Move experimental monitor-specific scaling preference to IDEApplication

Monitor-specific scaling needs to be activated before the display that
is supposed to run in that mode is created. Doing that in the Workbench,
like it has been done before, is insufficient, as the display has
already been created by then.

This change moves the evaluation of the experimental preference to the
IDEApplication right before the display creation. This limits the effect
to application based on the IDEApplication, which is also added to the
disclaimer for the according preference in the UI.

Author: HeikoKlare

bundles/org.eclipse.ui.ide.application/src/org/eclipse/ui/internal/ide/application/IDEApplication.java

@@ -62,6 +62,7 @@
 import org.eclipse.swt.widgets.Label;
 import org.eclipse.swt.widgets.Shell;
 import org.eclipse.ui.IWorkbench;
+import org.eclipse.ui.IWorkbenchPreferenceConstants;
 import org.eclipse.ui.PlatformUI;
 import org.eclipse.ui.internal.Workbench;
 import org.eclipse.ui.internal.WorkbenchPlugin;
@@ -105,6 +106,8 @@ public class IDEApplication implements IApplication, IExecutableExtension {
 
 	private static final String USER_NAME = "user.name"; //$NON-NLS-1$
 
+	private static final String SWT_RESCALE_AT_RUNTIME_PROPERTY = "swt.autoScale.updateOnRuntime"; //$NON-NLS-1$
+
 	// Use the branding plug-in of the platform feature since this is most likely
 	// to change on an update of the IDE.
 	private static final String WORKSPACE_CHECK_REFERENCE_BUNDLE_NAME = "org.eclipse.platform"; //$NON-NLS-1$
@@ -205,9 +208,22 @@ public Object start(IApplicationContext appContext) throws Exception {
 	 * @return the display used by the application
 	 */
 	protected Display createDisplay() {
+		setRescaleAtRuntimePropertyFromPreference();
 		return PlatformUI.createDisplay();
 	}
 
+	private static void setRescaleAtRuntimePropertyFromPreference() {
+		if (System.getProperty(SWT_RESCALE_AT_RUNTIME_PROPERTY) != null) {
+			WorkbenchPlugin.log(Status.warning(SWT_RESCALE_AT_RUNTIME_PROPERTY
+					+ " is configured (e.g., via the INI), but the according preference should be preferred instead." //$NON-NLS-1$
+			));
+		} else {
+			boolean rescaleAtRuntime = WorkbenchPlugin.getDefault().getPreferenceStore()
+					.getBoolean(IWorkbenchPreferenceConstants.RESCALING_AT_RUNTIME);
+			System.setProperty(SWT_RESCALE_AT_RUNTIME_PROPERTY, Boolean.toString(rescaleAtRuntime));
+		}
+	}
+
 	@Override
 	public void setInitializationData(IConfigurationElement config,
 			String propertyName, Object data) {

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

@@ -298,8 +298,6 @@ public final class Workbench extends EventManager implements IWorkbench, org.ecl
 
 	private static final String EDGE_USER_DATA_FOLDER = "org.eclipse.swt.internal.win32.Edge.userDataFolder"; //$NON-NLS-1$
 
-	private static final String SWT_RESCALE_AT_RUNTIME_PROPERTY = "swt.autoScale.updateOnRuntime"; //$NON-NLS-1$
-
 	private static final class StartupProgressBundleListener implements ServiceListener {
 
 		private final SubMonitor subMonitor;
@@ -588,7 +586,6 @@ public static int createAndRunWorkbench(final Display display, final WorkbenchAd
 				int orientation = store.getInt(IPreferenceConstants.LAYOUT_DIRECTION);
 				Window.setDefaultOrientation(orientation);
 			}
-			setRescaleAtRuntimePropertyFromPreference();
 			if (obj instanceof E4Application) {
 				E4Application e4app = (E4Application) obj;
 				E4Workbench e4Workbench = e4app.createE4Workbench(getApplicationContext(), display);
@@ -682,18 +679,6 @@ public void update() {
 		return returnCode[0];
 	}
 
