--- /dev/null
+/*******************************************************************************
+ * Copyright (c) 2000, 2016 IBM Corporation and others.
+ *
+ * This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License 2.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ * IBM Corporation - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.swt.graphics;
+
+
+import java.io.*;
+import java.util.*;
+
+import org.eclipse.swt.*;
+import org.eclipse.swt.internal.image.*;
+
+/**
+ * Instances of this class are used to load images from,
+ * and save images to, a file or stream.
+ * <p>
+ * Currently supported image formats are:
+ * </p><ul>
+ * <li>BMP (Windows or OS/2 Bitmap)</li>
+ * <li>ICO (Windows Icon)</li>
+ * <li>JPEG</li>
+ * <li>GIF</li>
+ * <li>PNG</li>
+ * <li>TIFF</li>
+ * </ul>
+ * <code>ImageLoaders</code> can be used to:
+ * <ul>
+ * <li>load/save single images in all formats</li>
+ * <li>load/save multiple images (GIF/ICO/TIFF)</li>
+ * <li>load/save animated GIF images</li>
+ * <li>load interlaced GIF/PNG images</li>
+ * <li>load progressive JPEG images</li>
+ * </ul>
+ *
+ * <p>
+ * NOTE: <code>ImageLoader</code> is implemented in Java on some platforms, which has
+ * certain performance implications. Performance and memory sensitive applications may
+ * benefit from using one of the constructors provided by <code>Image</code>, as these
+ * are implemented natively.</p>
+ *
+ * @see <a href="http://www.eclipse.org/swt/examples.php">SWT Example: ImageAnalyzer</a>
+ * @see <a href="http://www.eclipse.org/swt/">Sample code and further information</a>
+ */
+public class ImageLoader {
+
+ /**
+ * the array of ImageData objects in this ImageLoader.
+ * This array is read in when the load method is called,
+ * and it is written out when the save method is called
+ */
+ public ImageData[] data;
+
+ /**
+ * the width of the logical screen on which the images
+ * reside, in pixels (this corresponds to the GIF89a
+ * Logical Screen Width value)
+ */
+ public int logicalScreenWidth;
+
+ /**
+ * the height of the logical screen on which the images
+ * reside, in pixels (this corresponds to the GIF89a
+ * Logical Screen Height value)
+ */
+ public int logicalScreenHeight;
+
+ /**
+ * the background pixel for the logical screen (this
+ * corresponds to the GIF89a Background Color Index value).
+ * The default is -1 which means 'unspecified background'
+ *
+ */
+ public int backgroundPixel;
+
+ /**
+ * the number of times to repeat the display of a sequence
+ * of animated images (this corresponds to the commonly-used
+ * GIF application extension for "NETSCAPE 2.0 01").
+ * The default is 1. A value of 0 means 'display repeatedly'
+ */
+ public int repeatCount;
+
+ /**
+ * This is the compression used when saving jpeg and png files.
+ * <p>
+ * When saving jpeg files, the value is from 1 to 100,
+ * where 1 is very high compression but low quality, and 100 is
+ * no compression and high quality; default is 75.
+ * </p><p>
+ * When saving png files, the value is from 0 to 3, but they do not impact the quality
+ * because PNG is lossless compression. 0 is uncompressed, 1 is low compression and fast,
+ * 2 is default compression, and 3 is high compression but slow.
+ * </p>
+ *
+ * @since 3.8
+ */
+ public int compression;
+
+ /*
+ * the set of ImageLoader event listeners, created on demand
+ */
+ List<ImageLoaderListener> imageLoaderListeners;
+
+/**
+ * Construct a new empty ImageLoader.
+ */
+public ImageLoader() {
+ reset();
+}
+
+/**
+ * Resets the fields of the ImageLoader, except for the
+ * <code>imageLoaderListeners</code> field.
+ */
+void reset() {
+ data = null;
+ logicalScreenWidth = 0;
+ logicalScreenHeight = 0;
+ backgroundPixel = -1;
+ repeatCount = 1;
+ compression = -1;
+}
+
+/**
+ * Loads an array of <code>ImageData</code> objects from the
+ * specified input stream. Throws an error if either an error
+ * occurs while loading the images, or if the images are not
+ * of a supported type. Returns the loaded image data array.
