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 * Copyright (c) 1996, 2008, 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

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 */

package java.awt.event;

import java.awt.Window;

import sun.awt.AppContext;

import sun.awt.SunToolkit;

/**

 * A low-level event that indicates that a window has changed its status. This

 * low-level event is generated by a Window object when it is opened, closed,

 * activated, deactivated, iconified, or deiconified, or when focus is

 * transfered into or out of the Window.

 * <P>

 * The event is passed to every <code>WindowListener</code>

 * or <code>WindowAdapter</code> object which registered to receive such

 * events using the window's <code>addWindowListener</code> method.

 * (<code>WindowAdapter</code> objects implement the

 * <code>WindowListener</code> interface.) Each such listener object

 * gets this <code>WindowEvent</code> when the event occurs.

 * <p>

 * An unspecified behavior will be caused if the {@code id} parameter

 * of any particular {@code WindowEvent} instance is not

 * in the range from {@code WINDOW_FIRST} to {@code WINDOW_LAST}.

 *

 * @author Carl Quinn

 * @author Amy Fowler

 *

 * @see WindowAdapter

 * @see WindowListener

 * @see <a href="http://java.sun.com/docs/books/tutorial/post1.0/ui/windowlistener.html">Tutorial: Writing a Window Listener</a>

 *

 * @since JDK1.1

 */

public class WindowEvent extends ComponentEvent {

    /**

     * The first number in the range of ids used for window events.

     */

    public static final int WINDOW_FIRST        = 200;

    /**

     * The window opened event.  This event is delivered only

     * the first time a window is made visible.

     */

    public static final int WINDOW_OPENED       = WINDOW_FIRST; // 200

    /**

     * The "window is closing" event. This event is delivered when

     * the user attempts to close the window from the window's system menu.

     * If the program does not explicitly hide or dispose the window

     * while processing this event, the window close operation will be

     * cancelled.

     */

    public static final int WINDOW_CLOSING      = 1 + WINDOW_FIRST; //Event.WINDOW_DESTROY

    /**

     * The window closed event. This event is delivered after

     * the window has been closed as the result of a call to dispose.

     */

    public static final int WINDOW_CLOSED       = 2 + WINDOW_FIRST;

    /**

     * The window iconified event. This event is delivered when

     * the window has been changed from a normal to a minimized state.

     * For many platforms, a minimized window is displayed as

     * the icon specified in the window's iconImage property.

     * @see java.awt.Frame#setIconImage

     */

    public static final int WINDOW_ICONIFIED    = 3 + WINDOW_FIRST; //Event.WINDOW_ICONIFY

    /**

     * The window deiconified event type. This event is delivered when

     * the window has been changed from a minimized to a normal state.

     */

    public static final int WINDOW_DEICONIFIED  = 4 + WINDOW_FIRST; //Event.WINDOW_DEICONIFY

    /**

     * The window-activated event type. This event is delivered when the Window

     * becomes the active Window. Only a Frame or a Dialog can be the active

     * Window. 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.

     */

    public static final int WINDOW_ACTIVATED    = 5 + WINDOW_FIRST;

    /**

     * The window-deactivated event type. This event is delivered when the

     * Window is no longer the active Window. Only a Frame or a Dialog can be

     * the active Window. 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.

     */

    public static final int WINDOW_DEACTIVATED  = 6 + WINDOW_FIRST;

    /**

     * The window-gained-focus event type. This event is delivered when the

     * Window becomes the focused Window, which means that the Window, or one

     * of its subcomponents, will receive keyboard events.

     */

    public static final int WINDOW_GAINED_FOCUS = 7 + WINDOW_FIRST;

    /**

     * The window-lost-focus event type. This event is delivered when a Window

     * is no longer the focused Window, which means keyboard events will no

     * longer be delivered to the Window or any of its subcomponents.

     */

    public static final int WINDOW_LOST_FOCUS   = 8 + WINDOW_FIRST;

    /**

     * The window-state-changed event type.  This event is delivered

     * when a Window's state is changed by virtue of it being

     * iconified, maximized etc.

     * @since 1.4

     */

    public static final int WINDOW_STATE_CHANGED = 9 + WINDOW_FIRST;

    /**

     * The last number in the range of ids used for window events.

     */

    public static final int WINDOW_LAST         = WINDOW_STATE_CHANGED;

    /**

     * The other Window involved in this focus or activation change. For a

     * WINDOW_ACTIVATED or WINDOW_GAINED_FOCUS event, this is the Window that

     * lost activation or focus. For a WINDOW_DEACTIVATED or WINDOW_LOST_FOCUS

     * event, this is the Window that gained activation or focus. For any other

     * type of WindowEvent, or if the focus or activation change occurs with a

     * native application, a Java application in a different VM, or with no

     * other Window, null is returned.

