/*
 * Copyright (c) 1997, 2009, 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 sun.awt;

import java.awt.*;
import static java.awt.RenderingHints.*;
import java.awt.dnd.*;
import java.awt.dnd.peer.DragSourceContextPeer;
import java.awt.peer.*;
import java.awt.event.WindowEvent;
import java.awt.event.KeyEvent;
import java.awt.image.*;
import java.awt.TrayIcon;
import java.awt.SystemTray;
import java.net.URL;
import java.util.*;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.ReentrantLock;
import sun.util.logging.PlatformLogger;
import sun.misc.SoftCache;
import sun.font.FontDesignMetrics;
import sun.awt.im.InputContext;
import sun.awt.image.*;
import sun.security.action.GetPropertyAction;
import sun.security.action.GetBooleanAction;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.security.PrivilegedActionException;
import java.security.PrivilegedExceptionAction;

public abstract class SunToolkit extends Toolkit
    implements WindowClosingSupport, WindowClosingListener,
    ComponentFactory, InputMethodSupport, KeyboardFocusManagerPeerProvider {

    private static final PlatformLogger log = PlatformLogger.getLogger("sun.awt.SunToolkit");

    /* Load debug settings for native code */
    static {
        if (AccessController.doPrivileged(new GetBooleanAction("sun.awt.nativedebug"))) {
            DebugSettings.init();
        }
    };

    /**
     * Special mask for the UngrabEvent events, in addition to the
     * public masks defined in AWTEvent.  Should be used as the mask
     * value for Toolkit.addAWTEventListener.
     */
    public static final int GRAB_EVENT_MASK = 0x80000000;

    private static Method  wakeupMethod;
    /* The key to put()/get() the PostEventQueue into/from the AppContext.
     */
    private static final String POST_EVENT_QUEUE_KEY = "PostEventQueue";

    /**
     * Number of buttons.
     * By default it's taken from the system. If system value does not
     * fit into int type range, use our own MAX_BUTTONS_SUPPORT value.
     */
    protected static int numberOfButtons = 0;


    /* XFree standard mention 24 buttons as maximum:
     * http://www.xfree86.org/current/mouse.4.html
     * We workaround systems supporting more than 24 buttons.
     * Otherwise, we have to use long type values as masks
     * which leads to API change.
     * InputEvent.BUTTON_DOWN_MASK may contain only 21 masks due to
     * the 4-bytes limit for the int type. (CR 6799099)
     * One more bit is reserved for FIRST_HIGH_BIT.
     */
    public final static int MAX_BUTTONS_SUPPORTED = 20;

    public SunToolkit() {
        /* If awt.threadgroup is set to class name the instance of
         * this class is created (should be subclass of ThreadGroup)
         * and EventDispatchThread is created inside of it
         *
         * If loaded class overrides uncaughtException instance
         * handles all uncaught exception on EventDispatchThread
         */
        ThreadGroup threadGroup = null;
        String tgName = System.getProperty("awt.threadgroup", "");

        if (tgName.length() != 0) {
            try {
                Constructor ctor = Class.forName(tgName).
                    getConstructor(new Class[] {String.class});
                threadGroup = (ThreadGroup)ctor.newInstance(new Object[] {"AWT-ThreadGroup"});
            } catch (Exception e) {
                System.err.println("Failed loading " + tgName + ": " + e);
            }
        }

        Runnable initEQ = new Runnable() {
            public void run () {
                EventQueue eventQueue;

                String eqName = System.getProperty("AWT.EventQueueClass",
                                                   "java.awt.EventQueue");

                try {
                    eventQueue = (EventQueue)Class.forName(eqName).newInstance();
                } catch (Exception e) {
                    e.printStackTrace();
                    System.err.println("Failed loading " + eqName + ": " + e);
                    eventQueue = new EventQueue();
                }
                AppContext appContext = AppContext.getAppContext();
                appContext.put(AppContext.EVENT_QUEUE_KEY, eventQueue);

                PostEventQueue postEventQueue = new PostEventQueue(eventQueue);
                appContext.put(POST_EVENT_QUEUE_KEY, postEventQueue);
            }
        };

        if (threadGroup != null) {
            Thread eqInitThread = new Thread(threadGroup, initEQ, "EventQueue-Init");
            eqInitThread.start();
            try {
                eqInitThread.join();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        } else {
            initEQ.run();
        }
    }

    public boolean useBufferPerWindow() {
        return false;
    }

    public abstract WindowPeer createWindow(Window target)
        throws HeadlessException;

    public abstract FramePeer createFrame(Frame target)
        throws HeadlessException;

    public abstract DialogPeer createDialog(Dialog target)
        throws HeadlessException;

    public abstract ButtonPeer createButton(Button target)
        throws HeadlessException;

    public abstract TextFieldPeer createTextField(TextField target)
        throws HeadlessException;

    public abstract ChoicePeer createChoice(Choice target)
        throws HeadlessException;

    public abstract LabelPeer createLabel(Label target)
        throws HeadlessException;

    public abstract ListPeer createList(java.awt.List target)
        throws HeadlessException;

    public abstract CheckboxPeer createCheckbox(Checkbox target)
        throws HeadlessException;

    public abstract ScrollbarPeer createScrollbar(Scrollbar target)
        throws HeadlessException;

    public abstract ScrollPanePeer createScrollPane(ScrollPane target)
        throws HeadlessException;

    public abstract TextAreaPeer createTextArea(TextArea target)
        throws HeadlessException;

    public abstract FileDialogPeer createFileDialog(FileDialog target)
        throws HeadlessException;

    public abstract MenuBarPeer createMenuBar(MenuBar target)
        throws HeadlessException;

    public abstract MenuPeer createMenu(Menu target)
        throws HeadlessException;

    public abstract PopupMenuPeer createPopupMenu(PopupMenu target)
        throws HeadlessException;

    public abstract MenuItemPeer createMenuItem(MenuItem target)
        throws HeadlessException;

    public abstract CheckboxMenuItemPeer createCheckboxMenuItem(
        CheckboxMenuItem target)
        throws HeadlessException;

    public abstract DragSourceContextPeer createDragSourceContextPeer(
        DragGestureEvent dge)
        throws InvalidDnDOperationException;

    public abstract TrayIconPeer createTrayIcon(TrayIcon target)
        throws HeadlessException, AWTException;

    public abstract SystemTrayPeer createSystemTray(SystemTray target);

    public abstract boolean isTraySupported();

    public abstract FontPeer getFontPeer(String name, int style);

    public abstract RobotPeer createRobot(Robot target, GraphicsDevice screen)
        throws AWTException;

    public abstract KeyboardFocusManagerPeer createKeyboardFocusManagerPeer(KeyboardFocusManager manager)
        throws HeadlessException;

    /**
     * The AWT lock is typically only used on Unix platforms to synchronize
     * access to Xlib, OpenGL, etc.  However, these methods are implemented
     * in SunToolkit so that they can be called from shared code (e.g.
     * from the OGL pipeline) or from the X11 pipeline regardless of whether
     * XToolkit or MToolkit is currently in use.  There are native macros
     * (such as AWT_LOCK) defined in awt.h, so if the implementation of these
     * methods is changed, make sure it is compatible with the native macros.
     *
     * Note: The following methods (awtLock(), awtUnlock(), etc) should be
     * used in place of:
     *     synchronized (getAWTLock()) {
     *         ...
     *     }
     *
     * By factoring these methods out specially, we are able to change the
     * implementation of these methods (e.g. use more advanced locking
     * mechanisms) without impacting calling code.
     *
     * Sample usage:
     *     private void doStuffWithXlib() {
     *         assert !SunToolkit.isAWTLockHeldByCurrentThread();
     *         SunToolkit.awtLock();
     *         try {
     *             ...
     *             XlibWrapper.XDoStuff();
     *         } finally {
     *             SunToolkit.awtUnlock();
     *         }
     *     }
     */

    private static final ReentrantLock AWT_LOCK = new ReentrantLock();
    private static final Condition AWT_LOCK_COND = AWT_LOCK.newCondition();

    public static final void awtLock() {
        AWT_LOCK.lock();
    }

    public static final boolean awtTryLock() {
        return AWT_LOCK.tryLock();
    }

    public static final void awtUnlock() {
        AWT_LOCK.unlock();
    }

    public static final void awtLockWait()
        throws InterruptedException
    {
        AWT_LOCK_COND.await();
    }

    public static final void awtLockWait(long timeout)
        throws InterruptedException
    {
        AWT_LOCK_COND.await(timeout, TimeUnit.MILLISECONDS);
    }

    public static final void awtLockNotify() {
        AWT_LOCK_COND.signal();
    }

    public static final void awtLockNotifyAll() {
        AWT_LOCK_COND.signalAll();
    }

    public static final boolean isAWTLockHeldByCurrentThread() {
        return AWT_LOCK.isHeldByCurrentThread();
    }

