/*

 * Copyright 2003-2005 Sun Microsystems, Inc.  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.  Sun designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 */

/**

 * This class is a placeholder for all internal static objects that represent

 * system state. We keep our representation up-to-date with actual system

 * state by tracking events, such as X Focus, Component under cursor etc.

 * All attributes should be static private with accessors to simpify change

 * tracking.

 */

package sun.awt.X11;

import java.awt.Component;

import java.lang.ref.WeakReference;

class XAwtState {

    /**

     * The mouse is over this component.

     * If the component is not disabled, it received MOUSE_ENTERED but no MOUSE_EXITED.

     */

    private static WeakReference componentMouseEnteredRef = null;

    static void setComponentMouseEntered(Component component) {

        XToolkit.awtLock();

        try {

            if (component == null) {

                componentMouseEnteredRef = null;

                return;

            }

            if (component != getComponentMouseEntered()) {

                componentMouseEnteredRef = new WeakReference(component);

            }

        } finally {

            XToolkit.awtUnlock();

        }

    }

    static Component getComponentMouseEntered() {

        XToolkit.awtLock();

        try {

            if (componentMouseEnteredRef == null) {

                return null;

            }

            return (Component)componentMouseEnteredRef.get();

        } finally {

            XToolkit.awtUnlock();

        }

    }

    /**

     * The XBaseWindow is created with OwnerGrabButtonMask

     * (see X vol. 1, 8.3.3.2) so inside the app Key, Motion, and Button events

     * are received by the window they actualy happened on, not the grabber.

     * Then XBaseWindow dispatches them to the grabber. As a result

     * XAnyEvent.get_window() returns actual window the event is originated,

     * though the event is dispatched by  the grabber.

     */

    private static boolean inManualGrab = false;

    static boolean isManualGrab() {

        return inManualGrab;

    }

    private static WeakReference grabWindowRef = null;

    /**

     * The X Active Grab overrides any other active grab by the same

     * client see XGrabPointer, XGrabKeyboard

     */

    static void setGrabWindow(XBaseWindow grabWindow) {

        setGrabWindow(grabWindow, false);

    }

    /**

     * Automatic passive grab doesn't override active grab see XGrabButton

     */

    static void setAutoGrabWindow(XBaseWindow grabWindow) {

        setGrabWindow(grabWindow, true);

    }

    private static void setGrabWindow(XBaseWindow grabWindow, boolean isAutoGrab) {

        XToolkit.awtLock();

        try {

            if (inManualGrab && isAutoGrab) {

                return;

            }

            inManualGrab = grabWindow != null && !isAutoGrab;

            if (grabWindow == null) {

                grabWindowRef = null;

                return;

            }

            if (grabWindow != getGrabWindow()) {

                grabWindowRef = new WeakReference(grabWindow);

            }

        } finally {

            XToolkit.awtUnlock();

        }

    }

    static XBaseWindow getGrabWindow() {

        XToolkit.awtLock();

        try {

            if (grabWindowRef == null) {

                return null;

            }

            XBaseWindow xbw = (XBaseWindow)grabWindowRef.get();

            if( xbw != null && xbw.isDisposed() ) {

                xbw = null;

                grabWindowRef = null;

            }else if( xbw == null ) {

                grabWindowRef = null;

            }

            return xbw;

        } finally {

            XToolkit.awtUnlock();

        }

    }

}