.length; i++) {
                    Window child = (Window) (((WeakReference)
                                   (ownedWindowArray[i])).get());
                    if (child != null) {
                        child.disposeImpl();
                    }
                }
                hide();
                beforeFirstShow = true;
                removeNotify();
                synchronized (inputContextLock) {
                    if (inputContext != null) {
                        inputContext.dispose();
                        inputContext = null;
                    }
                }
                clearCurrentFocusCycleRootOnHide();
            } finally {
                disposing = false;
            }
        }
    }
        boolean fireWindowClosedEvent = isDisplayable();
        DisposeAction action = new DisposeAction();
        if (EventQueue.isDispatchThread()) {
            action.run();
        }
        else {
            try {
                EventQueue.invokeAndWait(this, action);
            }
            catch (InterruptedException e) {
                System.err.println("Disposal was interrupted:");
                e.printStackTrace();
            }
            catch (InvocationTargetException e) {
                System.err.println("Exception during disposal:");
                e.printStackTrace();
            }
        }
        // Execute outside the Runnable because postWindowEvent is
        // synchronized on (this). We don't need to synchronize the call
        // on the EventQueue anyways.
        if (fireWindowClosedEvent) {
            postWindowEvent(WindowEvent.WINDOW_CLOSED);
        }
    }

    /*
     * Should only be called while holding the tree lock.
     * It's overridden here because parent == owner in Window,
     * and we shouldn't adjust counter on owner
     */
    void adjustListeningChildrenOnParent(long mask, int num) {
    }

    // Should only be called while holding tree lock
    void adjustDescendantsOnParent(int num) {
        // do nothing since parent == owner and we shouldn't
        // adjust counter on owner
    }

    /**
     * If this Window is visible, brings this Window to the front and may make
     * it the focused Window.
     * <p>
     * Places this Window at the top of the stacking order and shows it in
     * front of any other Windows in this VM. No action will take place if this
     * Window is not visible. Some platforms do not allow Windows which own
     * other Windows to appear on top of those owned Windows. Some platforms
     * may not permit this VM to place its Windows above windows of native
     * applications, or Windows of other VMs. This permission may depend on
     * whether a Window in this VM is already focused. Every attempt will be
     * made to move this Window as high as possible in the stacking order;
     * however, developers should not assume that this method will move this
     * Window above all other windows in every situation.
     * <p>
     * Developers must never assume that this Window is the focused or active
     * Window until this Window receives a WINDOW_GAINED_FOCUS or WINDOW_ACTIVATED
     * event. On platforms where the top-most window is the focused window, this
     * method will <b>probably</b> focus this Window (if it is not already focused)
     * under the following conditions:
     * <ul>
     * <li> The window meets the requirements outlined in the
     *      {@link #isFocusableWindow} method.
     * <li> The window's property {@code autoRequestFocus} is of the
     *      {@code true} value.
     * <li> Native windowing system allows the window to get focused.
     * </ul>
     * On platforms where the stacking order does not typically affect the focused
     * window, this method will <b>probably</b> leave the focused and active
     * Windows unchanged.
     * <p>
     * If this method causes this Window to be focused, and this Window is a
     * Frame or a Dialog, it will also become activated. If this Window is
     * focused, but it is not a Frame or a Dialog, then the first Frame or
     * Dialog that is an owner of this Window will be activated.
     * <p>
     * If this window is blocked by modal dialog, then the blocking dialog
     * is brought to the front and remains above the blocked window.
     *
     * @see       #toBack
     * @see       #setAutoRequestFocus
     * @see       #isFocusableWindow
     */
    public void toFront() {
        toFront_NoClientCode();
    }

    // This functionality is implemented in a final package-private method
    // to insure that it cannot be overridden by client subclasses.
    final void toFront_NoClientCode() {
        if (visible) {
            WindowPeer peer = (WindowPeer)this.peer;
            if (peer != null) {
                peer.toFront();
            }
            if (isModalBlocked()) {
                modalBlocker.toFront_NoClientCode();
            }
        }
    }

    /**
     * If this Window is visible, sends this Window to the back and may cause
     * it to lose focus or activation if it is the focused or active Window.
     * <p>
     * Places this Window at the bottom of the stacking order and shows it
     * behind any other Windows in this VM. No action will take place is this
     * Window is not visible. Some platforms do not allow Windows which are
     * owned by other Windows to appear below their owners. Every attempt will
     * be made to move this Window as low as possible in the stacking order;
     * however, developers should not assume that this method will move this
     * Window below all other windows in every situation.
     * <p>
     * Because of variations in native windowing systems, no guarantees about
     * changes to the focused and active Windows can be made. Developers must
     * never assume that this Window is no longer the focused or active Window
     * until this Window receives a WINDOW_LOST_FOCUS or WINDOW_DEACTIVATED
     * event. On platforms where the top-most window is the focused window,
     * this method will <b>probably</b> cause this Window to lose focus. In
     * that case, the next highest, focusable Window in this VM will receive
     * focus. On platforms where the stacking order does not typically affect
     * the focused window, this method will <b>probably</b> leave the focused
     * and active Windows unchanged.
     *
     * @see       #toFront
     */
    public void toBack() {
        toBack_NoClientCode();
    }

    // This functionality is implemented in a final package-private method
    // to insure that it cannot be overridden by client subclasses.
    final void toBack_NoClientCode() {
        if(isAlwaysOnTop()) {
            setAlwaysOnTop(false);
        }
        if (visible) {
            WindowPeer peer = (WindowPeer)this.peer;
            if (peer != null) {
                peer.toBack();
            }
        }
    }

    /**
     * Returns the toolkit of this frame.
     * @return    the toolkit of this window.
     * @see       Toolkit
     * @see       Toolkit#getDefaultToolkit
     * @see       Component#getToolkit
     */
    public Toolkit getToolkit() {
        return Toolkit.getDefaultToolkit();
    }

    /**
     * Gets the warning string that is displayed with this window.
     * <p>
     * Warning strings are no longer applicable,
     * so this method always returns {@code null} and may be
     * removed in a future release.
     * @return    null
     * @deprecated since JDK 24
     */
    @Deprecated(since="24", forRemoval=true)
    public final String getWarningString() {
        return null;
    }

    /**
     * Gets the {@code Locale} object that is associated
     * with this window, if the locale has been set.
     * If no locale has been set, then the default locale
     * is returned.
     * @return    the locale that is set for this window.
     * @see       java.util.Locale
     * @since     1.1
     */
    public Locale getLocale() {
      if (this.locale == null) {
        return Locale.getDefault();
      }
      return this.locale;
    }

    /**
     * Gets the input context for this window. A window always has an input context,
     * which is shared by subcomponents unless they create and set their own.
     * @see Component#getInputContext
     * @since 1.2
     */
    public InputContext getInputContext() {
        synchronized (inputContextLock) {
            if (inputContext == null) {
                inputContext = InputContext.getInstance();
            }
        }
        return inputContext;
    }

    /**
     * Set the cursor image to a specified cursor.
     * <p>
     * The method may have no visual effect if the Java platform
     * implementation and/or the native system do not support
     * changing the mouse cursor shape.
     * @param     cursor One of the constants defined
     *            by the {@code Cursor} class. If this parameter is null
     *            then the cursor for this window will be set to the type
     *            Cursor.DEFAULT_CURSOR.
     * @see       Component#getCursor
     * @see       Cursor
     * @since     1.1
     */
    public void setCursor(Cursor cursor) {
        if (cursor == null) {
            cursor = Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR);
        }
        super.setCursor(cursor);
    }

    /**
     * Returns the owner of this window.
     *
     * @return the owner of this window
     * @since 1.2
     */
    public Window getOwner() {
        return getOwner_NoClientCode();
    }
    final Window getOwner_NoClientCode() {
        return (Window)parent;
    }

    /**
     * Return an array containing all the windows this
     * window currently owns.
     *
     * @return the array of all the owned windows
     * @since 1.2
     */
    public Window[] getOwnedWindows() {
        return getOwnedWindows_NoClientCode();
    }
    final Window[] getOwnedWindows_NoClientCode() {
        Window[] realCopy;

        synchronized(ownedWindowList) {
            // Recall that ownedWindowList is actually a Vector of
            // WeakReferences and calling get() on one of these references
            // may return null. Make two arrays-- one the size of the
            // Vector (fullCopy with size fullSize), and one the size of
            // all non-null get()s (realCopy with size realSize).
            int fullSize = ownedWindowList.size();
            int realSize = 0;
            Window[] fullCopy = new Window[fullSize];

            for (int i = 0; i < fullSize; i++) {
                fullCopy[realSize] = ownedWindowList.elementAt(i).get();

                if (fullCopy[realSize] != null) {
                    realSize++;
                }
            }

            if (fullSize != realSize) {
                realCopy = Arrays.copyOf(fullCopy, realSize);
            } else {
                realCopy = fullCopy;
            }
        }

        return realCopy;
    }

    boolean isModalBlocked() {
        return modalBlocker != null;
    }

    void setModalBlocked(Dialog blocker, boolean blocked, boolean peerCall) {
        this.modalBlocker = blocked ? blocker : null;
        if (peerCall) {
            WindowPeer peer = (WindowPeer)this.peer;
            if (peer != null) {
                peer.setModalBlocked(blocker, blocked);
            }
        }
    }

    Dialog getModalBlocker() {
        return modalBlocker;
    }

    /*
     * Returns a list of all displayable Windows, i. e. all the
     * Windows which peer is not null.
     *
     * @see #addNotify
     * @see #removeNotify
     */
    static IdentityArrayList<Window> getAllWindows() {
        synchronized (allWindows) {
            IdentityArrayList<Window> v = new IdentityArrayList<Window>();
            v.addAll(allWindows);
            return v;
        }
    }

    static IdentityArrayList<Window> getAllUnblockedWindows() {
        synchronized (allWindows) {
            IdentityArrayList<Window> unblocked = new IdentityArrayList<Window>();
            for (int i = 0; i < allWindows.size(); i++) {
                Window w = allWindows.get(i);
                if (!w.isModalBlocked()) {
                    unblocked.add(w);
                }
            }
            return unblocked;
        }
    }

    private static Window[] getWindows(AppContext appContext) {
        synchronized (Window.class) {
            Window[] realCopy;
            @SuppressWarnings("unchecked")
            Vector<WeakReference<Window>> windowList =
                (Vector<WeakReference<Window>>)appContext.get(Window.class);
            if (windowList != null) {
                int fullSize = windowList.size();
                int realSize = 0;
                Window[] fullCopy = new Window[fullSize];
                for (int i = 0; i < fullSize; i++) {
                    Window w = windowList.get(i).get();
                    if (w != null) {
                        fullCopy[realSize++] = w;
                    }
                }
                if (fullSize != realSize) {
                    realCopy = Arrays.copyOf(fullCopy, realSize);
                } else {
                    realCopy = fullCopy;
                }
            } else {
                realCopy = new Window[0];
            }
            return realCopy;
        }
    }

    /**
     * Returns an array of all {@code Window}s, both owned and ownerless,
     * created by this application.
     * If called from an applet, the array includes only the {@code Window}s
     * accessible by that applet.
     * <p>
     * <b>Warning:</b> this method may return system created windows, such
     * as a print dialog. Applications should not assume the existence of
     * these dialogs, nor should an application assume anything about these
     * dialogs such as component positions, {@code LayoutManager}s
     * or serialization.
     *
     * @return the array of all the {@code Window}s created by the application
     * @see Frame#getFrames
     * @see Window#getOwnerlessWindows
     *
     * @since 1.6
     */
    public static Window[] getWindows() {
        return getWindows(AppContext.getAppContext());
    }

