Mercurial > projects > dwt-linux
annotate dwt/graphics/ImageLoader.d @ 12:0c78fa47d476
helper classes
| author | Frank Benoit <benoit@tionex.de> |
|---|---|
| date | Sun, 06 Jan 2008 19:36:29 +0100 |
| parents | 63c023465156 |
| children | 92223a4ecca7 |
| rev | line source |
|---|---|
| 6 | 1 /******************************************************************************* |
| 2 * Copyright (c) 2000, 2006 IBM Corporation and others. | |
| 3 * All rights reserved. This program and the accompanying materials | |
| 4 * are made available under the terms of the Eclipse Public License v1.0 | |
| 5 * which accompanies this distribution, and is available at | |
| 6 * http://www.eclipse.org/legal/epl-v10.html | |
| 7 * | |
| 8 * Contributors: | |
| 9 * IBM Corporation - initial API and implementation | |
| 10 *******************************************************************************/ | |
|
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11 module dwt.graphics.ImageLoader; |
| 6 | 12 |
| 13 | |
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14 public import dwt.graphics.ImageLoaderListener; |
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15 public import dwt.graphics.ImageLoaderEvent; |
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16 public import dwt.graphics.ImageData; |
| 12 | 17 //public import dwt.dwthelper.InputStream; |
| 18 //public import dwt.dwthelper.OutputStream; | |
| 6 | 19 |
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20 import dwt.SWT; |
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21 import dwt.internal.Compatibility; |
| 12 | 22 import dwt.internal.image.FileFormat; |
| 6 | 23 |
| 24 import tango.core.Exception; | |
| 25 import tango.core.Array; | |
| 26 | |
| 27 | |
| 28 /** | |
| 29 * Instances of this class are used to load images from, | |
| 30 * and save images to, a file or stream. | |
| 31 * <p> | |
| 32 * Currently supported image formats are: | |
| 33 * </p><ul> | |
| 34 * <li>BMP (Windows or OS/2 Bitmap)</li> | |
| 35 * <li>ICO (Windows Icon)</li> | |
| 36 * <li>JPEG</li> | |
| 37 * <li>GIF</li> | |
| 38 * <li>PNG</li> | |
| 39 * <li>TIFF</li> | |
| 40 * </ul> | |
| 41 * <code>ImageLoaders</code> can be used to: | |
| 42 * <ul> | |
| 43 * <li>load/save single images in all formats</li> | |
| 44 * <li>load/save multiple images (GIF/ICO/TIFF)</li> | |
| 45 * <li>load/save animated GIF images</li> | |
| 46 * <li>load interlaced GIF/PNG images</li> | |
| 47 * <li>load progressive JPEG images</li> | |
| 48 * </ul> | |
| 49 */ | |
| 50 | |
| 51 public class ImageLoader { | |
| 52 | |
| 53 /** | |
| 54 * the array of ImageData objects in this ImageLoader. | |
| 55 * This array is read in when the load method is called, | |
| 56 * and it is written out when the save method is called | |
| 57 */ | |
| 58 public ImageData[] data; | |
| 59 | |
| 60 /** | |
| 61 * the width of the logical screen on which the images | |
| 62 * reside, in pixels (this corresponds to the GIF89a | |
| 63 * Logical Screen Width value) | |
| 64 */ | |
| 65 public int logicalScreenWidth; | |
| 66 | |
| 67 /** | |
| 68 * the height of the logical screen on which the images | |
| 69 * reside, in pixels (this corresponds to the GIF89a | |
| 70 * Logical Screen Height value) | |
| 71 */ | |
| 72 public int logicalScreenHeight; | |
| 73 | |
| 74 /** | |
| 75 * the background pixel for the logical screen (this | |
| 76 * corresponds to the GIF89a Background Color Index value). | |
