Proper rescaling for win32 splash screen image

This commit adds an ImageDataProvider to properly scale the splash
image, if it is shown in Windows. If the monitor specific scaling is
active, the autoScale mode used when the native launcher calculated the
initial size was calculated, might be different than when the splash
image is refreshed via the Workbench. The ImageDataProvider ensures,
that either the explicitly defined mode or the default mode is used.

Author: akoch-yatta

bundles/org.eclipse.ui.workbench/eclipseui/org/eclipse/ui/internal/Workbench.java

@@ -51,6 +51,7 @@
 import java.util.Objects;
 import java.util.Set;
 import java.util.UUID;
+import java.util.concurrent.atomic.AtomicReference;
 import org.eclipse.core.commands.Command;
 import org.eclipse.core.commands.CommandManager;
 import org.eclipse.core.commands.ExecutionException;
@@ -157,6 +158,7 @@
 import org.eclipse.swt.graphics.Point;
 import org.eclipse.swt.graphics.Rectangle;
 import org.eclipse.swt.graphics.Transform;
+import org.eclipse.swt.internal.DPIUtil;
 import org.eclipse.swt.widgets.Display;
 import org.eclipse.swt.widgets.Listener;
 import org.eclipse.swt.widgets.Monitor;
@@ -315,7 +317,8 @@ private static final class StartupProgressBundleListener implements ServiceListe
 		@Override
 		public void serviceChanged(ServiceEvent event) {
 			subMonitor.setWorkRemaining(5).worked(1);
-			spinEventQueueToUpdateSplash(displayForStartupListener);
+			AUTOSCALE_ADAPTATION
+					.runWithInitialAutoScaleValue(() -> spinEventQueueToUpdateSplash(displayForStartupListener));
 		}
 	}
 
@@ -351,6 +354,11 @@ public void serviceChanged(ServiceEvent event) {
 	 */
 	private static AbstractSplashHandler splash;
 
+	/**
+	 * Helper to adapt auto-scaling for the splash screen
+	 */
+	private static final AutoscaleAdaptation AUTOSCALE_ADAPTATION = new AutoscaleAdaptation();
+
 	/**
 	 * The display used for all UI interactions with this workbench.
 	 *
@@ -627,9 +635,9 @@ public void update() {
 						properties);
 
 				// listener for updating the splash screen
-				ServiceListener serviceListener = null;
+				AtomicReference<ServiceListener> serviceListener = new AtomicReference<>();
 				createSplash = WorkbenchPlugin.isSplashHandleSpecified();
-				if (createSplash) {
+				Runnable splashCreation = () -> {
 
 					// prime the splash nice and early
 					workbench.createSplashWrapper();
@@ -649,10 +657,13 @@ public void update() {
 
 					if (handler != null && showProgress) {
 						IProgressMonitor progressMonitor = SubMonitor.convert(handler.getBundleProgressMonitor());
-						serviceListener = new Workbench.StartupProgressBundleListener(progressMonitor, display);
-						WorkbenchPlugin.getDefault().getBundleContext().addServiceListener(serviceListener);
+						serviceListener.set(new Workbench.StartupProgressBundleListener(progressMonitor, display));
+						WorkbenchPlugin.getDefault().getBundleContext().addServiceListener(serviceListener.get());
 					}
+				};
 
+				if (createSplash) {
+					AUTOSCALE_ADAPTATION.runWithInitialAutoScaleValue(splashCreation);
 				}
 
 				setSearchContribution(appModel, true);
@@ -661,8 +672,8 @@ public void update() {
 
 				if (returnCode[0] == PlatformUI.RETURN_OK) {
 					// run the e4 event loop and instantiate ... well, stuff
-					if (serviceListener != null) {
-						WorkbenchPlugin.getDefault().getBundleContext().removeServiceListener(serviceListener);
+					if (serviceListener.get() != null) {
+						WorkbenchPlugin.getDefault().getBundleContext().removeServiceListener(serviceListener.get());
 					}
 					e4Workbench.createAndRunUI(e4Workbench.getApplication());
 				}
@@ -3649,4 +3660,19 @@ public String getId() {
 	protected String createId() {
 		return UUID.randomUUID().toString();
 	}
+
+	private static class AutoscaleAdaptation {
+		private static final String SWT_AUTOSCALE = "swt.autoScale"; //$NON-NLS-1$
+
+		private final String initialAutoScaleValue;
+
+		public AutoscaleAdaptation() {
+			initialAutoScaleValue = System.getProperty(SWT_AUTOSCALE);
+		}
+
+		public void runWithInitialAutoScaleValue(Runnable runnable) {
+			DPIUtil.runWithAutoScaleValue(initialAutoScaleValue, runnable);
+		}
+
+	}
 }