+ *
+ * @param stream the input stream to load the images from
+ * @return an array of <code>ImageData</code> objects loaded from the specified input stream
+ *
+ * @exception IllegalArgumentException <ul>
+ * <li>ERROR_NULL_ARGUMENT - if the stream is null</li>
+ * </ul>
+ * @exception SWTException <ul>
+ * <li>ERROR_IO - if an IO error occurs while reading from the stream</li>
+ * <li>ERROR_INVALID_IMAGE - if the image stream contains invalid data</li>
+ * <li>ERROR_UNSUPPORTED_FORMAT - if the image stream contains an unrecognized format</li>
+ * </ul>
+ */
+public ImageData[] load(InputStream stream) {
+ if (stream == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
+ reset();
+ data = FileFormat.load(stream, this);
+ return data;
+}
+
+/**
+ * Loads an array of <code>ImageData</code> objects from the
+ * file with the specified name. Throws an error if either
+ * an error occurs while loading the images, or if the images are
+ * not of a supported type. Returns the loaded image data array.
+ *
+ * @param filename the name of the file to load the images from
+ * @return an array of <code>ImageData</code> objects loaded from the specified file
+ *
+ * @exception IllegalArgumentException <ul>
+ * <li>ERROR_NULL_ARGUMENT - if the file name is null</li>
+ * </ul>
+ * @exception SWTException <ul>
+ * <li>ERROR_IO - if an IO error occurs while reading from the file</li>
+ * <li>ERROR_INVALID_IMAGE - if the image file contains invalid data</li>
+ * <li>ERROR_UNSUPPORTED_FORMAT - if the image file contains an unrecognized format</li>
+ * </ul>
+ */
+public ImageData[] load(String filename) {
+ if (filename == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
+ InputStream stream = null;
+ try {
+ stream = new FileInputStream(filename);
+ return load(stream);
+ } catch (IOException e) {
+ SWT.error(SWT.ERROR_IO, e);
+ } finally {
+ try {
+ if (stream != null) stream.close();
+ } catch (IOException e) {
+ // Ignore error
+ }
+ }
+ return null;
+}
+
+/**
+ * Saves the image data in this ImageLoader to the specified stream.
+ * The format parameter can have one of the following values:
+ * <dl>
+ * <dt><code>IMAGE_BMP</code></dt>
+ * <dd>Windows BMP file format, no compression</dd>
+ * <dt><code>IMAGE_BMP_RLE</code></dt>
+ * <dd>Windows BMP file format, RLE compression if appropriate</dd>
+ * <dt><code>IMAGE_GIF</code></dt>
+ * <dd>GIF file format</dd>
+ * <dt><code>IMAGE_ICO</code></dt>
+ * <dd>Windows ICO file format</dd>
+ * <dt><code>IMAGE_JPEG</code></dt>
+ * <dd>JPEG file format</dd>
+ * <dt><code>IMAGE_PNG</code></dt>
+ * <dd>PNG file format</dd>
+ * </dl>
+ *
+ * @param stream the output stream to write the images to
+ * @param format the format to write the images in
+ *
+ * @exception IllegalArgumentException <ul>
+ * <li>ERROR_NULL_ARGUMENT - if the stream is null</li>
+ * </ul>
+ * @exception SWTException <ul>
+ * <li>ERROR_IO - if an IO error occurs while writing to the stream</li>
+ * <li>ERROR_INVALID_IMAGE - if the image data contains invalid data</li>
+ * <li>ERROR_UNSUPPORTED_FORMAT - if the image data cannot be saved to the requested format</li>
+ * </ul>
+ */
+public void save(OutputStream stream, int format) {
+ if (stream == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
+ FileFormat.save(stream, format, this);
+}
+
+/**
+ * Saves the image data in this ImageLoader to a file with the specified name.
