📄 image.java
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* the new image unchanged. * * <p> This method is useful for placing the contents of mutable images * into <code>Choice</code> objects. The application can create * an off-screen image * using the * {@link #createImage(int, int) createImage(w, h)} * method, draw into it using a <code>Graphics</code> object * obtained with the * {@link #getGraphics() getGraphics()} * method, and then create an immutable copy of it with this method. * The immutable copy may then be placed into <code>Choice</code> * objects. </p> * * @param source the source image to be copied * @return the new, immutable image * * @throws NullPointerException if <code>source</code> is <code>null</code> */ public static Image createImage(Image source) { // SYNC NOTE: Not accessing any shared data, no locking necessary if (source.isMutable()) { return new Image(ImageDataFactory.getImageDataFactory(). createImmutableCopy(source.imageData)); } else { return source; } } /** * Creates an immutable image from decoded image data obtained from the * named resource. The name parameter is a resource name as defined by * {@link Class#getResourceAsStream(String) * Class.getResourceAsStream(name)}. The rules for resolving resource * names are defined in the * <a href="../../../java/lang/package-summary.html"> * Application Resource Files</a> section of the * <code>java.lang</code> package documentation. * * @param name the name of the resource containing the image data in one of * the supported image formats * @return the created image * @throws NullPointerException if <code>name</code> is <code>null</code> * @throws java.io.IOException if the resource does not exist, * the data cannot * be loaded, or the image data cannot be decoded */ public static Image createImage(java.lang.String name) throws java.io.IOException { return new Image(ImageDataFactory.getImageDataFactory(). createResourceImageData(name)); } /** * Creates an immutable image which is decoded from the data stored in * the specified byte array at the specified offset and length. The data * must be in a self-identifying image file format supported by the * implementation, such as <a href="#PNG">PNG</A>. * * <p>The <code>imageoffset</code> and <code>imagelength</code> * parameters specify a range of * data within the <code>imageData</code> byte array. The * <code>imageOffset</code> parameter * specifies the * offset into the array of the first data byte to be used. It must * therefore lie within the range * <code>[0..(imageData.length-1)]</code>. The * <code>imageLength</code> * parameter specifies the number of data bytes to be used. It must be a * positive integer and it must not cause the range to extend beyond * the end * of the array. That is, it must be true that * <code>imageOffset + imageLength < imageData.length</code>. </p> * * <p> This method is intended for use when loading an * image from a variety of sources, such as from * persistent storage or from the network.</p> * * @param imageData the array of image data in a supported image format * @param imageOffset the offset of the start of the data in the array * @param imageLength the length of the data in the array * * @return the created image * @throws ArrayIndexOutOfBoundsException if <code>imageOffset</code> * and <code>imageLength</code> * specify an invalid range * @throws NullPointerException if <code>imageData</code> is * <code>null</code> * @throws IllegalArgumentException if <code>imageData</code> is incorrectly * formatted or otherwise cannot be decoded */ public static Image createImage(byte[] imageData, int imageOffset, int imageLength) { if (imageOffset < 0 || imageOffset >= imageData.length || imageLength < 0 || imageOffset + imageLength > imageData.length) { throw new ArrayIndexOutOfBoundsException(); } return new Image(ImageDataFactory.getImageDataFactory(). createImmutableImageData(imageData, imageOffset, imageLength)); } /** * Creates an immutable image using pixel data from the specified * region of a source image, transformed as specified. * * <p>The source image may be mutable or immutable. For immutable source * images, transparency information, if any, is copied to the new * image unchanged.</p> * * <p>On some devices, pre-transformed images may render more quickly * than images that are transformed on the fly using * <code>drawRegion</code>. * However, creating such images does consume additional heap space, * so this technique should be applied only to images whose rendering * speed is critical.</p> * * <p>The transform function used must be one of the following, as defined * in the {@link javax.microedition.lcdui.game.Sprite Sprite} class:<br> * * <code>Sprite.TRANS_NONE</code> - causes the specified image * region to be copied unchanged<br> * <code>Sprite.TRANS_ROT90</code> - causes the specified image * region to be rotated clockwise by 90 degrees.<br> * <code>Sprite.TRANS_ROT180</code> - causes the specified image * region to be rotated clockwise by 180 degrees.<br> * <code>Sprite.TRANS_ROT270</code> - causes the specified image * region to be rotated clockwise by 270 degrees.<br> * <code>Sprite.TRANS_MIRROR</code> - causes the specified image * region to be reflected about its vertical center.<br> * <code>Sprite.TRANS_MIRROR_ROT90</code> - causes the specified image * region to be reflected about its vertical center and then rotated * clockwise by 90 degrees.<br> * <code>Sprite.TRANS_MIRROR_ROT180</code> - causes the specified image * region to be reflected about its vertical center and then rotated * clockwise by 180 degrees.