    /**
     * Returns an array of all {@code Window}s created by this application
     * that have no owner. They include {@code Frame}s and ownerless
     * {@code Dialog}s and {@code Window}s.
     * If called from an applet, the array includes only the {@code Window}s
     * accessible by that applet.
     * <p>
     * <b>Warning:</b> this method may return system created windows, such
     * as a print dialog. Applications should not assume the existence of
     * these dialogs, nor should an application assume anything about these
     * dialogs such as component positions, {@code LayoutManager}s
     * or serialization.
     *
     * @return the array of all the ownerless {@code Window}s
     *         created by this application
     * @see Frame#getFrames
     * @see Window#getWindows()
     *
     * @since 1.6
     */
    public static Window[] getOwnerlessWindows() {
        Window[] allWindows = Window.getWindows();

        int ownerlessCount = 0;
        for (Window w : allWindows) {
            if (w.getOwner() == null) {
                ownerlessCount++;
            }
        }

        Window[] ownerless = new Window[ownerlessCount];
        int c = 0;
        for (Window w : allWindows) {
            if (w.getOwner() == null) {
                ownerless[c++] = w;
            }
        }

        return ownerless;
    }

    Window getDocumentRoot() {
        synchronized (getTreeLock()) {
            Window w = this;
            while (w.getOwner() != null) {
                w = w.getOwner();
            }
            return w;
        }
    }

    /**
     * Specifies the modal exclusion type for this window. If a window is modal
     * excluded, it is not blocked by some modal dialogs. See {@link
     * java.awt.Dialog.ModalExclusionType Dialog.ModalExclusionType} for
     * possible modal exclusion types.
     * <p>
     * If the given type is not supported, {@code NO_EXCLUDE} is used.
     * <p>
     * Note: changing the modal exclusion type for a visible window may have no
     * effect until it is hidden and then shown again.
     *
     * @param exclusionType the modal exclusion type for this window; a {@code null}
     *     value is equivalent to {@link Dialog.ModalExclusionType#NO_EXCLUDE
     *     NO_EXCLUDE}
     * @see java.awt.Dialog.ModalExclusionType
     * @see java.awt.Window#getModalExclusionType
     * @see java.awt.Toolkit#isModalExclusionTypeSupported
     *
     * @since 1.6
     */
    public void setModalExclusionType(Dialog.ModalExclusionType exclusionType) {
        if (exclusionType == null) {
            exclusionType = Dialog.ModalExclusionType.NO_EXCLUDE;
        }
        if (!Toolkit.getDefaultToolkit().isModalExclusionTypeSupported(exclusionType)) {
            exclusionType = Dialog.ModalExclusionType.NO_EXCLUDE;
        }
        if (modalExclusionType == exclusionType) {
            return;
        }
        modalExclusionType = exclusionType;

        // if we want on-fly changes, we need to uncomment the lines below
        //   and override the method in Dialog to use modalShow() instead
        //   of updateChildrenBlocking()
 /*
        if (isModalBlocked()) {
            modalBlocker.unblockWindow(this);
        }
        Dialog.checkShouldBeBlocked(this);
        updateChildrenBlocking();
 */
    }

    /**
     * Returns the modal exclusion type of this window.
     *
     * @return the modal exclusion type of this window
     *
     * @see java.awt.Dialog.ModalExclusionType
     * @see java.awt.Window#setModalExclusionType
     *
     * @since 1.6
     */
    public Dialog.ModalExclusionType getModalExclusionType() {
        return modalExclusionType;
    }

    boolean isModalExcluded(Dialog.ModalExclusionType exclusionType) {
        if ((modalExclusionType != null) &&
            modalExclusionType.compareTo(exclusionType) >= 0)
        {
            return true;
        }
        Window owner = getOwner_NoClientCode();
        return (owner != null) && owner.isModalExcluded(exclusionType);
    }

    void updateChildrenBlocking() {
        ArrayList<Window> childHierarchy = new ArrayList<>();
        Window[] ownedWindows = getOwnedWindows();
        for (int i = 0; i < ownedWindows.length; i++) {
            childHierarchy.add(ownedWindows[i]);
        }
        int k = 0;
        while (k < childHierarchy.size()) {
            Window w = childHierarchy.get(k);
            if (w.isVisible()) {
                if (w.isModalBlocked()) {
                    Dialog blocker = w.getModalBlocker();
                    blocker.unblockWindow(w);
                }
                Dialog.checkShouldBeBlocked(w);
                Window[] wOwned = w.getOwnedWindows();
                for (int j = 0; j < wOwned.length; j++) {
                    childHierarchy.add(wOwned[j]);
                }
            }
            k++;
        }
    }

    /**
     * Adds the specified window listener to receive window events from
     * this window.
     * If l is null, no exception is thrown and no action is performed.
     * <p>Refer to <a href="doc-files/AWTThreadIssues.html#ListenersThreads"
     * >AWT Threading Issues</a> for details on AWT's threading model.
     *
     * @param   l the window listener
     * @see #removeWindowListener
     * @see #getWindowListeners
     */
    public synchronized void addWindowListener(WindowListener l) {
        if (l == null) {
            return;
        }
        newEventsOnly = true;
        windowListener = AWTEventMulticaster.add(windowListener, l);
    }

    /**
     * Adds the specified window state listener to receive window
     * events from this window.  If {@code l} is {@code null},
     * no exception is thrown and no action is performed.
     * <p>Refer to <a href="doc-files/AWTThreadIssues.html#ListenersThreads"
     * >AWT Threading Issues</a> for details on AWT's threading model.
     *
     * @param   l the window state listener
     * @see #removeWindowStateListener
     * @see #getWindowStateListeners
     * @since 1.4
     */
    public synchronized void addWindowStateListener(WindowStateListener l) {
        if (l == null) {
            return;
        }
        windowStateListener = AWTEventMulticaster.add(windowStateListener, l);
        newEventsOnly = true;
    }

    /**
     * Adds the specified window focus listener to receive window events
     * from this window.
     * If l is null, no exception is thrown and no action is performed.
     * <p>Refer to <a href="doc-files/AWTThreadIssues.html#ListenersThreads"
     * >AWT Threading Issues</a> for details on AWT's threading model.
     *
     * @param   l the window focus listener
     * @see #removeWindowFocusListener
     * @see #getWindowFocusListeners
     * @since 1.4
     */
    public synchronized void addWindowFocusListener(WindowFocusListener l) {
        if (l == null) {
            return;
        }
        windowFocusListener = AWTEventMulticaster.add(windowFocusListener, l);
        newEventsOnly = true;
    }

    /**
     * Removes the specified window listener so that it no longer
     * receives window events from this window.
     * If l is null, no exception is thrown and no action is performed.
     * <p>Refer to <a href="doc-files/AWTThreadIssues.html#ListenersThreads"
     * >AWT Threading Issues</a> for details on AWT's threading model.
     *
     * @param   l the window listener
     * @see #addWindowListener
     * @see #getWindowListeners
     */
    public synchronized void removeWindowListener(WindowListener l) {
        if (l == null) {
            return;
        }
        windowListener = AWTEventMulticaster.remove(windowListener, l);
    }

    /**
     * Removes the specified window state listener so that it no
     * longer receives window events from this window.  If
     * {@code l} is {@code null}, no exception is thrown and
     * no action is performed.
     * <p>Refer to <a href="doc-files/AWTThreadIssues.html#ListenersThreads"
     * >AWT Threading Issues</a> for details on AWT's threading model.
     *
     * @param   l the window state listener
     * @see #addWindowStateListener
     * @see #getWindowStateListeners
     * @since 1.4
     */
    public synchronized void removeWindowStateListener(WindowStateListener l) {
        if (l == null) {
            return;
        }
        windowStateListener = AWTEventMulticaster.remove(windowStateListener, l);
    }

    /**
     * Removes the specified window focus listener so that it no longer
     * receives window events from this window.
     * If l is null, no exception is thrown and no action is performed.
     * <p>Refer to <a href="doc-files/AWTThreadIssues.html#ListenersThreads"
     * >AWT Threading Issues</a> for details on AWT's threading model.
     *
     * @param   l the window focus listener
     * @see #addWindowFocusListener
     * @see #getWindowFocusListeners
     * @since 1.4
     */
    public synchronized void removeWindowFocusListener(WindowFocusListener l) {
        if (l == null) {
            return;
        }
        windowFocusListener = AWTEventMulticaster.remove(windowFocusListener, l);
    }

    /**
     * Returns an array of all the window listeners
     * registered on this window.
     *
     * @return all of this window's {@code WindowListener}s
     *         or an empty array if no window
     *         listeners are currently registered
     *
     * @see #addWindowListener
     * @see #removeWindowListener
     * @since 1.4
     */
    public synchronized WindowListener[] getWindowListeners() {
        return getListeners(WindowListener.class);
    }

    /**
     * Returns an array of all the window focus listeners
     * registered on this window.
     *
     * @return all of this window's {@code WindowFocusListener}s
     *         or an empty array if no window focus
     *         listeners are currently registered
     *
     * @see #addWindowFocusListener
     * @see #removeWindowFocusListener
     * @since 1.4
     */
    public synchronized WindowFocusListener[] getWindowFocusListeners() {
        return getListeners(WindowFocusListener.class);
    }

    /**
     * Returns an array of all the window state listeners
     * registered on this window.
     *
     * @return all of this window's {@code WindowStateListener}s
     *         or an empty array if no window state
     *         listeners are currently registered
     *
     * @see #addWindowStateListener
     * @see #removeWindowStateListener
     * @since 1.4
     */
    public synchronized WindowStateListener[] getWindowStateListeners() {
        return getListeners(WindowStateListener.class);
    }


    /**
     * Returns an array of all the objects currently registered
     * as <code><em>Foo</em>Listener</code>s
     * upon this {@code Window}.
     * <code><em>Foo</em>Listener</code>s are registered using the
     * <code>add<em>Foo</em>Listener</code> method.
     *
     * <p>
     *
     * You can specify the {@code listenerType} argument
     * with a class literal, such as
     * <code><em>Foo</em>Listener.class</code>.
     * For example, you can query a
     * {@code Window w}
     * for its window listeners with the following code:
     *
     * <pre>WindowListener[] wls = (WindowListener[])(w.getListeners(WindowListener.class));</pre>
     *
     * If no such listeners exist, this method returns an empty array.
     *
     * @param listenerType the type of listeners requested; this parameter
     *          should specify an interface that descends from
     *          {@code java.util.EventListener}
     * @return an array of all objects registered as
     *          <code><em>Foo</em>Listener</code>s on this window,
     *          or an empty array if no such
     *          listeners have been added
     * @throws ClassCastException if {@code listenerType}
     *          doesn't specify a class or interface that implements
     *          {@code java.util.EventListener}
     * @throws NullPointerException if {@code listenerType} is {@code null}
     *
     * @see #getWindowListeners
     * @since 1.3
     */
    public <T extends EventListener> T[] getListeners(Class<T> listenerType) {
        EventListener l = null;
        if (listenerType == WindowFocusListener.class) {
            l = windowFocusListener;
        } else if (listenerType == WindowStateListener.class) {
            l = windowStateListener;
        } else if (listenerType == WindowListener.class) {
            l = windowListener;
        } else {
            return super.getListeners(listenerType);
        }
        return AWTEventMulticaster.getListeners(l, listenerType);
    }