+ * The format parameter can have one of the following values:
+ * <dl>
+ * <dt><code>IMAGE_BMP</code></dt>
+ * <dd>Windows BMP file format, no compression</dd>
+ * <dt><code>IMAGE_BMP_RLE</code></dt>
+ * <dd>Windows BMP file format, RLE compression if appropriate</dd>
+ * <dt><code>IMAGE_GIF</code></dt>
+ * <dd>GIF file format</dd>
+ * <dt><code>IMAGE_ICO</code></dt>
+ * <dd>Windows ICO file format</dd>
+ * <dt><code>IMAGE_JPEG</code></dt>
+ * <dd>JPEG file format</dd>
+ * <dt><code>IMAGE_PNG</code></dt>
+ * <dd>PNG file format</dd>
+ * </dl>
+ *
+ * @param filename the name of the file to write the images to
+ * @param format the format to write the images in
+ *
+ * @exception IllegalArgumentException <ul>
+ * <li>ERROR_NULL_ARGUMENT - if the file name is null</li>
+ * </ul>
+ * @exception SWTException <ul>
+ * <li>ERROR_IO - if an IO error occurs while writing to the file</li>
+ * <li>ERROR_INVALID_IMAGE - if the image data contains invalid data</li>
+ * <li>ERROR_UNSUPPORTED_FORMAT - if the image data cannot be saved to the requested format</li>
+ * </ul>
+ */
+public void save(String filename, int format) {
+ if (filename == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
+ OutputStream stream = null;
+ try {
+ stream = new FileOutputStream(filename);
+ } catch (IOException e) {
+ SWT.error(SWT.ERROR_IO, e);
+ }
+ save(stream, format);
+ try {
+ stream.close();
+ } catch (IOException e) {
+ }
+}
+
+/**
+ * Adds the listener to the collection of listeners who will be
+ * notified when image data is either partially or completely loaded.
+ * <p>
+ * An ImageLoaderListener should be added before invoking
+ * one of the receiver's load methods. The listener's
+ * <code>imageDataLoaded</code> method is called when image
+ * data has been partially loaded, as is supported by interlaced
+ * GIF/PNG or progressive JPEG images.
+ *
+ * @param listener the listener which should be notified
+ *
+ * @exception IllegalArgumentException <ul>
+ * <li>ERROR_NULL_ARGUMENT - if the listener is null</li>
+ * </ul>
+ *
+ * @see ImageLoaderListener
+ * @see ImageLoaderEvent
+ */
+public void addImageLoaderListener(ImageLoaderListener listener) {
+ if (listener == null) SWT.error (SWT.ERROR_NULL_ARGUMENT);
+ if (imageLoaderListeners == null) {
+ imageLoaderListeners = new ArrayList<>();
+ }
+ imageLoaderListeners.add(listener);
+}
+
+/**
+ * Removes the listener from the collection of listeners who will be
+ * notified when image data is either partially or completely loaded.
+ *
+ * @param listener the listener which should no longer be notified
+ *
+ * @exception IllegalArgumentException <ul>
+ * <li>ERROR_NULL_ARGUMENT - if the listener is null</li>
+ * </ul>
+ *
+ * @see #addImageLoaderListener(ImageLoaderListener)
+ */
+public void removeImageLoaderListener(ImageLoaderListener listener) {
+ if (listener == null) SWT.error (SWT.ERROR_NULL_ARGUMENT);
+ if (imageLoaderListeners == null) return;
+ imageLoaderListeners.remove(listener);
+}
+
+/**
+ * Returns <code>true</code> if the receiver has image loader
+ * listeners, and <code>false</code> otherwise.
+ *
+ * @return <code>true</code> if there are <code>ImageLoaderListener</code>s, and <code>false</code> otherwise
+ *
+ * @see #addImageLoaderListener(ImageLoaderListener)
+ * @see #removeImageLoaderListener(ImageLoaderListener)
+ */
+public boolean hasListeners() {
+ return imageLoaderListeners != null && imageLoaderListeners.size() > 0;
+}
+
+/**
+ * Notifies all image loader listeners that an image loader event
+ * has occurred. Pass the specified event object to each listener.
+ *
+ * @param event the <code>ImageLoaderEvent</code> to send to each <code>ImageLoaderListener</code>
+ */
+public void notifyListeners(ImageLoaderEvent event) {
+ if (!hasListeners()) return;
+ int size = imageLoaderListeners.size();
+ for (int i = 0; i < size; i++) {
+ ImageLoaderListener listener = imageLoaderListeners.get(i);
+ listener.imageDataLoaded(event);
+ }
+}
+
+}
Code Review / simantics / platform.git / blobdiff