Enable Draw2D auto-scaling by default

This renames the "draw2d.disableAutoscale" environment variable
introduced with 1bd2883 to
"draw2d.enableAutoscale". In addition, this property now needs to be
explicitly disabled.

By doing so, we drastically increase the visibility of this feature and
reduce the changes that need to be done by consumer projects.

Author: ptziegler

org.eclipse.draw2d/src/org/eclipse/draw2d/PopUpHelper.java

@@ -77,7 +77,7 @@ protected PopUpHelper(Control c, int shellStyle) {
 	 * @since 2.0
 	 */
 	protected LightweightSystem createLightweightSystem() {
-		return InternalDraw2dUtils.disableAutoscale ? new PopupHelperLightweightSystem() : new LightweightSystem();
+		return InternalDraw2dUtils.isAutoScaleEnabled() ? new PopupHelperLightweightSystem() : new LightweightSystem();
 	}
 
 	/**

org.eclipse.draw2d/src/org/eclipse/draw2d/internal/InternalDraw2dUtils.java

@@ -19,17 +19,20 @@
 
 public class InternalDraw2dUtils {
 	/**
-	 * System property that controls the disablement of any autoScale functionality.
+	 * System property that controls the enabled of the Draw2D autoScale
+	 * functionality (replacing the native SWT autoScale functionality).
+	 * <p>
 	 * Currently it only has effects when executed on Windows.
+	 * </p>
 	 *
 	 * <ul>
-	 * <li><b>false</b>: autoScale functionality is enabled</li>
-	 * <li><b>true</b>: autoScale functionality is disabled<</li>
+	 * <li><b>true</b>: autoScale functionality is enabled</li>
+	 * <li><b>false</b>: autoScale functionality is disabled<</li>
 	 *
 	 * </ul>
-	 * The current default is "false".
+	 * The current default is "true".
 	 */
-	private static final String DRAW2D_DISABLE_AUTOSCALE = "draw2d.disableAutoscale"; //$NON-NLS-1$
+	private static final String DRAW2D_ENABLE_AUTOSCALE = "draw2d.enableAutoscale"; //$NON-NLS-1$
 
 	/**
 	 * Internal flag for fetching the shell zoom
@@ -41,15 +44,15 @@ public class InternalDraw2dUtils {
 	 */
 	private static final String DATA_AUTOSCALE_DISABLED = "AUTOSCALE_DISABLED"; //$NON-NLS-1$
 
-	public static boolean disableAutoscale;
+	private static final boolean enableAutoScale = "win32".equals(SWT.getPlatform()) //$NON-NLS-1$
+			&& Boolean.parseBoolean(System.getProperty(DRAW2D_ENABLE_AUTOSCALE, Boolean.TRUE.toString()));
 
-	static {
-		disableAutoscale = "win32".equals(SWT.getPlatform()) //$NON-NLS-1$
-				&& Boolean.parseBoolean(System.getProperty(DRAW2D_DISABLE_AUTOSCALE));
+	public static boolean isAutoScaleEnabled() {
+		return enableAutoScale;
 	}
 
 	public static void configureForAutoscalingMode(Control control, Consumer<Double> zoomConsumer) {
-		if (control == null || !disableAutoscale) {
+		if (control == null || !isAutoScaleEnabled()) {
 			return;
 		}
 		control.setData(InternalDraw2dUtils.DATA_AUTOSCALE_DISABLED, true);

org.eclipse.gef/src/org/eclipse/gef/ui/parts/AbstractEditPartViewer.java

@@ -486,7 +486,7 @@ protected void hookControl() {
 		if (contextMenu != null) {
 			control.setMenu(contextMenu.createContextMenu(getControl()));
 		}
-		if (InternalDraw2dUtils.disableAutoscale) {
+		if (InternalDraw2dUtils.isAutoScaleEnabled()) {
 			InternalDraw2dUtils.configureForAutoscalingMode(control,
 					scale -> setProperty(InternalGEFPlugin.MONITOR_SCALE_PROPERTY, scale));
 		}

org.eclipse.zest.core/src/org/eclipse/zest/core/widgets/Graph.java

@@ -240,7 +240,7 @@ public void dispatchMouseMoved(org.eclipse.swt.events.MouseEvent me) {
 		this.zoomListener = new ZoomGestureListener();
 		this.rotateListener = new RotateGestureListener();
 
-		if (InternalDraw2dUtils.disableAutoscale) {
+		if (InternalDraw2dUtils.isAutoScaleEnabled()) {
 			InternalDraw2dUtils.configureForAutoscalingMode(this, rootlayer::setScale);
 		}