    // REMIND: remove when filtering is handled at lower level
    boolean eventEnabled(AWTEvent e) {
        switch(e.id) {
          case WindowEvent.WINDOW_OPENED:
          case WindowEvent.WINDOW_CLOSING:
          case WindowEvent.WINDOW_CLOSED:
          case WindowEvent.WINDOW_ICONIFIED:
          case WindowEvent.WINDOW_DEICONIFIED:
          case WindowEvent.WINDOW_ACTIVATED:
          case WindowEvent.WINDOW_DEACTIVATED:
            if ((eventMask & AWTEvent.WINDOW_EVENT_MASK) != 0 ||
                windowListener != null) {
                return true;
            }
            return false;
          case WindowEvent.WINDOW_GAINED_FOCUS:
          case WindowEvent.WINDOW_LOST_FOCUS:
            if ((eventMask & AWTEvent.WINDOW_FOCUS_EVENT_MASK) != 0 ||
                windowFocusListener != null) {
                return true;
            }
            return false;
          case WindowEvent.WINDOW_STATE_CHANGED:
            if ((eventMask & AWTEvent.WINDOW_STATE_EVENT_MASK) != 0 ||
                windowStateListener != null) {
                return true;
            }
            return false;
          default:
            break;
        }
        return super.eventEnabled(e);
    }

    /**
     * Processes events on this window. If the event is an
     * {@code WindowEvent}, it invokes the
     * {@code processWindowEvent} method, else it invokes its
     * superclass's {@code processEvent}.
     * <p>Note that if the event parameter is {@code null}
     * the behavior is unspecified and may result in an
     * exception.
     *
     * @param e the event
     */
    protected void processEvent(AWTEvent e) {
        if (e instanceof WindowEvent) {
            switch (e.getID()) {
                case WindowEvent.WINDOW_OPENED:
                case WindowEvent.WINDOW_CLOSING:
                case WindowEvent.WINDOW_CLOSED:
                case WindowEvent.WINDOW_ICONIFIED:
                case WindowEvent.WINDOW_DEICONIFIED:
                case WindowEvent.WINDOW_ACTIVATED:
                case WindowEvent.WINDOW_DEACTIVATED:
                    processWindowEvent((WindowEvent)e);
                    break;
                case WindowEvent.WINDOW_GAINED_FOCUS:
                case WindowEvent.WINDOW_LOST_FOCUS:
                    processWindowFocusEvent((WindowEvent)e);
                    break;
                case WindowEvent.WINDOW_STATE_CHANGED:
                    processWindowStateEvent((WindowEvent)e);
                    break;
            }
            return;
        }
        super.processEvent(e);
    }

    /**
     * Processes window events occurring on this window by
     * dispatching them to any registered WindowListener objects.
     * NOTE: This method will not be called unless window events
     * are enabled for this component; this happens when one of the
     * following occurs:
     * <ul>
     * <li>A WindowListener object is registered via
     *     {@code addWindowListener}
     * <li>Window events are enabled via {@code enableEvents}
     * </ul>
     * <p>Note that if the event parameter is {@code null}
     * the behavior is unspecified and may result in an
     * exception.
     *
     * @param e the window event
     * @see Component#enableEvents
     */
    protected void processWindowEvent(WindowEvent e) {
        WindowListener listener = windowListener;
        if (listener != null) {
            switch(e.getID()) {
                case WindowEvent.WINDOW_OPENED:
                    listener.windowOpened(e);
                    break;
                case WindowEvent.WINDOW_CLOSING:
                    listener.windowClosing(e);
                    break;
                case WindowEvent.WINDOW_CLOSED:
                    listener.windowClosed(e);
                    break;
                case WindowEvent.WINDOW_ICONIFIED:
                    listener.windowIconified(e);
                    break;
                case WindowEvent.WINDOW_DEICONIFIED:
                    listener.windowDeiconified(e);
                    break;
                case WindowEvent.WINDOW_ACTIVATED:
                    listener.windowActivated(e);
                    break;
                case WindowEvent.WINDOW_DEACTIVATED:
                    listener.windowDeactivated(e);
                    break;
                default:
                    break;
            }
        }
    }

    /**
     * Processes window focus event occurring on this window by
     * dispatching them to any registered WindowFocusListener objects.
     * NOTE: this method will not be called unless window focus events
     * are enabled for this window. This happens when one of the
     * following occurs:
     * <ul>
     * <li>a WindowFocusListener is registered via
     *     {@code addWindowFocusListener}
     * <li>Window focus events are enabled via {@code enableEvents}
     * </ul>
     * <p>Note that if the event parameter is {@code null}
     * the behavior is unspecified and may result in an
     * exception.
     *
     * @param e the window focus event
     * @see Component#enableEvents
     * @since 1.4
     */
    protected void processWindowFocusEvent(WindowEvent e) {
        WindowFocusListener listener = windowFocusListener;
        if (listener != null) {
            switch (e.getID()) {
                case WindowEvent.WINDOW_GAINED_FOCUS:
                    listener.windowGainedFocus(e);
                    break;
                case WindowEvent.WINDOW_LOST_FOCUS:
                    listener.windowLostFocus(e);
                    break;
                default:
                    break;
            }
        }
    }

    /**
     * Processes window state event occurring on this window by
     * dispatching them to any registered {@code WindowStateListener}
     * objects.
     * NOTE: this method will not be called unless window state events
     * are enabled for this window.  This happens when one of the
     * following occurs:
     * <ul>
     * <li>a {@code WindowStateListener} is registered via
     *    {@code addWindowStateListener}
     * <li>window state events are enabled via {@code enableEvents}
     * </ul>
     * <p>Note that if the event parameter is {@code null}
     * the behavior is unspecified and may result in an
     * exception.
     *
     * @param e the window state event
     * @see java.awt.Component#enableEvents
     * @since 1.4
     */
    protected void processWindowStateEvent(WindowEvent e) {
        WindowStateListener listener = windowStateListener;
        if (listener != null) {
            switch (e.getID()) {
                case WindowEvent.WINDOW_STATE_CHANGED:
                    listener.windowStateChanged(e);
                    break;
                default:
                    break;
            }
        }
    }

    /**
     * Implements a debugging hook -- checks to see if
     * the user has typed <i>control-shift-F1</i>.  If so,
     * the list of child windows is dumped to {@code System.out}.
     * @param e  the keyboard event
     */
    void preProcessKeyEvent(KeyEvent e) {
        // Dump the list of child windows to System.out if debug is enabled.
        if (DebugSettings.getInstance().getBoolean("on", false)) {
            if (e.isActionKey() && e.getKeyCode() == KeyEvent.VK_F1 &&
                    e.isControlDown() && e.isShiftDown() &&
                    e.getID() == KeyEvent.KEY_PRESSED) {
                list(System.out, 0);
            }
        }
    }

    void postProcessKeyEvent(KeyEvent e) {
        // Do nothing
    }


    /**
     * Sets whether this window should always be above other windows.  If
     * there are multiple always-on-top windows, their relative order is
     * unspecified and platform dependent.
     * <p>
     * If some other window is already always-on-top then the
     * relative order between these windows is unspecified (depends on
     * platform).  No window can be brought to be over the always-on-top
     * window except maybe another always-on-top window.
     * <p>
     * All windows owned by an always-on-top window inherit this state and
     * automatically become always-on-top.  If a window ceases to be
     * always-on-top, the windows that it owns will no longer be
     * always-on-top.  When an always-on-top window is sent {@link #toBack
     * toBack}, its always-on-top state is set to {@code false}.
     *
     * <p> When this method is called on a window with a value of
     * {@code true}, and the window is visible and the platform
     * supports always-on-top for this window, the window is immediately
     * brought forward, "sticking" it in the top-most position. If the
     * window isn`t currently visible, this method sets the always-on-top
     * state to {@code true} but does not bring the window forward.
     * When the window is later shown, it will be always-on-top.
     *
     * <p> When this method is called on a window with a value of
     * {@code false} the always-on-top state is set to normal. It may also
     * cause an unspecified, platform-dependent change in the z-order of
     * top-level windows, but other always-on-top windows will remain in
     * top-most position. Calling this method with a value of {@code false}
     * on a window that has a normal state has no effect.
     *
     * <p><b>Note</b>: some platforms might not support always-on-top
     * windows.  To detect if always-on-top windows are supported by the
     * current platform, use {@link Toolkit#isAlwaysOnTopSupported()} and
     * {@link Window#isAlwaysOnTopSupported()}.  If always-on-top mode
     * isn't supported for this window or this window's toolkit does not
     * support always-on-top windows, calling this method has no effect.
     *
     * @param alwaysOnTop true if the window should always be above other
     *        windows
     *
     * @see #isAlwaysOnTop
     * @see #toFront
     * @see #toBack
     * @see #isAlwaysOnTopSupported
     * @see #getToolkit
     * @see Toolkit#isAlwaysOnTopSupported
     * @since 1.5
     */
    public final void setAlwaysOnTop(boolean alwaysOnTop) {
        boolean oldAlwaysOnTop;
        synchronized(this) {
            oldAlwaysOnTop = this.alwaysOnTop;
            this.alwaysOnTop = alwaysOnTop;
        }
        if (oldAlwaysOnTop != alwaysOnTop ) {
            if (isAlwaysOnTopSupported()) {
                WindowPeer peer = (WindowPeer)this.peer;
                synchronized(getTreeLock()) {
                    if (peer != null) {
                        peer.updateAlwaysOnTopState();
                    }
                }
            }
            firePropertyChange("alwaysOnTop", oldAlwaysOnTop, alwaysOnTop);
        }
        setOwnedWindowsAlwaysOnTop(alwaysOnTop);
    }

    @SuppressWarnings({"rawtypes", "unchecked"})
    private void setOwnedWindowsAlwaysOnTop(boolean alwaysOnTop) {
        WeakReference<Window>[] ownedWindowArray;
        synchronized (ownedWindowList) {
            ownedWindowArray = new WeakReference[ownedWindowList.size()];
            ownedWindowList.copyInto(ownedWindowArray);
        }

        for (WeakReference<Window> ref : ownedWindowArray) {
            Window window = ref.get();
            if (window != null) {
                window.setAlwaysOnTop(alwaysOnTop);
            }
        }
    }

    /**
     * Returns whether the always-on-top mode is supported for this
     * window. Some platforms may not support always-on-top windows, some
     * may support only some kinds of top-level windows; for example,
     * a platform may not support always-on-top modal dialogs.
     *
     * @return {@code true}, if the always-on-top mode is supported for
     *         this window and this window's toolkit supports always-on-top windows,
     *         {@code false} otherwise
     *
     * @see #setAlwaysOnTop(boolean)
     * @see #getToolkit
     * @see Toolkit#isAlwaysOnTopSupported
     * @since 1.6
     */
    public boolean isAlwaysOnTopSupported() {
        return Toolkit.getDefaultToolkit().isAlwaysOnTopSupported();
    }


    /**
     * Returns whether this window is an always-on-top window.
     * @return {@code true}, if the window is in always-on-top state,
     *         {@code false} otherwise
     * @see #setAlwaysOnTop
     * @since 1.5
     */
    public final boolean isAlwaysOnTop() {
        return alwaysOnTop;
    }


    /**
     * Returns the child Component of this Window that has focus if this Window
     * is focused; returns null otherwise.
     *
     * @return the child Component with focus, or null if this Window is not
     *         focused
     * @see #getMostRecentFocusOwner
     * @see #isFocused
     */
    public Component getFocusOwner() {
        return (isFocused())
            ? KeyboardFocusManager.getCurrentKeyboardFocusManager().
                  getFocusOwner()
            : null;
    }

    /**
     * Returns the child Component of this Window that will receive the focus
     * when this Window is focused. If this Window is currently focused, this
     * method returns the same Component as {@code getFocusOwner()}. If
     * this Window is not focused, then the child Component that most recently
     * requested focus will be returned. If no child Component has ever
     * requested focus, and this is a focusable Window, then this Window's
     * initial focusable Component is returned. If no child Component has ever
     * requested focus, and this is a non-focusable Window, null is returned.
     *
     * @return the child Component that will receive focus when this Window is
     *         focused
     * @see #getFocusOwner
     * @see #isFocused
     * @see #isFocusableWindow
     * @since 1.4
     */
    public Component getMostRecentFocusOwner() {
        if (isFocused()) {
            return getFocusOwner();
        } else {
            Component mostRecent =
                KeyboardFocusManager.getMostRecentFocusOwner(this);
            if (mostRecent != null) {
                return mostRecent;
            } else {
                return (isFocusableWindow())
                    ? getFocusTraversalPolicy().getInitialComponent(this)
                    : null;
            }
        }
    }