    /*
     * Create a new AppContext, along with its EventQueue, for a
     * new ThreadGroup.  Browser code, for example, would use this
     * method to create an AppContext & EventQueue for an Applet.
     */
    public static AppContext createNewAppContext() {
        ThreadGroup threadGroup = Thread.currentThread().getThreadGroup();
        EventQueue eventQueue;
        String eqName = System.getProperty("AWT.EventQueueClass",
                                           "java.awt.EventQueue");
        try {
            eventQueue = (EventQueue)Class.forName(eqName).newInstance();
        } catch (Exception e) {
            System.err.println("Failed loading " + eqName + ": " + e);
            eventQueue = new EventQueue();
        }
        AppContext appContext = new AppContext(threadGroup);
        appContext.put(AppContext.EVENT_QUEUE_KEY, eventQueue);

        PostEventQueue postEventQueue = new PostEventQueue(eventQueue);
        appContext.put(POST_EVENT_QUEUE_KEY, postEventQueue);

        return appContext;
    }

    public static Field getField(final Class klass, final String fieldName) {
        return AccessController.doPrivileged(new PrivilegedAction<Field>() {
            public Field run() {
                try {
                    Field field = klass.getDeclaredField(fieldName);
                    assert (field != null);
                    field.setAccessible(true);
                    return field;
                } catch (SecurityException e) {
                    assert false;
                } catch (NoSuchFieldException e) {
                    assert false;
                }
                return null;
            }//run
        });
    }

    static void wakeupEventQueue(EventQueue q, boolean isShutdown){
        if (wakeupMethod == null){
            wakeupMethod = (Method)AccessController.doPrivileged(new PrivilegedAction(){
                    public Object run(){
                        try {
                            Method method  = EventQueue.class.getDeclaredMethod("wakeup",new Class [] {Boolean.TYPE} );
                            if (method != null) {
                                method.setAccessible(true);
                            }
                            return method;
                        } catch (NoSuchMethodException e) {
                            assert false;
                        } catch (SecurityException e) {
                            assert false;
                        }
                        return null;
                    }//run
                });
        }
        try{
            if (wakeupMethod != null){
                wakeupMethod.invoke(q, new Object[]{Boolean.valueOf(isShutdown)});
            }
        } catch (InvocationTargetException e){
            assert false;
        } catch (IllegalAccessException e) {
            assert false;
        }
    }

    /*
     * Fetch the peer associated with the given target (as specified
     * in the peer creation method).  This can be used to determine
     * things like what the parent peer is.  If the target is null
     * or the target can't be found (either because the a peer was
     * never created for it or the peer was disposed), a null will
     * be returned.
     */
    protected static Object targetToPeer(Object target) {
        if (target != null && !GraphicsEnvironment.isHeadless()) {
            return AWTAutoShutdown.getInstance().getPeer(target);
        }
        return null;
    }

    protected static void targetCreatedPeer(Object target, Object peer) {
        if (target != null && peer != null &&
            !GraphicsEnvironment.isHeadless())
        {
            AWTAutoShutdown.getInstance().registerPeer(target, peer);
        }
    }

    protected static void targetDisposedPeer(Object target, Object peer) {
        if (target != null && peer != null &&
            !GraphicsEnvironment.isHeadless())
        {
            AWTAutoShutdown.getInstance().unregisterPeer(target, peer);
        }
    }

    // Maps from non-Component/MenuComponent to AppContext.
    // WeakHashMap<Component,AppContext>
    private static final Map appContextMap =
        Collections.synchronizedMap(new WeakHashMap());

    /**
     * Sets the appContext field of target. If target is not a Component or
     * MenuComponent, this returns false.
     */
    private static boolean setAppContext(Object target,
                                         AppContext context) {
        if (target instanceof Component) {
            AWTAccessor.getComponentAccessor().
                setAppContext((Component)target, context);
        } else if (target instanceof MenuComponent) {
            AWTAccessor.getMenuComponentAccessor().
                setAppContext((MenuComponent)target, context);
        } else {
            return false;
        }
        return true;
    }

    /**
     * Returns the appContext field for target. If target is not a
     * Component or MenuComponent this returns null.
     */
    private static AppContext getAppContext(Object target) {
        if (target instanceof Component) {
            return AWTAccessor.getComponentAccessor().
                       getAppContext((Component)target);
        } else if (target instanceof MenuComponent) {
            return AWTAccessor.getMenuComponentAccessor().
                       getAppContext((MenuComponent)target);
        } else {
            return null;
        }
    }

    /*
     * Fetch the AppContext associated with the given target.
     * This can be used to determine things like which EventQueue
     * to use for posting events to a Component.  If the target is
     * null or the target can't be found, a null with be returned.
     */
    public static AppContext targetToAppContext(Object target) {
        if (target == null || GraphicsEnvironment.isHeadless()) {
            return null;
        }
        AppContext context = getAppContext(target);
        if (context == null) {
            // target is not a Component/MenuComponent, try the
            // appContextMap.
            context = (AppContext)appContextMap.get(target);
        }
        return context;
    }

     /**
      * Sets the synchronous status of focus requests on lightweight
      * components in the specified window to the specified value.
      * If the boolean parameter is <code>true</code> then the focus
      * requests on lightweight components will be performed
      * synchronously, if it is <code>false</code>, then asynchronously.
      * By default, all windows have their lightweight request status
      * set to asynchronous.
      * <p>
      * The application can only set the status of lightweight focus
      * requests to synchronous for any of its windows if it doesn't
      * perform focus transfers between different heavyweight containers.
      * In this case the observable focus behaviour is the same as with
      * asynchronous status.
      * <p>
      * If the application performs focus transfer between different
      * heavyweight containers and sets the lightweight focus request
      * status to synchronous for any of its windows, then further focus
      * behaviour is unspecified.
      * <p>
      * @param    w window for which the lightweight focus request status
      *             should be set
      * @param    status the value of lightweight focus request status
      */

    public static void setLWRequestStatus(Window changed,boolean status){
        AWTAccessor.getWindowAccessor().setLWRequestStatus(changed, status);
    };

    public static void checkAndSetPolicy(Container cont, boolean isSwingCont)
    {
        FocusTraversalPolicy defaultPolicy = KeyboardFocusManager
            .getCurrentKeyboardFocusManager().getDefaultFocusTraversalPolicy();

        String toolkitName = Toolkit.getDefaultToolkit().getClass().getName();
        // if this is not XAWT then use default policy
        // because Swing change it
        if (!"sun.awt.X11.XToolkit".equals(toolkitName)) {
            cont.setFocusTraversalPolicy(defaultPolicy);
            return;
        }

        String policyName = defaultPolicy.getClass().getName();

        if (DefaultFocusTraversalPolicy.class != defaultPolicy.getClass()) {
            // Policy was changed
            // Check if it is awt policy or swing policy
            // If it is Swing policy we shouldn't use it in AWT frames
            // If it is AWT policy  we shouldn't use it in Swing frames
            // Otherwise we should use this policy
            if (policyName.startsWith("java.awt.")) {
                // AWT
                if (isSwingCont) {
                    // Can't use AWT policy in Swing windows - should use Swing's one.
                    defaultPolicy = createLayoutPolicy();
                } else {
                    // New awt policy.
                }
            } else if (policyName.startsWith("javax.swing.")) {
                if (isSwingCont) {
                    // New Swing's policy
                } else {
                    defaultPolicy = new DefaultFocusTraversalPolicy();
                }
            }
        } else {
            // Policy is default, use different default policy for swing
            if (isSwingCont) {
                defaultPolicy = createLayoutPolicy();
            }
        }
        cont.setFocusTraversalPolicy(defaultPolicy);
    }

    private static FocusTraversalPolicy createLayoutPolicy() {
        FocusTraversalPolicy policy = null;
        try {
            Class layoutPolicyClass =
                Class.forName("javax.swing.LayoutFocusTraversalPolicy");
            policy = (FocusTraversalPolicy) layoutPolicyClass.newInstance();
        }
        catch (ClassNotFoundException e) {
            assert false;
        }
        catch (InstantiationException e) {
            assert false;
        }
        catch (IllegalAccessException e) {
            assert false;
        }

        return policy;
    }

    /*
     * Insert a mapping from target to AppContext, for later retrieval
     * via targetToAppContext() above.
     */
    public static void insertTargetMapping(Object target, AppContext appContext) {
        if (!GraphicsEnvironment.isHeadless()) {
            if (!setAppContext(target, appContext)) {
                // Target is not a Component/MenuComponent, use the private Map
                // instead.
                appContextMap.put(target, appContext);
            }
        }
    }

