Java tutorial
/* * Copyright (c) 1997, 2015, 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 javax.swing; import java.awt.*; import java.awt.event.*; import java.beans.JavaBean; import java.beans.BeanProperty; import javax.accessibility.*; /** * A <code>JWindow</code> is a container that can be displayed anywhere on the * user's desktop. It does not have the title bar, window-management buttons, * or other trimmings associated with a <code>JFrame</code>, but it is still a * "first-class citizen" of the user's desktop, and can exist anywhere * on it. * <p> * The <code>JWindow</code> component contains a <code>JRootPane</code> * as its only child. The <code>contentPane</code> should be the parent * of any children of the <code>JWindow</code>. * As a convenience, the {@code add}, {@code remove}, and {@code setLayout} * methods of this class are overridden, so that they delegate calls * to the corresponding methods of the {@code ContentPane}. * For example, you can add a child component to a window as follows: * <pre> * window.add(child); * </pre> * And the child will be added to the contentPane. * The <code>contentPane</code> will always be non-<code>null</code>. * Attempting to set it to <code>null</code> will cause the <code>JWindow</code> * to throw an exception. The default <code>contentPane</code> will have a * <code>BorderLayout</code> manager set on it. * Refer to {@link javax.swing.RootPaneContainer} * for details on adding, removing and setting the <code>LayoutManager</code> * of a <code>JWindow</code>. * <p> * Please see the {@link JRootPane} documentation for a complete description of * the <code>contentPane</code>, <code>glassPane</code>, and * <code>layeredPane</code> components. * <p> * In a multi-screen environment, you can create a <code>JWindow</code> * on a different screen device. See {@link java.awt.Window} for more * information. * <p> * <strong>Warning:</strong> Swing is not thread safe. For more * information see <a * href="package-summary.html#threading">Swing's Threading * Policy</a>. * <p> * <strong>Warning:</strong> * Serialized objects of this class will not be compatible with * future Swing releases. The current serialization support is * appropriate for short term storage or RMI between applications running * the same version of Swing. As of 1.4, support for long term storage * of all JavaBeans™ * has been added to the <code>java.beans</code> package. * Please see {@link java.beans.XMLEncoder}. * * @see JRootPane * * @author David Kloba * @since 1.2 */ @JavaBean(defaultProperty = "accessibleContext", description = "A toplevel window which has no system border or controls.") @SwingContainer(delegate = "getContentPane") @SuppressWarnings("serial") public class JWindow extends Window implements Accessible, RootPaneContainer, TransferHandler.HasGetTransferHandler { /** * The <code>JRootPane</code> instance that manages the * <code>contentPane</code> * and optional <code>menuBar</code> for this frame, as well as the * <code>glassPane</code>. * * @see #getRootPane * @see #setRootPane */ protected JRootPane rootPane; /** * If true then calls to <code>add</code> and <code>setLayout</code> * will be forwarded to the <code>contentPane</code>. This is initially * false, but is set to true when the <code>JWindow</code> is constructed. * * @see #isRootPaneCheckingEnabled * @see #setRootPaneCheckingEnabled * @see javax.swing.RootPaneContainer */ protected boolean rootPaneCheckingEnabled = false; /** * The <code>TransferHandler</code> for this window. */ private TransferHandler transferHandler; /** * Creates a window with no specified owner. This window will not be * focusable. * <p> * This constructor sets the component's locale property to the value * returned by <code>JComponent.getDefaultLocale</code>. * * @throws HeadlessException if * <code>GraphicsEnvironment.isHeadless()</code> returns true. * @see java.awt.GraphicsEnvironment#isHeadless * @see #isFocusableWindow * @see JComponent#getDefaultLocale */ public JWindow() { this((Frame) null); } /** * Creates a window with the specified <code>GraphicsConfiguration</code> * of a screen device. This window will not be focusable. * <p> * This constructor sets the component's locale property to the value * returned by <code>JComponent.getDefaultLocale</code>. * * @param gc the <code>GraphicsConfiguration</code> that is used * to construct the new window with; if gc is <code>null</code>, * the system default <code>GraphicsConfiguration</code> * is assumed * @throws HeadlessException If * <code>GraphicsEnvironment.isHeadless()</code> returns true. * @throws IllegalArgumentException if <code>gc</code> is not from * a screen device. * * @see java.awt.GraphicsEnvironment#isHeadless * @see #isFocusableWindow * @see JComponent#getDefaultLocale * * @since 1.3 */ public JWindow(GraphicsConfiguration gc) { this(null, gc); super.setFocusableWindowState(false); } /** * Creates a window with the specified owner frame. * If <code>owner</code> is <code>null</code>, the shared owner * will be used and this window will not be focusable. Also, * this window will not be focusable unless its owner is showing * on the screen. * <p> * This constructor sets the component's locale property to the value * returned by <code>JComponent.getDefaultLocale</code>. * * @param owner the frame from which the window is displayed * @throws HeadlessException if GraphicsEnvironment.isHeadless() * returns true. * @see java.awt.GraphicsEnvironment#isHeadless * @see #isFocusableWindow * @see JComponent#getDefaultLocale */ public JWindow(Frame owner) { super(owner == null ? SwingUtilities.getSharedOwnerFrame() : owner); if (owner == null) { WindowListener ownerShutdownListener = SwingUtilities.getSharedOwnerFrameShutdownListener(); addWindowListener(ownerShutdownListener); } windowInit(); } /** * Creates a window with the specified owner window. This window * will not be focusable unless its owner is showing on the screen. * If <code>owner</code> is <code>null</code>, the shared owner * will be used and this window will not be focusable. * <p> * This constructor sets the component's locale property to the value * returned by <code>JComponent.getDefaultLocale</code>. * * @param owner the window from which the window is displayed * @throws HeadlessException if * <code>GraphicsEnvironment.isHeadless()</code> returns true. * @see java.awt.GraphicsEnvironment#isHeadless * @see #isFocusableWindow * @see JComponent#getDefaultLocale */ public JWindow(Window owner) { super(owner == null ? (Window) SwingUtilities.getSharedOwnerFrame() : owner); if (owner == null) { WindowListener ownerShutdownListener = SwingUtilities.getSharedOwnerFrameShutdownListener(); addWindowListener(ownerShutdownListener); } windowInit(); } /** * Creates a window with the specified owner window and * <code>GraphicsConfiguration</code> of a screen device. If * <code>owner</code> is <code>null</code>, the shared owner will be used * and this window will not be focusable. * <p> * This constructor sets the component's locale property to the value * returned by <code>JComponent.getDefaultLocale</code>. * * @param owner the window from which the window is displayed * @param gc the <code>GraphicsConfiguration</code> that is used * to construct the new window with; if gc is <code>null</code>, * the system default <code>GraphicsConfiguration</code> * is assumed, unless <code>owner</code> is also null, in which * case the <code>GraphicsConfiguration</code> from the * shared owner frame will be used. * @throws HeadlessException if * <code>GraphicsEnvironment.isHeadless()</code> returns true. * @throws IllegalArgumentException if <code>gc</code> is not from * a screen device. * * @see java.awt.GraphicsEnvironment#isHeadless * @see #isFocusableWindow * @see JComponent#getDefaultLocale * * @since 1.3 */ public JWindow(Window owner, GraphicsConfiguration gc) { super(owner == null ? (Window) SwingUtilities.getSharedOwnerFrame() : owner, gc); if (owner == null) { WindowListener ownerShutdownListener = SwingUtilities.getSharedOwnerFrameShutdownListener(); addWindowListener(ownerShutdownListener); } windowInit(); } /** * Called by the constructors to init the <code>JWindow</code> properly. */ protected void windowInit() { setLocale(JComponent.getDefaultLocale()); setRootPane(createRootPane()); setRootPaneCheckingEnabled(true); sun.awt.SunToolkit.checkAndSetPolicy(this); } /** * Called by the constructor methods to create the default * <code>rootPane</code>. * * @return a new {@code JRootPane} */ protected JRootPane createRootPane() { JRootPane rp = new JRootPane(); // NOTE: this uses setOpaque vs LookAndFeel.installProperty as there // is NO reason for the RootPane not to be opaque. For painting to // work the contentPane must be opaque, therefor the RootPane can // also be opaque. rp.setOpaque(true); return rp; } /** * Returns whether calls to <code>add</code> and * <code>setLayout</code> are forwarded to the <code>contentPane</code>. * * @return true if <code>add</code> and <code>setLayout</code> * are forwarded; false otherwise * * @see #addImpl * @see #setLayout * @see #setRootPaneCheckingEnabled * @see javax.swing.RootPaneContainer */ protected boolean isRootPaneCheckingEnabled() { return rootPaneCheckingEnabled; } /** * Sets the {@code transferHandler} property, which is a mechanism to * support transfer of data into this component. Use {@code null} * if the component does not support data transfer operations. * <p> * If the system property {@code suppressSwingDropSupport} is {@code false} * (the default) and the current drop target on this component is either * {@code