Rework new Image constructors accepting a ImageGcDrawer

binaries/org.eclipse.swt.win32.win32.x86_64/.settings/.api_filters

@@ -582,10 +582,11 @@
         </filter>
     </resource>
     <resource path="Eclipse SWT/common/org/eclipse/swt/graphics/ImageGcDrawer.java" type="org.eclipse.swt.graphics.ImageGcDrawer">
-        <filter id="404000815">
+        <filter id="403984517">
             <message_arguments>
                 <message_argument value="org.eclipse.swt.graphics.ImageGcDrawer"/>
-                <message_argument value="getGcStyle()"/>
+                <message_argument value="org.eclipse.swt.graphics.ImageDrawer"/>
+                <message_argument value="withGCStyle(int, ImageDrawer)"/>
             </message_arguments>
         </filter>
     </resource>

bundles/org.eclipse.swt/Eclipse SWT Custom Widgets/common/org/eclipse/swt/custom/CTabFolder.java

@@ -734,16 +734,15 @@ Image createButtonImage(Display display, int button) {
 	final Rectangle trim = renderer.computeTrim(button, SWT.NONE, 0, 0, 0, 0);
 	final Point imageSize = new Point(size.x - trim.width, size.y - trim.height);
 	Color transColor = renderer.parent.getBackground();
-	final ImageGcDrawer imageGcDrawer = new TransparencyColorImageGcDrawer(transColor) {
+	return new Image(display, imageSize.x, imageSize.y, new TransparencyColorImageGcDrawer(transColor) {
 		@Override
 		public void drawOn(GC gc, int imageWidth, int imageHeight) {
 			Rectangle imageBounds = new Rectangle(0, 0, imageWidth, imageHeight);
 			gc.setBackground(transColor);
 			gc.fillRectangle(imageBounds);
 			renderer.draw(button, SWT.NONE, imageBounds, gc);
 		}
-	};
-	return new Image(display, imageGcDrawer, imageSize.x, imageSize.y);
+	});
 }
 
 private void notifyItemCountChange() {
@@ -4007,7 +4006,8 @@ void updateBkImages(boolean colorChanged) {
 						if (colorChanged || !bounds.equals(bkImageBounds[i])) {
 							bkImageBounds[i] = bounds;
 							if (controlBkImages[i] != null) controlBkImages[i].dispose();
-							controlBkImages[i] = new Image(control.getDisplay(), (gc, imageWidth, imageHeight) -> renderer.draw(CTabFolderRenderer.PART_BACKGROUND, 0, bounds, gc), bounds.width, bounds.height);
+							controlBkImages[i] = new Image(control.getDisplay(), bounds.width, bounds.height,
+									(gc, w, h) -> renderer.draw(CTabFolderRenderer.PART_BACKGROUND, 0, bounds, gc));
 							control.setBackground(null);
 							control.setBackgroundImage(controlBkImages[i]);
 						}

bundles/org.eclipse.swt/Eclipse SWT Custom Widgets/common/org/eclipse/swt/custom/StyledText.java

@@ -1593,32 +1593,31 @@ void createCaretBitmaps() {
 		leftCaretBitmap.dispose();
 	}
 	int lineHeight = renderer.getLineHeight();
-	final ImageGcDrawer leftCaretDrawer = (gc, width, height) -> {
+	leftCaretBitmap = new Image(display, caretWidth, lineHeight, (gc, width, height) -> {
 		gc.setBackground(display.getSystemColor(SWT.COLOR_BLACK));
 		gc.fillRectangle(0, 0, width, height);
 		gc.setForeground(display.getSystemColor(SWT.COLOR_WHITE));
 		gc.drawLine(0,0,0,height);
 		gc.drawLine(0,0,width-1,0);
 		gc.drawLine(0,1,1,1);
-	};
-	leftCaretBitmap = new Image(display, leftCaretDrawer, caretWidth, lineHeight);
+	});
 
 	if (rightCaretBitmap != null) {
 		if (defaultCaret != null && rightCaretBitmap.equals(defaultCaret.getImage())) {
 			defaultCaret.setImage(null);
 		}
 		rightCaretBitmap.dispose();
 	}
-	final ImageGcDrawer rightCaretDrawer = (gc, width, height) -> {
+	rightCaretBitmap = new Image(display, caretWidth, lineHeight, (gc, width, height) -> {
 		gc.setBackground(display.getSystemColor(SWT.COLOR_BLACK));
 		gc.fillRectangle(0, 0, width, height);
 		gc.setForeground(display.getSystemColor(SWT.COLOR_WHITE));
 		gc.drawLine(width-1,0,width-1,height);
 		gc.drawLine(0,0,width-1,0);
 		gc.drawLine(width-1,1,1,1);
-	};
-	rightCaretBitmap = new Image(display, rightCaretDrawer, caretWidth, lineHeight);
+	});
 }
+
 /**
  * Moves the selected text to the clipboard.  The text will be put in the
  * clipboard in plain text, HTML, and RTF formats.