    /**
     * Returns whether this Window is active. Only a Frame or a Dialog may be
     * active. The native windowing system may denote the active Window or its
     * children with special decorations, such as a highlighted title bar. The
     * active Window is always either the focused Window, or the first Frame or
     * Dialog that is an owner of the focused Window.
     *
     * @return whether this is the active Window.
     * @see #isFocused
     * @since 1.4
     */
    public boolean isActive() {
        return (KeyboardFocusManager.getCurrentKeyboardFocusManager().
                getActiveWindow() == this);
    }

    /**
     * Returns whether this Window is focused. If there exists a focus owner,
     * the focused Window is the Window that is, or contains, that focus owner.
     * If there is no focus owner, then no Window is focused.
     * <p>
     * If the focused Window is a Frame or a Dialog it is also the active
     * Window. Otherwise, the active Window is the first Frame or Dialog that
     * is an owner of the focused Window.
     *
     * @return whether this is the focused Window.
     * @see #isActive
     * @since 1.4
     */
    public boolean isFocused() {
        return (KeyboardFocusManager.getCurrentKeyboardFocusManager().
                getGlobalFocusedWindow() == this);
    }

    /**
     * Gets a focus traversal key for this Window. (See {@code
     * setFocusTraversalKeys} for a full description of each key.)
     * <p>
     * If the traversal key has not been explicitly set for this Window,
     * then this Window's parent's traversal key is returned. If the
     * traversal key has not been explicitly set for any of this Window's
     * ancestors, then the current KeyboardFocusManager's default traversal key
     * is returned.
     *
     * @param id one of KeyboardFocusManager.FORWARD_TRAVERSAL_KEYS,
     *         KeyboardFocusManager.BACKWARD_TRAVERSAL_KEYS,
     *         KeyboardFocusManager.UP_CYCLE_TRAVERSAL_KEYS, or
     *         KeyboardFocusManager.DOWN_CYCLE_TRAVERSAL_KEYS
     * @return the AWTKeyStroke for the specified key
     * @see Container#setFocusTraversalKeys
     * @see KeyboardFocusManager#FORWARD_TRAVERSAL_KEYS
     * @see KeyboardFocusManager#BACKWARD_TRAVERSAL_KEYS
     * @see KeyboardFocusManager#UP_CYCLE_TRAVERSAL_KEYS
     * @see KeyboardFocusManager#DOWN_CYCLE_TRAVERSAL_KEYS
     * @throws IllegalArgumentException if id is not one of
     *         KeyboardFocusManager.FORWARD_TRAVERSAL_KEYS,
     *         KeyboardFocusManager.BACKWARD_TRAVERSAL_KEYS,
     *         KeyboardFocusManager.UP_CYCLE_TRAVERSAL_KEYS, or
     *         KeyboardFocusManager.DOWN_CYCLE_TRAVERSAL_KEYS
     * @since 1.4
     */
    @SuppressWarnings("unchecked")
    public Set<AWTKeyStroke> getFocusTraversalKeys(int id) {
        if (id < 0 || id >= KeyboardFocusManager.TRAVERSAL_KEY_LENGTH) {
            throw new IllegalArgumentException("invalid focus traversal key identifier");
        }

        // Okay to return Set directly because it is an unmodifiable view
        @SuppressWarnings("rawtypes")
        Set keystrokes = (focusTraversalKeys != null)
            ? focusTraversalKeys[id]
            : null;

        if (keystrokes != null) {
            return keystrokes;
        } else {
            return KeyboardFocusManager.getCurrentKeyboardFocusManager().
                getDefaultFocusTraversalKeys(id);
        }
    }

    /**
     * Does nothing because Windows must always be roots of a focus traversal
     * cycle. The passed-in value is ignored.
     *
     * @param focusCycleRoot this value is ignored
     * @see #isFocusCycleRoot
     * @see Container#setFocusTraversalPolicy
     * @see Container#getFocusTraversalPolicy
     * @since 1.4
     */
    public final void setFocusCycleRoot(boolean focusCycleRoot) {
    }

    /**
     * Always returns {@code true} because all Windows must be roots of a
     * focus traversal cycle.
     *
     * @return {@code true}
     * @see #setFocusCycleRoot
     * @see Container#setFocusTraversalPolicy
     * @see Container#getFocusTraversalPolicy
     * @since 1.4
     */
    public final boolean isFocusCycleRoot() {
        return true;
    }

    /**
     * Always returns {@code null} because Windows have no ancestors; they
     * represent the top of the Component hierarchy.
     *
     * @return {@code null}
     * @see Container#isFocusCycleRoot()
     * @since 1.4
     */
    public final Container getFocusCycleRootAncestor() {
        return null;
    }

    /**
     * Returns whether this Window can become the focused Window, that is,
     * whether this Window or any of its subcomponents can become the focus
     * owner. For a Frame or Dialog to be focusable, its focusable Window state
     * must be set to {@code true}. For a Window which is not a Frame or
     * Dialog to be focusable, its focusable Window state must be set to
     * {@code true}, its nearest owning Frame or Dialog must be
     * showing on the screen, and it must contain at least one Component in
     * its focus traversal cycle. If any of these conditions is not met, then
     * neither this Window nor any of its subcomponents can become the focus
     * owner.
     *
     * @return {@code true} if this Window can be the focused Window;
     *         {@code false} otherwise
     * @see #getFocusableWindowState
     * @see #setFocusableWindowState
     * @see #isShowing
     * @see Component#isFocusable
     * @since 1.4
     */
    public final boolean isFocusableWindow() {
        // If a Window/Frame/Dialog was made non-focusable, then it is always
        // non-focusable.
        if (!getFocusableWindowState()) {
            return false;
        }

        // All other tests apply only to Windows.
        if (this instanceof Frame || this instanceof Dialog) {
            return true;
        }

        // A Window must have at least one Component in its root focus
        // traversal cycle to be focusable.
        if (getFocusTraversalPolicy().getDefaultComponent(this) == null) {
            return false;
        }

        // A Window's nearest owning Frame or Dialog must be showing on the
        // screen.
        for (Window owner = getOwner(); owner != null;
             owner = owner.getOwner())
        {
            if (owner instanceof Frame || owner instanceof Dialog) {
                return owner.isShowing();
            }
        }

        return false;
    }

    /**
     * Returns whether this Window can become the focused Window if it meets
     * the other requirements outlined in {@code isFocusableWindow}. If
     * this method returns {@code false}, then
     * {@code isFocusableWindow} will return {@code false} as well.
     * If this method returns {@code true}, then
     * {@code isFocusableWindow} may return {@code true} or
     * {@code false} depending upon the other requirements which must be
     * met in order for a Window to be focusable.
     * <p>
     * By default, all Windows have a focusable Window state of
     * {@code true}.
     *
     * @return whether this Window can be the focused Window
     * @see #isFocusableWindow
     * @see #setFocusableWindowState
     * @see #isShowing
     * @see Component#setFocusable
     * @since 1.4
     */
    public boolean getFocusableWindowState() {
        return focusableWindowState;
    }

    /**
     * Sets whether this Window can become the focused Window if it meets
     * the other requirements outlined in {@code isFocusableWindow}. If
     * this Window's focusable Window state is set to {@code false}, then
     * {@code isFocusableWindow} will return {@code false}. If this
     * Window's focusable Window state is set to {@code true}, then
     * {@code isFocusableWindow} may return {@code true} or
     * {@code false} depending upon the other requirements which must be
     * met in order for a Window to be focusable.
     * <p>
     * Setting a Window's focusability state to {@code false} is the
     * standard mechanism for an application to identify to the AWT a Window
     * which will be used as a floating palette or toolbar, and thus should be
     * a non-focusable Window.
     *
     * Setting the focusability state on a visible {@code Window}
     * can have a delayed effect on some platforms &#8212; the actual
     * change may happen only when the {@code Window} becomes
     * hidden and then visible again.  To ensure consistent behavior
     * across platforms, set the {@code Window}'s focusable state
     * when the {@code Window} is invisible and then show it.
     *
     * @param focusableWindowState whether this Window can be the focused
     *        Window
     * @see #isFocusableWindow
     * @see #getFocusableWindowState
     * @see #isShowing
     * @see Component#setFocusable
     * @since 1.4
     */
    public void setFocusableWindowState(boolean focusableWindowState) {
        boolean oldFocusableWindowState;
        synchronized (this) {
            oldFocusableWindowState = this.focusableWindowState;
            this.focusableWindowState = focusableWindowState;
        }
        WindowPeer peer = (WindowPeer)this.peer;
        if (peer != null) {
            peer.updateFocusableWindowState();
        }
        firePropertyChange("focusableWindowState", oldFocusableWindowState,
                           focusableWindowState);
        if (oldFocusableWindowState && !focusableWindowState && isFocused()) {
            for (Window owner = getOwner();
                 owner != null;
                 owner = owner.getOwner())
                {
                    Component toFocus =
                        KeyboardFocusManager.getMostRecentFocusOwner(owner);
                    if (toFocus != null && toFocus.requestFocus(false, FocusEvent.Cause.ACTIVATION)) {
                        return;
                    }
                }
            KeyboardFocusManager.getCurrentKeyboardFocusManager().
                clearGlobalFocusOwnerPriv();
        }
    }

    /**
     * Sets whether this window should receive focus on
     * subsequently being shown (with a call to {@link #setVisible setVisible(true)}),
     * or being moved to the front (with a call to {@link #toFront}).
     * <p>
     * Note that {@link #setVisible setVisible(true)} may be called indirectly
     * (e.g. when showing an owner of the window makes the window to be shown).
     * {@link #toFront} may also be called indirectly (e.g. when
     * {@link #setVisible setVisible(true)} is called on already visible window).
     * In all such cases this property takes effect as well.
     * <p>
     * The value of the property is not inherited by owned windows.
     *
     * @param autoRequestFocus whether this window should be focused on
     *        subsequently being shown or being moved to the front
     * @see #isAutoRequestFocus
     * @see #isFocusableWindow
     * @see #setVisible
     * @see #toFront
     * @since 1.7
     */
    public void setAutoRequestFocus(boolean autoRequestFocus) {
        this.autoRequestFocus = autoRequestFocus;
    }

    /**
     * Returns whether this window should receive focus on subsequently being shown
     * (with a call to {@link #setVisible setVisible(true)}), or being moved to the front
     * (with a call to {@link #toFront}).
     * <p>
     * By default, the window has {@code autoRequestFocus} value of {@code true}.
     *
     * @return {@code autoRequestFocus} value
     * @see #setAutoRequestFocus
     * @since 1.7
     */
    public boolean isAutoRequestFocus() {
        return autoRequestFocus;
    }

