Rescaling of widgets on DPI zoom changes for basic controls (win32)

bundles/org.eclipse.swt/Eclipse SWT PI/win32/library/os.c

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2000, 2022 IBM Corporation and others.
+ * Copyright (c) 2000, 2023 IBM Corporation and others.
  *
  * This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License 2.0
@@ -3258,6 +3258,18 @@ JNIEXPORT jint JNICALL OS_NATIVE(GetSystemMetrics)
 }
 #endif
 
+#ifndef NO_GetSystemMetricsForDpi
+JNIEXPORT jint JNICALL OS_NATIVE(GetSystemMetricsForDpi)
+	(JNIEnv *env, jclass that, jint arg0, jint arg1)
+{
+	jint rc = 0;
+	OS_NATIVE_ENTER(env, that, GetSystemMetricsForDpi_FUNC);
+	rc = (jint)GetSystemMetricsForDpi(arg0, arg1);
+	OS_NATIVE_EXIT(env, that, GetSystemMetricsForDpi_FUNC);
+	return rc;
+}
+#endif
+
 #ifndef NO_GetTextColor
 JNIEXPORT jint JNICALL OS_NATIVE(GetTextColor)
 	(JNIEnv *env, jclass that, jlong arg0)
@@ -9128,6 +9140,22 @@ JNIEXPORT jboolean JNICALL OS_NATIVE(SystemParametersInfo__II_3II)
 }
 #endif
 
+#ifndef NO_SystemParametersInfoForDpi
+JNIEXPORT jboolean JNICALL OS_NATIVE(SystemParametersInfoForDpi)
+	(JNIEnv *env, jclass that, jint arg0, jint arg1, jobject arg2, jint arg3, jint arg4)
+{
+	NONCLIENTMETRICS _arg2, *lparg2=NULL;
+	jboolean rc = 0;
+	OS_NATIVE_ENTER(env, that, SystemParametersInfoForDpi_FUNC);
+	if (arg2) if ((lparg2 = getNONCLIENTMETRICSFields(env, arg2, &_arg2)) == NULL) goto fail;
+	rc = (jboolean)SystemParametersInfoForDpi(arg0, arg1, lparg2, arg3, arg4);
+fail:
+	if (arg2 && lparg2) setNONCLIENTMETRICSFields(env, arg2, lparg2);
+	OS_NATIVE_EXIT(env, that, SystemParametersInfoForDpi_FUNC);
+	return rc;
+}
+#endif
+
 #ifndef NO_TBBUTTONINFO_1sizeof
 JNIEXPORT jint JNICALL OS_NATIVE(TBBUTTONINFO_1sizeof)
 	(JNIEnv *env, jclass that)

bundles/org.eclipse.swt/Eclipse SWT PI/win32/library/os_stats.h

@@ -257,6 +257,7 @@ typedef enum {
 	GetSysColorBrush_FUNC,
 	GetSystemMenu_FUNC,
 	GetSystemMetrics_FUNC,
+	GetSystemMetricsForDpi_FUNC,
 	GetTextColor_FUNC,
 	GetTextExtentPoint32_FUNC,
 	GetTextMetrics_FUNC,
@@ -680,6 +681,7 @@ typedef enum {
 	SystemParametersInfo__IILorg_eclipse_swt_internal_win32_NONCLIENTMETRICS_2I_FUNC,
 	SystemParametersInfo__IILorg_eclipse_swt_internal_win32_RECT_2I_FUNC,
 	SystemParametersInfo__II_3II_FUNC,
+	SystemParametersInfoForDpi_FUNC,
 	TBBUTTONINFO_1sizeof_FUNC,
 	TBBUTTON_1sizeof_FUNC,
 	TCHITTESTINFO_1sizeof_FUNC,

bundles/org.eclipse.swt/Eclipse SWT PI/win32/org/eclipse/swt/internal/win32/OS.java