     *

     * @see #getOppositeWindow

     * @since 1.4

     */

    transient Window opposite;

    /**

     * TBS

     */

    int oldState;

    int newState;

    /*

     * JDK 1.1 serialVersionUID

     */

    private static final long serialVersionUID = -1567959133147912127L;

    /**

     * Constructs a <code>WindowEvent</code> object.

     * <p>This method throws an

     * <code>IllegalArgumentException</code> if <code>source</code>

     * is <code>null</code>.

     *

     * @param source    The <code>Window</code> object

     *                    that originated the event

     * @param id        An integer indicating the type of event.

     *                     For information on allowable values, see

     *                     the class description for {@link WindowEvent}

     * @param opposite  The other window involved in the focus or activation

     *                      change, or <code>null</code>

     * @param oldState  Previous state of the window for window state change event.

     *                  See {@code #getOldState()} for allowable values

     * @param newState  New state of the window for window state change event.

     *                  See {@code #getNewState()} for allowable values

     * @throws IllegalArgumentException if <code>source</code> is null

     * @see #getWindow()

     * @see #getID()

     * @see #getOppositeWindow()

     * @see #getOldState()

     * @see #getNewState()

     * @since 1.4

     */

    public WindowEvent(Window source, int id, Window opposite,

                       int oldState, int newState)

    {

        super(source, id);

        this.opposite = opposite;

        this.oldState = oldState;

        this.newState = newState;

    }

    /**

     * Constructs a <code>WindowEvent</code> object with the

     * specified opposite <code>Window</code>. The opposite

     * <code>Window</code> is the other <code>Window</code>

     * involved in this focus or activation change.

     * For a <code>WINDOW_ACTIVATED</code> or

     * <code>WINDOW_GAINED_FOCUS</code> event, this is the

     * <code>Window</code> that lost activation or focus.

     * For a <code>WINDOW_DEACTIVATED</code> or

     * <code>WINDOW_LOST_FOCUS</code> event, this is the

     * <code>Window</code> that gained activation or focus.

     * If this focus change occurs with a native application, with a

     * Java application in a different VM, or with no other

     * <code>Window</code>, then the opposite Window is <code>null</code>.

     * <p>This method throws an

     * <code>IllegalArgumentException</code> if <code>source</code>

     * is <code>null</code>.

     *

     * @param source     The <code>Window</code> object that

     *                   originated the event

     * @param id        An integer indicating the type of event.

     *                     For information on allowable values, see

     *                     the class description for {@link WindowEvent}.

     *                  It is expected that this constructor will not

     *                  be used for other then

     *                  {@code WINDOW_ACTIVATED},{@code WINDOW_DEACTIVATED},

     *                  {@code WINDOW_GAINED_FOCUS}, or {@code WINDOW_LOST_FOCUS}.

     *                  {@code WindowEvent} types,

     *                  because the opposite <code>Window</code> of other event types

     *                  will always be {@code null}.

     * @param opposite   The other <code>Window</code> involved in the

     *                   focus or activation change, or <code>null</code>

     * @throws IllegalArgumentException if <code>source</code> is null

     * @see #getWindow()

     * @see #getID()

     * @see #getOppositeWindow()

     * @since 1.4

     */

    public WindowEvent(Window source, int id, Window opposite) {

        this(source, id, opposite, 0, 0);

    }

    /**

     * Constructs a <code>WindowEvent</code> object with the specified

     * previous and new window states.

     * <p>This method throws an

     * <code>IllegalArgumentException</code> if <code>source</code>

     * is <code>null</code>.

     *

     * @param source    The <code>Window</code> object

     *                  that originated the event

     * @param id        An integer indicating the type of event.

     *                     For information on allowable values, see

     *                     the class description for {@link WindowEvent}.

     *                  It is expected that this constructor will not

     *                  be used for other then

     *                  {@code WINDOW_STATE_CHANGED}

     *                  {@code WindowEvent}

     *                  types, because the previous and new window

     *                  states are meaningless for other event types.

     * @param oldState  An integer representing the previous window state.

     *                  See {@code #getOldState()} for allowable values

     * @param newState  An integer representing the new window state.

     *                  See {@code #getNewState()} for allowable values

     * @throws IllegalArgumentException if <code>source</code> is null

     * @see #getWindow()

     * @see #getID()

     * @see #getOldState()

     * @see #getNewState()

     * @since 1.4

     */

    public WindowEvent(Window source, int id, int oldState, int newState) {

        this(source, id, null, oldState, newState);

    }

    /**

     * Constructs a <code>WindowEvent</code> object.