    /**
     * Adds a PropertyChangeListener to the listener list. The listener is
     * registered for all bound properties of this class, including the
     * following:
     * <ul>
     *    <li>this Window's font ("font")</li>
     *    <li>this Window's background color ("background")</li>
     *    <li>this Window's foreground color ("foreground")</li>
     *    <li>this Window's focusability ("focusable")</li>
     *    <li>this Window's focus traversal keys enabled state
     *        ("focusTraversalKeysEnabled")</li>
     *    <li>this Window's Set of FORWARD_TRAVERSAL_KEYS
     *        ("forwardFocusTraversalKeys")</li>
     *    <li>this Window's Set of BACKWARD_TRAVERSAL_KEYS
     *        ("backwardFocusTraversalKeys")</li>
     *    <li>this Window's Set of UP_CYCLE_TRAVERSAL_KEYS
     *        ("upCycleFocusTraversalKeys")</li>
     *    <li>this Window's Set of DOWN_CYCLE_TRAVERSAL_KEYS
     *        ("downCycleFocusTraversalKeys")</li>
     *    <li>this Window's focus traversal policy ("focusTraversalPolicy")
     *        </li>
     *    <li>this Window's focusable Window state ("focusableWindowState")
     *        </li>
     *    <li>this Window's always-on-top state("alwaysOnTop")</li>
     * </ul>
     * Note that if this Window is inheriting a bound property, then no
     * event will be fired in response to a change in the inherited property.
     * <p>
     * If listener is null, no exception is thrown and no action is performed.
     *
     * @param    listener  the PropertyChangeListener to be added
     *
     * @see Component#removePropertyChangeListener
     * @see #addPropertyChangeListener(java.lang.String,java.beans.PropertyChangeListener)
     */
    public void addPropertyChangeListener(PropertyChangeListener listener) {
        super.addPropertyChangeListener(listener);
    }

    /**
     * Adds a PropertyChangeListener to the listener list for a specific
     * property. The specified property may be user-defined, or one of the
     * following:
     * <ul>
     *    <li>this Window's font ("font")</li>
     *    <li>this Window's background color ("background")</li>
     *    <li>this Window's foreground color ("foreground")</li>
     *    <li>this Window's focusability ("focusable")</li>
     *    <li>this Window's focus traversal keys enabled state
     *        ("focusTraversalKeysEnabled")</li>
     *    <li>this Window's Set of FORWARD_TRAVERSAL_KEYS
     *        ("forwardFocusTraversalKeys")</li>
     *    <li>this Window's Set of BACKWARD_TRAVERSAL_KEYS
     *        ("backwardFocusTraversalKeys")</li>
     *    <li>this Window's Set of UP_CYCLE_TRAVERSAL_KEYS
     *        ("upCycleFocusTraversalKeys")</li>
     *    <li>this Window's Set of DOWN_CYCLE_TRAVERSAL_KEYS
     *        ("downCycleFocusTraversalKeys")</li>
     *    <li>this Window's focus traversal policy ("focusTraversalPolicy")
     *        </li>
     *    <li>this Window's focusable Window state ("focusableWindowState")
     *        </li>
     *    <li>this Window's always-on-top state("alwaysOnTop")</li>
     * </ul>
     * Note that if this Window is inheriting a bound property, then no
     * event will be fired in response to a change in the inherited property.
     * <p>
     * If listener is null, no exception is thrown and no action is performed.
     *
     * @param propertyName one of the property names listed above
     * @param listener the PropertyChangeListener to be added
     *
     * @see #addPropertyChangeListener(java.beans.PropertyChangeListener)
     * @see Component#removePropertyChangeListener
     */
    public void addPropertyChangeListener(String propertyName,
                                          PropertyChangeListener listener) {
        super.addPropertyChangeListener(propertyName, listener);
    }

    /**
     * Indicates if this container is a validate root.
     * <p>
     * {@code Window} objects are the validate roots, and, therefore, they
     * override this method to return {@code true}.
     *
     * @return {@code true}
     * @since 1.7
     * @see java.awt.Container#isValidateRoot
     */
    @Override
    public boolean isValidateRoot() {
        return true;
    }

    /**
     * Dispatches an event to this window or one of its sub components.
     * @param e the event
     */
    void dispatchEventImpl(AWTEvent e) {
        if (e.getID() == ComponentEvent.COMPONENT_RESIZED) {
            invalidate();
            validate();
        }
        super.dispatchEventImpl(e);
    }

    /**
     * @deprecated As of JDK version 1.1
     * replaced by {@code dispatchEvent(AWTEvent)}.
     */
    @Deprecated
    public boolean postEvent(Event e) {
        if (handleEvent(e)) {
            e.consume();
            return true;
        }
        return false;
    }

    /**
     * Checks if this Window is showing on screen.
     * @see Component#setVisible
    */
    public boolean isShowing() {
        return visible;
    }

    boolean isDisposing() {
        return disposing;
    }

    /**
     * @deprecated As of J2SE 1.4, replaced by
     * {@link Component#applyComponentOrientation Component.applyComponentOrientation}.
     * @param rb the resource bundle
     */
    @Deprecated
    public void applyResourceBundle(ResourceBundle rb) {
        applyComponentOrientation(ComponentOrientation.getOrientation(rb));
    }

    /**
     * @deprecated As of J2SE 1.4, replaced by
     * {@link Component#applyComponentOrientation Component.applyComponentOrientation}.
     * @param rbName the resource name
     */
    @Deprecated
    public void applyResourceBundle(String rbName) {
        // Use the unnamed module from the TCCL or system class loader.
        ClassLoader cl = Thread.currentThread().getContextClassLoader();
        if (cl == null) {
            cl = ClassLoader.getSystemClassLoader();
        }
        applyResourceBundle(ResourceBundle.getBundle(rbName, cl.getUnnamedModule()));
    }

   /*
    * Support for tracking all windows owned by this window
    */
    void addOwnedWindow(WeakReference<Window> weakWindow) {
        if (weakWindow != null) {
            synchronized(ownedWindowList) {
                // this if statement should really be an assert, but we don't
                // have asserts...
                if (!ownedWindowList.contains(weakWindow)) {
                    ownedWindowList.addElement(weakWindow);
                }
            }
        }
    }

    void removeOwnedWindow(WeakReference<Window> weakWindow) {
        if (weakWindow != null) {
            // synchronized block not required since removeElement is
            // already synchronized
            ownedWindowList.removeElement(weakWindow);
        }
    }

    void connectOwnedWindow(Window child) {
        child.parent = this;
        addOwnedWindow(child.weakThis);
        child.disposerRecord.updateOwner();
    }

    private void addToWindowList() {
        synchronized (Window.class) {
            @SuppressWarnings("unchecked")
            Vector<WeakReference<Window>> windowList = (Vector<WeakReference<Window>>)appContext.get(Window.class);
            if (windowList == null) {
                windowList = new Vector<WeakReference<Window>>();
                appContext.put(Window.class, windowList);
            }
            windowList.add(weakThis);
        }
    }

    private static void removeFromWindowList(AppContext context, WeakReference<Window> weakThis) {
        synchronized (Window.class) {
            @SuppressWarnings("unchecked")
            Vector<WeakReference<Window>> windowList = (Vector<WeakReference<Window>>)context.get(Window.class);
            if (windowList != null) {
                windowList.remove(weakThis);
            }
        }
    }

    private void removeFromWindowList() {
        removeFromWindowList(appContext, weakThis);
    }

    /**
     * @serial Window type.
     *
     * Synchronization: ObjectLock
     */
    private Type type = Type.NORMAL;

    /**
     * Sets the type of the window.
     *
     * This method can only be called while the window is not displayable.
     *
     * @param  type the window type
     * @throws IllegalComponentStateException if the window
     *         is displayable.
     * @throws IllegalArgumentException if the type is {@code null}
     * @see    Component#isDisplayable
     * @see    #getType
     * @since 1.7
     */
    public void setType(Type type) {
        if (type == null) {
            throw new IllegalArgumentException("type should not be null.");
        }
        synchronized (getTreeLock()) {
            if (isDisplayable()) {
                throw new IllegalComponentStateException(
                        "The window is displayable.");
            }
            synchronized (getObjectLock()) {
                this.type = type;
            }
        }
    }

    /**
     * Returns the type of the window.
     *
     * @return the type of the window
     * @see   #setType
     * @since 1.7
     */
    public Type getType() {
        synchronized (getObjectLock()) {
            return type;
        }
    }

    /**
     * The window serialized data version.
     *
     * @serial
     */
    private int windowSerializedDataVersion = 2;

    /**
     * Writes default serializable fields to stream.  Writes
     * a list of serializable {@code WindowListener}s and
     * {@code WindowFocusListener}s as optional data.
     * Writes a list of child windows as optional data.
     * Writes a list of icon images as optional data
     *
     * @param  s the {@code ObjectOutputStream} to write
     * @throws IOException if an I/O error occurs
     * @serialData {@code null} terminated sequence of
     *    0 or more pairs; the pair consists of a {@code String}
     *    and {@code Object}; the {@code String}
     *    indicates the type of object and is one of the following:
     *    {@code windowListenerK} indicating a
     *      {@code WindowListener} object;
     *    {@code windowFocusWindowK} indicating a
     *      {@code WindowFocusListener} object;
     *    {@code ownedWindowK} indicating a child
     *      {@code Window} object
     *
     * @see AWTEventMulticaster#save(java.io.ObjectOutputStream, java.lang.String, java.util.EventListener)
     * @see Component#windowListenerK
     * @see Component#windowFocusListenerK
     * @see Component#ownedWindowK
     * @see #readObject(ObjectInputStream)
     */
    @Serial
    private void writeObject(ObjectOutputStream s) throws IOException {
        synchronized (this) {
            // Update old focusMgr fields so that our object stream can be read
            // by previous releases
            focusMgr = new FocusManager();
            focusMgr.focusRoot = this;
            focusMgr.focusOwner = getMostRecentFocusOwner();

            s.defaultWriteObject();

            // Clear fields so that we don't keep extra references around
            focusMgr = null;

            AWTEventMulticaster.save(s, windowListenerK, windowListener);
            AWTEventMulticaster.save(s, windowFocusListenerK, windowFocusListener);
            AWTEventMulticaster.save(s, windowStateListenerK, windowStateListener);
        }

        s.writeObject(null);

        synchronized (ownedWindowList) {
            for (int i = 0; i < ownedWindowList.size(); i++) {
                Window child = ownedWindowList.elementAt(i).get();
                if (child != null) {
                    s.writeObject(ownedWindowK);
                    s.writeObject(child);
                }
            }
        }
        s.writeObject(null);

        //write icon array
        if (icons != null) {
            for (Image i : icons) {
                if (i instanceof Serializable) {
                    s.writeObject(i);
                }
            }
        }
        s.writeObject(null);
    }

    //
    // Part of deserialization procedure to be called before
    // user's code.
    //
    private void initDeserializedWindow() {
        inputContextLock = new Object();

        // Deserialized Windows are not yet visible.
        visible = false;

        weakThis = new WeakReference<>(this);

        anchor = new Object();
        disposerRecord = new WindowDisposerRecord(appContext, this);
        sun.java2d.Disposer.addRecord(anchor, disposerRecord);

        addToWindowList();
        initGC(null);
        ownedWindowList = new Vector<>();
    }

    private void deserializeResources(ObjectInputStream s)
        throws ClassNotFoundException, IOException, HeadlessException {

            if (windowSerializedDataVersion < 2) {
                // Translate old-style focus tracking to new model. For 1.4 and
                // later releases, we'll rely on the Window's initial focusable
                // Component.
                if (focusMgr != null) {
                    if (focusMgr.focusOwner != null) {
                        KeyboardFocusManager.
                            setMostRecentFocusOwner(this, focusMgr.focusOwner);
                    }
                }

                // This field is non-transient and relies on default serialization.
                // However, the default value is insufficient, so we need to set
                // it explicitly for object data streams prior to 1.4.
                focusableWindowState = true;


            }

        Object keyOrNull;
        while(null != (keyOrNull = s.readObject())) {
            String key = ((String)keyOrNull).intern();

            if (windowListenerK == key) {
                addWindowListener((WindowListener)(s.readObject()));
            } else if (windowFocusListenerK == key) {
                addWindowFocusListener((WindowFocusListener)(s.readObject()));
            } else if (windowStateListenerK == key) {
                addWindowStateListener((WindowStateListener)(s.readObject()));
            } else // skip value for unrecognized key
                s.readObject();
        }

        try {
            while (null != (keyOrNull = s.readObject())) {
                String key = ((String)keyOrNull).intern();

                if (ownedWindowK == key)
                    connectOwnedWindow((Window) s.readObject());

                else // skip value for unrecognized key
                    s.readObject();
            }

