| /* | |
| * Copyright (c) 1997, 2024, 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.image.BufferedImage; | |
| import java.util.Locale; | |
| import sun.awt.PlatformGraphicsInfo; | |
| import sun.font.FontManager; | |
| import sun.font.FontManagerFactory; | |
| import sun.java2d.HeadlessGraphicsEnvironment; | |
| import sun.java2d.SunGraphicsEnvironment; | |
| /** | |
| * | |
| * The {@code GraphicsEnvironment} class describes the collection | |
| * of {@link GraphicsDevice} objects and {@link java.awt.Font} objects | |
| * available to a Java(tm) application on a particular platform. | |
| * The resources in this {@code GraphicsEnvironment} might be local | |
| * or on a remote machine. {@code GraphicsDevice} objects can be | |
| * screens, printers or image buffers and are the destination of | |
| * {@link Graphics2D} drawing methods. Each {@code GraphicsDevice} | |
| * has a number of {@link GraphicsConfiguration} objects associated with | |
| * it. These objects specify the different configurations in which the | |
| * {@code GraphicsDevice} can be used. | |
| * @see GraphicsDevice | |
| * @see GraphicsConfiguration | |
| */ | |
| public abstract class GraphicsEnvironment { | |
| /** | |
| * The headless state of the Toolkit and GraphicsEnvironment | |
| */ | |
| private static Boolean headless; | |
| /** | |
| * The headless state assumed by default | |
| */ | |
| private static Boolean defaultHeadless; | |
| /** | |
| * This is an abstract class and cannot be instantiated directly. | |
| * Instances must be obtained from a suitable factory or query method. | |
| */ | |
| protected GraphicsEnvironment() { | |
| } | |
| /** | |
| * Lazy initialization of local graphics environment using holder idiom. | |
| */ | |
| private static final class LocalGE { | |
| /** | |
| * The instance of the local {@code GraphicsEnvironment}. | |
| */ | |
| static final GraphicsEnvironment INSTANCE = createGE(); | |
| /** | |
| * Creates and returns the GraphicsEnvironment, according to the | |
| * platform-specific proxy class. | |
| * | |
| * @return the graphics environment | |
| */ | |
| private static GraphicsEnvironment createGE() { | |
| GraphicsEnvironment ge = PlatformGraphicsInfo.createGE(); | |
| if (isHeadless()) { | |
| ge = new HeadlessGraphicsEnvironment(ge); | |
| } | |
| return ge; | |
| } | |
| } | |
| /** | |
| * Returns the local {@code GraphicsEnvironment}. | |
| * @return the local {@code GraphicsEnvironment} | |
| */ | |
| public static GraphicsEnvironment getLocalGraphicsEnvironment() { | |
| return LocalGE.INSTANCE; | |
| } | |
| /** | |
| * Tests whether or not a display, keyboard, and mouse can be | |
| * supported in this environment. If this method returns true, | |
| * a HeadlessException is thrown from areas of the Toolkit | |
| * and GraphicsEnvironment that are dependent on a display, | |
| * keyboard, or mouse. | |
| * @return {@code true} if this environment cannot support | |
| * a display, keyboard, and mouse; {@code false} | |
| * otherwise | |
| * @see java.awt.HeadlessException | |
| * @since 1.4 | |
| */ | |
| public static boolean isHeadless() { | |
| return getHeadlessProperty(); | |
| } | |
| /** | |
| * @return warning message if headless state is assumed by default; | |
| * null otherwise | |
| * @since 1.5 | |
| */ | |
| static String getHeadlessMessage() { | |
| if (headless == null) { | |
| getHeadlessProperty(); // initialize the values | |
| } | |
| return defaultHeadless != Boolean.TRUE ? null : | |
| PlatformGraphicsInfo.getDefaultHeadlessMessage(); | |
| } | |
| /** | |
| * @return the value of the property "java.awt.headless" | |
| * @since 1.4 | |
| */ | |
| private static boolean getHeadlessProperty() { | |
| if (headless == null) { | |
| String nm = System.getProperty("java.awt.headless"); | |
| if (nm == null) { | |
| headless = defaultHeadless = | |
| PlatformGraphicsInfo.getDefaultHeadlessProperty(); | |
| } else { | |
| headless = Boolean.valueOf(nm); | |
