Limit autoscale mode to quarter and exact only

swt applications will be limited to use autoscale modes quarter and
exact only otherwise user will see an error message stating the
incompatibility. Also the tests testing other autoscale values have been
removed.

Author: ShahzaibIbrahim

bundles/org.eclipse.swt/Eclipse SWT Tests/win32/org/eclipse/swt/widgets/ControlWin32Tests.java

@@ -111,7 +111,7 @@ public void testCorrectScaleUpUsingDifferentSetBoundsMethod() {
 	}
 
 	@ParameterizedTest
-	@CsvSource({ "0.5, 100, true", "1.0, 200, true", "2.0, 200, true", "2.0, quarter, true", "0.5, 100, false",
+	@CsvSource({ "2.0, quarter, true", "0.5, 100, false",
 			"1.0, 200, false", "2.0, 200, false", "2.0, quarter, false", })
 	public void testAutoScaleImageData(float scaleFactor, String autoScale, boolean monitorSpecificScaling) {
 		Win32DPIUtils.setMonitorSpecificScaling(monitorSpecificScaling);

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

@@ -51,7 +51,13 @@ public static Optional<AutoScaleMethod> forString(String s) {
 
 	private static String autoScaleValue;
 
-	private static final Set<String> ALLOWED_AUTOSCALE_VALUES_FOR_UPDATE_ON_RUNTIME = Set.of("quarter", "exact", "false");
+	private static final Set<String> ALLOWED_AUTOSCALE_VALUES_FOR_UPDATE_ON_RUNTIME = Set.of("quarter", "exact");
+
+	/**
+	 * System property that enforces to use autoScale value despite incompatibility
+	 * For e.g. Monitor-specific scaling with int200 autoscale value
+	 */
+	private static final String SWT_AUTOSCALE_DISABLE_COMPATIBILITY_CHECK = "swt.autoScale.force";
 	/**
 	 * System property to enable to scale the application on runtime
 	 * when a DPI change is detected.
@@ -128,20 +134,20 @@ static void setAutoScaleValue(String autoScaleValueArg) {
  *
  */
 public static boolean isSetupCompatibleToMonitorSpecificScaling() {
-	if (DPIUtil.getAutoScaleValue() == null) {
-		return false;
-	}
+	// Per-monitor DPI supported only on Windows
+    if (!"win32".equals(SWT.getPlatform())) {
+        return false;
+    }
 
-	if(ALLOWED_AUTOSCALE_VALUES_FOR_UPDATE_ON_RUNTIME.contains(DPIUtil.getAutoScaleValue().toLowerCase())) {
-		return true;
-	}
-	try {
-		Integer.parseInt(DPIUtil.getAutoScaleValue());
-		return true;
-	} catch (NumberFormatException e) {
-		// unsupported value, use default
-	}
-	return false;
+    // Default means: treat as "quarter" (compatible)
+    if (autoScaleValue == null || "true".equalsIgnoreCase(System.getProperty(SWT_AUTOSCALE_DISABLE_COMPATIBILITY_CHECK))) {
+        return true;
+    }
+
+    String value = autoScaleValue.toLowerCase(Locale.ROOT);
+
+    // Compatible only if one of the known values
+    return ALLOWED_AUTOSCALE_VALUES_FOR_UPDATE_ON_RUNTIME.contains(value);
 }
 
 public static boolean isMonitorSpecificScalingActive() {