            //read icons
            Object obj = s.readObject(); //Throws OptionalDataException
                                         //for pre1.6 objects.
            icons = new ArrayList<Image>(); //Frame.readObject() assumes
                                            //pre1.6 version if icons is null.
            while (obj != null) {
                if (obj instanceof Image) {
                    icons.add((Image)obj);
                }
                obj = s.readObject();
            }
        }
        catch (OptionalDataException e) {
            // 1.1 serialized form
            // ownedWindowList will be updated by Frame.readObject
        }

    }

    /**
     * Reads the {@code ObjectInputStream} and an optional
     * list of listeners to receive various events fired by
     * the component; also reads a list of
     * (possibly {@code null}) child windows.
     * Unrecognized keys or values will be ignored.
     *
     * @param  s the {@code ObjectInputStream} to read
     * @throws ClassNotFoundException if the class of a serialized object could
     *         not be found
     * @throws IOException if an I/O error occurs
     * @throws HeadlessException if {@code GraphicsEnvironment.isHeadless()}
     *         returns {@code true}
     * @see java.awt.GraphicsEnvironment#isHeadless
     * @see #writeObject
     */
    @Serial
    private void readObject(ObjectInputStream s)
      throws ClassNotFoundException, IOException, HeadlessException
    {
         GraphicsEnvironment.checkHeadless();
         initDeserializedWindow();
         ObjectInputStream.GetField f = s.readFields();

         syncLWRequests = f.get("syncLWRequests", systemSyncLWRequests);
         state = f.get("state", 0);
         focusableWindowState = f.get("focusableWindowState", true);
         windowSerializedDataVersion = f.get("windowSerializedDataVersion", 1);
         locationByPlatform = f.get("locationByPlatform", locationByPlatformProp);
         // Note: 1.4 (or later) doesn't use focusMgr
         focusMgr = (FocusManager)f.get("focusMgr", null);
         Dialog.ModalExclusionType et = (Dialog.ModalExclusionType)
             f.get("modalExclusionType", Dialog.ModalExclusionType.NO_EXCLUDE);
         setModalExclusionType(et); // since 6.0
         boolean aot = f.get("alwaysOnTop", false);
         if(aot) {
             setAlwaysOnTop(aot);
         }
         shape = (Shape)f.get("shape", null);
         opacity = (Float)f.get("opacity", 1.0f);

         deserializeResources(s);
    }

    /*
     * --- Accessibility Support ---
     *
     */

    /**
     * Gets the AccessibleContext associated with this Window.
     * For windows, the AccessibleContext takes the form of an
     * AccessibleAWTWindow.
     * A new AccessibleAWTWindow instance is created if necessary.
     *
     * @return an AccessibleAWTWindow that serves as the
     *         AccessibleContext of this Window
     * @since 1.3
     */
    public AccessibleContext getAccessibleContext() {
        if (accessibleContext == null) {
            accessibleContext = new AccessibleAWTWindow();
        }
        return accessibleContext;
    }

    /**
     * This class implements accessibility support for the
     * {@code Window} class.  It provides an implementation of the
     * Java Accessibility API appropriate to window user-interface elements.
     * @since 1.3
     */
    protected class AccessibleAWTWindow extends AccessibleAWTContainer
    {
        /**
         * Use serialVersionUID from JDK 1.3 for interoperability.
         */
        @Serial
        private static final long serialVersionUID = 4215068635060671780L;

        /**
         * Constructs an {@code AccessibleAWTWindow}.
         */
        protected AccessibleAWTWindow() {}

        /**
         * Get the role of this object.
         *
         * @return an instance of AccessibleRole describing the role of the
         * object
         * @see javax.accessibility.AccessibleRole
         */
        public AccessibleRole getAccessibleRole() {
            return AccessibleRole.WINDOW;
        }

        /**
         * Get the state of this object.
         *
         * @return an instance of AccessibleStateSet containing the current
         * state set of the object
         * @see javax.accessibility.AccessibleState
         */
        public AccessibleStateSet getAccessibleStateSet() {
            AccessibleStateSet states = super.getAccessibleStateSet();
            if (getFocusOwner() != null) {
                states.add(AccessibleState.ACTIVE);
            }
            return states;
        }

    } // inner class AccessibleAWTWindow

    @Override
    void setGraphicsConfiguration(GraphicsConfiguration gc) {
        if (gc == null) {
            gc = GraphicsEnvironment.
                    getLocalGraphicsEnvironment().
                    getDefaultScreenDevice().
                    getDefaultConfiguration();
        }

        synchronized (getTreeLock()) {
            WindowPeer peer = (WindowPeer) this.peer;
            if (peer != null) {
                gc = peer.getAppropriateGraphicsConfiguration(gc);
            }
            super.setGraphicsConfiguration(gc);
            if (log.isLoggable(PlatformLogger.Level.FINER)) {
                log.finer("+ Window.setGraphicsConfiguration(): new GC is \n+ " + getGraphicsConfiguration_NoClientCode() + "\n+ this is " + this);
            }
        }
    }

    /**
     * Sets the location of the window relative to the specified
     * component according to the following scenarios.
     * <p>
     * The target screen mentioned below is a screen to which
     * the window should be placed after the setLocationRelativeTo
     * method is called.
     * <ul>
     * <li>If the component is {@code null}, or the {@code
     * GraphicsConfiguration} associated with this component is
     * {@code null}, the window is placed in the center of the
     * screen. The center point can be obtained with the {@link
     * GraphicsEnvironment#getCenterPoint
     * GraphicsEnvironment.getCenterPoint} method.
     * <li>If the component is not {@code null}, but it is not
     * currently showing, the window is placed in the center of
     * the target screen defined by the {@code
     * GraphicsConfiguration} associated with this component.
     * <li>If the component is not {@code null} and is shown on
     * the screen, then the window is located in such a way that
     * the center of the window coincides with the center of the
     * component.
     * </ul>
     * <p>
     * If the screens configuration does not allow the window to
     * be moved from one screen to another, then the window is
     * only placed at the location determined according to the
     * above conditions and its {@code GraphicsConfiguration} is
     * not changed.
     * <p>
     * <b>Note</b>: If the lower edge of the window is out of the screen,
     * then the window is placed to the side of the {@code Component}
     * that is closest to the center of the screen. So if the
     * component is on the right part of the screen, the window
     * is placed to its left, and vice versa.
     * <p>
     * If after the window location has been calculated, the upper,
     * left, or right edge of the window is out of the screen,
     * then the window is located in such a way that the upper,
     * left, or right edge of the window coincides with the
     * corresponding edge of the screen. If both left and right
     * edges of the window are out of the screen, the window is
     * placed at the left side of the screen. The similar placement
     * will occur if both top and bottom edges are out of the screen.
     * In that case, the window is placed at the top side of the screen.
     * <p>
     * The method changes the geometry-related data. Therefore,
     * the native windowing system may ignore such requests, or it may modify
     * the requested data, so that the {@code Window} object is placed and sized
     * in a way that corresponds closely to the desktop settings.
     *
     * @param c  the component in relation to which the window's location
     *           is determined
     * @see java.awt.GraphicsEnvironment#getCenterPoint
     * @since 1.4
     */
    public void setLocationRelativeTo(Component c) {
        // target location
        int dx = 0, dy = 0;
        // target GC
        GraphicsConfiguration gc = getGraphicsConfiguration_NoClientCode();
        Rectangle gcBounds = gc.getBounds();

        Dimension windowSize = getSize();

        // search a top-level of c
        Window componentWindow = SunToolkit.getContainingWindow(c);
        if ((c == null) || (componentWindow == null)) {
            GraphicsEnvironment ge = GraphicsEnvironment.getLocalGraphicsEnvironment();
            gc = ge.getDefaultScreenDevice().getDefaultConfiguration();
            gcBounds = gc.getBounds();
            Point centerPoint = ge.getCenterPoint();
            dx = centerPoint.x - windowSize.width / 2;
            dy = centerPoint.y - windowSize.height / 2;
        } else if (!c.isShowing()) {
            gc = componentWindow.getGraphicsConfiguration();
            gcBounds = gc.getBounds();
            dx = gcBounds.x + (gcBounds.width - windowSize.width) / 2;
            dy = gcBounds.y + (gcBounds.height - windowSize.height) / 2;
        } else {
            gc = componentWindow.getGraphicsConfiguration();
            gcBounds = gc.getBounds();
            Dimension compSize = c.getSize();
            Point compLocation = c.getLocationOnScreen();
            dx = compLocation.x + ((compSize.width - windowSize.width) / 2);
            dy = compLocation.y + ((compSize.height - windowSize.height) / 2);

            // Adjust for bottom edge being offscreen
            if (dy + windowSize.height > gcBounds.y + gcBounds.height) {
                dy = gcBounds.y + gcBounds.height - windowSize.height;
                if (compLocation.x - gcBounds.x + compSize.width / 2 < gcBounds.width / 2) {
                    dx = compLocation.x + compSize.width;
                } else {
                    dx = compLocation.x - windowSize.width;
                }
            }
        }

        // Avoid being placed off the edge of the screen:
        // bottom
        if (dy + windowSize.height > gcBounds.y + gcBounds.height) {
            dy = gcBounds.y + gcBounds.height - windowSize.height;
        }
        // top
        if (dy < gcBounds.y) {
            dy = gcBounds.y;
        }
        // right
        if (dx + windowSize.width > gcBounds.x + gcBounds.width) {
            dx = gcBounds.x + gcBounds.width - windowSize.width;
        }
        // left
        if (dx < gcBounds.x) {
            dx = gcBounds.x;
        }

        setLocation(dx, dy);
    }

    /**
     * Overridden from Component.  Top-level Windows should not propagate a
     * MouseWheelEvent beyond themselves into their owning Windows.
     */
    void deliverMouseWheelToAncestor(MouseWheelEvent e) {}

    /**
     * Overridden from Component.  Top-level Windows don't dispatch to ancestors
     */
    boolean dispatchMouseWheelToAncestor(MouseWheelEvent e) {return false;}

    /**
     * Creates a new strategy for multi-buffering on this component.
     * Multi-buffering is useful for rendering performance.  This method
     * attempts to create the best strategy available with the number of
     * buffers supplied.  It will always create a {@code BufferStrategy}
     * with that number of buffers.
     * A page-flipping strategy is attempted first, then a blitting strategy
     * using accelerated buffers.  Finally, an unaccelerated blitting
     * strategy is used.
     * <p>
     * Each time this method is called,
     * the existing buffer strategy for this component is discarded.
     * @param numBuffers number of buffers to create
     * @throws IllegalArgumentException if numBuffers is less than 1.
     * @throws IllegalStateException if the component is not displayable
     * @see #isDisplayable
     * @see #getBufferStrategy
     * @since 1.4
     */
    public void createBufferStrategy(int numBuffers) {
        super.createBufferStrategy(numBuffers);
    }

    /**
     * Creates a new strategy for multi-buffering on this component with the
     * required buffer capabilities.  This is useful, for example, if only
     * accelerated memory or page flipping is desired (as specified by the
     * buffer capabilities).
     * <p>
     * Each time this method
     * is called, the existing buffer strategy for this component is discarded.
     * @param numBuffers number of buffers to create, including the front buffer
     * @param caps the required capabilities for creating the buffer strategy;
     * cannot be {@code null}
     * @throws AWTException if the capabilities supplied could not be
     * supported or met; this may happen, for example, if there is not enough
     * accelerated memory currently available, or if page flipping is specified
     * but not possible.
     * @throws IllegalArgumentException if numBuffers is less than 1, or if
     * caps is {@code null}
     * @see #getBufferStrategy
     * @since 1.4
     */
    public void createBufferStrategy(int numBuffers,
        BufferCapabilities caps) throws AWTException {
        super.createBufferStrategy(numBuffers, caps);
    }