| } | |
| } | |
| return headless; | |
| } | |
| /** | |
| * Check for headless state and throw HeadlessException if headless | |
| * @since 1.4 | |
| */ | |
| static void checkHeadless() throws HeadlessException { | |
| if (isHeadless()) { | |
| throw new HeadlessException(); | |
| } | |
| } | |
| /** | |
| * Returns whether or not a display, keyboard, and mouse can be | |
| * supported in this graphics environment. If this returns true, | |
| * {@code HeadlessException} will be thrown from areas of the | |
| * graphics environment that are dependent on a display, keyboard, or | |
| * mouse. | |
| * @return {@code true} if a display, keyboard, and mouse | |
| * can be supported in this environment; {@code false} | |
| * otherwise | |
| * @see java.awt.HeadlessException | |
| * @see #isHeadless | |
| * @since 1.4 | |
| */ | |
| public boolean isHeadlessInstance() { | |
| // By default (local graphics environment), simply check the | |
| // headless property. | |
| return getHeadlessProperty(); | |
| } | |
| /** | |
| * Returns an array of all of the screen {@code GraphicsDevice} | |
| * objects. | |
| * @return an array containing all the {@code GraphicsDevice} | |
| * objects that represent screen devices | |
| * @throws HeadlessException if isHeadless() returns true | |
| * @see #isHeadless() | |
| */ | |
| public abstract GraphicsDevice[] getScreenDevices() | |
| throws HeadlessException; | |
| /** | |
| * Returns the default screen {@code GraphicsDevice}. | |
| * @return the {@code GraphicsDevice} that represents the | |
| * default screen device | |
| * @throws HeadlessException if isHeadless() returns true | |
| * @see #isHeadless() | |
| */ | |
| public abstract GraphicsDevice getDefaultScreenDevice() | |
| throws HeadlessException; | |
| /** | |
| * Returns a {@code Graphics2D} object for rendering into the | |
| * specified {@link BufferedImage}. | |
| * @param img the specified {@code BufferedImage} | |
| * @return a {@code Graphics2D} to be used for rendering into | |
| * the specified {@code BufferedImage} | |
| * @throws NullPointerException if {@code img} is null | |
| */ | |
| public abstract Graphics2D createGraphics(BufferedImage img); | |
| /** | |
| * Returns an array containing a one-point size instance of all fonts | |
| * available in this {@code GraphicsEnvironment}. Typical usage | |
| * would be to allow a user to select a particular font. Then, the | |
| * application can size the font and set various font attributes by | |
| * calling the {@code deriveFont} method on the chosen instance. | |
| * <p> | |
| * This method provides for the application the most precise control | |
| * over which {@code Font} instance is used to render text. | |
| * If a font in this {@code GraphicsEnvironment} has multiple | |
| * programmable variations, only one | |
| * instance of that {@code Font} is returned in the array, and | |
| * other variations must be derived by the application. | |
| * <p> | |
| * If a font in this environment has multiple programmable variations, | |
| * such as Multiple-Master fonts, only one instance of that font is | |
| * returned in the {@code Font} array. The other variations | |
| * must be derived by the application. | |
| * | |
| * @return an array of {@code Font} objects | |
| * @see #getAvailableFontFamilyNames | |
| * @see java.awt.Font | |
| * @see java.awt.Font#deriveFont | |
| * @see java.awt.Font#getFontName | |
| * @since 1.2 | |
| */ | |
| public abstract Font[] getAllFonts(); | |
| /** | |
| * Returns an array containing the names of all font families in this | |
| * {@code GraphicsEnvironment} localized for the default locale, | |
| * as returned by {@code Locale.getDefault()}. | |
| * <p> | |
| * Typical usage would be for presentation to a user for selection of | |
| * a particular family name. An application can then specify this name | |
| * when creating a font, in conjunction with a style, such as bold or | |
