| /* | |
| * Copyright (c) 2000, 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.AdjustmentEvent; | |
| import java.awt.event.AdjustmentListener; | |
| import java.awt.peer.ScrollPanePeer; | |
| import java.io.Serial; | |
| import java.io.Serializable; | |
| import sun.awt.AWTAccessor; | |
| /** | |
| * This class represents the state of a horizontal or vertical | |
| * scrollbar of a {@code ScrollPane}. Objects of this class are | |
| * returned by {@code ScrollPane} methods. | |
| * | |
| * @since 1.4 | |
| */ | |
| public final class ScrollPaneAdjustable implements Adjustable, Serializable { | |
| /** | |
| * The {@code ScrollPane} this object is a scrollbar of. | |
| * @serial | |
| */ | |
| private ScrollPane sp; | |
| /** | |
| * Orientation of this scrollbar. | |
| * | |
| * @serial | |
| * @see #getOrientation | |
| * @see java.awt.Adjustable#HORIZONTAL | |
| * @see java.awt.Adjustable#VERTICAL | |
| */ | |
| private int orientation; | |
| /** | |
| * The value of this scrollbar. | |
| * {@code value} should be greater than {@code minimum} | |
| * and less than {@code maximum} | |
| * | |
| * @serial | |
| * @see #getValue | |
| * @see #setValue | |
| */ | |
| private int value; | |
| /** | |
| * The minimum value of this scrollbar. | |
| * This value can only be set by the {@code ScrollPane}. | |
| * <p> | |
| * <strong>ATTN:</strong> In current implementation | |
| * {@code minimum} is always {@code 0}. This field can | |
| * only be altered via {@code setSpan} method and | |
| * {@code ScrollPane} always calls that method with | |
| * {@code 0} for the minimum. {@code getMinimum} method | |
| * always returns {@code 0} without checking this field. | |
| * | |
| * @serial | |
| * @see #getMinimum | |
| * @see #setSpan(int, int, int) | |
| */ | |
| private int minimum; | |
| /** | |
| * The maximum value of this scrollbar. | |
| * This value can only be set by the {@code ScrollPane}. | |
| * | |
| * @serial | |
| * @see #getMaximum | |
| * @see #setSpan(int, int, int) | |
| */ | |
| private int maximum; | |
| /** | |
| * The size of the visible portion of this scrollbar. | |
| * This value can only be set by the {@code ScrollPane}. | |
| * | |
| * @serial | |
| * @see #getVisibleAmount | |
| * @see #setSpan(int, int, int) | |
| */ | |
| private int visibleAmount; | |
| /** | |
| * The adjusting status of the {@code Scrollbar}. | |
| * True if the value is in the process of changing as a result of | |
| * actions being taken by the user. | |
| * | |
| * @see #getValueIsAdjusting | |
| * @see #setValueIsAdjusting | |
| * @since 1.4 | |
| */ | |
| private transient boolean isAdjusting; | |
| /** | |
| * The amount by which the scrollbar value will change when going | |
| * up or down by a line. | |
| * This value should be a non negative integer. | |
| * | |
| * @serial | |
| * @see #getUnitIncrement | |
| * @see #setUnitIncrement | |
| */ | |
| private int unitIncrement = 1; | |
| /** | |
| * The amount by which the scrollbar value will change when going | |
| * up or down by a page. | |
| * This value should be a non negative integer. | |
| * | |
| * @serial | |
| * @see #getBlockIncrement | |
| * @see #setBlockIncrement | |
| */ | |
| private int blockIncrement = 1; | |
| /** | |
| * @serial Specified adjustment listener to receive adjustment events from this | |
| * {@code ScrollPaneAdjustable}. | |
| */ | |
| @SuppressWarnings("serial") // Not statically typed as Serializable | |
| private AdjustmentListener adjustmentListener; | |
| /** | |
| * Error message for {@code AWTError} reported when one of | |
| * the public but unsupported methods is called. | |
| */ | |
| private static final String SCROLLPANE_ONLY = | |
| "Can be set by scrollpane only"; | |
| /** | |
| * Initialize JNI field and method ids. | |
| */ | |
| private static native void initIDs(); | |
| static { | |
| Toolkit.loadLibraries(); | |
| if (!GraphicsEnvironment.isHeadless()) { | |
| initIDs(); | |
| } | |
| AWTAccessor.setScrollPaneAdjustableAccessor(new AWTAccessor.ScrollPaneAdjustableAccessor() { | |
| public void setTypedValue(final ScrollPaneAdjustable adj, | |
| final int v, final int type) { | |
| adj.setTypedValue(v, type); | |
| } | |
| }); | |
| } | |
| /** | |
| * Use serialVersionUID from JDK 1.1 for interoperability. | |
| */ | |
| @Serial | |