| 77 * The default is -1 which means 'unspecified background' | |
| 78 * | |
| 79 */ | |
| 80 public int backgroundPixel; | |
| 81 | |
| 82 /** | |
| 83 * the number of times to repeat the display of a sequence | |
| 84 * of animated images (this corresponds to the commonly-used | |
| 85 * GIF application extension for "NETSCAPE 2.0 01"). | |
| 86 * The default is 1. A value of 0 means 'display repeatedly' | |
| 87 */ | |
| 88 public int repeatCount; | |
| 89 | |
| 90 /* | |
| 91 * the set of ImageLoader event listeners, created on demand | |
| 92 */ | |
| 93 ImageLoaderListener[] imageLoaderListeners; | |
| 94 | |
| 95 /** | |
| 96 * Construct a new empty ImageLoader. | |
| 97 */ | |
| 98 public this() { | |
| 99 reset(); | |
| 100 } | |
| 101 | |
| 102 /** | |
| 103 * Resets the fields of the ImageLoader, except for the | |
| 104 * <code>imageLoaderListeners</code> field. | |
| 105 */ | |
| 106 void reset() { | |
| 107 data = null; | |
| 108 logicalScreenWidth = 0; | |
| 109 logicalScreenHeight = 0; | |
| 110 backgroundPixel = -1; | |
| 111 repeatCount = 1; | |
| 112 } | |
| 113 | |
| 114 /** | |
| 115 * Loads an array of <code>ImageData</code> objects from the | |
| 116 * specified input stream. Throws an error if either an error | |
| 117 * occurs while loading the images, or if the images are not | |
| 118 * of a supported type. Returns the loaded image data array. | |
| 119 * | |
| 120 * @param stream the input stream to load the images from | |
| 121 * @return an array of <code>ImageData</code> objects loaded from the specified input stream | |
| 122 * | |
| 123 * @exception IllegalArgumentException <ul> | |
| 124 * <li>ERROR_NULL_ARGUMENT - if the stream is null</li> | |
| 125 * </ul> | |
| 126 * @exception SWTException <ul> | |
| 127 * <li>ERROR_IO - if an IO error occurs while reading from the stream</li> | |
| 128 * <li>ERROR_INVALID_IMAGE - if the image stream contains invalid data</li> | |
| 129 * <li>ERROR_UNSUPPORTED_FORMAT - if the image stream contains an unrecognized format</li> | |
| 130 * </ul> | |
| 131 */ | |
| 132 public ImageData[] load(InputStream stream) { | |
| 133 if (stream is null) SWT.error(SWT.ERROR_NULL_ARGUMENT); | |
| 134 reset(); | |
| 135 data = FileFormat.load(stream, this); | |
| 136 return data; | |
| 137 } | |
| 138 | |
| 139 /** | |
| 140 * Loads an array of <code>ImageData</code> objects from the | |
| 141 * file with the specified name. Throws an error if either | |
| 142 * an error occurs while loading the images, or if the images are | |
| 143 * not of a supported type. Returns the loaded image data array. | |
| 144 * | |
| 145 * @param filename the name of the file to load the images from | |
| 146 * @return an array of <code>ImageData</code> objects loaded from the specified file | |
| 147 * | |
| 148 * @exception IllegalArgumentException <ul> | |
| 149 * <li>ERROR_NULL_ARGUMENT - if the file name is null</li> | |
| 150 * </ul> | |
| 151 * @exception SWTException <ul> | |
| 152 * <li>ERROR_IO - if an IO error occurs while reading from the file</li> | |
| 153 * <li>ERROR_INVALID_IMAGE - if the image file contains invalid data</li> | |
| 154 * <li>ERROR_UNSUPPORTED_FORMAT - if the image file contains an unrecognized format</li> | |
| 155 * </ul> | |
| 156 */ | |
| 157 public ImageData[] load(char[] filename) { | |
| 158 if (filename is null) SWT.error(SWT.ERROR_NULL_ARGUMENT); | |
| 159 InputStream stream = null; | |
| 160 void close(){ | |
