Introduce simple API to save ImageData to a file and support .jpg

Author: HannesWell

bundles/org.eclipse.swt/Eclipse SWT/common/org/eclipse/swt/graphics/ImageData.java

@@ -15,9 +15,11 @@
 
 
 import java.io.*;
+import java.nio.file.Path;
 
 import org.eclipse.swt.*;
 import org.eclipse.swt.internal.*;
+import org.eclipse.swt.internal.image.*;
 
 /**
  * Instances of this class are device-independent descriptions
@@ -1599,6 +1601,48 @@ public void setPixels(int x, int y, int putWidth, int[] pixels, int startIndex)
 	SWT.error(SWT.ERROR_UNSUPPORTED_DEPTH);
 }
 
+/**
+ * Saves this image to the specified file.
+ * The image format is derived from the file's extension and the following formats are supported:
+ * <dl>
+ * <dt>{@link SWT#IMAGE_BMP .bmp}</dt>
+ * <dd>Windows BMP file format, no compression</dd>
+ * <dt>{@link SWT#IMAGE_GIF .gif}</dt>
+ * <dd>GIF file format</dd>
+ * <dt>{@link SWT#IMAGE_ICO .ico}</dt>
+ * <dd>Windows ICO file format</dd>
+ * <dt>{@link SWT#IMAGE_JPEG .jpg or .jpeg}</dt>
+ * <dd>JPEG file format</dd>
+ * <dt>{@link SWT#IMAGE_PNG .png}</dt>
+ * <dd>PNG file format</dd>
+ * <dt>{@link SWT#IMAGE_TIFF .tiff}</dt>
+ * <dd>TIFF file format</dd>
+ * </dl>
+ *
+ * @param file the path to the file where this image is to be saved
+ *
+ * @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 this image data contains invalid data</li>
+ *    <li>ERROR_UNSUPPORTED_FORMAT - if the image data cannot be saved to the requested format</li>
+ * </ul>
+ * @since 3.130
+ */
+public void save(Path file) {
+	if (file == null) {
+		SWT.error(SWT.ERROR_NULL_ARGUMENT);
+	}
+	String filename = file.getFileName().toString();
+	String extension = filename.substring(filename.lastIndexOf('.') + 1);
+	int imageFormat = FileFormat.getImageFormatFromFileExtension(extension);
+	ImageLoader loader = new ImageLoader();
+	loader.data = new ImageData[] { this };
+	loader.save(file.toString(), imageFormat);
+}
+
 /**
  * Returns a palette with 2 colors: black & white.
  */

bundles/org.eclipse.swt/Eclipse SWT/common/org/eclipse/swt/internal/image/FileFormat.java

@@ -58,6 +58,34 @@ public abstract class FileFormat {
 		} catch (NoClassDefFoundError e) { } // ignore format
 	}
 
+	public static int getImageFormatFromFileExtension(String nameStr) {
+		return switch (nameStr) {
+		case "bmp" -> SWT.IMAGE_BMP;
+		case "gif" -> SWT.IMAGE_GIF;
+		case "ico" -> SWT.IMAGE_ICO;
+		case "jpg", "jpeg" -> SWT.IMAGE_JPEG;
+		case "png" -> SWT.IMAGE_PNG;
+		case "tiff" -> SWT.IMAGE_TIFF;
+		case "svg" -> SWT.IMAGE_SVG;
+		default -> SWT.IMAGE_UNDEFINED;
+		};
+	}
+
+	public static String getImageFileExtensionFromFormat(int format) {
+		String typeStr = switch (format) {
+		case SWT.IMAGE_BMP_RLE -> "bmp";
+		case SWT.IMAGE_BMP -> "bmp";
+		case SWT.IMAGE_GIF -> "gif";
+		case SWT.IMAGE_ICO -> "ico";
+		case SWT.IMAGE_JPEG -> "jpeg";
+		case SWT.IMAGE_PNG -> "png";
+		case SWT.IMAGE_TIFF -> "tiff";
+		case SWT.IMAGE_SVG -> "svg";
+		default -> "";
+		};
+		return typeStr;
+	}
+
 	public static final int DEFAULT_ZOOM = 100;
 
 	private static Optional<FileFormat> determineFileFormat(LEDataInputStream stream) {

bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/internal/NativeImageLoader.java

@@ -180,16 +180,7 @@ private static int getImageFormat(long loader) {
 		long name = GDK.gdk_pixbuf_format_get_name(format);
 		String nameStr = Converter.cCharPtrToJavaString(name, false);
 		OS.g_free(name);
-		return switch (nameStr) {
-		case "bmp" -> SWT.IMAGE_BMP;
-		case "gif" -> SWT.IMAGE_GIF;
-		case "ico" -> SWT.IMAGE_ICO;
-		case "jpeg" -> SWT.IMAGE_JPEG;
-		case "png" -> SWT.IMAGE_PNG;
-		case "tiff" -> SWT.IMAGE_TIFF;
-		case "svg" -> SWT.IMAGE_SVG;
-		default -> SWT.IMAGE_UNDEFINED;
-		};
+		return FileFormat.getImageFormatFromFileExtension(nameStr);
 	}
 
 	/**
@@ -351,17 +342,7 @@ public static void save(OutputStream stream, int format, ImageLoader imageLoader
 		}
 
 		// Write pixbuf to byte array and then to OutputStream
-		String typeStr = switch (format) {
-		case SWT.IMAGE_BMP_RLE -> "bmp";
-		case SWT.IMAGE_BMP -> "bmp";
-		case SWT.IMAGE_GIF -> "gif";
-		case SWT.IMAGE_ICO -> "ico";
-		case SWT.IMAGE_JPEG -> "jpeg";
-		case SWT.IMAGE_PNG -> "png";
-		case SWT.IMAGE_TIFF -> "tiff";
-		case SWT.IMAGE_SVG -> "svg";
-		default -> "";
-		};
+		String typeStr = FileFormat.getImageFileExtensionFromFormat(format);
 		byte[] type = Converter.wcsToMbcs(typeStr, true);
 
 		long[] buffer = new long[1];