    /*
     * Post an AWTEvent to the Java EventQueue, using the PostEventQueue
     * to avoid possibly calling client code (EventQueueSubclass.postEvent())
     * on the toolkit (AWT-Windows/AWT-Motif) thread.  This function should
     * not be called under another lock since it locks the EventQueue.
     * See bugids 4632918, 4526597.
     */
    public static void postEvent(AppContext appContext, AWTEvent event) {
        if (event == null) {
            throw new NullPointerException();
        }
        AppContext eventContext = targetToAppContext(event.getSource());
        if (eventContext != null && !eventContext.equals(appContext)) {
            log.fine("Event posted on wrong app context : " + event);
        }
        PostEventQueue postEventQueue =
            (PostEventQueue)appContext.get(POST_EVENT_QUEUE_KEY);
        if(postEventQueue != null) {
            postEventQueue.postEvent(event);
        }
    }

    /*
     * Post AWTEvent of high priority.
     */
    public static void postPriorityEvent(final AWTEvent e) {
        PeerEvent pe = new PeerEvent(Toolkit.getDefaultToolkit(), new Runnable() {
                public void run() {
                    AWTAccessor.getAWTEventAccessor().setPosted(e);
                    ((Component)e.getSource()).dispatchEvent(e);
                }
            }, PeerEvent.ULTIMATE_PRIORITY_EVENT);
        postEvent(targetToAppContext(e.getSource()), pe);
    }

    /*
     * Flush any pending events which haven't been posted to the AWT
     * EventQueue yet.
     */
    public static void flushPendingEvents()  {
        AppContext appContext = AppContext.getAppContext();
        PostEventQueue postEventQueue =
            (PostEventQueue)appContext.get(POST_EVENT_QUEUE_KEY);
        if(postEventQueue != null) {
            postEventQueue.flush();
        }
    }

    public static boolean isPostEventQueueEmpty()  {
        AppContext appContext = AppContext.getAppContext();
        PostEventQueue postEventQueue =
            (PostEventQueue)appContext.get(POST_EVENT_QUEUE_KEY);
        if (postEventQueue != null) {
            return postEventQueue.noEvents();
        } else {
            return true;
        }
    }

    /*
     * Execute a chunk of code on the Java event handler thread for the
     * given target.  Does not wait for the execution to occur before
     * returning to the caller.
     */
    public static void executeOnEventHandlerThread(Object target,
                                                   Runnable runnable) {
        executeOnEventHandlerThread(new PeerEvent(target, runnable, PeerEvent.PRIORITY_EVENT));
    }

    /*
     * Fixed 5064013: the InvocationEvent time should be equals
     * the time of the ActionEvent
     */
    public static void executeOnEventHandlerThread(Object target,
                                                   Runnable runnable,
                                                   final long when) {
        executeOnEventHandlerThread(new PeerEvent(target, runnable, PeerEvent.PRIORITY_EVENT){
                public long getWhen(){
                    return when;
                }
            });
    }

    /*
     * Execute a chunk of code on the Java event handler thread for the
     * given target.  Does not wait for the execution to occur before
     * returning to the caller.
     */
    public static void executeOnEventHandlerThread(PeerEvent peerEvent) {
        postEvent(targetToAppContext(peerEvent.getSource()), peerEvent);
    }

    /*
     * Execute a chunk of code on the Java event handler thread. The
     * method takes into account provided AppContext and sets
     * <code>SunToolkit.getDefaultToolkit()</code> as a target of the
     * event. See 6451487 for detailes.
     * Does not wait for the execution to occur before returning to
     * the caller.
     */
     public static void invokeLaterOnAppContext(
        AppContext appContext, Runnable dispatcher)
     {
        postEvent(appContext,
            new PeerEvent(Toolkit.getDefaultToolkit(), dispatcher,
                PeerEvent.PRIORITY_EVENT));
     }

    /*
     * Execute a chunk of code on the Java event handler thread for the
     * given target.  Waits for the execution to occur before returning
     * to the caller.
     */
    public static void executeOnEDTAndWait(Object target, Runnable runnable)
        throws InterruptedException, InvocationTargetException
    {
        if (EventQueue.isDispatchThread()) {
            throw new Error("Cannot call executeOnEDTAndWait from any event dispatcher thread");
        }

        class AWTInvocationLock {}
        Object lock = new AWTInvocationLock();

        PeerEvent event = new PeerEvent(target, runnable, lock, true, PeerEvent.PRIORITY_EVENT);

        synchronized (lock) {
            executeOnEventHandlerThread(event);
            lock.wait();
        }

        Throwable eventThrowable = event.getThrowable();
        if (eventThrowable != null) {
            throw new InvocationTargetException(eventThrowable);
        }
    }

    /*
     * Returns true if the calling thread is the event dispatch thread
     * contained within AppContext which associated with the given target.
     * Use this call to ensure that a given task is being executed
     * (or not being) on the event dispatch thread for the given target.
     */
    public static boolean isDispatchThreadForAppContext(Object target) {
        AppContext appContext = targetToAppContext(target);
        EventQueue eq = (EventQueue)appContext.get(AppContext.EVENT_QUEUE_KEY);

        AWTAccessor.EventQueueAccessor accessor = AWTAccessor.getEventQueueAccessor();
        return accessor.isDispatchThreadImpl(eq);
    }

    public Dimension getScreenSize() {
        return new Dimension(getScreenWidth(), getScreenHeight());
    }
    protected abstract int getScreenWidth();
    protected abstract int getScreenHeight();

    public FontMetrics getFontMetrics(Font font) {
        return FontDesignMetrics.getMetrics(font);
    }

    public String[] getFontList() {
        String[] hardwiredFontList = {
            Font.DIALOG, Font.SANS_SERIF, Font.SERIF, Font.MONOSPACED,
            Font.DIALOG_INPUT

            // -- Obsolete font names from 1.0.2.  It was decided that
            // -- getFontList should not return these old names:
            //    "Helvetica", "TimesRoman", "Courier", "ZapfDingbats"
        };
        return hardwiredFontList;
    }

    public PanelPeer createPanel(Panel target) {
        return (PanelPeer)createComponent(target);
    }

    public CanvasPeer createCanvas(Canvas target) {
        return (CanvasPeer)createComponent(target);
    }

    /**
     * Disables erasing of background on the canvas before painting if
     * this is supported by the current toolkit. It is recommended to
     * call this method early, before the Canvas becomes displayable,
     * because some Toolkit implementations do not support changing
     * this property once the Canvas becomes displayable.
     */
    public void disableBackgroundErase(Canvas canvas) {
        disableBackgroundEraseImpl(canvas);
    }

    /**
     * Disables the native erasing of the background on the given
     * component before painting if this is supported by the current
     * toolkit. This only has an effect for certain components such as
     * Canvas, Panel and Window. It is recommended to call this method
     * early, before the Component becomes displayable, because some
     * Toolkit implementations do not support changing this property
     * once the Component becomes displayable.
     */
    public void disableBackgroundErase(Component component) {
        disableBackgroundEraseImpl(component);
    }

    private void disableBackgroundEraseImpl(Component component) {
        AWTAccessor.getComponentAccessor().setBackgroundEraseDisabled(component, true);
    }

    /**
     * Returns the value of "sun.awt.noerasebackground" property. Default
     * value is {@code false}.
     */
    public static boolean getSunAwtNoerasebackground() {
        return AccessController.doPrivileged(new GetBooleanAction("sun.awt.noerasebackground"));
    }