| 161 try { | |
| 162 if( stream !is null ) stream.close(); | |
| 163 } catch (IOException e) { | |
| 164 // Ignore error | |
| 165 } | |
| 166 } | |
| 167 try { | |
| 168 stream = Compatibility.newFileInputStream(filename); | |
| 169 scope(exit) close(); | |
| 170 | |
| 171 return load(stream); | |
| 172 } catch (IOException e) { | |
| 173 SWT.error(SWT.ERROR_IO, e); | |
| 174 } | |
| 175 return null; | |
| 176 } | |
| 177 | |
| 178 /** | |
| 179 * Saves the image data in this ImageLoader to the specified stream. | |
| 180 * The format parameter can have one of the following values: | |
| 181 * <dl> | |
| 182 * <dt><code>IMAGE_BMP</code></dt> | |
| 183 * <dd>Windows BMP file format, no compression</dd> | |
| 184 * <dt><code>IMAGE_BMP_RLE</code></dt> | |
| 185 * <dd>Windows BMP file format, RLE compression if appropriate</dd> | |
| 186 * <dt><code>IMAGE_GIF</code></dt> | |
| 187 * <dd>GIF file format</dd> | |
| 188 * <dt><code>IMAGE_ICO</code></dt> | |
| 189 * <dd>Windows ICO file format</dd> | |
| 190 * <dt><code>IMAGE_JPEG</code></dt> | |
| 191 * <dd>JPEG file format</dd> | |
| 192 * <dt><code>IMAGE_PNG</code></dt> | |
| 193 * <dd>PNG file format</dd> | |
| 194 * </dl> | |
| 195 * | |
| 196 * @param stream the output stream to write the images to | |
| 197 * @param format the format to write the images in | |
| 198 * | |
| 199 * @exception IllegalArgumentException <ul> | |
| 200 * <li>ERROR_NULL_ARGUMENT - if the stream is null</li> | |
| 201 * </ul> | |
| 202 * @exception SWTException <ul> | |
| 203 * <li>ERROR_IO - if an IO error occurs while writing to the stream</li> | |
| 204 * <li>ERROR_INVALID_IMAGE - if the image data contains invalid data</li> | |
| 205 * <li>ERROR_UNSUPPORTED_FORMAT - if the image data cannot be saved to the requested format</li> | |
| 206 * </ul> | |
| 207 */ | |
| 208 public void save(OutputStream stream, int format) { | |
| 209 if (stream is null) SWT.error(SWT.ERROR_NULL_ARGUMENT); | |
| 210 FileFormat.save(stream, format, this); | |
| 211 } | |
| 212 | |
| 213 /** | |
| 214 * Saves the image data in this ImageLoader to a file with the specified name. | |
| 215 * The format parameter can have one of the following values: | |
| 216 * <dl> | |
| 217 * <dt><code>IMAGE_BMP</code></dt> | |
| 218 * <dd>Windows BMP file format, no compression</dd> | |
| 219 * <dt><code>IMAGE_BMP_RLE</code></dt> | |
| 220 * <dd>Windows BMP file format, RLE compression if appropriate</dd> | |
| 221 * <dt><code>IMAGE_GIF</code></dt> | |
| 222 * <dd>GIF file format</dd> | |
| 223 * <dt><code>IMAGE_ICO</code></dt> | |
| 224 * <dd>Windows ICO file format</dd> | |
| 225 * <dt><code>IMAGE_JPEG</code></dt> | |
| 226 * <dd>JPEG file format</dd> | |
| 227 * <dt><code>IMAGE_PNG</code></dt> | |
| 228 * <dd>PNG file format</dd> | |
| 229 * </dl> | |
| 230 * | |
| 231 * @param filename the name of the file to write the images to | |
| 232 * @param format the format to write the images in | |
| 233 * | |
| 234 * @exception IllegalArgumentException <ul> | |
| 235 * <li>ERROR_NULL_ARGUMENT - if the file name is null</li> | |
| 236 * </ul> | |
| 237 * @exception SWTException <ul> | |
| 238 * <li>ERROR_IO - if an IO error occurs while writing to the file</li> | |
| 239 * <li>ERROR_INVALID_IMAGE - if the image data contains invalid data</li> | |
| 240 * <li>ERROR_UNSUPPORTED_FORMAT - if the image data cannot be saved to the requested format</li> | |
| 241 * </ul> | |
| 242 */ | |
