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/* * Copyright (c) 1999, 2010, 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 sun.awt.ModalExclude;import sun.awt.SunToolkit; /** * Popups are used to display a <code>Component</code> to the user, typically * on top of all the other <code>Component</code>s in a particular containment * hierarchy. <code>Popup</code>s have a very small life cycle. Once you * have obtained a <code>Popup</code>, and hidden it (invoked the * <code>hide</code> method), you should no longer * invoke any methods on it. This allows the <code>PopupFactory</code> to cache * <code>Popup</code>s for later use. * <p> * The general contract is that if you need to change the size of the * <code>Component</code>, or location of the <code>Popup</code>, you should * obtain a new <code>Popup</code>. * <p> * <code>Popup</code> does not descend from <code>Component</code>, rather * implementations of <code>Popup</code> are responsible for creating * and maintaining their own <code>Component</code>s to render the * requested <code>Component</code> to the user. * <p> * You typically do not explicitly create an instance of <code>Popup</code>, * instead obtain one from a <code>PopupFactory</code>. * * @see PopupFactory * * @since 1.4 */public class Popup {    /**     * The Component representing the Popup.     */    private Component component;     /**     * Creates a <code>Popup</code> for the Component <code>owner</code>     * containing the Component <code>contents</code>. <code>owner</code>     * is used to determine which <code>Window</code> the new     * <code>Popup</code> will parent the <code>Component</code> the     * <code>Popup</code> creates to.     * A null <code>owner</code> implies there is no valid parent.     * <code>x</code> and     * <code>y</code> specify the preferred initial location to place     * the <code>Popup</code> at. Based on screen size, or other paramaters,     * the <code>Popup</code> may not display at <code>x</code> and     * <code>y</code>.     *     * @param owner    Component mouse coordinates are relative to, may be null     * @param contents Contents of the Popup     * @param x        Initial x screen coordinate     * @param y        Initial y screen coordinate     * @exception IllegalArgumentException if contents is null     */    protected Popup(Component owner, Component contents, int x, int y) {        this();        if (contents == null) {            throw new IllegalArgumentException("Contents must be non-null");        }        reset(owner, contents, x, y);    }     /**     * Creates a <code>Popup</code>. This is provided for subclasses.     */    protected Popup() {    }     /**     * Makes the <code>Popup</code> visible. If the <code>Popup</code> is     * currently visible, this has no effect.     */    public void show() {        Component component = getComponent();         if (component != null) {            component.show();        }    }     /**     * Hides and disposes of the <code>Popup</code>. Once a <code>Popup</code>     * has been disposed you should no longer invoke methods on it. A     * <code>dispose</code>d <code>Popup</code> may be reclaimed and later used     * based on the <code>PopupFactory</code>. As such, if you invoke methods     * on a <code>disposed</code> <code>Popup</code>, indeterminate     * behavior will result.     */    public void hide() {        Component component = getComponent();         if (component instanceof JWindow) {            component.hide();            ((JWindow)component).getContentPane().removeAll();        }        dispose();    }     /**     * Frees any resources the <code>Popup</code> may be holding onto.     */    void dispose() {        Component component = getComponent();        Window window = SwingUtilities.getWindowAncestor(component);         if (component instanceof JWindow) {            ((Window)component).dispose();            component = null;        }        // If our parent is a DefaultFrame, we need to dispose it, too.        if (window instanceof DefaultFrame) {            window.dispose();        }    }     /**     * Resets the <code>Popup</code> to an initial state.     */    void reset(Component owner, Component contents, int ownerX, int ownerY) {        if (getComponent() == null) {            component = createComponent(owner);        }         Component c = getComponent();         if (c instanceof JWindow) {            JWindow component = (JWindow)getComponent();             component.setLocation(ownerX, ownerY);            component.getContentPane().add(contents, BorderLayout.CENTER);            component.invalidate();            component.validate();            if(component.isVisible()) {                // Do not call pack() if window is not visible to                // avoid early native peer creation                pack();            }        }    }      /**     * Causes the <code>Popup</code> to be sized to fit the preferred size     * of the <code>Component</code> it contains.     */    void pack() {        Component component = getComponent();         if (component instanceof Window) {            ((Window)component).pack();        }    }     /**     * Returns the <code>Window</code> to use as the parent of the     * <code>Window</code> created for the <code>Popup</code>. This creates     * a new <code>DefaultFrame</code>, if necessary.     */    private Window getParentWindow(Component owner) {        Window window = null;         if (owner instanceof Window) {            window = (Window)owner;        }        else if (owner != null) {            window = SwingUtilities.getWindowAncestor(owner);        }        if (window == null) {            window = new DefaultFrame();        }        return window;    }     /**     * Creates the Component to use as the parent of the <code>Popup</code>.     * The default implementation creates a <code>Window</code>, subclasses     * should override.     */    Component createComponent(Component owner) {        if (GraphicsEnvironment.isHeadless()) {            // Generally not useful, bail.            return null;        }        return new HeavyWeightWindow(getParentWindow(owner));    }     /**     * Returns the <code>Component</code> returned from     * <code>createComponent</code> that will hold the <code>Popup</code>.     */    Component getComponent() {        return component;    }      /**     * Component used to house window.     */    static class HeavyWeightWindow extends JWindow implements ModalExclude {        HeavyWeightWindow(Window parent) {            super(parent);            setFocusableWindowState(false);            setType(Window.Type.POPUP);             // Popups are typically transient and most likely won't benefit            // from true double buffering.  Turn it off here.            getRootPane().setUseTrueDoubleBuffering(false);            // Try to set "always-on-top" for the popup window.            // Applets usually don't have sufficient permissions to do it.            // In this case simply ignore the exception.            try {                setAlwaysOnTop(true);            } catch (SecurityException se) {                // setAlwaysOnTop is restricted,                // the exception is ignored            }        }         public void update(Graphics g) {            paint(g);        }         public void show() {            this.pack();            if (getWidth() > 0 && getHeight() > 0) {                super.show();            }        }    }      /**     * Used if no valid Window ancestor of the supplied owner is found.     * <p>     * PopupFactory uses this as a way to know when the Popup shouldn't     * be cached based on the Window.     */    static class DefaultFrame extends Frame {    }}