GlobalAWTExceptionHandler.java

/*******************************************************************************
 * Copyright (c) 1998, 2015 Oracle and/or its affiliates. All rights reserved.
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
 * which accompanies this distribution.
 * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
 * and the Eclipse Distribution License is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * Contributors:
 *     Oracle - initial API and implementation from Oracle TopLink
******************************************************************************/
package org.eclipse.persistence.tools.workbench.uitools;

import java.awt.Cursor;
import java.awt.Frame;

import org.eclipse.persistence.tools.workbench.uitools.AWTExceptionHandler.GlobalHandler;
import org.eclipse.persistence.tools.workbench.utility.ClassTools;
import org.eclipse.persistence.tools.workbench.utility.ExceptionBroadcaster;


/**
 * This is the "global" handler that is stored in a static field so exceptions
 * that occurred during the processing of AWT events can be forwarded
 * to it by the AWTExceptionHandler.
 * @see AWTExceptionHandler
 */
public final class GlobalAWTExceptionHandler
    implements GlobalHandler
{
    /**
     * Broadcasting delegate.
     */
    private final ExceptionBroadcaster broadcaster;


    /**
     * Set up a "global" AWT exception handler and the "local" AWT
     * exception handler to broadcast any unhandled exceptions via
     * the specified broadcaster.
     */
    public static void register(ExceptionBroadcaster broadcaster) {
        AWTExceptionHandler.setGlobalHandler(new GlobalAWTExceptionHandler(broadcaster));
        AWTExceptionHandler.register();
    }

    /**
     * Construct a "global" AWT exception handler that will broadcast
     * via the specified broadcaster.
     */
    private GlobalAWTExceptionHandler(ExceptionBroadcaster broadcaster) {
        super();
        this.broadcaster = broadcaster;
    }


    // ********** GlobalHandler implementation **********

    /**
     * First, restore the cursor; then broadcast the exception.
     * @see AWTExceptionHandler.GlobalHandler#handle(Throwable)
     */
    public synchronized void handle(Throwable t) {
        this.restoreDefaultCursor();
        this.broadcaster.broadcast(Thread.currentThread(), t);
    }


    // ********** internal methods **********

    /**
     * Brute force approach for now: set the cursor for ALL the current
     * windows to the default cursor.
     */
    // TODO maybe something more elegant?
    private void restoreDefaultCursor() {
        Cursor defaultCursor = Cursor.getDefaultCursor();
        Frame[] frames = Frame.getFrames();
        for (int i = frames.length; i-- > 0; ) {
            frames[i].setCursor(defaultCursor);
        }
    }

    /**
     * @see Object#toString()
     */
    public String toString() {
        return ClassTools.shortClassNameForObject(this);
    }

}