/*
 * Copyright (c) 2010, Michael 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 THE COPYRIGHT OWNER OR CONTRIBUTORS 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.bridge.swt.awt.common.awt;

import java.awt.BorderLayout;
import java.awt.Canvas;
import java.awt.event.HierarchyEvent;
import java.awt.event.HierarchyListener;

import javax.swing.SwingUtilities;

import org.eclipse.swt.SWT;
import org.eclipse.swt.awt.SWT_AWT;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;
import org.jowidgets.spi.impl.bridge.swt.awt.common.awt.PeerObservablePanel.IPeerListener;
import org.jowidgets.spi.impl.swing.common.widgets.SwingControl;

class AwtSwtControlImpl extends SwingControl implements IAwtSwtControlSpi {

    private final Shell backboneShell;
    private final Composite composite;

    private boolean initialized;
    private Shell bridgeShell;

    AwtSwtControlImpl(final Object parentUiReference) {
        super(new PeerObservablePanel());

        if (!SwingUtilities.isEventDispatchThread()) {
            throw new IllegalArgumentException("The AwtSwtControl must be created in the event dispatching thread of swing");
        }

        this.initialized = false;
        this.backboneShell = new Shell(getCurrentDisplay());
        this.backboneShell.setLayout(new FillLayout());
        this.composite = new Composite(backboneShell, SWT.NONE);
        this.composite.setLayout(new FillLayout());

        getUiReference().setLayout(new BorderLayout());
        getUiReference().addPeerListener(new IPeerListener() {

            @Override
            public void afterPeerAdd() {
                //If initialize will be invoked here, there is a flicker artifact
                //that will not occur if initialize will be invoked in the 
                //HierarchyListener
            }

            @Override
            public void beforePeerRemove() {
                onPeerRemoved();
            }

        });
        getUiReference().addHierarchyListener(new HierarchyListener() {
            @Override
            public void hierarchyChanged(final HierarchyEvent e) {
                if (!initialized && getUiReference().isDisplayable()) {
                    onPeerAdded();
                }
            }
        });
    }

    private static Display getCurrentDisplay() {
        final Display currentDisplay = Display.getCurrent();
        if (currentDisplay != null) {
            return currentDisplay;
        }
        else {
            throw new IllegalStateException(
                "This thread has no swt display. "
                    + "To ensure that the awt event dispatching thread has a display, e.g. the class "
                    + "'"
                    + "BridgedSwtAwtApplicationRunner"
                    + "' could be used, or, if no application "
                    + "runner should be used, use the single ui thread pattern implemented there.");
        }
    }

    private void onPeerAdded() {
        final Canvas canvas = new Canvas();
        getUiReference().removeAll();
        getUiReference().add(BorderLayout.CENTER, canvas);
        bridgeShell = SWT_AWT.new_Shell(getCurrentDisplay(), canvas);
        bridgeShell.setLayout(new FillLayout());
        composite.setParent(bridgeShell);
        initialized = true;
    }

    private void onPeerRemoved() {
        if (!composite.isDisposed()) {
            composite.setParent(backboneShell);
        }
        tryToDispose(bridgeShell);
        bridgeShell = null;
        initialized = false;
    }

    @Override
    public PeerObservablePanel getUiReference() {
        return (PeerObservablePanel) super.getUiReference();
    }

    @Override
    public Composite getSwtComposite() {
        return composite;
    }

    @Override
    public void dispose() {
        tryToDispose(composite);
        tryToDispose(backboneShell);
        tryToDispose(bridgeShell);
    }

    private static void tryToDispose(final Composite composite) {
        if (composite != null && !composite.isDisposed()) {
            composite.dispose();
        }
    }
}