/*
 * Copyright (c) 2010, grossmann
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * * Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * * Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * * Neither the name of the jo-widgets.org nor the
 *   names of its contributors may be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL jo-widgets.org BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 */

package org.jowidgets.spi.impl.swt.common.application;

import java.util.concurrent.atomic.AtomicBoolean;

import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;
import org.jowidgets.common.application.IApplication;
import org.jowidgets.common.application.IApplicationLifecycle;
import org.jowidgets.common.application.IApplicationRunner;

public class SwtApplicationRunner implements IApplicationRunner {

    private final AtomicBoolean isRunning = new AtomicBoolean();
    private Display display;

    @Override
    public void run(final IApplication application) {

        isRunning.set(true);

        //now, if someone will run the application, get the display
        final Display currentDisplay = getDisplay();

        //Create a lifecycle that disposes all windows when finished
        final IApplicationLifecycle lifecycle = new IApplicationLifecycle() {

            @Override
            public void finish() {
                if (isRunning.getAndSet(false)) {
                    for (final Shell shell : currentDisplay.getShells()) {
                        shell.dispose();
                    }
                }
            }
        };

        //start the lifecycle
        application.start(lifecycle);

        //do the event dispatching
        while (!currentDisplay.isDisposed() && isRunning.get()) {
            if (!currentDisplay.readAndDispatch()) {
                currentDisplay.sleep();
            }
        }

    }

    private Display getDisplay() {
        if (display == null) {
            display = Display.getDefault();
            if (display.getThread() != Thread.currentThread()) {
                throw new IllegalStateException(
                    "A default Display exists, but the current thread is not the owner of this display.");
            }
        }
        return display;
    }

}