| 243 public void save(char[] filename, int format) { | |
| 244 if (filename is null) SWT.error(SWT.ERROR_NULL_ARGUMENT); | |
| 245 OutputStream stream = null; | |
| 246 try { | |
| 247 stream = Compatibility.newFileOutputStream(filename); | |
| 248 } catch (IOException e) { | |
| 249 SWT.error(SWT.ERROR_IO, e); | |
| 250 } | |
| 251 save(stream, format); | |
| 252 try { | |
| 253 stream.close(); | |
| 254 } catch (IOException e) { | |
| 255 } | |
| 256 } | |
| 257 | |
| 258 /** | |
| 259 * Adds the listener to the collection of listeners who will be | |
| 260 * notified when image data is either partially or completely loaded. | |
| 261 * <p> | |
| 262 * An ImageLoaderListener should be added before invoking | |
| 263 * one of the receiver's load methods. The listener's | |
| 264 * <code>imageDataLoaded</code> method is called when image | |
| 265 * data has been partially loaded, as is supported by interlaced | |
| 266 * GIF/PNG or progressive JPEG images. | |
| 267 * | |
| 268 * @param listener the listener which should be notified | |
| 269 * | |
| 270 * @exception IllegalArgumentException <ul> | |
| 271 * <li>ERROR_NULL_ARGUMENT - if the listener is null</li> | |
| 272 * </ul> | |
| 273 * | |
| 274 * @see ImageLoaderListener | |
| 275 * @see ImageLoaderEvent | |
| 276 */ | |
| 277 public void addImageLoaderListener(ImageLoaderListener listener) { | |
| 278 if (listener is null) SWT.error (SWT.ERROR_NULL_ARGUMENT); | |
| 279 imageLoaderListeners ~= listener; | |
| 280 } | |
| 281 | |
| 282 /** | |
| 283 * Removes the listener from the collection of listeners who will be | |
| 284 * notified when image data is either partially or completely loaded. | |
| 285 * | |
| 286 * @param listener the listener which should no longer be notified | |
| 287 * | |
| 288 * @exception IllegalArgumentException <ul> | |
| 289 * <li>ERROR_NULL_ARGUMENT - if the listener is null</li> | |
| 290 * </ul> | |
| 291 * | |
| 292 * @see #addImageLoaderListener(ImageLoaderListener) | |
| 293 */ | |
| 294 public void removeImageLoaderListener(ImageLoaderListener listener) { | |
| 295 if (listener is null) SWT.error (SWT.ERROR_NULL_ARGUMENT); | |
| 296 if (imageLoaderListeners.length == 0 ) return; | |
| 297 tango.core.Array.remove( imageLoaderListeners, listener, delegate bool(ImageLoaderListener l1, ImageLoaderListener l2 ){ return l1 is l2; }); | |
| 298 } | |
| 299 | |
| 300 /** | |
| 301 * Returns <code>true</code> if the receiver has image loader | |
| 302 * listeners, and <code>false</code> otherwise. | |
| 303 * | |
| 304 * @return <code>true</code> if there are <code>ImageLoaderListener</code>s, and <code>false</code> otherwise | |
| 305 * | |
| 306 * @see #addImageLoaderListener(ImageLoaderListener) | |
| 307 * @see #removeImageLoaderListener(ImageLoaderListener) | |
| 308 */ | |
| 309 public bool hasListeners() { | |
| 310 return imageLoaderListeners.length > 0; | |
| 311 } | |
| 312 | |
| 313 /** | |
| 314 * Notifies all image loader listeners that an image loader event | |
| 315 * has occurred. Pass the specified event object to each listener. | |
| 316 * | |
| 317 * @param event the <code>ImageLoaderEvent</code> to send to each <code>ImageLoaderListener</code> | |
| 318 */ | |
| 319 public void notifyListeners(ImageLoaderEvent event) { | |
| 320 if (!hasListeners()) return; | |
| 321 foreach( listener; imageLoaderListeners ){ | |
| 322 listener.imageDataLoaded(event); | |
| 323 } | |
| 324 } | |
| 325 | |
| 326 } |