bundles/org.eclipse.swt/Eclipse SWT/cocoa/org/eclipse/swt/graphics/Image.java

@@ -142,7 +142,7 @@ public final class Image extends Resource implements Drawable {
 	/**
 	 * ImageGcDrawer to provide a callback to draw on a GC for various zoom levels
 	 */
-	private ImageGcDrawer imageGcDrawer;
+	private ImageDrawer imageGcDrawer;
 
 	/**
 	 * Style flag used to differentiate normal, gray-scale and disabled images based
@@ -878,9 +878,9 @@ public Image(Device device, ImageDataProvider imageDataProvider) {
  *    <li>ERROR_NULL_ARGUMENT - if device is null and there is no current device</li>
  *    <li>ERROR_NULL_ARGUMENT - if the ImageGcDrawer is null</li>
  * </ul>
- * @since 3.129
+ * @since 3.130
  */
-public Image(Device device, ImageGcDrawer imageGcDrawer, int width, int height) {
+public Image(Device device, int width, int height, ImageDrawer imageGcDrawer) {
 	super(device);
 	if (imageGcDrawer == null) SWT.error(SWT.ERROR_NULL_ARGUMENT);
 	this.imageGcDrawer = imageGcDrawer;
@@ -905,13 +905,22 @@ public Image(Device device, ImageGcDrawer imageGcDrawer, int width, int height)
 	}
 }
 
-private ImageData drawWithImageGcDrawer(ImageGcDrawer imageGcDrawer, int width, int height, int zoom) {
+/**
+ * @since 3.129
+ * @deprecated Instead use {@link #Image(Device, int, int, ImageGcDrawer)}
+ */
+@Deprecated(forRemoval = true, since = "2025-06 (removal in 2027-06 or later)")
+public Image(Device device, ImageGcDrawer imageGcDrawer, int width, int height) {
+	this(device, width, height, imageGcDrawer);
+}
+
+private ImageData drawWithImageGcDrawer(ImageDrawer imageGcDrawer, int width, int height, int zoom) {
 	Image image = new Image(device, width, height);
-	GC gc = new GC(image);
+	GC gc = new GC(image, ExtendedImageDrawer.getGCStyle(imageGcDrawer));
 	try {
 		imageGcDrawer.drawOn(gc, width, height);
 		ImageData imageData = image.getImageData(zoom);
-		imageGcDrawer.postProcess(imageData);
+		ExtendedImageDrawer.postProcess(imageGcDrawer, imageData);
 		return imageData;
 	} finally {
 		gc.dispose();

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

@@ -0,0 +1,66 @@
+/*******************************************************************************
+ * Copyright (c) 2025 Yatta 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:
+ *     Yatta - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.swt.graphics;
+
+import java.util.function.*;
+
+import org.eclipse.swt.*;
+import org.eclipse.swt.internal.image.*;
+
+/**
+ * Interface to provide a callback mechanism to draw on different GC instances
+ * depending on the zoom the image will be used for. A common use case is when
+ * the application is moved from a low DPI monitor to a high DPI monitor. This
+ * provides API which will be called by SWT during the image rendering.
+ *
+ * This interface needs to be implemented by client code to provide logic that
+ * draws on the empty GC on demand.
+ *
+ * @since 3.130
+ */
+@FunctionalInterface
+public interface ImageDrawer {
+
+	/**
+	 * Draws an image on a GC for a requested zoom level.
+	 *
+	 * @param gc          The GC will draw on the underlying Image and is configured
+	 *                    for the targeted zoom
+	 * @param imageWidth  The width of the image in points to draw on
+	 * @param imageHeight The height of the image in points to draw on
+	 */
+	void drawOn(GC gc, int imageWidth, int imageHeight);
+
+	/**
+	 * @since 3.130
+	 */
+	public static ImageDrawer withGCStyle(int style, ImageDrawer drawer) {
+		if (drawer instanceof  ExtendedImageDrawer extendedDrawer) {
+			return new ExtendedImageDrawer(extendedDrawer.original(), extendedDrawer.postProcessor(), style);
+		}
+		return new ExtendedImageDrawer(drawer, null, style);
+	}
+
+	/**
+	 * @since 3.130
+	 */
+	public static ImageDrawer create(ImageDrawer drawer, Consumer<ImageData> postProcessor) {
+		if (drawer instanceof ExtendedImageDrawer extendedDrawer) {
+			return new ExtendedImageDrawer(extendedDrawer.original(), postProcessor, extendedDrawer.style());
+		}
+		return new ExtendedImageDrawer(drawer, postProcessor, SWT.NONE);
+	}
+
+	// TODO: or use some kind of builder pattern?
+}

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

@@ -13,8 +13,6 @@
  *******************************************************************************/
 package org.eclipse.swt.graphics;
 
-import org.eclipse.swt.*;
-
 /**
  * Interface to provide a callback mechanism to draw on different GC instances
  * depending on the zoom the image will be used for. A common use case is when
@@ -26,7 +24,8 @@
  *
  * @since 3.129
  */
-public interface ImageGcDrawer {
+@Deprecated(forRemoval = true, since = "2025-06 (removal in 2027-06 or later)")
+public interface ImageGcDrawer extends ImageDrawer {
 