    /**
     * Returns the value of "sun.awt.erasebackgroundonresize" property. Default
     * value is {@code false}.
     */
    public static boolean getSunAwtErasebackgroundonresize() {
        return AccessController.doPrivileged(new GetBooleanAction("sun.awt.erasebackgroundonresize"));
    }


    static final SoftCache imgCache = new SoftCache();

    static Image getImageFromHash(Toolkit tk, URL url) {
        SecurityManager sm = System.getSecurityManager();
        if (sm != null) {
            try {
                java.security.Permission perm =
                    url.openConnection().getPermission();
                if (perm != null) {
                    try {
                        sm.checkPermission(perm);
                    } catch (SecurityException se) {
                        // fallback to checkRead/checkConnect for pre 1.2
                        // security managers
                        if ((perm instanceof java.io.FilePermission) &&
                            perm.getActions().indexOf("read") != -1) {
                            sm.checkRead(perm.getName());
                        } else if ((perm instanceof
                            java.net.SocketPermission) &&
                            perm.getActions().indexOf("connect") != -1) {
                            sm.checkConnect(url.getHost(), url.getPort());
                        } else {
                            throw se;
                        }
                    }
                }
            } catch (java.io.IOException ioe) {
                    sm.checkConnect(url.getHost(), url.getPort());
            }
        }
        synchronized (imgCache) {
            Image img = (Image)imgCache.get(url);
            if (img == null) {
                try {
                    img = tk.createImage(new URLImageSource(url));
                    imgCache.put(url, img);
                } catch (Exception e) {
                }
            }
            return img;
        }
    }

    static Image getImageFromHash(Toolkit tk,
                                               String filename) {
        SecurityManager security = System.getSecurityManager();
        if (security != null) {
            security.checkRead(filename);
        }
        synchronized (imgCache) {
            Image img = (Image)imgCache.get(filename);
            if (img == null) {
                try {
                    img = tk.createImage(new FileImageSource(filename));
                    imgCache.put(filename, img);
                } catch (Exception e) {
                }
            }
            return img;
        }
    }

    public Image getImage(String filename) {
        return getImageFromHash(this, filename);
    }

    public Image getImage(URL url) {
        return getImageFromHash(this, url);
    }

    public Image createImage(String filename) {
        SecurityManager security = System.getSecurityManager();
        if (security != null) {
            security.checkRead(filename);
        }
        return createImage(new FileImageSource(filename));
    }

    public Image createImage(URL url) {
        SecurityManager sm = System.getSecurityManager();
        if (sm != null) {
            try {
                java.security.Permission perm =
                    url.openConnection().getPermission();
                if (perm != null) {
                    try {
                        sm.checkPermission(perm);
                    } catch (SecurityException se) {
                        // fallback to checkRead/checkConnect for pre 1.2
                        // security managers
                        if ((perm instanceof java.io.FilePermission) &&
                            perm.getActions().indexOf("read") != -1) {
                            sm.checkRead(perm.getName());
                        } else if ((perm instanceof
                            java.net.SocketPermission) &&
                            perm.getActions().indexOf("connect") != -1) {
                            sm.checkConnect(url.getHost(), url.getPort());
                        } else {
                            throw se;
                        }
                    }
                }
            } catch (java.io.IOException ioe) {
                    sm.checkConnect(url.getHost(), url.getPort());
            }
        }
        return createImage(new URLImageSource(url));
    }

    public Image createImage(byte[] data, int offset, int length) {
        return createImage(new ByteArrayImageSource(data, offset, length));
    }

    public Image createImage(ImageProducer producer) {
        return new ToolkitImage(producer);
    }

    public int checkImage(Image img, int w, int h, ImageObserver o) {
        if (!(img instanceof ToolkitImage)) {
            return ImageObserver.ALLBITS;
        }

        ToolkitImage tkimg = (ToolkitImage)img;
        int repbits;
        if (w == 0 || h == 0) {
            repbits = ImageObserver.ALLBITS;
        } else {
            repbits = tkimg.getImageRep().check(o);
        }
        return tkimg.check(o) | repbits;
    }

    public boolean prepareImage(Image img, int w, int h, ImageObserver o) {
        if (w == 0 || h == 0) {
            return true;
        }

        // Must be a ToolkitImage
        if (!(img instanceof ToolkitImage)) {
            return true;
        }

        ToolkitImage tkimg = (ToolkitImage)img;
        if (tkimg.hasError()) {
            if (o != null) {
                o.imageUpdate(img, ImageObserver.ERROR|ImageObserver.ABORT,
                              -1, -1, -1, -1);
            }
            return false;
        }
        ImageRepresentation ir = tkimg.getImageRep();
        return ir.prepare(o);
    }

    /**
     * Scans {@code imageList} for best-looking image of specified dimensions.
     * Image can be scaled and/or padded with transparency.
     */
    public static BufferedImage getScaledIconImage(java.util.List<Image> imageList, int width, int height) {
        if (width == 0 || height == 0) {
            return null;
        }
        Image bestImage = null;
        int bestWidth = 0;
        int bestHeight = 0;
        double bestSimilarity = 3; //Impossibly high value
        double bestScaleFactor = 0;
        for (Iterator<Image> i = imageList.iterator();i.hasNext();) {
            //Iterate imageList looking for best matching image.
            //'Similarity' measure is defined as good scale factor and small insets.
            //best possible similarity is 0 (no scale, no insets).
            //It's found while the experiments that good-looking result is achieved
            //with scale factors x1, x3/4, x2/3, xN, x1/N.
            Image im = i.next();
            if (im == null) {
                if (log.isLoggable(PlatformLogger.FINER)) {
                    log.finer("SunToolkit.getScaledIconImage: " +
                              "Skipping the image passed into Java because it's null.");
                }
                continue;
            }
            if (im instanceof ToolkitImage) {
                ImageRepresentation ir = ((ToolkitImage)im).getImageRep();
                ir.reconstruct(ImageObserver.ALLBITS);
            }
            int iw;
            int ih;
            try {
                iw = im.getWidth(null);
                ih = im.getHeight(null);
            } catch (Exception e){
                if (log.isLoggable(PlatformLogger.FINER)) {
                    log.finer("SunToolkit.getScaledIconImage: " +
                              "Perhaps the image passed into Java is broken. Skipping this icon.");
                }
                continue;
            }
            if (iw > 0 && ih > 0) {
                //Calc scale factor
                double scaleFactor = Math.min((double)width / (double)iw,
                                              (double)height / (double)ih);
                //Calculate scaled image dimensions
                //adjusting scale factor to nearest "good" value
                int adjw = 0;
                int adjh = 0;
                double scaleMeasure = 1; //0 - best (no) scale, 1 - impossibly bad
                if (scaleFactor >= 2) {
                    //Need to enlarge image more than twice
                    //Round down scale factor to multiply by integer value
                    scaleFactor = Math.floor(scaleFactor);
                    adjw = iw * (int)scaleFactor;
                    adjh = ih * (int)scaleFactor;
                    scaleMeasure = 1.0 - 0.5 / scaleFactor;
                } else if (scaleFactor >= 1) {
                    //Don't scale
                    scaleFactor = 1.0;
                    adjw = iw;
                    adjh = ih;
                    scaleMeasure = 0;
                } else if (scaleFactor >= 0.75) {
                    //Multiply by 3/4
                    scaleFactor = 0.75;
                    adjw = iw * 3 / 4;
                    adjh = ih * 3 / 4;
                    scaleMeasure = 0.3;
                } else if (scaleFactor >= 0.6666) {
                    //Multiply by 2/3
                    scaleFactor = 0.6666;
                    adjw = iw * 2 / 3;
                    adjh = ih * 2 / 3;
                    scaleMeasure = 0.33;
                } else {
                    //Multiply size by 1/scaleDivider
                    //where scaleDivider is minimum possible integer
                    //larger than 1/scaleFactor
                    double scaleDivider = Math.ceil(1.0 / scaleFactor);
                    scaleFactor = 1.0 / scaleDivider;
                    adjw = (int)Math.round((double)iw / scaleDivider);
                    adjh = (int)Math.round((double)ih / scaleDivider);
                    scaleMeasure = 1.0 - 1.0 / scaleDivider;
                }
                double similarity = ((double)width - (double)adjw) / (double)width +
                    ((double)height - (double)adjh) / (double)height + //Large padding is bad
                    scaleMeasure; //Large rescale is bad
                if (similarity < bestSimilarity) {
                    bestSimilarity = similarity;
                    bestScaleFactor = scaleFactor;
                    bestImage = im;
                    bestWidth = adjw;
                    bestHeight = adjh;
                }
                if (similarity == 0) break;
            }
        }
        if (bestImage == null) {
            //No images were found, possibly all are broken
            return null;
        }
        BufferedImage bimage =
            new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
        Graphics2D g = bimage.createGraphics();
        g.setRenderingHint(RenderingHints.KEY_INTERPOLATION,
                           RenderingHints.VALUE_INTERPOLATION_BILINEAR);
        try {
            int x = (width - bestWidth) / 2;
            int y = (height - bestHeight) / 2;
            if (log.isLoggable(PlatformLogger.FINER)) {
                log.finer("WWindowPeer.getScaledIconData() result : " +
                        "w : " + width + " h : " + height +
                        " iW : " + bestImage.getWidth(null) + " iH : " + bestImage.getHeight(null) +
                        " sim : " + bestSimilarity + " sf : " + bestScaleFactor +
                        " adjW : " + bestWidth + " adjH : " + bestHeight +
                        " x : " + x + " y : " + y);
            }
            g.drawImage(bestImage, x, y, bestWidth, bestHeight, null);
        } finally {
            g.dispose();
        }
        return bimage;
    }

    public static DataBufferInt getScaledIconData(java.util.List<Image> imageList, int width, int height) {
        BufferedImage bimage = getScaledIconImage(imageList, width, height);
        if (bimage == null) {
             if (log.isLoggable(PlatformLogger.FINER)) {
                 log.finer("SunToolkit.getScaledIconData: " +
                           "Perhaps the image passed into Java is broken. Skipping this icon.");
             }
            return null;
        }
        Raster raster = bimage.getRaster();
        DataBuffer buffer = raster.getDataBuffer();
        return (DataBufferInt)buffer;
    }

    protected EventQueue getSystemEventQueueImpl() {
        return getSystemEventQueueImplPP();
    }

