/*

* 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:

*

*/

package javax.microedition.lcdui.game;

import javax.microedition.lcdui.Graphics;

import javax.microedition.lcdui.Image;

/**

 * LCDUI Layer class.

 */

public abstract class Layer

{

    int x;

    int y;

    boolean visible;

    Image tileImage;

    int tileWidth;

    int tileHeight;

    int tileCount;

    int tileColumns;

    /**

     * Package level constructor prevents Layer being subclassed. This is

     * consistent with the MIDP 2.0 RI.

     */

    Layer(Image tileImage, int frameWidth, int frameHeight)

    {

        visible = true;

        setTileImage(tileImage, frameWidth, frameHeight);

    }

    Layer(Layer from)

    {

        x = from.x;

        y = from.y;

        visible = from.visible;

        tileImage = from.tileImage;

        tileWidth = from.tileWidth;

        tileHeight = from.tileHeight;

        tileCount = from.tileCount;

        tileColumns = from.tileColumns;

    }

    public void setPosition(int x, int y)

    {

        this.x = x;

        this.y = y;

    }

    public void move(int deltaX, int deltaY)

    {

        x += deltaX;

        y += deltaY;

    }

    public final int getX()

    {

        return x;

    }

    public final int getY()

    {

        return y;

    }

    public final int getWidth()

    {

        return getLayerWidth();

    }

    public final int getHeight()

    {

        return getLayerHeight();

    }

    public void setVisible(boolean visible)

    {

        this.visible = visible;

    }

    public final boolean isVisible()

    {

        return visible;

    }

    public abstract void paint(Graphics graphics);

    abstract int getLayerWidth();

    abstract int getLayerHeight();

    /**

     * Set the source image and tile size. checks that the image is completely

     * tiled. computes the tile count.

     */

    void setTileImage(Image tileImage, int tileWidth, int tileHeight)

    {

        if(tileWidth > 0 && tileHeight > 0)

        {

            final int imageWidth = tileImage.getWidth();

            final int imageHeight = tileImage.getHeight();

            int rows = imageHeight / tileHeight;

            int cols = imageWidth / tileWidth;

            int totalHeight = rows * tileHeight;

            int totalWidth = cols * tileWidth;

            if(totalHeight == imageHeight && totalWidth == imageWidth)

            {

                this.tileImage = tileImage;

                this.tileWidth = tileWidth;

                this.tileHeight = tileHeight;

                this.tileCount = rows * cols;

                this.tileColumns = cols;

                return;

            }

        }

        throw new IllegalArgumentException(

            MsgRepository.LAYER_EXCEPTION_INVALID_TILE_WIDTH_HEIGHT);

    }

    /**

     * Is Layer visible in Graphics clip region.

     */

    final boolean isVisible(Graphics graphics, int pX, int pY)

    {

        int x1 = x + pX;

        int y1 = y + pY;

        int x2 = x1 + getWidth();

        int y2 = y1 + getHeight();

        int clipX1 = graphics.getClipX();

        int clipY1 = graphics.getClipY();

        int clipX2 = clipX1 + graphics.getClipWidth();

        int clipY2 = clipY1 + graphics.getClipHeight();

        return !(clipX2 <= x1 || clipY2 <= y1 || clipX1 >= x2 || clipY1 >= y2);

    }

}