<br> * <code>Sprite.TRANS_MIRROR_ROT270</code> - causes the specified image * region to be reflected about its vertical center and then rotated * clockwise by 270 degrees.<br></p> * * <p> * The size of the returned image will be the size of the specified region * with the transform applied. For example, if the region is * <code>100 x 50</code> pixels and the transform is * <code>TRANS_ROT90</code>, the * returned image will be <code>50 x 100</code> pixels.</p> * * <p><strong>Note:</strong> If all of the following conditions * are met, this method may * simply return the source <code>Image</code> without creating a * new one:</p> * <ul> * <li>the source image is immutable;</li> * <li>the region represents the entire source image; and</li> * <li>the transform is <code>TRANS_NONE</code>.</li> * </ul> * * @param image the source image to be copied from * @param x the horizontal location of the region to be copied * @param y the vertical location of the region to be copied * @param width the width of the region to be copied * @param height the height of the region to be copied * @param transform the transform to be applied to the region * @return the new, immutable image * * @throws NullPointerException if <code>image</code> is <code>null</code> * @throws IllegalArgumentException if the region to be copied exceeds * the bounds of the source image * @throws IllegalArgumentException if either <code>width</code> or * <code>height</code> is zero or less * @throws IllegalArgumentException if the <code>transform</code> * is not valid * */ public static Image createImage(Image image, int x, int y, int width, int height, int transform) { if ((transform & INVALID_TRANSFORM_BITS) != 0) { throw new IllegalArgumentException(); } if (x < 0 || y < 0 || (x + width) > image.getWidth() || // throws NPE if image is null (y + height) > image.getHeight() || width <= 0 || height <= 0) { throw new IllegalArgumentException(); } if (x == 0 && y == 0 && width == image.getWidth() && height == image.getHeight() && transform == Sprite.TRANS_NONE) { return createImage(image); } else { return new Image(ImageDataFactory.getImageDataFactory(). createImmutableImageData(image.imageData, x, y, width, height, transform)); } } /** * Creates an immutable image from decoded image data obtained froH an * <code>InputStream</code>. This method blocks until all image data has * been read and decoded. After this method completes (whether by * returning or by throwing an exception) the stream is left open and its * current position is undefined. * * @param stream the name of the resource containing the image data * in one of the supported image formats * * @return the created image * @throws NullPointerException if <code>stream</code> is <code>null</code> * @throws java.io.IOException if an I/O error occurs, if the image data * cannot be loaded, or if the image data cannot be decoded * */ public static Image createImage(InputStream stream) throws java.io.IOException { if (stream == null) { throw new java.lang.NullPointerException(); } try { return new Image(ImageDataFactory.getImageDataFactory(). createImmutableImageData(stream)); } catch (IllegalArgumentException e) { throw new java.io.IOException(); } } /** * Creates an immutable image from a sequence of ARGB values, specified * as <code>0xAARRGGBB</code>. * The ARGB data within the <code>rgb</code> array is arranged * horizontally from left to right within each row, * row by row from top to bottom. * If <code>processAlpha</code> is <code>true</code>, * the high-order byte specifies opacity; that is, * <code>0x00RRGGBB</code> specifies * a fully transparent pixel and <code>0xFFRRGGBB</code> specifies * a fully opaque * pixel. Intermediate alpha values specify semitransparency. If the * implementation does not support alpha blending for image rendering * operations, it must replace any semitransparent pixels with fully * transparent pixels. (See <a href="#alpha">Alpha Processing</a> * for further discussion.) If <code>processAlpha</code> is * <code>false</code>, the alpha values * are ignored and all pixels must be treated as fully opaque. * * <p>Consider <code>P(a,b)</code> to be the value of the pixel * located at column <code>a</code> and row <code>b</code> of the * Image, where rows and columns are numbered downward from the * top starting at zero, and columns are numbered rightward from * the left starting at zero. This operation can then be defined * as:</p> * * <TABLE BORDER="2"> * <TR> * <TD ROWSPAN="1" COLSPAN="1"> * <pre><code> * P(a, b) = rgb[a + b * width]; </code></pre> * </TD> * </TR> * </TABLE> * <p>for</p> * * <TABLE BORDER="2"> * <TR> * <TD ROWSPAN="1" COLSPAN="1"> * <pre><code> * 0 <= a < width * 0 <= b < height </code></pre> * </TD> * </TR> * </TABLE> * <p> </p> * * @param rgb an array of ARGB values that composes the image * @param width the width of the image * @param height the height of the image * @param processAlpha <code>true</code> if <code>rgb</code> * has an alpha channel, * <code>false</code> if all pixels are fully opaque * @return the created image * @throws NullPointerException if <code>rgb</code> is <code>null</code>. * @throws IllegalArgumentException if either <code>width</code> or * <code>height</code> is zero or less * @throws ArrayIndexOutOfBoundsException if the length of * <code>rgb</code> is * less than<code> width * height</code>. * */ public static Image createRGBImage(int rgb[], int width, int height, boolean processAlpha) { if (width <= 0 || height <= 0) { throw new IllegalArgumentException();
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