    // Package private implementation
    static EventQueue getSystemEventQueueImplPP() {
        return getSystemEventQueueImplPP(AppContext.getAppContext());
    }

    public static EventQueue getSystemEventQueueImplPP(AppContext appContext) {
        EventQueue theEventQueue =
            (EventQueue)appContext.get(AppContext.EVENT_QUEUE_KEY);
        return theEventQueue;
    }

    /**
     * Give native peers the ability to query the native container
     * given a native component (eg the direct parent may be lightweight).
     */
    public static Container getNativeContainer(Component c) {
        return Toolkit.getNativeContainer(c);
    }

    /**
     * Gives native peers the ability to query the closest HW component.
     * If the given component is heavyweight, then it returns this. Otherwise,
     * it goes one level up in the hierarchy and tests next component.
     */
    public static Component getHeavyweightComponent(Component c) {
        while (c != null && AWTAccessor.getComponentAccessor().isLightweight(c)) {
            c = AWTAccessor.getComponentAccessor().getParent(c);
        }
        return c;
    }

    /**
     * Returns a new input method window, with behavior as specified in
     * {@link java.awt.im.spi.InputMethodContext#createInputMethodWindow}.
     * If the inputContext is not null, the window should return it from its
     * getInputContext() method. The window needs to implement
     * sun.awt.im.InputMethodWindow.
     * <p>
     * SunToolkit subclasses can override this method to return better input
     * method windows.
     */
    public Window createInputMethodWindow(String title, InputContext context) {
        return new sun.awt.im.SimpleInputMethodWindow(title, context);
    }

    /**
     * Returns whether enableInputMethods should be set to true for peered
     * TextComponent instances on this platform. False by default.
     */
    public boolean enableInputMethodsForTextComponent() {
        return false;
    }

    private static Locale startupLocale = null;

    /**
     * Returns the locale in which the runtime was started.
     */
    public static Locale getStartupLocale() {
        if (startupLocale == null) {
            String language, region, country, variant;
            language = (String) AccessController.doPrivileged(
                            new GetPropertyAction("user.language", "en"));
            // for compatibility, check for old user.region property
            region = (String) AccessController.doPrivileged(
                            new GetPropertyAction("user.region"));
            if (region != null) {
                // region can be of form country, country_variant, or _variant
                int i = region.indexOf('_');
                if (i >= 0) {
                    country = region.substring(0, i);
                    variant = region.substring(i + 1);
                } else {
                    country = region;
                    variant = "";
                }
            } else {
                country = (String) AccessController.doPrivileged(
                                new GetPropertyAction("user.country", ""));
                variant = (String) AccessController.doPrivileged(
                                new GetPropertyAction("user.variant", ""));
            }
            startupLocale = new Locale(language, country, variant);
        }
        return startupLocale;
    }

    /**
     * Returns the default keyboard locale of the underlying operating system
     */
    public Locale getDefaultKeyboardLocale() {
        return getStartupLocale();
    }

    private static String dataTransfererClassName = null;

    protected static void setDataTransfererClassName(String className) {
        dataTransfererClassName = className;
    }

    public static String getDataTransfererClassName() {
        if (dataTransfererClassName == null) {
            Toolkit.getDefaultToolkit(); // transferer set during toolkit init
        }
        return dataTransfererClassName;
    }

    // Support for window closing event notifications
    private transient WindowClosingListener windowClosingListener = null;
    /**
     * @see sun.awt.WindowClosingSupport#getWindowClosingListener
     */
    public WindowClosingListener getWindowClosingListener() {
        return windowClosingListener;
    }
    /**
     * @see sun.awt.WindowClosingSupport#setWindowClosingListener
     */
    public void setWindowClosingListener(WindowClosingListener wcl) {
        windowClosingListener = wcl;
    }

    /**
     * @see sun.awt.WindowClosingListener#windowClosingNotify
     */
    public RuntimeException windowClosingNotify(WindowEvent event) {
        if (windowClosingListener != null) {
            return windowClosingListener.windowClosingNotify(event);
        } else {
            return null;
        }
    }
    /**
     * @see sun.awt.WindowClosingListener#windowClosingDelivered
     */
    public RuntimeException windowClosingDelivered(WindowEvent event) {
        if (windowClosingListener != null) {
            return windowClosingListener.windowClosingDelivered(event);
        } else {
            return null;
        }
    }

    private static DefaultMouseInfoPeer mPeer = null;

    protected synchronized MouseInfoPeer getMouseInfoPeer() {
        if (mPeer == null) {
            mPeer = new DefaultMouseInfoPeer();
        }
        return mPeer;
    }


    /**
     * Returns whether default toolkit needs the support of the xembed
     * from embedding host(if any).
     * @return <code>true</code>, if XEmbed is needed, <code>false</code> otherwise
     */
    public static boolean needsXEmbed() {
        String noxembed = (String) AccessController.
            doPrivileged(new GetPropertyAction("sun.awt.noxembed", "false"));
        if ("true".equals(noxembed)) {
            return false;
        }

        Toolkit tk = Toolkit.getDefaultToolkit();
        if (tk instanceof SunToolkit) {
            // SunToolkit descendants should override this method to specify
            // concrete behavior
            return ((SunToolkit)tk).needsXEmbedImpl();
        } else {
            // Non-SunToolkit doubtly might support XEmbed
            return false;
        }
    }

    /**
     * Returns whether this toolkit needs the support of the xembed
     * from embedding host(if any).
     * @return <code>true</code>, if XEmbed is needed, <code>false</code> otherwise
     */
    protected boolean needsXEmbedImpl() {
        return false;
    }

    private static Dialog.ModalExclusionType DEFAULT_MODAL_EXCLUSION_TYPE = null;

    /**
     * Returns whether the XEmbed server feature is requested by
     * developer.  If true, Toolkit should return an
     * XEmbed-server-enabled CanvasPeer instead of the ordinary CanvasPeer.
     */
    protected final boolean isXEmbedServerRequested() {
        return AccessController.doPrivileged(new GetBooleanAction("sun.awt.xembedserver"));
    }

    /**
     * Returns whether the modal exclusion API is supported by the current toolkit.
     * When it isn't supported, calling <code>setModalExcluded</code> has no
     * effect, and <code>isModalExcluded</code> returns false for all windows.
     *
     * @return true if modal exclusion is supported by the toolkit, false otherwise
     *
     * @see sun.awt.SunToolkit#setModalExcluded(java.awt.Window)
     * @see sun.awt.SunToolkit#isModalExcluded(java.awt.Window)
     *
     * @since 1.5
     */
    public static boolean isModalExcludedSupported()
    {
        Toolkit tk = Toolkit.getDefaultToolkit();
        return tk.isModalExclusionTypeSupported(DEFAULT_MODAL_EXCLUSION_TYPE);
    }
    /*
     * Default implementation for isModalExcludedSupportedImpl(), returns false.
     *
     * @see sun.awt.windows.WToolkit#isModalExcludeSupportedImpl
     * @see sun.awt.X11.XToolkit#isModalExcludeSupportedImpl
     *
     * @since 1.5
     */
    protected boolean isModalExcludedSupportedImpl()
    {
        return false;
    }

    /*
     * Sets this window to be excluded from being modally blocked. When the
     * toolkit supports modal exclusion and this method is called, input
     * events, focus transfer and z-order will continue to work for the
     * window, it's owned windows and child components, even in the
     * presence of a modal dialog.
     * For details on which <code>Window</code>s are normally blocked
     * by modal dialog, see {@link java.awt.Dialog}.
     * Invoking this method when the modal exclusion API is not supported by
     * the current toolkit has no effect.
     * @param window Window to be marked as not modally blocked
     * @see java.awt.Dialog
     * @see java.awt.Dialog#setModal(boolean)
     * @see sun.awt.SunToolkit#isModalExcludedSupported
     * @see sun.awt.SunToolkit#isModalExcluded(java.awt.Window)
     */
    public static void setModalExcluded(Window window)
    {
        if (DEFAULT_MODAL_EXCLUSION_TYPE == null) {
            DEFAULT_MODAL_EXCLUSION_TYPE = Dialog.ModalExclusionType.APPLICATION_EXCLUDE;
        }
        window.setModalExclusionType(DEFAULT_MODAL_EXCLUSION_TYPE);
    }

