Refactoring DPIUtils

bundles/org.eclipse.swt/Eclipse SWT AWT/win32/org/eclipse/swt/awt/SWT_AWT.java

@@ -286,15 +286,14 @@ public static Shell new_Shell (final Display display, final Canvas parent) {
 		SWT.error (SWT.ERROR_NOT_IMPLEMENTED, e);
 	}
 	if (handle == 0) SWT.error (SWT.ERROR_INVALID_ARGUMENT, null, " [peer not created]");
-
 	final Shell shell = Shell.win32_new (display, handle);
 	final ComponentListener listener = new ComponentAdapter () {
 		@Override
 		public void componentResized (ComponentEvent e) {
 			display.syncExec (() -> {
 				if (shell.isDisposed()) return;
 				Dimension dim = parent.getSize ();
-				shell.setSize(DPIUtil.autoScaleDown(new Point(dim.width, dim.height))); // To Points
+				shell.setSize(DPIUtil.scaleDown(new Point(dim.width, dim.height), DPIUtil.getDeviceZoom())); // To Points
 			});
 		}
 	};

bundles/org.eclipse.swt/Eclipse SWT Browser/win32/org/eclipse/swt/browser/IE.java

@@ -1880,7 +1880,7 @@ void handleDOMEvent (OleEvent e) {
 	int screenY = pVarResult.getInt();
 	pVarResult.dispose();
 
-	Point position = DPIUtil.autoScaleDown(new Point(screenX, screenY)); // To Points
+	Point position = DPIUtil.scaleDown(new Point(screenX, screenY), DPIUtil.getDeviceZoom()); // To Points
 	position = browser.getDisplay().map(null, browser, position);
 	newEvent.x = position.x; newEvent.y = position.y;
 

bundles/org.eclipse.swt/Eclipse SWT Browser/win32/org/eclipse/swt/browser/WebSite.java

@@ -320,8 +320,8 @@ int ShowContextMenu(int dwID, long ppt, long pcmdtReserved, long pdispReserved)
 	Event event = new Event();
 	POINT pt = new POINT();
 	OS.MoveMemory(pt, ppt, POINT.sizeof);
-	pt.x = DPIUtil.autoScaleDown(pt.x); // To Points
-	pt.y = DPIUtil.autoScaleDown(pt.y); // To Points
+	pt.x = DPIUtil.scaleDown(pt.x, DPIUtil.getDeviceZoom()); // To Points
+	pt.y = DPIUtil.scaleDown(pt.y, DPIUtil.getDeviceZoom()); // To Points
 	event.x = pt.x;
 	event.y = pt.y;
 	browser.notifyListeners(SWT.MenuDetect, event);

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

@@ -1822,11 +1822,11 @@ public String toString () {
  * @noreference This method is not intended to be referenced by clients.
  */
 public static void drawScaled(GC gc, Image original, int width, int height, float scaleFactor) {
-	gc.drawImage (original, 0, 0, DPIUtil.autoScaleDown (width), DPIUtil.autoScaleDown (height),
+	gc.drawImage (original, 0, 0, CocoaDPIUtil.autoScaleDown (width), CocoaDPIUtil.autoScaleDown (height),
 			/* E.g. destWidth here is effectively DPIUtil.autoScaleDown (scaledWidth), but avoiding rounding errors.
 			 * Nevertheless, we still have some rounding errors due to the point-based API GC#drawImage(..).
 			 */
-			0, 0, Math.round (DPIUtil.autoScaleDown (width * scaleFactor)), Math.round (DPIUtil.autoScaleDown (height * scaleFactor)));
+			0, 0, Math.round (CocoaDPIUtil.autoScaleDown (width * scaleFactor)), Math.round (CocoaDPIUtil.autoScaleDown (height * scaleFactor)));
 }
 
 }

bundles/org.eclipse.swt/Eclipse SWT/cocoa/org/eclipse/swt/internal/CocoaDPIUtil.java