| private static final long serialVersionUID = -3359745691033257079L; | |
| /** | |
| * Constructs a new object to represent specified scrollabar | |
| * of the specified {@code ScrollPane}. | |
| * Only ScrollPane creates instances of this class. | |
| * @param sp {@code ScrollPane} | |
| * @param l {@code AdjustmentListener} to add upon creation. | |
| * @param orientation specifies which scrollbar this object represents, | |
| * can be either {@code Adjustable.HORIZONTAL} | |
| * or {@code Adjustable.VERTICAL}. | |
| */ | |
| ScrollPaneAdjustable(ScrollPane sp, AdjustmentListener l, int orientation) { | |
| this.sp = sp; | |
| this.orientation = orientation; | |
| addAdjustmentListener(l); | |
| } | |
| /** | |
| * This is called by the scrollpane itself to update the | |
| * {@code minimum}, {@code maximum} and | |
| * {@code visible} values. The scrollpane is the only one | |
| * that should be changing these since it is the source of these | |
| * values. | |
| */ | |
| void setSpan(int min, int max, int visible) { | |
| // adjust the values to be reasonable | |
| minimum = min; | |
| maximum = Math.max(max, minimum + 1); | |
| visibleAmount = Math.min(visible, maximum - minimum); | |
| visibleAmount = Math.max(visibleAmount, 1); | |
| blockIncrement = Math.max((int)(visible * .90), 1); | |
| setValue(value); | |
| } | |
| /** | |
| * Returns the orientation of this scrollbar. | |
| * @return the orientation of this scrollbar, either | |
| * {@code Adjustable.HORIZONTAL} or | |
| * {@code Adjustable.VERTICAL} | |
| */ | |
| public int getOrientation() { | |
| return orientation; | |
| } | |
| /** | |
| * This method should <strong>NOT</strong> be called by user code. | |
| * This method is public for this class to properly implement | |
| * {@code Adjustable} interface. | |
| * | |
| * @throws AWTError Always throws an error when called. | |
| */ | |
| public void setMinimum(int min) { | |
| throw new AWTError(SCROLLPANE_ONLY); | |
| } | |
| public int getMinimum() { | |
| // XXX: This relies on setSpan always being called with 0 for | |
| // the minimum (which is currently true). | |
| return 0; | |
| } | |
| /** | |
| * This method should <strong>NOT</strong> be called by user code. | |
| * This method is public for this class to properly implement | |
| * {@code Adjustable} interface. | |
| * | |
| * @throws AWTError Always throws an error when called. | |
| */ | |
| public void setMaximum(int max) { | |
| throw new AWTError(SCROLLPANE_ONLY); | |
| } | |
| public int getMaximum() { | |
| return maximum; | |
| } | |
| public synchronized void setUnitIncrement(int u) { | |
| if (u != unitIncrement) { | |
| unitIncrement = u; | |
| if (sp.peer != null) { | |
| ScrollPanePeer peer = (ScrollPanePeer) sp.peer; | |
| peer.setUnitIncrement(this, u); | |
| } | |
| } | |
| } | |
| public int getUnitIncrement() { | |
| return unitIncrement; | |
| } | |
| public synchronized void setBlockIncrement(int b) { | |
| blockIncrement = b; | |
| } | |
| public int getBlockIncrement() { | |
| return blockIncrement; | |
| } | |
| /** | |
| * This method should <strong>NOT</strong> be called by user code. | |
| * This method is public for this class to properly implement | |
| * {@code Adjustable} interface. | |
| * | |
| * @throws AWTError Always throws an error when called. | |
| */ | |
| public void setVisibleAmount(int v) { | |
| throw new AWTError(SCROLLPANE_ONLY); | |
| } | |
| public int getVisibleAmount() { | |
| return visibleAmount; | |
| } | |
| /** | |
| * Sets the {@code valueIsAdjusting} property. | |
| * | |
| * @param b new adjustment-in-progress status | |
| * @see #getValueIsAdjusting | |
| * @since 1.4 | |
| */ | |
| public void setValueIsAdjusting(boolean b) { | |
| if (isAdjusting != b) { | |
| isAdjusting = b; | |
| AdjustmentEvent e = | |
| new AdjustmentEvent(this, | |
| AdjustmentEvent.ADJUSTMENT_VALUE_CHANGED, | |
| AdjustmentEvent.TRACK, value, b); | |
| adjustmentListener.adjustmentValueChanged(e); | |
| } | |
| } | |
| /** | |
| * Returns true if the value is in the process of changing as a | |
| * result of actions being taken by the user. | |
| * | |
| * @return the value of the {@code valueIsAdjusting} property | |
| * @see #setValueIsAdjusting | |
| */ | |
| public boolean getValueIsAdjusting() { | |
| return isAdjusting; | |
| } | |
| /** | |
| * Sets the value of this scrollbar to the specified value. | |