    /*
     * Returns whether the specified window is blocked by modal dialogs.
     * If the modal exclusion API isn't supported by the current toolkit,
     * it returns false for all windows.
     *
     * @param window Window to test for modal exclusion
     *
     * @return true if the window is modal excluded, false otherwise. If
     * the modal exclusion isn't supported by the current Toolkit, false
     * is returned
     *
     * @see sun.awt.SunToolkit#isModalExcludedSupported
     * @see sun.awt.SunToolkit#setModalExcluded(java.awt.Window)
     *
     * @since 1.5
     */
    public static boolean isModalExcluded(Window window)
    {
        if (DEFAULT_MODAL_EXCLUSION_TYPE == null) {
            DEFAULT_MODAL_EXCLUSION_TYPE = Dialog.ModalExclusionType.APPLICATION_EXCLUDE;
        }
        return window.getModalExclusionType().compareTo(DEFAULT_MODAL_EXCLUSION_TYPE) >= 0;
    }

    /**
     * Overridden in XToolkit and WToolkit
     */
    public boolean isModalityTypeSupported(Dialog.ModalityType modalityType) {
        return (modalityType == Dialog.ModalityType.MODELESS) ||
               (modalityType == Dialog.ModalityType.APPLICATION_MODAL);
    }

    /**
     * Overridden in XToolkit and WToolkit
     */
    public boolean isModalExclusionTypeSupported(Dialog.ModalExclusionType exclusionType) {
        return (exclusionType == Dialog.ModalExclusionType.NO_EXCLUDE);
    }

    ///////////////////////////////////////////////////////////////////////////
    //
    // The following is used by the Java Plug-in to coordinate dialog modality
    // between containing applications (browsers, ActiveX containers etc) and
    // the AWT.
    //
    ///////////////////////////////////////////////////////////////////////////

    private ModalityListenerList modalityListeners = new ModalityListenerList();

    public void addModalityListener(ModalityListener listener) {
        modalityListeners.add(listener);
    }

    public void removeModalityListener(ModalityListener listener) {
        modalityListeners.remove(listener);
    }

    public void notifyModalityPushed(Dialog dialog) {
        notifyModalityChange(ModalityEvent.MODALITY_PUSHED, dialog);
    }

    public void notifyModalityPopped(Dialog dialog) {
        notifyModalityChange(ModalityEvent.MODALITY_POPPED, dialog);
    }

    final void notifyModalityChange(int id, Dialog source) {
        ModalityEvent ev = new ModalityEvent(source, modalityListeners, id);
        ev.dispatch();
    }

    static class ModalityListenerList implements ModalityListener {

        Vector<ModalityListener> listeners = new Vector<ModalityListener>();

        void add(ModalityListener listener) {
            listeners.addElement(listener);
        }

        void remove(ModalityListener listener) {
            listeners.removeElement(listener);
        }

        public void modalityPushed(ModalityEvent ev) {
            Iterator<ModalityListener> it = listeners.iterator();
            while (it.hasNext()) {
                it.next().modalityPushed(ev);
            }
        }

        public void modalityPopped(ModalityEvent ev) {
            Iterator<ModalityListener> it = listeners.iterator();
            while (it.hasNext()) {
                it.next().modalityPopped(ev);
            }
        }
    } // end of class ModalityListenerList

    ///////////////////////////////////////////////////////////////////////////
    // End Plug-in code
    ///////////////////////////////////////////////////////////////////////////

    public static boolean isLightweightOrUnknown(Component comp) {
        if (comp.isLightweight()
            || !(getDefaultToolkit() instanceof SunToolkit))
        {
            return true;
        }
        return !(comp instanceof Button
            || comp instanceof Canvas
            || comp instanceof Checkbox
            || comp instanceof Choice
            || comp instanceof Label
            || comp instanceof java.awt.List
            || comp instanceof Panel
            || comp instanceof Scrollbar
            || comp instanceof ScrollPane
            || comp instanceof TextArea
            || comp instanceof TextField
            || comp instanceof Window);
    }

    public static Method getMethod(final Class clz, final String methodName, final Class[] params) {
        Method res = null;
        try {
            res = AccessController.doPrivileged(new PrivilegedExceptionAction<Method>() {
                    public Method run() throws Exception {
                        Method m = clz.getDeclaredMethod(methodName, params);
                        m.setAccessible(true);
                        return m;
                    }
                });
        } catch (PrivilegedActionException ex) {
            ex.printStackTrace();
        }
        return res;
    }

    public static class OperationTimedOut extends RuntimeException {
        public OperationTimedOut(String msg) {
            super(msg);
        }
        public OperationTimedOut() {
        }
    }
    public static class InfiniteLoop extends RuntimeException {
    }

    public static class IllegalThreadException extends RuntimeException {
        public IllegalThreadException(String msg) {
            super(msg);
        }
        public IllegalThreadException() {
        }
    }

    public static final int DEFAULT_WAIT_TIME = 10000;
    private static final int MAX_ITERS = 20;
    private static final int MIN_ITERS = 0;
    private static final int MINIMAL_EDELAY = 0;

    /**
     * Parameterless version of realsync which uses default timout (see DEFAUL_WAIT_TIME).
     */
    public void realSync() throws OperationTimedOut, InfiniteLoop {
        realSync(DEFAULT_WAIT_TIME);
    }

    /**
     * Forces toolkit to synchronize with the native windowing
     * sub-system, flushing all pending work and waiting for all the
     * events to be processed.  This method guarantees that after
     * return no additional Java events will be generated, unless
     * cause by user. Obviously, the method cannot be used on the
     * event dispatch thread (EDT). In case it nevertheless gets
     * invoked on this thread, the method throws the
     * IllegalThreadException runtime exception.
     *
     * <p> This method allows to write tests without explicit timeouts
     * or wait for some event.  Example:
     * <code>
     * Frame f = ...;
     * f.setVisible(true);
     * ((SunToolkit)Toolkit.getDefaultToolkit()).realSync();
     * </code>
     *
     * <p> After realSync, <code>f</code> will be completely visible
     * on the screen, its getLocationOnScreen will be returning the
     * right result and it will be the focus owner.
     *
     * <p> Another example:
     * <code>
     * b.requestFocus();
     * ((SunToolkit)Toolkit.getDefaultToolkit()).realSync();
     * </code>
     *
     * <p> After realSync, <code>b</code> will be focus owner.
     *
     * <p> Notice that realSync isn't guaranteed to work if recurring
     * actions occur, such as if during processing of some event
     * another request which may generate some events occurs.  By
     * default, sync tries to perform as much as {@value MAX_ITERS}
     * cycles of event processing, allowing for roughly {@value
     * MAX_ITERS} additional requests.
     *
     * <p> For example, requestFocus() generates native request, which
     * generates one or two Java focus events, which then generate a
     * serie of paint events, a serie of Java focus events, which then
     * generate a serie of paint events which then are processed -
     * three cycles, minimum.
     *
     * @param timeout the maximum time to wait in milliseconds, negative means "forever".
     */
    public void realSync(final long timeout) throws OperationTimedOut, InfiniteLoop
    {
        if (EventQueue.isDispatchThread()) {
            throw new IllegalThreadException("The SunToolkit.realSync() method cannot be used on the event dispatch thread (EDT).");
        }
        int bigLoop = 0;
        do {
            // Let's do sync first
            sync();

            // During the wait process, when we were processing incoming
            // events, we could have made some new request, which can
            // generate new events.  Example: MapNotify/XSetInputFocus.
            // Therefore, we dispatch them as long as there is something
            // to dispatch.
            int iters = 0;
            while (iters < MIN_ITERS) {
                syncNativeQueue(timeout);
                iters++;
            }
            while (syncNativeQueue(timeout) && iters < MAX_ITERS) {
                iters++;
            }
            if (iters >= MAX_ITERS) {
                throw new InfiniteLoop();
            }