     * <p>This method throws an

     * <code>IllegalArgumentException</code> if <code>source</code>

     * is <code>null</code>.

     *

     * @param source The <code>Window</code> object that originated the event

     * @param id     An integer indicating the type of event.

     *                     For information on allowable values, see

     *                     the class description for {@link WindowEvent}.

     * @throws IllegalArgumentException if <code>source</code> is null

     * @see #getWindow()

     * @see #getID()

     */

    public WindowEvent(Window source, int id) {

        this(source, id, null, 0, 0);

    }

    /**

     * Returns the originator of the event.

     *

     * @return the Window object that originated the event

     */

    public Window getWindow() {

        return (source instanceof Window) ? (Window)source : null;

    }

    /**

     * Returns the other Window involved in this focus or activation change.

     * For a WINDOW_ACTIVATED or WINDOW_GAINED_FOCUS event, this is the Window

     * that lost activation or focus. For a WINDOW_DEACTIVATED or

     * WINDOW_LOST_FOCUS event, this is the Window that gained activation or

     * focus. For any other type of WindowEvent, or if the focus or activation

     * change occurs with a native application, with a Java application in a

     * different VM or context, or with no other Window, null is returned.

     *

     * @return the other Window involved in the focus or activation change, or

     *         null

     * @since 1.4

     */

    public Window getOppositeWindow() {

        if (opposite == null) {

            return null;

        }

        return (SunToolkit.targetToAppContext(opposite) ==

                AppContext.getAppContext())

            ? opposite

            : null;

    }

    /**

     * For <code>WINDOW_STATE_CHANGED</code> events returns the

     * previous state of the window. The state is

     * represented as a bitwise mask.

     * <ul>

     * <li><code>NORMAL</code>

     * <br>Indicates that no state bits are set.

     * <li><code>ICONIFIED</code>

     * <li><code>MAXIMIZED_HORIZ</code>

     * <li><code>MAXIMIZED_VERT</code>

     * <li><code>MAXIMIZED_BOTH</code>

     * <br>Concatenates <code>MAXIMIZED_HORIZ</code>

     * and <code>MAXIMIZED_VERT</code>.

     * </ul>

     *

     * @return a bitwise mask of the previous window state

     * @see java.awt.Frame#getExtendedState()

     * @since 1.4

     */

    public int getOldState() {

        return oldState;

    }

    /**

     * For <code>WINDOW_STATE_CHANGED</code> events returns the

     * new state of the window. The state is

     * represented as a bitwise mask.

     * <ul>

     * <li><code>NORMAL</code>

     * <br>Indicates that no state bits are set.

     * <li><code>ICONIFIED</code>

     * <li><code>MAXIMIZED_HORIZ</code>

     * <li><code>MAXIMIZED_VERT</code>

     * <li><code>MAXIMIZED_BOTH</code>

     * <br>Concatenates <code>MAXIMIZED_HORIZ</code>

     * and <code>MAXIMIZED_VERT</code>.

     * </ul>

     *

     * @return a bitwise mask of the new window state

     * @see java.awt.Frame#getExtendedState()

     * @since 1.4

     */

    public int getNewState() {

        return newState;

    }

    /**

     * Returns a parameter string identifying this event.

     * This method is useful for event-logging and for debugging.

     *

     * @return a string identifying the event and its attributes

     */

    public String paramString() {

        String typeStr;

        switch(id) {

          case WINDOW_OPENED:

              typeStr = "WINDOW_OPENED";

              break;

          case WINDOW_CLOSING:

              typeStr = "WINDOW_CLOSING";

              break;

          case WINDOW_CLOSED:

              typeStr = "WINDOW_CLOSED";

              break;

          case WINDOW_ICONIFIED:

              typeStr = "WINDOW_ICONIFIED";

              break;

          case WINDOW_DEICONIFIED:

              typeStr = "WINDOW_DEICONIFIED";

              break;

          case WINDOW_ACTIVATED:

              typeStr = "WINDOW_ACTIVATED";

              break;

          case WINDOW_DEACTIVATED:

              typeStr = "WINDOW_DEACTIVATED";

              break;

          case WINDOW_GAINED_FOCUS:

              typeStr = "WINDOW_GAINED_FOCUS";

              break;

          case WINDOW_LOST_FOCUS:

              typeStr = "WINDOW_LOST_FOCUS";

              break;

          case WINDOW_STATE_CHANGED:

              typeStr = "WINDOW_STATE_CHANGED";

              break;

          default:

              typeStr = "unknown type";

        }

        typeStr += ",opposite=" + getOppositeWindow()

            + ",oldState=" + oldState + ",newState=" + newState;

        return typeStr;

    }

}