Add internal API in SVGrasterizer to rasterize images at given height and width

Adding internal API to SVGRasterizer and simple tests to see if the svgs
are loaded at right sizes by the rasterizer

Author: arunjose696

bundles/org.eclipse.swt.svg/src/org/eclipse/swt/svg/JSVGRasterizer.java

@@ -74,34 +74,47 @@ public ImageData rasterizeSVG(InputStream inputStream, int zoom) {
 		if (zoom < 0) {
 			SWT.error(SWT.ERROR_INVALID_ARGUMENT);
 		}
-		SVGDocument svgDocument = loadSVG(inputStream);
-		if (svgDocument == null) {
-			SWT.error(SWT.ERROR_INVALID_IMAGE);
-		}
+		SVGDocument svgDocument = loadAndValidateSVG(inputStream);
 		BufferedImage rasterizedImage = renderSVG(svgDocument, zoom);
 		return convertToSWTImageData(rasterizedImage);
 	}
 
-	private SVGDocument loadSVG(InputStream inputStream) {
-		return SVG_LOADER.load(inputStream, null, LoaderContext.createDefault());
+	@Override
+	public ImageData rasterizeSVG(InputStream inputStream, int width, int height) {
+		SVGDocument svgDocument = loadAndValidateSVG(inputStream);
+		BufferedImage rasterizedImage = renderSVG(svgDocument, width, height);
+		return convertToSWTImageData(rasterizedImage);
+	}
+	
+	private SVGDocument loadAndValidateSVG(InputStream inputStream) {
+		SVGDocument svgDocument = SVG_LOADER.load(inputStream, null, LoaderContext.createDefault());
+		if (svgDocument == null) {
+			SWT.error(SWT.ERROR_INVALID_IMAGE);
+		}
+		return svgDocument;
 	}
 
 	private BufferedImage renderSVG(SVGDocument svgDocument, int zoom) {
+		FloatSize sourceImageSize = svgDocument.size();
 		float scalingFactor = zoom / 100.0f;
-		BufferedImage image = createImageBase(svgDocument, scalingFactor);
-		Graphics2D g = configureRenderingOptions(scalingFactor, image);
+		int targetImageWidth = calculateTargetWidth(scalingFactor, sourceImageSize);
+		int targetImageHeight = calculateTargetHeight(scalingFactor, sourceImageSize);
+		return renderSVG(svgDocument, targetImageWidth, targetImageHeight);
+	}
+	
+	private BufferedImage renderSVG(SVGDocument svgDocument, int width, int height) {
+		if (width <= 0 || height <= 0) {
+			SWT.error(SWT.ERROR_INVALID_ARGUMENT);
+		}
+		BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
+		float widthScalingFactor = width / svgDocument.size().width;
+		float heightScalingFactor = height / svgDocument.size().height;
+		Graphics2D g = configureRenderingOptions(widthScalingFactor, heightScalingFactor, image);
 		svgDocument.render(null, g);
 		g.dispose();
 		return image;
 	}
 
-	private BufferedImage createImageBase(SVGDocument svgDocument, float scalingFactor) {
-		FloatSize sourceImageSize = svgDocument.size();
-		int targetImageWidth = calculateTargetWidth(scalingFactor, sourceImageSize);
-		int targetImageHeight = calculateTargetHeight(scalingFactor, sourceImageSize);
-		return new BufferedImage(targetImageWidth, targetImageHeight, BufferedImage.TYPE_INT_ARGB);
-	}
-
 	private int calculateTargetWidth(float scalingFactor, FloatSize sourceImageSize) {
 		double sourceImageWidth = sourceImageSize.getWidth();
 		return (int) Math.round(sourceImageWidth * scalingFactor);
@@ -112,10 +125,11 @@ private int calculateTargetHeight(float scalingFactor, FloatSize sourceImageSize
 		return (int) Math.round(sourceImageHeight * scalingFactor);
 	}
 
-	private Graphics2D configureRenderingOptions(float scalingFactor, BufferedImage image) {
+	private Graphics2D configureRenderingOptions(float widthScalingFactor, float heightScalingFactor,
+			BufferedImage image) {
 		Graphics2D g = image.createGraphics();
 		g.setRenderingHints(RENDERING_HINTS);
-		g.scale(scalingFactor, scalingFactor);
+		g.scale(widthScalingFactor, heightScalingFactor);
 		return g;
 	}
 

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

@@ -41,4 +41,24 @@ public interface SVGRasterizer {
 	 * </ul>
 	 */
 	public ImageData rasterizeSVG(InputStream stream, int zoom);
+
+	/**
+	 * Rasterizes an SVG image from the provided {@code InputStream} into a raster
+	 * image of the specified width and height.
+	 *
+	 * @param stream the SVG image as an {@link InputStream}.
+	 * @param width  the width of the rasterized image in pixels (must be positive).
+	 * @param height the height of the rasterized image in pixels (must be positive).
+	 * @return the {@link ImageData} for the rasterized image.
+	 *
+	 * @exception SWTException
+	 * <ul>
+	 *    <li>ERROR_INVALID_IMAGE - if the SVG cannot be loaded</li>
+	 * </ul>
+	 * @exception IllegalArgumentException
+	 * <ul>
+	 *    <li>ERROR_INVALID_ARGUMENT - if the width or height is less than zero</li>
+	 * </ul>
+	 */
+	public ImageData rasterizeSVG(InputStream stream, int width, int height);
 }

tests/org.eclipse.swt.tests/JUnit Tests/org/eclipse/swt/tests/junit/JSVGRasterizerTest.java

@@ -68,4 +68,33 @@ void testRasterizeWithZoomWithInvalidSVG() {
 		assertEquals(SWT.ERROR_INVALID_IMAGE, exception.code);
 	}
 
+	@Test
+	void testRasterizeWithTargetSize() {
+		ImageData data = rasterizer.rasterizeSVG(svgStream(svgString), 300, 150);
+		assertEquals(300, data.width);
+		assertEquals(150, data.height);
+	}
+
+	@Test
+	void testRasterizeWithTargetSizeHavingInvalidHeight() {
+		assertThrows(IllegalArgumentException.class, () -> {
+			rasterizer.rasterizeSVG(svgStream(svgString), -1, 150);
+		});
+	}
+
+	@Test
+	void testRasterizeWithTargetSizeHavingInvalidWidth() {
+		assertThrows(IllegalArgumentException.class, () -> {
+			rasterizer.rasterizeSVG(svgStream(svgString), 150, -1);
+		});
+	}
+
+	@Test
+	void testRasterizeWithTargetSizeWithInvalidSVG() {
+		SWTException exception = assertThrows(SWTException.class, () -> {
+			rasterizer.rasterizeSVG(invalidSvg, 150, 150);
+		});
+		assertEquals(SWT.ERROR_INVALID_IMAGE, exception.code);
+	}
+
 }