From 5626775b8fd92383e05d48550be4481dd366d3fe Mon Sep 17 00:00:00 2001
From: Sebastian Ratz <sebastian.ratz@sap.com>
Date: Thu, 20 Aug 2026 13:58:24 +0200
Subject: [PATCH] [Win32] Use primary monitor zoom in Display.getBounds()
 scaling

Display.getBounds() must not be affected by
"zoom-of-the-last-moved-shell", which currently DPIUtil.getDeviceZoom()
represents on Windows.

Instead, Display.getBounds() should be consistent with the way a GC for
the display is created: via Display.getDeviceZoom(), which in turn uses
the zoom of the primary monitor.

The same applies to Display.getClientArea() as well.

Fixes #3530.
---
 .../eclipse/swt/widgets/DisplayWin32Test.java | 23 +++++++++++++++++--
 .../org/eclipse/swt/widgets/Display.java      |  4 ++--
 2 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/bundles/org.eclipse.swt/Eclipse SWT Tests/win32/org/eclipse/swt/widgets/DisplayWin32Test.java b/bundles/org.eclipse.swt/Eclipse SWT Tests/win32/org/eclipse/swt/widgets/DisplayWin32Test.java
index 3d380ef1469..96dcd965168 100644
--- a/bundles/org.eclipse.swt/Eclipse SWT Tests/win32/org/eclipse/swt/widgets/DisplayWin32Test.java	
+++ b/bundles/org.eclipse.swt/Eclipse SWT Tests/win32/org/eclipse/swt/widgets/DisplayWin32Test.java	
@@ -1,9 +1,9 @@
 package org.eclipse.swt.widgets;
 
 import static org.eclipse.swt.internal.DPIUtil.setMonitorSpecificScaling;
-import static org.junit.jupiter.api.Assertions.assertFalse;
-import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.junit.jupiter.api.Assertions.*;
 
+import org.eclipse.swt.graphics.*;
 import org.eclipse.swt.internal.*;
 import org.eclipse.swt.internal.win32.*;
 import org.junit.jupiter.api.*;
@@ -104,4 +104,23 @@ public void setRescaleAtRuntime_toggling() {
 		assertExpectedDpiAwareness(OS.DPI_AWARENESS_CONTEXT_SYSTEM_AWARE);
 	}
 
+	// https://github.com/eclipse-platform/eclipse.platform.swt/issues/3530
+	@Test
+	public void getBoundsAndGetClientAreaUseZoomOfPrimaryMonitor_MatchingGCZoom() throws Exception {
+		Display display = Display.getDefault();
+
+		DPIUtil.setDeviceZoom(200); // must not be considered
+		Rectangle bounds1 = display.getBounds();
+		Rectangle clientArea1 = display.getClientArea();
+		DPIUtil.setDeviceZoom(100); // must not be considered
+		Rectangle bounds2 = display.getBounds();
+		Rectangle clientArea2 = display.getClientArea();
+
+		assertEquals(bounds2.width, bounds1.width);
+		assertEquals(clientArea2.width, clientArea1.width);
+
+		GC gc = new GC(display);
+		assertEquals(display.getPrimaryMonitor().getZoom(), gc.getGCData().nativeZoom);
+	}
+
 }
diff --git a/bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/widgets/Display.java b/bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/widgets/Display.java
index bf07037f1fc..25a8366ca1c 100644
--- a/bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/widgets/Display.java	
+++ b/bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/widgets/Display.java	
@@ -1592,7 +1592,7 @@ public Menu getMenuBar () {
 @Override
 public Rectangle getBounds() {
 	checkDevice ();
-	return Win32DPIUtils.pixelToPoint(getBoundsInPixels(), DPIUtil.getDeviceZoom());
+	return Win32DPIUtils.pixelToPoint(getBoundsInPixels(), getDeviceZoom());
 }
 
 Rectangle getBoundsInPixels () {
@@ -1665,7 +1665,7 @@ int getClickCount (int type, int button, long hwnd, long lParam) {
 @Override
 public Rectangle getClientArea () {
 	checkDevice ();
-	return Win32DPIUtils.pixelToPoint(getClientAreaInPixels(), DPIUtil.getDeviceZoom());
+	return Win32DPIUtils.pixelToPoint(getClientAreaInPixels(), getDeviceZoom());
 }
 
 Rectangle getClientAreaInPixels () {