-	private static void setRescaleAtRuntimePropertyFromPreference() {
-		if (System.getProperty(SWT_RESCALE_AT_RUNTIME_PROPERTY) != null) {
-			WorkbenchPlugin.log(StatusUtil.newStatus(IStatus.WARNING, SWT_RESCALE_AT_RUNTIME_PROPERTY
-					+ " is configured (e.g., via the INI), but the according preference should be preferred instead.", //$NON-NLS-1$
-					new RuntimeException()));
-		} else {
-			boolean rescaleAtRuntime = PrefUtil.getAPIPreferenceStore()
-					.getBoolean(IWorkbenchPreferenceConstants.RESCALING_AT_RUNTIME);
-			System.setProperty(SWT_RESCALE_AT_RUNTIME_PROPERTY, Boolean.toString(rescaleAtRuntime));
-		}
-	}
-
 	private static void setSearchContribution(MApplication app, boolean enabled) {
 		for (MTrimContribution contribution : app.getTrimContributions()) {
 			if ("org.eclipse.ui.ide.application.trimcontribution.QuickAccess".contains(contribution //$NON-NLS-1$

bundles/org.eclipse.ui.workbench/eclipseui/org/eclipse/ui/internal/dialogs/ViewsPreferencePage.java

@@ -218,7 +218,7 @@ private void createHiDPISettingsGroup(Composite parent) {
 		infoLabel.setLayoutData(GridDataFactory.defaultsFor(infoLabel).create());
 		createLabel(group, ""); //$NON-NLS-1$
 
-		boolean initialStateRescaleAtRuntime = PrefUtil.getAPIPreferenceStore()
+		boolean initialStateRescaleAtRuntime = WorkbenchPlugin.getDefault().getPreferenceStore()
 				.getBoolean(IWorkbenchPreferenceConstants.RESCALING_AT_RUNTIME);
 		rescaleAtRuntime = createCheckButton(group, WorkbenchMessages.RescaleAtRuntimeEnabled, initialStateRescaleAtRuntime);
 	}
@@ -373,10 +373,12 @@ public boolean performOk() {
 
 		boolean isRescaleAtRuntimeChanged = false;
 		if (rescaleAtRuntime != null) {
-			boolean initialStateRescaleAtRuntime = PrefUtil.getAPIPreferenceStore()
+			IPreferenceStore workbenchStore = WorkbenchPlugin.getDefault().getPreferenceStore();
+			boolean initialStateRescaleAtRuntime = workbenchStore
 					.getBoolean(IWorkbenchPreferenceConstants.RESCALING_AT_RUNTIME);
 			isRescaleAtRuntimeChanged = initialStateRescaleAtRuntime != rescaleAtRuntime.getSelection();
-			apiStore.setValue(IWorkbenchPreferenceConstants.RESCALING_AT_RUNTIME, rescaleAtRuntime.getSelection());
+			workbenchStore.setValue(IWorkbenchPreferenceConstants.RESCALING_AT_RUNTIME,
+					rescaleAtRuntime.getSelection());
 		}
 
 		prefs.putBoolean(CTabRendering.USE_ROUND_TABS, useRoundTabs.getSelection());

bundles/org.eclipse.ui.workbench/eclipseui/org/eclipse/ui/internal/messages.properties

@@ -504,7 +504,7 @@ RescaleAtRuntimeSettingChangeWarningTitle = DPI Setting Changed
 RescaleAtRuntimeSettingChangeWarningText = Restart for the DPI setting changes to take effect
 HiDpiSettingsGroupTitle = HiDPI settings
 RescaleAtRuntimeEnabled = Monitor-specific UI &scaling
-RescaleAtRuntimeDisclaimer = EXPERIMENTAL! Activating this option will dynamically scale all windows according to the monitor they are currently in. It will also set the default browser to Edge in order to provide the appropriate scaling of content displayed in a browser. This feature is still in development and therefore considered experimental.
+RescaleAtRuntimeDisclaimer = EXPERIMENTAL! Activating this option will dynamically scale all windows according to the monitor they are currently in. This feature will currently only have an effect when running an IDEApplication. It is still in development and therefore considered experimental.
 # --- Workbench -----
 WorkbenchPreference_openMode=Open mode
 WorkbenchPreference_doubleClick=D&ouble click