 	/**
 	 * Draws an image on a GC for a requested zoom level.
@@ -36,6 +35,7 @@ public interface ImageGcDrawer {
 	 * @param imageWidth  The width of the image in points to draw on
 	 * @param imageHeight The height of the image in points to draw on
 	 */
+	@Override
 	void drawOn(GC gc, int imageWidth, int imageHeight);
 
 	/**
@@ -47,15 +47,4 @@ public interface ImageGcDrawer {
 	default void postProcess(ImageData imageData) {
 	}
 
-	/**
-	 * Returns the GC style used when creating the GC instance. Default
-	 * implementation returns <code>SWT.NONE</code>.
-	 *
-	 * @return the GC style constant
-	 *
-	 * @since 3.130
-	 */
-	default int getGcStyle() {
-		return SWT.NONE;
-	}
 }

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

@@ -0,0 +1,53 @@
+/*******************************************************************************
+ * Copyright (c) 2025 Hannes Wellmann 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:
+ *     Hannes Wellmann - initial API and implementation
+ *******************************************************************************/
+
+package org.eclipse.swt.internal.image;
+
+import java.util.*;
+import java.util.function.*;
+
+import org.eclipse.swt.*;
+import org.eclipse.swt.graphics.*;
+
+public record ExtendedImageDrawer(ImageDrawer original, Consumer<ImageData> postProcessor, int style)
+		implements ImageDrawer {
+
+	public ExtendedImageDrawer {
+		Objects.requireNonNull(original);
+	}
+
+	@Override
+	public void drawOn(GC gc, int imageWidth, int imageHeight) {
+		original.drawOn(gc, imageWidth, imageHeight);
+	}
+
+	public static int getGCStyle(ImageDrawer drawer) {
+		if (drawer instanceof ExtendedImageDrawer extendedDrawer) {
+			return extendedDrawer.style();
+		}
+		return SWT.NONE;
+	}
+
+	public static void postProcess(ImageDrawer drawer, ImageData data) {
+		if (drawer instanceof @SuppressWarnings("removal") ImageGcDrawer gcDrawer) {
+			gcDrawer.postProcess(data);
+		} else if (drawer instanceof ExtendedImageDrawer extendedDrawer) {
+			Consumer<ImageData> postProcessor2 = extendedDrawer.postProcessor();
+			if (postProcessor2 != null) {
+				postProcessor2.accept(data);
+			}
+		}
+	}
+
+}

bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/graphics/Image.java

@@ -156,7 +156,7 @@ public final class Image extends Resource implements Drawable {
 	/**
 	 * ImageGcDrawer to provide a callback to draw on a GC for various zoom levels
 	 */
-	private ImageGcDrawer imageGcDrawer;
+	private ImageDrawer imageGcDrawer;
 
 	/**
 	 * Style flag used to differentiate normal, gray-scale and disabled images based
@@ -670,9 +670,9 @@ public Image(Device device, ImageDataProvider imageDataProvider) {
  *    <li>ERROR_NULL_ARGUMENT - if device is null and there is no current device</li>
  *    <li>ERROR_NULL_ARGUMENT - if the ImageGcDrawer is null</li>
  * </ul>
- * @since 3.129
+ * @since 3.130
  */
-public Image(Device device, ImageGcDrawer imageGcDrawer, int width, int height) {
+public Image(Device device, int width, int height, ImageDrawer imageGcDrawer) {
 	super(device);
 	if (imageGcDrawer == null) {
 		SWT.error(SWT.ERROR_NULL_ARGUMENT);
@@ -684,6 +684,15 @@ public Image(Device device, ImageGcDrawer imageGcDrawer, int width, int height)
 	init ();
 }
 
+/**
+ * @since 3.129
+ * @deprecated Instead use {@link #Image(Device, int, int, ImageGcDrawer)}
+ */
+@Deprecated(forRemoval = true, since = "2025-06 (removal in 2027-06 or later)")
+public Image(Device device, ImageGcDrawer imageGcDrawer, int width, int height) {
+	this(device, width, height, imageGcDrawer);
+}
+
 /**
  * Refreshes the image for the current device scale factor.
  * <p>
@@ -1159,11 +1168,11 @@ public ImageData getImageData (int zoom) {
 
 private ImageData drawWithImageGcDrawer(int width, int height, int zoom) {
 	Image image = new Image(device, width, height);
-	GC gc = new GC(image);
+	GC gc = new GC(image, ExtendedImageDrawer.getGCStyle(imageGcDrawer));
 	try {
 		imageGcDrawer.drawOn(gc, width, height);
 		ImageData imageData = image.getImageData(zoom);
-		imageGcDrawer.postProcess(imageData);
+		ExtendedImageDrawer.postProcess(imageGcDrawer, imageData);
 		return imageData;
 	} finally {
 		gc.dispose();