@@ -39,6 +39,7 @@ public class OS extends C {
 	/**
 	 * Values taken from https://en.wikipedia.org/wiki/List_of_Microsoft_Windows_versions
 	 */
+	public static final int WIN32_BUILD_WIN10_1607 = 14393; // "Windows 10 August 2016 Update"
 	public static final int WIN32_BUILD_WIN10_1809 = 17763; // "Windows 10 October 2018 Update"
 	public static final int WIN32_BUILD_WIN10_2004 = 19041; // "Windows 10 May 2020 Update"
 	public static final int WIN32_BUILD_WIN11_21H2 = 22000; // Initial Windows 11 release
@@ -2975,6 +2976,7 @@ public static int HRESULT_FROM_WIN32(int x) {
 /** @param hWnd cast=(HWND) */
 public static final native long GetSystemMenu (long hWnd, boolean bRevert);
 public static final native int GetSystemMetrics (int nIndex);
+public static final native int GetSystemMetricsForDpi (int nIndex, int dpi);
 /** @param hDC cast=(HDC) */
 public static final native int GetTextColor (long hDC);
 /**
@@ -4436,6 +4438,7 @@ public static int HRESULT_FROM_WIN32(int x) {
 public static final native boolean SystemParametersInfo (int uiAction, int uiParam, RECT pvParam, int fWinIni);
 public static final native boolean SystemParametersInfo (int uiAction, int uiParam, NONCLIENTMETRICS pvParam, int fWinIni);
 public static final native boolean SystemParametersInfo (int uiAction, int uiParam, int [] pvParam, int fWinIni);
+public static final native boolean SystemParametersInfoForDpi (int uiAction, int uiParam, NONCLIENTMETRICS pvParam, int fWinIni, int dpi);
 /**
  * @param lpKeyState cast=(PBYTE)
  * @param pwszBuff cast=(LPWSTR)

bundles/org.eclipse.swt/Eclipse SWT/common/org/eclipse/swt/internal/DPIUtil.java

@@ -44,6 +44,7 @@ public class DPIUtil {
 	private static enum AutoScaleMethod { AUTO, NEAREST, SMOOTH }
 	private static AutoScaleMethod autoScaleMethodSetting = AutoScaleMethod.AUTO;
 	private static AutoScaleMethod autoScaleMethod = AutoScaleMethod.NEAREST;
+	private static boolean autoScaleOnRuntime = false;
 
 	private static String autoScaleValue;
 	private static boolean useCairoAutoScale = false;
@@ -84,6 +85,16 @@ private static enum AutoScaleMethod { AUTO, NEAREST, SMOOTH }
 	 * <a href="https://bugs.eclipse.org/493455">bug 493455</a>.
 	 */
 	private static final String SWT_AUTOSCALE_METHOD = "swt.autoScale.method";
+
+	/**
+	 * System property to enable to scale the applicaiton on runtime
+	 * when a DPI change is detected.
+	 * <ul>
+	 * <li>"true": the application is scaled on DPI changes</li>
+	 * <li>"false": the application will remain in its initial scaling</li>
+	 * </ul>
+	 */
+	private static final String SWT_AUTOSCALE_UPDATE_ON_RUNTIME = "swt.autoScale.updateOnRuntime";
 	static {
 		autoScaleValue = System.getProperty (SWT_AUTOSCALE);
 
@@ -95,6 +106,9 @@ private static enum AutoScaleMethod { AUTO, NEAREST, SMOOTH }
 				autoScaleMethod = autoScaleMethodSetting = AutoScaleMethod.SMOOTH;
 			}
 		}
+
+		String updateOnRuntimeValue = System.getProperty (SWT_AUTOSCALE_UPDATE_ON_RUNTIME);
+		autoScaleOnRuntime = Boolean.parseBoolean(updateOnRuntimeValue);
 	}
 
 /**
@@ -227,6 +241,11 @@ public static ImageData autoScaleImageData (Device device, final ImageData image
 	return autoScaleImageData(device, imageData, scaleFactor);
 }
 
+
+public static ImageData autoScaleImageData (Device device, final ElementAtZoom<ImageData> elementAtZoom, int targetZoom) {
+	return autoScaleImageData(device, elementAtZoom.element(), targetZoom, elementAtZoom.zoom());
+}
+
 private static ImageData autoScaleImageData (Device device, final ImageData imageData, float scaleFactor) {
 	// Guards are already implemented in callers: if (deviceZoom == 100 || imageData == null || scaleFactor == 1.0f) return imageData;
 	int width = imageData.width;
@@ -261,7 +280,7 @@ private static ImageData autoScaleImageData (Device device, final ImageData imag
  * Returns a new rectangle as per the scaleFactor.
  */
 public static Rectangle autoScaleBounds (Rectangle rect, int targetZoom, int currentZoom) {
-	if (deviceZoom == 100 || rect == null || targetZoom == currentZoom) return rect;
+	if (rect == null || targetZoom == currentZoom) return rect;
 	float scaleFactor = ((float)targetZoom) / (float)currentZoom;
 	Rectangle returnRect = new Rectangle (0,0,0,0);
 	returnRect.x = Math.round (rect.x * scaleFactor);
@@ -287,6 +306,10 @@ public static ImageData autoScaleUp (Device device, final ImageData imageData) {
 	return autoScaleImageData(device, imageData, 100);
 }
 
