1 /*

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

     3 * All rights reserved.

     4 * This component and the accompanying materials are made available

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

     6 * which accompanies this distribution, and is available

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

     8 *

     9 * Initial Contributors:

    10 * Nokia Corporation - initial contribution.

    11 *

    12 * Contributors:

    13 *

    14 * Description: 

    15 *

    16 */

    17 package javax.microedition.lcdui.game;

    18 

    19 import javax.microedition.lcdui.Graphics;

    20 import javax.microedition.lcdui.Image;

    21 

    22 /**

    23  * LCDUI Layer class.

    24  */

    25 public abstract class Layer {

    26 

    27     int x;

    28     int y;

    29     boolean visible;

    30 

    31     Image tileImage;

    32 

    33     int tileWidth;

    34     int tileHeight;

    35 

    36     int tileCount;

    37     int tileColumns;

    38 

    39     /**

    40      * Package level constructor prevents Layer being subclassed. This is

    41      * consistent with the MIDP 2.0 RI.

    42      */

    43     Layer(Image tileImage, int frameWidth, int frameHeight) {

    44         visible = true;

    45         setTileImage(tileImage, frameWidth, frameHeight);

    46     }

    47 

    48     Layer(Layer from) {

    49         x = from.x;

    50         y = from.y;

    51         visible = from.visible;

    52         tileImage = from.tileImage;

    53         tileWidth = from.tileWidth;

    54         tileHeight = from.tileHeight;

    55         tileCount = from.tileCount;

    56         tileColumns = from.tileColumns;

    57     }

    58 

    59     public void setPosition(int x, int y) {

    60         this.x = x;

    61         this.y = y;

    62     }

    63 

    64     public void move(int deltaX, int deltaY) {

    65         x += deltaX;

    66         y += deltaY;

    67     }

    68 

    69     public final int getX() {

    70         return x;

    71     }

    72 

    73     public final int getY() {

    74         return y;

    75     }

    76 

    77     public final int getWidth() {

    78         return getLayerWidth();

    79     }

    80 

    81     public final int getHeight() {

    82         return getLayerHeight();

    83     }

    84 

    85     public void setVisible(boolean visible) {

    86         this.visible = visible;

    87     }

    88 

    89     public final boolean isVisible() {

    90         return visible;

    91     }

    92 

    93     public abstract void paint(Graphics graphics);

    94 

    95     abstract int getLayerWidth();

    96 

    97     abstract int getLayerHeight();

    98 

    99     /**

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

   101      * tiled. computes the tile count.

   102      */

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

   104         if (tileWidth > 0 && tileHeight > 0) {

   105             final int imageWidth = tileImage.getWidth();

   106             final int imageHeight = tileImage.getHeight();

   107 

   108             int rows = imageHeight / tileHeight;

   109             int cols = imageWidth / tileWidth;

   110 

   111             int totalHeight = rows * tileHeight;

   112             int totalWidth = cols * tileWidth;

   113 

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

   115                 this.tileImage = tileImage;

   116                 this.tileWidth = tileWidth;

   117                 this.tileHeight = tileHeight;

   118                 this.tileCount = rows * cols;

   119                 this.tileColumns = cols;

   120                 return;

   121             }

   122         }

   123         throw new IllegalArgumentException(

   124                 MsgRepository.LAYER_EXCEPTION_INVALID_TILE_WIDTH_HEIGHT);

   125     }

   126 

   127     /**

   128      * Is Layer visible in Graphics clip region.

   129      */

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

   131         int x1 = x + pX;

   132         int y1 = y + pY;

   133         int x2 = x1 + getWidth();

   134         int y2 = y1 + getHeight();

   135         int clipX1 = graphics.getClipX();

   136         int clipY1 = graphics.getClipY();

   137         int clipX2 = clipX1 + graphics.getClipWidth();

   138         int clipY2 = clipY1 + graphics.getClipHeight();

   139 

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

   141     }

   142 

   143 }