/*

* Copyright (c) 2009 Nokia Corporation and/or its subsidiary(-ies).

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - initial contribution.

*

* Contributors:

*

* Description:

*

*/

/**

 * \file

 * \brief Target platform dependent Java module for Symbian.

 *

 */

package javax.microedition.m3g;

import javax.microedition.lcdui.Graphics;

import javax.microedition.lcdui.Image;

import org.eclipse.swt.widgets.Display;

import com.nokia.mj.impl.nokialcdui.LCDUIInvoker;

import org.eclipse.swt.internal.extension.DisplayExtension;

/**

 * Implements platform-dependent functionality. At the moment, this

 * includes native finalization and some helper methods for

 * synchronizing 2D and 3D rendering.

 */

class Platform

{

    /**

     * eSWT display for ui thread access

     */

    private static Display display = null;

    private static boolean libraryLoaded = false;

    //------------------------------------------------------------------

    // Package private methods

    //------------------------------------------------------------------

    /**

     * Executes given runnable in UI thread if caller thread is not UI thread

     */

    static void executeInUIThread(M3gRunnable obj)

    {

        if (display == null)

        {

            if (!uiThreadAvailable())

            {

                throw new Error("Ui thread not available");

            }

        }

        if (display.isDisposed())

        {

            throw new Error("Display already disposed");

        }

        if (obj != null)

        {

            // If we are not in UI thread use display

            if (Thread.currentThread() != display.getThread())

            {

                display.syncExec(obj);

            }

            else

            {

                // In this case we are in UI thread so just execute directly

                obj.run();

            }

            // Check if any exceptions occured in execution

            // and throw forward in caller thread

            obj.checkAndThrow();

        }

    }

    /**

     * Check the UI thread / toolkit init status and store display if it is available

     * @return true if either lcdui or eswt toolkit is initialized and ui thread is accessible

     *              otherwise false

     */

    static boolean uiThreadAvailable()

    {

        if (display != null)

        {

            return true;

        }

        else

        {

            display = DisplayExtension.getDisplayInstance();

            if (display == null)

            {

                return false;

            }

            else

            {

                // UI thread is available, so load native library if not already loaded

                if (!libraryLoaded)

                {

                    com.nokia.mj.impl.rt.support.Jvm.loadSystemLibrary("javam3g");

                    libraryLoaded = true;

                }

                return true;

            }

        }

    }

    /**

     * Registers an Object3D in the global handle-to-object map. The

     * handle of the object must already be set at this point!

     */

    static final void registerFinalizer(Object3D obj)

    {

        //heuristicGC();

    }

    /**

     * Registers a Graphics3D object (not derived from Object3D) for

     * finalization.

     */

    static final void registerFinalizer(Graphics3D g3d)

    {

        //heuristicGC();

    }

    /**

     * Registers an Interface object for finalization

     */

    static final void registerFinalizer(Interface m3g)

    {

    }

    /**

     * Registers a Loader object for finalization

     */

    static final void registerFinalizer(Loader loader)

    {

    }

    /**

     * Flushes all pending rendering to a Graphics context and blocks

     * until finished

     */

    static final void sync(Graphics g)

    {

        //ToolkitInvoker invoker = ToolkitInvoker.getToolkitInvoker();

        //invoker.toolkitSync(invoker.getToolkit());

    }

    /**

     * Flushes all pending rendering to an Image object

     */

    static final void sync(Image img)

    {

        //ToolkitInvoker invoker = ToolkitInvoker.getToolkitInvoker();

        //invoker.toolkitSync(invoker.getToolkit());

    }

    /**

     * Finalizes the native peer of an interface

     */

    static final native void finalizeInterface(int handle);

    /**

     * Finalizes the native peer of an object

     * JCF: added this wrapper method so we could pass the toolkit handle to the native method.

     */

    static final void finalizeObject(int handle)

    {

        try

        {

            final int finalHandle = handle;

            executeInUIThread(

                new M3gRunnable()

            {

                void doRun()

                {

                    _finalizeObject(finalHandle);

                }

            });

        }

        catch (Exception e)

        {

            // do nothing

        }

    }

    /**

     * Finalizes the native peer of an object associated with

     * given Interface instance

     */

    static final void finalizeObject(int handle, Interface aInterface)

    {

        try

        {

            final int finalHandle = handle;

            executeInUIThread(

                new M3gRunnable()

            {

                public void doRun()

                {

                    _finalizeObject(finalHandle);

                }

            });

        }

        catch (Exception e)

        {

            // do nothing

        }

    }

    //------------------------------------------------------------------

    // Private methods

    //------------------------------------------------------------------

    /**

     * Trigger GC if minimum free memory limit has been exceeded in the native side

     */

    static final void heuristicGC()

    {

    }

    private static final native void _finalizeObject(int handle);

}