Detect the desired size from the path or Query parameters.

Currently we have the problem that I want to replace some icons with a
SVG variant. Currently Icons can be organized in folders like
/icons/16x16, /icons/32x32 and so on for high resolution support.
Currently if one want to replace such structure with SVG it is required
to scale down the SVG to 16x16 pixel document size as otherwise they get
rendered at there native size (what usually is much larger).

As it is not really desirable to restrict the size of the SVG design for
technical reasons, JFace now can detect two cases:

1) the SVG is places in a folder with "classic" folder layout the size
is extracted and passed down as a hint for dynamic sizable icons
2) one can additionally add a query parameter, e.g. if I have an icon
like /icons/obj16/search.svg and I have two places where I want to use
it one for a toolbar (16x16) and once for a Wizard Images (usually
128x128) I can use the url
bundle:/example.id/icons/obj16/search.svg?size=16x16 and
bundle:/example.id/icons/obj16/search.svg?size=128x128 to accomplish
this task without the need to even store two SVGs

Author: laeubi

bundles/org.eclipse.jface/src/org/eclipse/jface/resource/URLHintProvider.java

@@ -0,0 +1,50 @@
+/*******************************************************************************
+ * Copyright (c) 2025 Christoph Läubrich 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:
+ *     Christoph Läubrich - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.jface.resource;
+
+import java.net.URL;
+import java.util.function.Supplier;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+import org.eclipse.swt.graphics.Point;
+
+class URLHintProvider implements Supplier<Point> {
+
+	private static final Pattern QUERY_PATTERN = Pattern.compile("&size=(\\d+)x(\\d+)"); //$NON-NLS-1$
+	private static final Pattern PATH_PATTERN = Pattern.compile("/(\\d+)x(\\d+)/"); //$NON-NLS-1$
+
+	private URL url;
+
+	public URLHintProvider(URL url) {
+		this.url = url;
+	}
+
+	@Override
+	public Point get() {
+		String query = url.getQuery();
+		Matcher matcher;
+		if (query != null && !query.isEmpty()) {
+			matcher = QUERY_PATTERN.matcher("&" + query); //$NON-NLS-1$
+		} else {
+			String path = url.getPath();
+			matcher = PATH_PATTERN.matcher(path);
+		}
+		if (matcher.find()) {
+			return new Point(Integer.parseInt(matcher.group(1)), Integer.parseInt(matcher.group(1)));
+		}
+		return null;
+	}
+
+}

bundles/org.eclipse.jface/src/org/eclipse/jface/resource/URLImageDescriptor.java

@@ -25,6 +25,7 @@
 import java.net.MalformedURLException;
 import java.net.URL;
 import java.util.function.Function;
+import java.util.function.Supplier;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
@@ -42,6 +43,7 @@
 import org.eclipse.swt.graphics.ImageDataProvider;
 import org.eclipse.swt.graphics.ImageFileNameProvider;
 import org.eclipse.swt.graphics.ImageLoader;
+import org.eclipse.swt.graphics.Point;
 import org.eclipse.swt.internal.DPIUtil.ElementAtZoom;
 import org.eclipse.swt.internal.NativeImageLoader;
 import org.eclipse.swt.internal.image.FileFormat;
@@ -133,7 +135,7 @@ private static <R> R getZoomedImageSource(URL url, String urlString, int zoom, F
 	private static ImageData getImageData(URL url, int fileZoom, int targetZoom) {
 		try (InputStream in = getStream(url)) {
 			if (in != null) {
-				return loadImageFromStream(new BufferedInputStream(in), fileZoom, targetZoom);
+				return loadImageFromStream(new BufferedInputStream(in), fileZoom, targetZoom, new URLHintProvider(url));
 			}
 		} catch (SWTException e) {
 			if (e.code != SWT.ERROR_INVALID_IMAGE) {
@@ -147,8 +149,10 @@ private static ImageData getImageData(URL url, int fileZoom, int targetZoom) {
 	}
 
 	@SuppressWarnings("restriction")
-	private static ImageData loadImageFromStream(InputStream stream, int fileZoom, int targetZoom) {
-		return NativeImageLoader.load(new ElementAtZoom<>(stream, fileZoom), new ImageLoader(), targetZoom).get(0)
+	private static ImageData loadImageFromStream(InputStream stream, int fileZoom, int targetZoom,
+			Supplier<Point> hintProvider) {
+		return NativeImageLoader
+				.load(new ElementAtZoom<>(stream, fileZoom), new ImageLoader(), targetZoom, hintProvider).get(0)
 				.element();
 	}