    /**
     * Returns the {@code BufferStrategy} used by this component.  This
     * method will return null if a {@code BufferStrategy} has not yet
     * been created or has been disposed.
     *
     * @return the buffer strategy used by this component
     * @see #createBufferStrategy
     * @since 1.4
     */
    public BufferStrategy getBufferStrategy() {
        return super.getBufferStrategy();
    }

    Component getTemporaryLostComponent() {
        return temporaryLostComponent;
    }
    Component setTemporaryLostComponent(Component component) {
        Component previousComp = temporaryLostComponent;
        // Check that "component" is an acceptable focus owner and don't store it otherwise
        // - or later we will have problems with opposite while handling  WINDOW_GAINED_FOCUS
        if (component == null || component.canBeFocusOwner()) {
            temporaryLostComponent = component;
        } else {
            temporaryLostComponent = null;
        }
        return previousComp;
    }

    /**
     * Checks whether this window can contain focus owner.
     * Verifies that it is focusable and as container it can container focus owner.
     * @since 1.5
     */
    boolean canContainFocusOwner(Component focusOwnerCandidate) {
        return super.canContainFocusOwner(focusOwnerCandidate) && isFocusableWindow();
    }

    /**
     * @serial {@code true} if this Window should appear at the default location,
     * {@code false} if at the current location.
     */
    private volatile boolean locationByPlatform = locationByPlatformProp;


    /**
     * Sets whether this Window should appear at the default location for the
     * native windowing system or at the current location (returned by
     * {@code getLocation}) the next time the Window is made visible.
     * This behavior resembles a native window shown without programmatically
     * setting its location.  Most windowing systems cascade windows if their
     * locations are not explicitly set. The actual location is determined once the
     * window is shown on the screen.
     * <p>
     * This behavior can also be enabled by setting the System Property
     * "java.awt.Window.locationByPlatform" to "true", though calls to this method
     * take precedence.
     * <p>
     * Calls to {@code setVisible}, {@code setLocation} and
     * {@code setBounds} after calling {@code setLocationByPlatform} clear
     * this property of the Window.
     * <p>
     * For example, after the following code is executed:
     * <pre>
     * setLocationByPlatform(true);
     * setVisible(true);
     * boolean flag = isLocationByPlatform();
     * </pre>
     * The window will be shown at platform's default location and
     * {@code flag} will be {@code false}.
     * <p>
     * In the following sample:
     * <pre>
     * setLocationByPlatform(true);
     * setLocation(10, 10);
     * boolean flag = isLocationByPlatform();
     * setVisible(true);
     * </pre>
     * The window will be shown at (10, 10) and {@code flag} will be
     * {@code false}.
     *
     * @param locationByPlatform {@code true} if this Window should appear
     *        at the default location, {@code false} if at the current location
     * @throws IllegalComponentStateException if the window
     *         is showing on screen and locationByPlatform is {@code true}.
     * @see #setLocation
     * @see #isShowing
     * @see #setVisible
     * @see #isLocationByPlatform
     * @see java.lang.System#getProperty(String)
     * @since 1.5
     */
    public void setLocationByPlatform(boolean locationByPlatform) {
        synchronized (getTreeLock()) {
            if (locationByPlatform && isShowing()) {
                throw new IllegalComponentStateException("The window is showing on screen.");
            }
            this.locationByPlatform = locationByPlatform;
        }
    }

    /**
     * Returns {@code true} if this Window will appear at the default location
     * for the native windowing system the next time this Window is made visible.
     * This method always returns {@code false} if the Window is showing on the
     * screen.
     *
     * @return whether this Window will appear at the default location
     * @see #setLocationByPlatform
     * @see #isShowing
     * @since 1.5
     */
    public boolean isLocationByPlatform() {
        return locationByPlatform;
    }

    /**
     * {@inheritDoc}
     * <p>
     * The {@code width} or {@code height} values
     * are automatically enlarged if either is less than
     * the minimum size as specified by previous call to
     * {@code setMinimumSize}.
     * <p>
     * The method changes the geometry-related data. Therefore,
     * the native windowing system may ignore such requests, or it may modify
     * the requested data, so that the {@code Window} object is placed and sized
     * in a way that corresponds closely to the desktop settings.
     *
     * @see #getBounds
     * @see #setLocation(int, int)
     * @see #setLocation(Point)
     * @see #setSize(int, int)
     * @see #setSize(Dimension)
     * @see #setMinimumSize
     * @see #setLocationByPlatform
     * @see #isLocationByPlatform
     * @since 1.6
     */
    public void setBounds(int x, int y, int width, int height) {
        synchronized (getTreeLock()) {
            if (getBoundsOp() == ComponentPeer.SET_LOCATION ||
                getBoundsOp() == ComponentPeer.SET_BOUNDS)
            {
                locationByPlatform = false;
            }
            super.setBounds(x, y, width, height);
        }
    }

    /**
     * {@inheritDoc}
     * <p>
     * The {@code r.width} or {@code r.height} values
     * will be automatically enlarged if either is less than
     * the minimum size as specified by previous call to
     * {@code setMinimumSize}.
     * <p>
     * The method changes the geometry-related data. Therefore,
     * the native windowing system may ignore such requests, or it may modify
     * the requested data, so that the {@code Window} object is placed and sized
     * in a way that corresponds closely to the desktop settings.
     *
     * @see #getBounds
     * @see #setLocation(int, int)
     * @see #setLocation(Point)
     * @see #setSize(int, int)
     * @see #setSize(Dimension)
     * @see #setMinimumSize
     * @see #setLocationByPlatform
     * @see #isLocationByPlatform
     * @since 1.6
     */
    public void setBounds(Rectangle r) {
        setBounds(r.x, r.y, r.width, r.height);
    }

    /**
     * Determines whether this component will be displayed on the screen.
     * @return {@code true} if the component and all of its ancestors
     *          until a toplevel window are visible, {@code false} otherwise
     */
    boolean isRecursivelyVisible() {
        // 5079694 fix: for a toplevel to be displayed, its parent doesn't have to be visible.
        // We're overriding isRecursivelyVisible to implement this policy.
        return visible;
    }


    // ******************** SHAPES & TRANSPARENCY CODE ********************

    /**
     * Returns the opacity of the window.
     *
     * @return the opacity of the window
     *
     * @see Window#setOpacity(float)
     * @see GraphicsDevice.WindowTranslucency
     *
     * @since 1.7
     */
    public float getOpacity() {
        return opacity;
    }

    /**
     * Sets the opacity of the window.
     * <p>
     * The opacity value is in the range [0..1]. Note that setting the opacity
     * level of 0 may or may not disable the mouse event handling on this
     * window. This is a platform-dependent behavior.
     * <p>
     * The following conditions must be met in order to set the opacity value
     * less than {@code 1.0f}:
     * <ul>
     * <li>The {@link GraphicsDevice.WindowTranslucency#TRANSLUCENT TRANSLUCENT}
     * translucency must be supported by the underlying system
     * <li>The window must be undecorated (see {@link Frame#setUndecorated}
     * and {@link Dialog#setUndecorated})
     * <li>The window must not be in full-screen mode (see {@link
     * GraphicsDevice#setFullScreenWindow(Window)})
     * </ul>
     * <p>
     * If the requested opacity value is less than {@code 1.0f}, and any of the
     * above conditions are not met, the window opacity will not change,
     * and the {@code IllegalComponentStateException} will be thrown.
     * <p>
     * The translucency levels of individual pixels may also be effected by the
     * alpha component of their color (see {@link Window#setBackground(Color)}) and the
     * current shape of this window (see {@link #setShape(Shape)}).
     *
     * @param opacity the opacity level to set to the window
     *
     * @throws IllegalArgumentException if the opacity is out of the range
     *     [0..1]
     * @throws IllegalComponentStateException if the window is decorated and
     *     the opacity is less than {@code 1.0f}
     * @throws IllegalComponentStateException if the window is in full screen
     *     mode, and the opacity is less than {@code 1.0f}
     * @throws UnsupportedOperationException if the {@code
     *     GraphicsDevice.WindowTranslucency#TRANSLUCENT TRANSLUCENT}
     *     translucency is not supported and the opacity is less than
     *     {@code 1.0f}
     *
     * @see Window#getOpacity
     * @see Window#setBackground(Color)
     * @see Window#setShape(Shape)
     * @see Frame#isUndecorated
     * @see Dialog#isUndecorated
     * @see GraphicsDevice.WindowTranslucency
     * @see GraphicsDevice#isWindowTranslucencySupported(GraphicsDevice.WindowTranslucency)
     *
     * @since 1.7
     */
    public void setOpacity(float opacity) {
        synchronized (getTreeLock()) {
            if (opacity < 0.0f || opacity > 1.0f) {
                throw new IllegalArgumentException(
                    "The value of opacity should be in the range [0.0f .. 1.0f].");
            }
            if (opacity < 1.0f) {
                GraphicsConfiguration gc = getGraphicsConfiguration();
                GraphicsDevice gd = gc.getDevice();
                if (gc.getDevice().getFullScreenWindow() == this) {
                    throw new IllegalComponentStateException(
                        "Setting opacity for full-screen window is not supported.");
                }
                if (!gd.isWindowTranslucencySupported(
                    GraphicsDevice.WindowTranslucency.TRANSLUCENT))
                {
                    throw new UnsupportedOperationException(
                        "TRANSLUCENT translucency is not supported.");
                }
            }
            this.opacity = opacity;
            WindowPeer peer = (WindowPeer) this.peer;
            if (peer != null) {
                peer.setOpacity(opacity);
            }
        }
    }

    /**
     * Returns the shape of the window.
     *
     * The value returned by this method may not be the same as
     * previously set with {@code setShape(shape)}, but it is guaranteed
     * to represent the same shape.
     *
     * @return the shape of the window or {@code null} if no
     *     shape is specified for the window
     *
     * @see Window#setShape(Shape)
     * @see GraphicsDevice.WindowTranslucency
     *
     * @since 1.7
     */
    public Shape getShape() {
        synchronized (getTreeLock()) {
            return shape == null ? null : new Path2D.Float(shape);
        }
    }