| * italic, giving the font system flexibility in choosing its own best | |
| * match among multiple fonts in the same font family. | |
| * | |
| * @return an array of {@code String} containing font family names | |
| * localized for the default locale, or a suitable alternative | |
| * name if no name exists for this locale. | |
| * @see #getAllFonts | |
| * @see java.awt.Font | |
| * @see java.awt.Font#getFamily | |
| * @since 1.2 | |
| */ | |
| public abstract String[] getAvailableFontFamilyNames(); | |
| /** | |
| * Returns an array containing the names of all font families in this | |
| * {@code GraphicsEnvironment} localized for the specified locale. | |
| * <p> | |
| * Typical usage would be for presentation to a user for selection of | |
| * a particular family name. An application can then specify this name | |
| * when creating a font, in conjunction with a style, such as bold or | |
| * italic, giving the font system flexibility in choosing its own best | |
| * match among multiple fonts in the same font family. | |
| * | |
| * @param l a {@link Locale} object that represents a | |
| * particular geographical, political, or cultural region. | |
| * Specifying {@code null} is equivalent to | |
| * specifying {@code Locale.getDefault()}. | |
| * @return an array of {@code String} containing font family names | |
| * localized for the specified {@code Locale}, or a | |
| * suitable alternative name if no name exists for the specified locale. | |
| * @see #getAllFonts | |
| * @see java.awt.Font | |
| * @see java.awt.Font#getFamily | |
| * @since 1.2 | |
| */ | |
| public abstract String[] getAvailableFontFamilyNames(Locale l); | |
| /** | |
| * Registers a <i>created</i> {@code Font} in this | |
| * {@code GraphicsEnvironment}. | |
| * A created font is one that was returned from calling | |
| * {@link Font#createFont}, or derived from a created font by | |
| * calling {@link Font#deriveFont}. | |
| * After calling this method for such a font, it is available to | |
| * be used in constructing new {@code Font}s by name or family name, | |
| * and is enumerated by {@link #getAvailableFontFamilyNames} and | |
| * {@link #getAllFonts} within the execution context of this | |
| * application or applet. This means applets cannot register fonts in | |
| * a way that they are visible to other applets. | |
| * <p> | |
| * Reasons that this method might not register the font and therefore | |
| * return {@code false} are: | |
| * <ul> | |
| * <li>The font is not a <i>created</i> {@code Font}. | |
| * <li>The font conflicts with a non-created {@code Font} already | |
| * in this {@code GraphicsEnvironment}. For example if the name | |
| * is that of a system font, or a logical font as described in the | |
| * documentation of the {@link Font} class. It is implementation dependent | |
| * whether a font may also conflict if it has the same family name | |
| * as a system font. | |
| * <p>Notice that an application can supersede the registration | |
| * of an earlier created font with a new one. | |
| * </ul> | |
| * | |
| * @param font the font to be registered | |
| * @return true if the {@code font} is successfully | |
| * registered in this {@code GraphicsEnvironment}. | |
| * @throws NullPointerException if {@code font} is null | |
| * @since 1.6 | |
| */ | |
| public boolean registerFont(Font font) { | |
| if (font == null) { | |
| throw new NullPointerException("font cannot be null."); | |
| } | |
| FontManager fm = FontManagerFactory.getInstance(); | |
| return fm.registerFont(font); | |
| } | |
| /** | |
| * Indicates a preference for locale-specific fonts in the mapping of | |
| * logical fonts to physical fonts. Calling this method indicates that font | |
| * rendering should primarily use fonts specific to the primary writing | |
| * system (the one indicated by the default encoding and the initial | |
| * default locale). For example, if the primary writing system is | |
| * Japanese, then characters should be rendered using a Japanese font | |