            // native requests were dispatched by X/Window Manager or Windows
            // Moreover, we processed them all on Toolkit thread
            // Now wait while EDT processes them.
            //
            // During processing of some events (focus, for example),
            // some other events could have been generated.  So, after
            // waitForIdle, we may end up with full EventQueue
            iters = 0;
            while (iters < MIN_ITERS) {
                waitForIdle(timeout);
                iters++;
            }
            while (waitForIdle(timeout) && iters < MAX_ITERS) {
                iters++;
            }
            if (iters >= MAX_ITERS) {
                throw new InfiniteLoop();
            }

            bigLoop++;
            // Again, for Java events, it was simple to check for new Java
            // events by checking event queue, but what if Java events
            // resulted in native requests?  Therefor, check native events again.
        } while ((syncNativeQueue(timeout) || waitForIdle(timeout)) && bigLoop < MAX_ITERS);
    }

    /**
     * Platform toolkits need to implement this method to perform the
     * sync of the native queue.  The method should wait until native
     * requests are processed, all native events are processed and
     * corresponding Java events are generated.  Should return
     * <code>true</code> if some events were processed,
     * <code>false</code> otherwise.
     */
    protected abstract boolean syncNativeQueue(final long timeout);

    private boolean eventDispatched = false;
    private boolean queueEmpty = false;
    private final Object waitLock = "Wait Lock";

    static Method eqNoEvents;

    private boolean isEQEmpty() {
        EventQueue queue = getSystemEventQueueImpl();
        synchronized(SunToolkit.class) {
            if (eqNoEvents == null) {
                eqNoEvents = getMethod(java.awt.EventQueue.class, "noEvents", null);
            }
        }
        try {
            return (Boolean)eqNoEvents.invoke(queue);
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
    }

    /**
     * Waits for the Java event queue to empty.  Ensures that all
     * events are processed (including paint events), and that if
     * recursive events were generated, they are also processed.
     * Should return <code>true</code> if more processing is
     * necessary, <code>false</code> otherwise.
     */
    protected final boolean waitForIdle(final long timeout) {
        flushPendingEvents();
        boolean queueWasEmpty = isEQEmpty();
        queueEmpty = false;
        eventDispatched = false;
        synchronized(waitLock) {
            postEvent(AppContext.getAppContext(),
                      new PeerEvent(getSystemEventQueueImpl(), null, PeerEvent.LOW_PRIORITY_EVENT) {
                          public void dispatch() {
                              // Here we block EDT.  It could have some
                              // events, it should have dispatched them by
                              // now.  So native requests could have been
                              // generated.  First, dispatch them.  Then,
                              // flush Java events again.
                              int iters = 0;
                              while (iters < MIN_ITERS) {
                                  syncNativeQueue(timeout);
                                  iters++;
                              }
                              while (syncNativeQueue(timeout) && iters < MAX_ITERS) {
                                  iters++;
                              }
                              flushPendingEvents();

                              synchronized(waitLock) {
                                  queueEmpty = isEQEmpty();
                                  eventDispatched = true;
                                  waitLock.notifyAll();
                              }
                          }
                      });
            try {
                while (!eventDispatched) {
                    waitLock.wait();
                }
            } catch (InterruptedException ie) {
                return false;
            }
        }

        try {
            Thread.sleep(MINIMAL_EDELAY);
        } catch (InterruptedException ie) {
            throw new RuntimeException("Interrupted");
        }

        flushPendingEvents();

        // Lock to force write-cache flush for queueEmpty.
        synchronized (waitLock) {
            return !(queueEmpty && isEQEmpty() && queueWasEmpty);
        }
    }

    /**
     * Grabs the mouse input for the given window.  The window must be
     * visible.  The window or its children do not receive any
     * additional mouse events besides those targeted to them.  All
     * other events will be dispatched as before - to the respective
     * targets.  This Window will receive UngrabEvent when automatic
     * ungrab is about to happen.  The event can be listened to by
     * installing AWTEventListener with WINDOW_EVENT_MASK.  See
     * UngrabEvent class for the list of conditions when ungrab is
     * about to happen.
     * @see UngrabEvent
     */
    public abstract void grab(Window w);

    /**
     * Forces ungrab.  No event will be sent.
     */
    public abstract void ungrab(Window w);


    /**
     * Locates the splash screen library in a platform dependent way and closes
     * the splash screen. Should be invoked on first top-level frame display.
     * @see java.awt.SplashScreen
     * @since 1.6
     */
    public static native void closeSplashScreen();

    /* The following methods and variables are to support retrieving
     * desktop text anti-aliasing settings
     */

    /* Need an instance method because setDesktopProperty(..) is protected. */
    private void fireDesktopFontPropertyChanges() {
        setDesktopProperty(SunToolkit.DESKTOPFONTHINTS,
                           SunToolkit.getDesktopFontHints());
    }

    private static boolean checkedSystemAAFontSettings;
    private static boolean useSystemAAFontSettings;
    private static boolean lastExtraCondition = true;
    private static RenderingHints desktopFontHints;

    /* Since Swing is the reason for this "extra condition" logic its
     * worth documenting it in some detail.
     * First, a goal is for Swing and applications to both retrieve and
     * use the same desktop property value so that there is complete
     * consistency between the settings used by JDK's Swing implementation
     * and 3rd party custom Swing components, custom L&Fs and any general
     * text rendering that wants to be consistent with these.
     * But by default on Solaris & Linux Swing will not use AA text over
     * remote X11 display (unless Xrender can be used which is TBD and may not
     * always be available anyway) as that is a noticeable performance hit.
     * So there needs to be a way to express that extra condition so that
     * it is seen by all clients of the desktop property API.
     * If this were the only condition it could be handled here as it would
     * be the same for any L&F and could reasonably be considered to be
     * a static behaviour of those systems.
     * But GTK currently has an additional test based on locale which is
     * not applied by Metal. So mixing GTK in a few locales with Metal
     * would mean the last one wins.
     * This could be stored per-app context which would work
     * for different applets, but wouldn't help for a single application
     * using GTK and some other L&F concurrently.
     * But it is expected this will be addressed within GTK and the font
     * system so is a temporary and somewhat unlikely harmless corner case.
     */
    public static void setAAFontSettingsCondition(boolean extraCondition) {
        if (extraCondition != lastExtraCondition) {
            lastExtraCondition = extraCondition;
            if (checkedSystemAAFontSettings) {
                /* Someone already asked for this info, under a different
                 * condition.
                 * We'll force re-evaluation instead of replicating the
                 * logic, then notify any listeners of any change.
                 */
                checkedSystemAAFontSettings = false;
                Toolkit tk = Toolkit.getDefaultToolkit();
                if (tk instanceof SunToolkit) {
                     ((SunToolkit)tk).fireDesktopFontPropertyChanges();
                }
            }
        }
    }

    /* "false", "off", ""default" aren't explicitly tested, they
     * just fall through to produce a null return which all are equated to
     * "false".
     */
    private static RenderingHints getDesktopAAHintsByName(String hintname) {
        Object aaHint = null;
        hintname = hintname.toLowerCase(Locale.ENGLISH);
        if (hintname.equals("on")) {
            aaHint = VALUE_TEXT_ANTIALIAS_ON;
        } else if (hintname.equals("gasp")) {
            aaHint = VALUE_TEXT_ANTIALIAS_GASP;
        } else if (hintname.equals("lcd") || hintname.equals("lcd_hrgb")) {
            aaHint = VALUE_TEXT_ANTIALIAS_LCD_HRGB;
        } else if (hintname.equals("lcd_hbgr")) {
            aaHint = VALUE_TEXT_ANTIALIAS_LCD_HBGR;
        } else if (hintname.equals("lcd_vrgb")) {
            aaHint = VALUE_TEXT_ANTIALIAS_LCD_VRGB;
        } else if (hintname.equals("lcd_vbgr")) {
            aaHint = VALUE_TEXT_ANTIALIAS_LCD_VBGR;
        }
        if (aaHint != null) {
            RenderingHints map = new RenderingHints(null);
            map.put(KEY_TEXT_ANTIALIASING, aaHint);
            return map;
        } else {
            return null;
        }
    }

    /* This method determines whether to use the system font settings,
     * or ignore them if a L&F has specified they should be ignored, or
     * to override both of these with a system property specified value.
     * If the toolkit isn't a SunToolkit, (eg may be headless) then that
     * system property isn't applied as desktop properties are considered
     * to be inapplicable in that case. In that headless case although
     * this method will return "true" the toolkit will return a null map.
     */
    private static boolean useSystemAAFontSettings() {
        if (!checkedSystemAAFontSettings) {
            useSystemAAFontSettings = true; /* initially set this true */
            String systemAAFonts = null;
            Toolkit tk = Toolkit.getDefaultToolkit();
            if (tk instanceof SunToolkit) {
                systemAAFonts =
                    (String)AccessController.doPrivileged(
                         new GetPropertyAction("awt.useSystemAAFontSettings"));
            }
            if (systemAAFonts != null) {
                useSystemAAFontSettings =
                    Boolean.valueOf(systemAAFonts).booleanValue();
                /* If it is anything other than "true", then it may be
                 * a hint name , or it may be "off, "default", etc.
                 */
                if (!useSystemAAFontSettings) {
                    desktopFontHints = getDesktopAAHintsByName(systemAAFonts);
                }
            }
            /* If its still true, apply the extra condition */
            if (useSystemAAFontSettings) {
                 useSystemAAFontSettings = lastExtraCondition;
            }
            checkedSystemAAFontSettings = true;
        }
        return useSystemAAFontSettings;
    }