null} or not a user-set drop target, this method will change the * drop target as follows: If {@code newHandler} is {@code null} it will * clear the drop target. If not {@code null} it will install a new * {@code DropTarget}. * <p> * Note: When used with {@code JWindow}, {@code TransferHandler} only * provides data import capability, as the data export related methods * are currently typed to {@code JComponent}. * <p> * Please see * <a href="https://docs.oracle.com/javase/tutorial/uiswing/dnd/index.html"> * How to Use Drag and Drop and Data Transfer</a>, a section in * <em>The Java Tutorial</em>, for more information. * * @param newHandler the new {@code TransferHandler} * * @see TransferHandler * @see #getTransferHandler * @see java.awt.Component#setDropTarget * @since 1.6 */ @BeanProperty(hidden = true, description = "Mechanism for transfer of data into the component") public void setTransferHandler(TransferHandler newHandler) { TransferHandler oldHandler = transferHandler; transferHandler = newHandler; SwingUtilities.installSwingDropTargetAsNecessary(this, transferHandler); firePropertyChange("transferHandler", oldHandler, newHandler); } /** * Gets the <code>transferHandler</code> property. * * @return the value of the <code>transferHandler</code> property * * @see TransferHandler * @see #setTransferHandler * @since 1.6 */ public TransferHandler getTransferHandler() { return transferHandler; } /** * Calls <code>paint(g)</code>. This method was overridden to * prevent an unnecessary call to clear the background. * * @param g the <code>Graphics</code> context in which to paint */ public void update(Graphics g) { paint(g); } /** * Sets whether calls to <code>add</code> and * <code>setLayout</code> are forwarded to the <code>contentPane</code>. * * @param enabled true if <code>add</code> and <code>setLayout</code> * are forwarded, false if they should operate directly on the * <code>JWindow</code>. * * @see #addImpl * @see #setLayout * @see #isRootPaneCheckingEnabled * @see javax.swing.RootPaneContainer */ @BeanProperty(hidden = true, description = "Whether the add and setLayout methods are forwarded") protected void setRootPaneCheckingEnabled(boolean enabled) { rootPaneCheckingEnabled = enabled; } /** * Adds the specified child <code>Component</code>. * This method is overridden to conditionally forward calls to the * <code>contentPane</code>. * By default, children are added to the <code>contentPane</code> instead * of the frame, refer to {@link javax.swing.RootPaneContainer} for * details. * * @param comp the component to be enhanced * @param constraints the constraints to be respected * @param index the index * @exception IllegalArgumentException if <code>index</code> is invalid * @exception IllegalArgumentException if adding the container's parent * to itself * @exception IllegalArgumentException if adding a window to a container * * @see #setRootPaneCheckingEnabled * @see javax.swing.RootPaneContainer */ protected void addImpl(Component comp, Object constraints, int index) { if (isRootPaneCheckingEnabled()) { getContentPane().add(comp, constraints, index); } else { super.addImpl(comp, constraints, index); } } /** * Removes the specified component from the container. If * <code>comp</code> is not the <code>rootPane</code>, this will forward * the call to the <code>contentPane</code>. This will do nothing if * <code>comp</code> is not a child of the <code>JWindow</code> or * <code>contentPane</code>. * * @param comp the component to be removed * @throws NullPointerException if <code>comp</code> is null * @see #add * @see javax.swing.RootPaneContainer */ public void remove(Component comp) { if (comp == rootPane) { super.remove(comp); } else { getContentPane().remove(comp); } } /** * Sets the <code>LayoutManager</code>. * Overridden to conditionally forward the call to the * <code>contentPane</code>. * Refer to {@link javax.swing.RootPaneContainer} for * more information. * * @param manager the <code>LayoutManager</code> * @see #setRootPaneCheckingEnabled * @see javax.swing.RootPaneContainer */ public void setLayout(LayoutManager manager) { if (isRootPaneCheckingEnabled()) { getContentPane().setLayout(manager); } else { super.setLayout(manager); } } /** * Returns the <code>rootPane</code> object for this window. * @return the <code>rootPane</code> property for this window * * @see #setRootPane * @see RootPaneContainer#getRootPane */ @BeanProperty(bound = false, hidden = true, description = "the RootPane object for this window.") public JRootPane getRootPane() { return rootPane; } /** * Sets the new <code>rootPane</code> object for this window. * This method is called by the constructor. * * @param root the new <code>rootPane</code> property * @see #getRootPane */ protected void setRootPane(JRootPane root) { if (rootPane != null) { remove(rootPane); } rootPane = root; if (rootPane != null) { boolean checkingEnabled = isRootPaneCheckingEnabled(); try { setRootPaneCheckingEnabled(false); add(rootPane, BorderLayout.CENTER); } finally { setRootPaneCheckingEnabled(checkingEnabled); } } } /** * Returns the <code>Container</code> which is the <code>contentPane</code> * for this window. * * @return the <code>contentPane</code> property * @see #setContentPane * @see RootPaneContainer#getContentPane */ public Container getContentPane() { return getRootPane().getContentPane(); } /** * Sets the <code>contentPane</code> property for this window. * This method is called by the constructor. * * @param contentPane the new <code>contentPane</code> * * @exception IllegalComponentStateException (a runtime * exception) if the content pane parameter is <code>null</code> * @see #getContentPane * @see RootPaneContainer#setContentPane */ @BeanProperty(bound = false, hidden = true, description = "The client area of the window where child components are normally inserted.") public void setContentPane(Container contentPane) { getRootPane().setContentPane(contentPane); } /** * Returns the <code>layeredPane</code> object for this window. * * @return the <code>layeredPane</code> property * @see #setLayeredPane * @see RootPaneContainer#getLayeredPane */ public JLayeredPane getLayeredPane() { return getRootPane().getLayeredPane(); } /** * Sets the <code>layeredPane</code> property. * This method is called by the constructor. * * @param layeredPane the new <code>layeredPane</code> object * * @exception IllegalComponentStateException (a runtime * exception) if the content pane parameter is <code>null</code> * @see #getLayeredPane * @see RootPaneContainer#setLayeredPane */ @BeanProperty(bound = false, hidden = true, description = "The pane which holds the various window layers.") public void setLayeredPane(JLayeredPane layeredPane) { getRootPane().setLayeredPane(layeredPane); } /** * Returns the <code>glassPane Component</code> for this window. * * @return the <code>glassPane</code> property * @see #setGlassPane * @see RootPaneContainer#getGlassPane */ public Component getGlassPane() { return getRootPane().getGlassPane(); } /** * Sets the <code>glassPane</code> property. * This method is called by the constructor. * @param glassPane the <code>glassPane</code> object for this window * * @see #getGlassPane * @see RootPaneContainer#setGlassPane */ @BeanProperty(bound = false, hidden = true, description = "A transparent pane used for menu rendering.") public void setGlassPane(Component glassPane) { getRootPane().setGlassPane(glassPane); } /** * {@inheritDoc} * * @since 1.6 */ @BeanProperty(bound = false) public Graphics getGraphics() { JComponent.getGraphicsInvoked(this); return super.getGraphics(); } /** * Repaints the specified rectangle of this component within * <code>time</code> milliseconds. Refer to <code>RepaintManager</code> * for details on how the repaint is handled. * * @param time maximum time in milliseconds before update * @param x the <i>x</i> coordinate * @param y the <i>y</i> coordinate * @param width the width * @param height the height * @see RepaintManager * @since 1.6 */ public void repaint(long time, int x, int y, int width, int height) { if (RepaintManager.HANDLE_TOP_LEVEL_PAINT) { RepaintManager.currentManager(this).addDirtyRegion(this, x, y, width, height); } else { super.repaint(time, x, y, width, height); } } /** * Returns a string representation of this <code>JWindow</code>. * 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</code>. * * @return a string representation of this <code>JWindow</code> */ protected String paramString() { String rootPaneCheckingEnabledString = (rootPaneCheckingEnabled ? "true" : "false"); return super.paramString() + ",rootPaneCheckingEnabled=" + rootPaneCheckingEnabledString; } ///////////////// // Accessibility support //////////////// /** The accessible context property. */ protected AccessibleContext accessibleContext = null; /** * Gets the AccessibleContext associated with this JWindow. * For JWindows, the AccessibleContext takes the form of an * AccessibleJWindow. * A new AccessibleJWindow instance is created if necessary. * * @return an AccessibleJWindow that serves as the * AccessibleContext of this JWindow */ public AccessibleContext getAccessibleContext() { if (accessibleContext == null) { accessibleContext = new AccessibleJWindow(); } return accessibleContext; } /** * This class implements accessibility support for the * <code>JWindow</code> class. It provides an implementation of the * Java Accessibility API appropriate to window user-interface * elements. */ @SuppressWarnings("serial") protected class AccessibleJWindow extends AccessibleAWTWindow { // everything is in the new parent, AccessibleAWTWindow } }