+public static ImageData autoScaleUp (Device device, final ElementAtZoom<ImageData> elementAtZoom) {
+	return autoScaleImageData(device, elementAtZoom.element(), elementAtZoom.zoom());
+}
+
 public static int[] autoScaleUp(int[] pointArray) {
 	if (deviceZoom == 100 || pointArray == null) return pointArray;
 	float scaleFactor = getScalingFactor ();
@@ -311,6 +334,14 @@ public static int autoScaleUp (int size) {
 	return Math.round (size * scaleFactor);
 }
 
+/**
+ * Auto-scale up int dimensions to match the given zoom level
+ */
+public static int autoScaleUp (int size, int zoom) {
+	float scaleFactor = getScalingFactor (zoom);
+	return Math.round (size * scaleFactor);
+}
+
 /**
  * Auto-scale up int dimensions using Native DPI
  */
@@ -388,10 +419,18 @@ public static Rectangle autoScaleUp (Drawable drawable, Rectangle rect) {
  * @return float scaling factor
  */
 private static float getScalingFactor () {
+	return getScalingFactor(deviceZoom);
+}
+
+/**
+ * Returns scaling factor from the given device zoom
+ * @return float scaling factor
+ */
+private static float getScalingFactor (int shellDeviceZoom) {
 	if (useCairoAutoScale) {
 		return 1;
 	}
-	return deviceZoom / 100f;
+	return shellDeviceZoom / 100f;
 }
 
 /**
@@ -405,6 +444,17 @@ public static int mapDPIToZoom (int dpi) {
 	return roundedZoom;
 }
 
+/**
+ * Compute the DPI value value based on the zoom.
+ *
+ * @return DPI
+ */
+public static int mapZoomToDPI (int zoom) {
+	double dpi = (double) zoom / 100 * DPI_ZOOM_100;
+	int roundedDpi = (int) Math.round (dpi);
+	return roundedDpi;
+}
+
 /**
  * Represents an element, such as some image data, at a specific zoom level.
  *
@@ -479,6 +529,10 @@ private static <T> ElementAtZoom<T> getElementAtZoom(Function<Integer, T> elemen
 	return null;
 }
 
+public static int getNativeDeviceZoom() {
+	return nativeDeviceZoom;
+}
+
 public static int getDeviceZoom() {
 	return deviceZoom;
 }
@@ -535,6 +589,10 @@ public static int getZoomForAutoscaleProperty (int nativeDeviceZoom) {
 	return zoom;
 }
 
+public static boolean isAutoScaleOnRuntimeActive() {
+	return autoScaleOnRuntime;
+}
+
 /**
  * AutoScale ImageDataProvider.
  */

bundles/org.eclipse.swt/Eclipse SWT/win32/org/eclipse/swt/graphics/Device.java

@@ -264,6 +264,10 @@ int computePixels(float height) {
 }
 
 float computePoints(LOGFONT logFont, long hFont) {
+	return computePoints(logFont, hFont, -1);
+}
+
+float computePoints(LOGFONT logFont, long hFont, int currentFontDPI) {
 	long hDC = internal_new_GC (null);
 	int logPixelsY = OS.GetDeviceCaps(hDC, OS.LOGPIXELSY);
 	int pixels = 0;
@@ -284,7 +288,14 @@ float computePoints(LOGFONT logFont, long hFont) {
 		pixels = -logFont.lfHeight;
 	}
 	internal_dispose_GC (hDC, null);
-	return pixels * 72f / logPixelsY;
+	float adjustedZoomFactor = 1.0f;
+	if (currentFontDPI > 0) {
+		// as Device::computePoints will always return point on the basis of the
+		// primary monitor zoom, a custom zoomFactor must be calculated if the font
+		// is used for a different zoom level
+		adjustedZoomFactor *= (float) logPixelsY / (float) currentFontDPI;
+	}
+	return adjustedZoomFactor * pixels * 72f / logPixelsY;
 }
 
 /**
@@ -905,6 +916,7 @@ protected void release () {
 		fontCollection = 0;
 		Gdip.GdiplusShutdown (gdipToken[0]);
 	}
+	SWTFontProvider.disposeFontRegistry(this);
 	gdipToken = null;
 	scripts = null;
 	logFonts = null;
@@ -946,5 +958,4 @@ void setEnableAutoScaling(boolean value) {
 protected int getDeviceZoom () {
 	return DPIUtil.mapDPIToZoom ( _getDPIx ());
 }
-
 }