    /* A variable defined for the convenience of JDK code */
    public static final String DESKTOPFONTHINTS = "awt.font.desktophints";

    /* Overridden by subclasses to return platform/desktop specific values */
    protected RenderingHints getDesktopAAHints() {
        return null;
    }

    /* Subclass desktop property loading methods call this which
     * in turn calls the appropriate subclass implementation of
     * getDesktopAAHints() when system settings are being used.
     * Its public rather than protected because subclasses may delegate
     * to a helper class.
     */
    public static RenderingHints getDesktopFontHints() {
        if (useSystemAAFontSettings()) {
             Toolkit tk = Toolkit.getDefaultToolkit();
             if (tk instanceof SunToolkit) {
                 Object map = ((SunToolkit)tk).getDesktopAAHints();
                 return (RenderingHints)map;
             } else { /* Headless Toolkit */
                 return null;
             }
        } else if (desktopFontHints != null) {
            /* cloning not necessary as the return value is cloned later, but
             * its harmless.
             */
            return (RenderingHints)(desktopFontHints.clone());
        } else {
            return null;
        }
    }


    public abstract boolean isDesktopSupported();

    /*
     * consumeNextKeyTyped() method is not currently used,
     * however Swing could use it in the future.
     */
    private static Method consumeNextKeyTypedMethod = null;
    public static synchronized void consumeNextKeyTyped(KeyEvent keyEvent) {
        if (consumeNextKeyTypedMethod == null) {
            consumeNextKeyTypedMethod = getMethod(DefaultKeyboardFocusManager.class,
                                                  "consumeNextKeyTyped",
                                                  new Class[] {KeyEvent.class});
        }
        try {
            consumeNextKeyTypedMethod.invoke(KeyboardFocusManager.getCurrentKeyboardFocusManager(),
                                             keyEvent);
        } catch (IllegalAccessException iae) {
            iae.printStackTrace();
        } catch (InvocationTargetException ite) {
            ite.printStackTrace();
        }
    }

    protected static void dumpPeers(final PlatformLogger aLog) {
        AWTAutoShutdown.getInstance().dumpPeers(aLog);
    }

    /**
     * Returns the <code>Window</code> ancestor of the component <code>comp</code>.
     * @return Window ancestor of the component or component by itself if it is Window;
     *         null, if component is not a part of window hierarchy
     */
    public static Window getContainingWindow(Component comp) {
        while (comp != null && !(comp instanceof Window)) {
            comp = comp.getParent();
        }
        return (Window)comp;
    }

    private static Boolean sunAwtDisableMixing = null;

    /**
     * Returns the value of "sun.awt.disableMixing" property. Default
     * value is {@code false}.
     */
    public synchronized static boolean getSunAwtDisableMixing() {
        if (sunAwtDisableMixing == null) {
            sunAwtDisableMixing = Boolean.valueOf(
                    AccessController.doPrivileged(
                        new GetBooleanAction("sun.awt.disableMixing")));
        }
        return sunAwtDisableMixing.booleanValue();
    }

    /**
     * Returns true if the native GTK libraries are available.  The
     * default implementation returns false, but UNIXToolkit overrides this
     * method to provide a more specific answer.
     */
    public boolean isNativeGTKAvailable() {
        return false;
    }

    // Cosntant alpha
    public boolean isWindowOpacitySupported() {
        return false;
    }

    // Shaping
    public boolean isWindowShapingSupported() {
        return false;
    }

    // Per-pixel alpha
    public boolean isWindowTranslucencySupported() {
        return false;
    }

    public boolean isTranslucencyCapable(GraphicsConfiguration gc) {
        return false;
    }

    /**
     * Returns whether or not a containing top level window for the passed
     * component is
     * {@link GraphicsDevice.WindowTranslucency#PERPIXEL_TRANSLUCENT PERPIXEL_TRANSLUCENT}.
     *
     * @param c a Component which toplevel's to check
     * @return {@code true}  if the passed component is not null and has a
     * containing toplevel window which is opaque (so per-pixel translucency
     * is not enabled), {@code false} otherwise
     * @see GraphicsDevice.WindowTranslucency#PERPIXEL_TRANSLUCENT
     */
    public static boolean isContainingTopLevelOpaque(Component c) {
        Window w = getContainingWindow(c);
        return w != null && w.isOpaque();
    }

    /**
     * Returns whether or not a containing top level window for the passed
     * component is
     * {@link GraphicsDevice.WindowTranslucency#TRANSLUCENT TRANSLUCENT}.
     *
     * @param c a Component which toplevel's to check
     * @return {@code true} if the passed component is not null and has a
     * containing toplevel window which has opacity less than
     * 1.0f (which means that it is translucent), {@code false} otherwise
     * @see GraphicsDevice.WindowTranslucency#TRANSLUCENT
     */
    public static boolean isContainingTopLevelTranslucent(Component c) {
        Window w = getContainingWindow(c);
        return w != null && ((Window)w).getOpacity() < 1.0f;
    }

    /**
     * Returns whether the native system requires using the peer.updateWindow()
     * method to update the contents of a non-opaque window, or if usual
     * painting procedures are sufficient. The default return value covers
     * the X11 systems. On MS Windows this method is overriden in WToolkit
     * to return true.
     */
    public boolean needUpdateWindow() {
        return false;
    }

    /**
     * Descendants of the SunToolkit should override and put their own logic here.
     */
    public int getNumberOfButtons(){
        return 3;
    }

    /**
     * Checks that the given object implements/extends the given
     * interface/class.
     *
     * Note that using the instanceof operator causes a class to be loaded.
     * Using this method doesn't load a class and it can be used instead of
     * the instanceof operator for performance reasons.
     *
     * @param obj Object to be checked
     * @param type The name of the interface/class. Must be
     * fully-qualified interface/class name.
     * @return true, if this object implements/extends the given
     *         interface/class, false, otherwise, or if obj or type is null
     */
    public static boolean isInstanceOf(Object obj, String type) {
        if (obj == null) return false;
        if (type == null) return false;

        return isInstanceOf(obj.getClass(), type);
    }

    private static boolean isInstanceOf(Class cls, String type) {
        if (cls == null) return false;

        if (cls.getName().equals(type)) {
            return true;
        }

        for (Class c : cls.getInterfaces()) {
            if (c.getName().equals(type)) {
                return true;
            }
        }
        return isInstanceOf(cls.getSuperclass(), type);
    }
} // class SunToolkit


/*
 * PostEventQueue is a Thread that runs in the same AppContext as the
 * Java EventQueue.  It is a queue of AWTEvents to be posted to the
 * Java EventQueue.  The toolkit Thread (AWT-Windows/AWT-Motif) posts
 * events to this queue, which then calls EventQueue.postEvent().
 *
 * We do this because EventQueue.postEvent() may be overridden by client
 * code, and we mustn't ever call client code from the toolkit thread.
 */
class PostEventQueue {
    private EventQueueItem queueHead = null;
    private EventQueueItem queueTail = null;
    private final EventQueue eventQueue;

    PostEventQueue(EventQueue eq) {
        eventQueue = eq;
    }

    public boolean noEvents() {
        return queueHead == null;
    }

    /*
     * Continually post pending AWTEvents to the Java EventQueue.
     */
    public synchronized void flush() {
        EventQueueItem tempQueue = queueHead;
        queueHead = queueTail = null;
        while (tempQueue != null) {
            eventQueue.postEvent(tempQueue.event);
            tempQueue = tempQueue.next;
        }
    }

    /*
     * Enqueue an AWTEvent to be posted to the Java EventQueue.
     */
    void postEvent(AWTEvent event) {
        EventQueueItem item = new EventQueueItem(event);

        synchronized (this) {
            if (queueHead == null) {
                queueHead = queueTail = item;
            } else {
                queueTail.next = item;
                queueTail = item;
            }
        }
        SunToolkit.wakeupEventQueue(eventQueue, event.getSource() == AWTAutoShutdown.getInstance());
    }
} // class PostEventQueue