| * <p> | |
| * If the value supplied is less than the current minimum or | |
| * greater than the current maximum, then one of those values is | |
| * substituted, as appropriate. | |
| * | |
| * @param v the new value of the scrollbar | |
| */ | |
| public void setValue(int v) { | |
| setTypedValue(v, AdjustmentEvent.TRACK); | |
| } | |
| /** | |
| * Sets the value of this scrollbar to the specified value. | |
| * <p> | |
| * If the value supplied is less than the current minimum or | |
| * greater than the current maximum, then one of those values is | |
| * substituted, as appropriate. Also, creates and dispatches | |
| * the AdjustmentEvent with specified type and value. | |
| * | |
| * @param v the new value of the scrollbar | |
| * @param type the type of the scrolling operation occurred | |
| */ | |
| private void setTypedValue(int v, int type) { | |
| v = Math.max(v, minimum); | |
| v = Math.min(v, maximum - visibleAmount); | |
| if (v != value) { | |
| value = v; | |
| // Synchronously notify the listeners so that they are | |
| // guaranteed to be up-to-date with the Adjustable before | |
| // it is mutated again. | |
| AdjustmentEvent e = | |
| new AdjustmentEvent(this, | |
| AdjustmentEvent.ADJUSTMENT_VALUE_CHANGED, | |
| type, value, isAdjusting); | |
| adjustmentListener.adjustmentValueChanged(e); | |
| } | |
| } | |
| public int getValue() { | |
| return value; | |
| } | |
| /** | |
| * Adds the specified adjustment listener to receive adjustment | |
| * events from this {@code ScrollPaneAdjustable}. | |
| * 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 adjustment listener. | |
| * @see #removeAdjustmentListener | |
| * @see #getAdjustmentListeners | |
| * @see java.awt.event.AdjustmentListener | |
| * @see java.awt.event.AdjustmentEvent | |
| */ | |
| public synchronized void addAdjustmentListener(AdjustmentListener l) { | |
| if (l == null) { | |
| return; | |
| } | |
| adjustmentListener = AWTEventMulticaster.add(adjustmentListener, l); | |
| } | |
| /** | |
| * Removes the specified adjustment listener so that it no longer | |
| * receives adjustment events from this {@code ScrollPaneAdjustable}. | |
| * 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 adjustment listener. | |
| * @see #addAdjustmentListener | |
| * @see #getAdjustmentListeners | |
| * @see java.awt.event.AdjustmentListener | |
| * @see java.awt.event.AdjustmentEvent | |
| * @since 1.1 | |
| */ | |
| public synchronized void removeAdjustmentListener(AdjustmentListener l){ | |
| if (l == null) { | |
| return; | |
| } | |
| adjustmentListener = AWTEventMulticaster.remove(adjustmentListener, l); | |
| } | |
| /** | |
| * Returns an array of all the adjustment listeners | |
| * registered on this {@code ScrollPaneAdjustable}. | |
| * | |
| * @return all of this {@code ScrollPaneAdjustable}'s | |
| * {@code AdjustmentListener}s | |
| * or an empty array if no adjustment | |
| * listeners are currently registered | |
| * | |
| * @see #addAdjustmentListener | |
| * @see #removeAdjustmentListener | |
| * @see java.awt.event.AdjustmentListener | |
| * @see java.awt.event.AdjustmentEvent | |
| * @since 1.4 | |
| */ | |
| public synchronized AdjustmentListener[] getAdjustmentListeners() { | |
| return AWTEventMulticaster.getListeners(adjustmentListener, | |
| AdjustmentListener.class); | |
| } | |
| /** | |
| * Returns a string representation of this scrollbar and its values. | |
| * @return a string representation of this scrollbar. | |
| */ | |
| public String toString() { | |
| return getClass().getName() + "[" + paramString() + "]"; | |
| } | |
| /** | |
| * Returns a string representing the state of this scrollbar. | |
| * This method is intended to be used only for debugging purposes, | |
| * and the content and format of the returned string may vary | |
| * between implementations. The returned string may be empty but | |
| * may not be {@code null}. | |
| * | |
| * @return the parameter string of this scrollbar. | |
| */ | |
| public String paramString() { | |
| return ((orientation == Adjustable.VERTICAL ? "vertical," | |
| :"horizontal,") | |
| + "[0.."+maximum+"]" | |
| + ",val=" + value | |
| + ",vis=" + visibleAmount | |
| + ",unit=" + unitIncrement | |
| + ",block=" + blockIncrement | |
| + ",isAdjusting=" + isAdjusting); | |
| } | |
| } |