    /**
     * Sets the shape of the window.
     * <p>
     * Setting a shape cuts off some parts of the window. Only the parts that
     * belong to the given {@link Shape} remain visible and clickable. If
     * the shape argument is {@code null}, this method restores the default
     * shape, making the window rectangular on most platforms.
     * <p>
     * The following conditions must be met to set a non-null shape:
     * <ul>
     * <li>The {@link GraphicsDevice.WindowTranslucency#PERPIXEL_TRANSPARENT
     * PERPIXEL_TRANSPARENT} translucency must be supported by the
     * underlying system
     * <li>The window must be undecorated (see {@link Frame#setUndecorated}
     * and {@link Dialog#setUndecorated})
     * <li>The window must not be in full-screen mode (see {@link
     * GraphicsDevice#setFullScreenWindow(Window)})
     * </ul>
     * <p>
     * If the requested shape is not {@code null}, and any of the above
     * conditions are not met, the shape of this window will not change,
     * and either the {@code UnsupportedOperationException} or {@code
     * IllegalComponentStateException} will be thrown.
     * <p>
     * The translucency levels of individual pixels may also be effected by the
     * alpha component of their color (see {@link Window#setBackground(Color)}) and the
     * opacity value (see {@link #setOpacity(float)}). See {@link
     * GraphicsDevice.WindowTranslucency} for more details.
     *
     * @param shape the shape to set to the window
     *
     * @throws IllegalComponentStateException if the shape is not {@code
     *     null} and the window is decorated
     * @throws IllegalComponentStateException if the shape is not {@code
     *     null} and the window is in full-screen mode
     * @throws UnsupportedOperationException if the shape is not {@code
     *     null} and {@link GraphicsDevice.WindowTranslucency#PERPIXEL_TRANSPARENT
     *     PERPIXEL_TRANSPARENT} translucency is not supported
     *
     * @see Window#getShape()
     * @see Window#setBackground(Color)
     * @see Window#setOpacity(float)
     * @see Frame#isUndecorated
     * @see Dialog#isUndecorated
     * @see GraphicsDevice.WindowTranslucency
     * @see GraphicsDevice#isWindowTranslucencySupported(GraphicsDevice.WindowTranslucency)
     *
     * @since 1.7
     */
    public void setShape(Shape shape) {
        synchronized (getTreeLock()) {
            if (shape != null) {
                GraphicsConfiguration gc = getGraphicsConfiguration();
                GraphicsDevice gd = gc.getDevice();
                if (gc.getDevice().getFullScreenWindow() == this) {
                    throw new IllegalComponentStateException(
                        "Setting shape for full-screen window is not supported.");
                }
                if (!gd.isWindowTranslucencySupported(
                        GraphicsDevice.WindowTranslucency.PERPIXEL_TRANSPARENT))
                {
                    throw new UnsupportedOperationException(
                        "PERPIXEL_TRANSPARENT translucency is not supported.");
                }
            }
            this.shape = (shape == null) ? null : new Path2D.Float(shape);
            WindowPeer peer = (WindowPeer) this.peer;
            if (peer != null) {
                peer.applyShape(shape == null ? null : Region.getInstance(shape, null));
            }
        }
    }

    /**
     * Gets the background color of this window.
     * <p>
     * Note that the alpha component of the returned color indicates whether
     * the window is in the non-opaque (per-pixel translucent) mode.
     *
     * @return this component's background color
     *
     * @see Window#setBackground(Color)
     * @see Window#isOpaque
     * @see GraphicsDevice.WindowTranslucency
     */
    @Override
    public Color getBackground() {
        return super.getBackground();
    }

    /**
     * Sets the background color of this window.
     * <p>
     * If the windowing system supports the {@link
     * GraphicsDevice.WindowTranslucency#PERPIXEL_TRANSLUCENT PERPIXEL_TRANSLUCENT}
     * translucency, the alpha component of the given background color
     * may effect the mode of operation for this window: it indicates whether
     * this window must be opaque (alpha equals {@code 1.0f}) or per-pixel translucent
     * (alpha is less than {@code 1.0f}). If the given background color is
     * {@code null}, the window is considered completely opaque.
     * <p>
     * All the following conditions must be met to enable the per-pixel
     * transparency mode for this window:
     * <ul>
     * <li>The {@link GraphicsDevice.WindowTranslucency#PERPIXEL_TRANSLUCENT
     * PERPIXEL_TRANSLUCENT} translucency must be supported by the graphics
     * device where this window is located
     * <li>The window must be undecorated (see {@link Frame#setUndecorated}
     * and {@link Dialog#setUndecorated})
     * <li>The window must not be in full-screen mode (see {@link
     * GraphicsDevice#setFullScreenWindow(Window)})
     * </ul>
     * <p>
     * If the alpha component of the requested background color is less than
     * {@code 1.0f}, and any of the above conditions are not met, the background
     * color of this window will not change, the alpha component of the given
     * background color will not affect the mode of operation for this window,
     * and either the {@code UnsupportedOperationException} or {@code
     * IllegalComponentStateException} will be thrown.
     * <p>
     * When the window is per-pixel translucent, the drawing sub-system
     * respects the alpha value of each individual pixel. If a pixel gets
     * painted with the alpha color component equal to zero, it becomes
     * visually transparent. If the alpha of the pixel is equal to 1.0f, the
     * pixel is fully opaque. Interim values of the alpha color component make
     * the pixel semi-transparent. In this mode, the background of the window
     * gets painted with the alpha value of the given background color. If the
     * alpha value of the argument of this method is equal to {@code 0}, the
     * background is not painted at all.
     * <p>
     * The actual level of translucency of a given pixel also depends on window
     * opacity (see {@link #setOpacity(float)}), as well as the current shape of
     * this window (see {@link #setShape(Shape)}).
     * <p>
     * Note that painting a pixel with the alpha value of {@code 0} may or may
     * not disable the mouse event handling on this pixel. This is a
     * platform-dependent behavior. To make sure the mouse events do not get
     * dispatched to a particular pixel, the pixel must be excluded from the
     * shape of the window.
     * <p>
     * Enabling the per-pixel translucency mode may change the graphics
     * configuration of this window due to the native platform requirements.
     *
     * @param bgColor the color to become this window's background color.
     *
     * @throws IllegalComponentStateException if the alpha value of the given
     *     background color is less than {@code 1.0f} and the window is decorated
     * @throws IllegalComponentStateException if the alpha value of the given
     *     background color is less than {@code 1.0f} and the window is in
     *     full-screen mode
     * @throws UnsupportedOperationException if the alpha value of the given
     *     background color is less than {@code 1.0f} and {@link
     *     GraphicsDevice.WindowTranslucency#PERPIXEL_TRANSLUCENT
     *     PERPIXEL_TRANSLUCENT} translucency is not supported
     *
     * @see Window#getBackground
     * @see Window#isOpaque
     * @see Window#setOpacity(float)
     * @see Window#setShape(Shape)
     * @see Frame#isUndecorated
     * @see Dialog#isUndecorated
     * @see GraphicsDevice.WindowTranslucency
     * @see GraphicsDevice#isWindowTranslucencySupported(GraphicsDevice.WindowTranslucency)
     * @see GraphicsConfiguration#isTranslucencyCapable()
     */
    @Override
    public void setBackground(Color bgColor) {
        Color oldBg = getBackground();
        super.setBackground(bgColor);
        if (oldBg != null && oldBg.equals(bgColor)) {
            return;
        }
        int oldAlpha = oldBg != null ? oldBg.getAlpha() : 255;
        int alpha = bgColor != null ? bgColor.getAlpha() : 255;
        if ((oldAlpha == 255) && (alpha < 255)) { // non-opaque window
            GraphicsConfiguration gc = getGraphicsConfiguration();
            GraphicsDevice gd = gc.getDevice();
            if (gc.getDevice().getFullScreenWindow() == this) {
                throw new IllegalComponentStateException(
                    "Making full-screen window non opaque is not supported.");
            }
            if (!gc.isTranslucencyCapable()) {
                GraphicsConfiguration capableGC = gd.getTranslucencyCapableGC();
                if (capableGC == null) {
                    throw new UnsupportedOperationException(
                        "PERPIXEL_TRANSLUCENT translucency is not supported");
                }
                setGraphicsConfiguration(capableGC);
            }
            setLayersOpaque(this, false);
        } else if ((oldAlpha < 255) && (alpha == 255)) {
            setLayersOpaque(this, true);
        }
        WindowPeer peer = (WindowPeer) this.peer;
        if (peer != null) {
            peer.setOpaque(alpha == 255);
        }
    }

    /**
     * Indicates if the window is currently opaque.
     * <p>
     * The method returns {@code false} if the background color of the window
     * is not {@code null} and the alpha component of the color is less than
     * {@code 1.0f}. The method returns {@code true} otherwise.
     *
     * @return {@code true} if the window is opaque, {@code false} otherwise
     *
     * @see Window#getBackground
     * @see Window#setBackground(Color)
     * @since 1.7
     */
    @Override
    public boolean isOpaque() {
        Color bg = getBackground();
        return bg != null ? bg.getAlpha() == 255 : true;
    }

    private void updateWindow() {
        synchronized (getTreeLock()) {
            WindowPeer peer = (WindowPeer) this.peer;
            if (peer != null) {
                peer.updateWindow();
            }
        }
    }

    /**
     * {@inheritDoc}
     *
     * @since 1.7
     */
    @Override
    public void paint(Graphics g) {
        if (!isOpaque()) {
            Graphics gg = g.create();
            try {
                if (gg instanceof Graphics2D) {
                    gg.setColor(getBackground());
                    ((Graphics2D)gg).setComposite(AlphaComposite.getInstance(AlphaComposite.SRC));
                    gg.fillRect(0, 0, getWidth(), getHeight());
                }
            } finally {
                gg.dispose();
            }
        }
        super.paint(g);
    }

    private static void setLayersOpaque(Component component, boolean isOpaque) {
        // Shouldn't use instanceof to avoid loading Swing classes
        //    if it's a pure AWT application.
        if (SunToolkit.isInstanceOf(component, "javax.swing.RootPaneContainer")) {
            javax.swing.RootPaneContainer rpc = (javax.swing.RootPaneContainer)component;
            javax.swing.JRootPane root = rpc.getRootPane();
            javax.swing.JLayeredPane lp = root.getLayeredPane();
            Container c = root.getContentPane();
            javax.swing.JComponent content =
                (c instanceof javax.swing.JComponent) ? (javax.swing.JComponent)c : null;
            lp.setOpaque(isOpaque);
            root.setOpaque(isOpaque);
            if (content != null) {
                content.setOpaque(isOpaque);

                // Iterate down one level to see whether we have a JApplet
                // (which is also a RootPaneContainer) which requires processing
                int numChildren = content.getComponentCount();
                if (numChildren > 0) {
                    Component child = content.getComponent(0);
                    // It's OK to use instanceof here because we've
                    // already loaded the RootPaneContainer class by now
                    if (child instanceof javax.swing.RootPaneContainer) {
                        setLayersOpaque(child, isOpaque);
                    }
                }
            }
        }
    }


    // ************************** MIXING CODE *******************************

    // A window has an owner, but it does NOT have a container
    @Override
    final Container getContainer() {
        return null;
    }

    /**
     * Applies the shape to the component
     * @param shape Shape to be applied to the component
     */
    @Override
    final void applyCompoundShape(Region shape) {
        // The shape calculated by mixing code is not intended to be applied
        // to windows or frames
    }

    @Override
    final void applyCurrentShape() {
        // The shape calculated by mixing code is not intended to be applied
        // to windows or frames
    }

    @Override
    final void mixOnReshaping() {
        // The shape calculated by mixing code is not intended to be applied
        // to windows or frames
    }

    @Override
    final Point getLocationOnWindow() {
        return new Point(0, 0);
    }

    // ****************** END OF MIXING CODE ********************************

    /**
     * Limit the given double value with the given range.
     */
    private static double limit(double value, double min, double max) {
        value = Math.max(value, min);
        value = Math.min(value, max);
        return value;
    }

    static {
        AWTAccessor.setWindowAccessor(new AWTAccessor.WindowAccessor() {
            public void updateWindow(Window window) {
                window.updateWindow();
            }

            public void setLWRequestStatus(Window changed, boolean status) {
                changed.syncLWRequests = status;
            }

            public boolean isAutoRequestFocus(Window w) {
                return w.autoRequestFocus;
            }

            public boolean isTrayIconWindow(Window w) {
                return w.isTrayIconWindow;
            }

            public void setTrayIconWindow(Window w, boolean isTrayIconWindow) {
                w.isTrayIconWindow = isTrayIconWindow;
            }

            public Window[] getOwnedWindows(Window w) {
                return w.getOwnedWindows_NoClientCode();
            }
        }); // WindowAccessor
    } // static

    // a window doesn't need to be updated in the Z-order.
    @Override
    void updateZOrder() {}

} // class Window


/**
 * This class is no longer used, but is maintained for Serialization
 * backward-compatibility.
 */
class FocusManager implements java.io.Serializable {
    Container focusRoot;
    Component focusOwner;

    /**
     * Use serialVersionUID from JDK 1.1 for interoperability.
     */
    @Serial
    private static final long serialVersionUID = 2491878825643557906L;
}