| * if possible, and other fonts should only be used for characters for | |
| * which the Japanese font doesn't have glyphs. | |
| * <p> | |
| * The actual change in font rendering behavior resulting from a call | |
| * to this method is implementation dependent; it may have no effect at | |
| * all, or the requested behavior may already match the default behavior. | |
| * The behavior may differ between font rendering in lightweight | |
| * and peered components. Since calling this method requests a | |
| * different font, clients should expect different metrics, and may need | |
| * to recalculate window sizes and layout. Therefore this method should | |
| * be called before user interface initialisation. | |
| * @since 1.5 | |
| */ | |
| public void preferLocaleFonts() { | |
| FontManager fm = FontManagerFactory.getInstance(); | |
| fm.preferLocaleFonts(); | |
| } | |
| /** | |
| * Indicates a preference for proportional over non-proportional (for | |
| * example dual-spaced CJK fonts) fonts in the mapping of logical fonts | |
| * to physical fonts. If the default mapping contains fonts for which | |
| * proportional and non-proportional variants exist, then calling | |
| * this method indicates the mapping should use a proportional variant. | |
| * <p> | |
| * The actual change in font rendering behavior resulting from a call to | |
| * this method is implementation dependent; it may have no effect at all. | |
| * The behavior may differ between font rendering in lightweight and | |
| * peered components. Since calling this method requests a | |
| * different font, clients should expect different metrics, and may need | |
| * to recalculate window sizes and layout. Therefore this method should | |
| * be called before user interface initialisation. | |
| * @since 1.5 | |
| */ | |
| public void preferProportionalFonts() { | |
| FontManager fm = FontManagerFactory.getInstance(); | |
| fm.preferProportionalFonts(); | |
| } | |
| /** | |
| * Returns the Point where Windows should be centered. | |
| * It is recommended that centered Windows be checked to ensure they fit | |
| * within the available display area using getMaximumWindowBounds(). | |
| * @return the point where Windows should be centered | |
| * | |
| * @throws HeadlessException if isHeadless() returns true | |
| * @see #getMaximumWindowBounds | |
| * @since 1.4 | |
| */ | |
| public Point getCenterPoint() throws HeadlessException { | |
| // Default implementation: return the center of the usable bounds of the | |
| // default screen device. | |
| Rectangle usableBounds = | |
| SunGraphicsEnvironment.getUsableBounds(getDefaultScreenDevice()); | |
| return new Point((usableBounds.width / 2) + usableBounds.x, | |
| (usableBounds.height / 2) + usableBounds.y); | |
| } | |
| /** | |
| * Returns the maximum bounds for centered Windows. | |
| * These bounds account for objects in the native windowing system such as | |
| * task bars and menu bars. The returned bounds will reside on a single | |
| * display with one exception: on multi-screen systems where Windows should | |
| * be centered across all displays, this method returns the bounds of the | |
| * entire display area. | |
| * <p> | |
| * To get the usable bounds of a single display, use | |
| * {@code GraphicsConfiguration.getBounds()} and | |
| * {@code Toolkit.getScreenInsets()}. | |
| * @return the maximum bounds for centered Windows | |
| * | |
| * @throws HeadlessException if isHeadless() returns true | |
| * @see #getCenterPoint | |
| * @see GraphicsConfiguration#getBounds | |
| * @see Toolkit#getScreenInsets | |
| * @since 1.4 | |
| */ | |
| public Rectangle getMaximumWindowBounds() throws HeadlessException { | |
| // Default implementation: return the usable bounds of the default screen | |
| // device. This is correct for Microsoft Windows and non-Xinerama X11. | |
| return SunGraphicsEnvironment.getUsableBounds(getDefaultScreenDevice()); | |
| } | |
| } |