@@ -0,0 +1,48 @@
+/*******************************************************************************
+ * Copyright (c) 2022 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
+ *     Daniel Kruegler - #420 - [High DPI] "swt.autoScale" should add new "half" option
+ *     Yatta Solutions - #131 - Additional methods to specify target zoom directly
+ *******************************************************************************/
+package org.eclipse.swt.internal;
+
+/**
+ * This class hold common constants and utility functions w.r.t. to SWT high DPI
+ * functionality.
+ * <p>
+ * The {@code autoScaleUp(..)} methods convert from API coordinates (in SWT
+ * points) to internal high DPI coordinates (in pixels) that interface with
+ * native widgets.
+ * </p>
+ * <p>
+ * The {@code autoScaleDown(..)} convert from high DPI pixels to API coordinates
+ * (in SWT points).
+ * </p>
+ *
+ * @since 3.105
+ */
+public class CocoaDPIUtil {
+
+	/**
+	 * Auto-scale down int dimensions.
+	 */
+	public static int autoScaleDown(int size) {
+		return DPIUtil.scaleDown(size, DPIUtil.deviceZoom);
+	}
+
+	/**
+	 * Auto-scale down float dimensions.
+	 */
+	public static float autoScaleDown(float size) {
+		return DPIUtil.scaleDown(size, DPIUtil.deviceZoom);
+	}
+}

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

@@ -2613,31 +2613,31 @@ static void buildDitheredGradientChannel(int from, int to, int steps,
 static void fillGradientRectangle(GC gc, Device device,
 	int x, int y, int width, int height, boolean vertical,
 	RGB fromRGB, RGB toRGB,
-	int redBits, int greenBits, int blueBits) {
+	int redBits, int greenBits, int blueBits, int zoom) {
 	/* Create the bitmap and tile it */
 	ImageData band = createGradientBand(width, height, vertical,
 		fromRGB, toRGB, redBits, greenBits, blueBits);
 	Image image = new Image(device, band);
 	if ((band.width == 1) || (band.height == 1)) {
-			gc.drawImage(image, 0, 0, DPIUtil.autoScaleDown(band.width), DPIUtil.autoScaleDown(band.height),
-					DPIUtil.autoScaleDown(x), DPIUtil.autoScaleDown(y), DPIUtil.autoScaleDown(width),
-					DPIUtil.autoScaleDown(height));
+			gc.drawImage(image, 0, 0, DPIUtil.scaleDown(band.width, zoom), DPIUtil.scaleDown(band.height, zoom),
+					DPIUtil.scaleDown(x, zoom), DPIUtil.scaleDown(y, zoom), DPIUtil.scaleDown(width, zoom),
+					DPIUtil.scaleDown(height, zoom));
 		} else {
 		if (vertical) {
 			for (int dx = 0; dx < width; dx += band.width) {
 				int blitWidth = width - dx;
 				if (blitWidth > band.width) blitWidth = band.width;
-					gc.drawImage(image, 0, 0, DPIUtil.autoScaleDown(blitWidth), DPIUtil.autoScaleDown(band.height),
-							DPIUtil.autoScaleDown(dx + x), DPIUtil.autoScaleDown(y), DPIUtil.autoScaleDown(blitWidth),
-							DPIUtil.autoScaleDown(band.height));
+					gc.drawImage(image, 0, 0, DPIUtil.scaleDown(blitWidth, zoom), DPIUtil.scaleDown(band.height, zoom),
+							DPIUtil.scaleDown(dx + x, zoom), DPIUtil.scaleDown(y, zoom), DPIUtil.scaleDown(blitWidth, zoom),
+							DPIUtil.scaleDown(band.height, zoom));
 				}
 		} else {
 			for (int dy = 0; dy < height; dy += band.height) {
 				int blitHeight = height - dy;
 				if (blitHeight > band.height) blitHeight = band.height;
-					gc.drawImage(image, 0, 0, DPIUtil.autoScaleDown(band.width), DPIUtil.autoScaleDown(blitHeight),
-							DPIUtil.autoScaleDown(x), DPIUtil.autoScaleDown(dy + y), DPIUtil.autoScaleDown(band.width),
-							DPIUtil.autoScaleDown(blitHeight));
+					gc.drawImage(image, 0, 0, DPIUtil.scaleDown(band.width, zoom), DPIUtil.scaleDown(blitHeight, zoom),
+							DPIUtil.scaleDown(x, zoom), DPIUtil.scaleDown(dy + y, zoom), DPIUtil.scaleDown(band.width, zoom),
+							DPIUtil.scaleDown(blitHeight, zoom));
 				}
 		}
 	}