Fix rulers and guides for enabled custom autoscaling

This commit adapts guides and rulers to properly work when the custom
autoscaling is enabled. To achieve that the monitor scale is applied
where necessary.

Author: akoch-yatta

org.eclipse.gef/src/org/eclipse/gef/internal/ui/rulers/DragGuidePolicy.java

@@ -17,6 +17,7 @@
 import org.eclipse.draw2d.Cursors;
 import org.eclipse.draw2d.Figure;
 import org.eclipse.draw2d.IFigure;
+import org.eclipse.draw2d.geometry.Dimension;
 import org.eclipse.draw2d.geometry.Point;
 import org.eclipse.draw2d.geometry.Rectangle;
 
@@ -89,10 +90,12 @@ public Command getCommand(Request request) {
 			cmd = getGuideEditPart().getRulerProvider().getDeleteGuideCommand(getHost().getModel());
 		} else {
 			int pDelta;
+			Dimension moveDelta = new Dimension(req.getMoveDelta().x, req.getMoveDelta().y);
+			getHostFigure().translateToRelative(moveDelta);
 			if (getGuideEditPart().isHorizontal()) {
-				pDelta = req.getMoveDelta().y;
+				pDelta = moveDelta.height;
 			} else {
-				pDelta = req.getMoveDelta().x;
+				pDelta = moveDelta.width;
 			}
 			if (isMoveValid(getGuideEditPart().getZoomedPosition() + pDelta)) {
 				ZoomManager zoomManager = getGuideEditPart().getZoomManager();
@@ -217,10 +220,13 @@ public void showSourceFeedback(Request request) {
 			eraseAttachedPartsFeedback(request);
 		} else {
 			int newPosition;
+
+			Dimension moveDelta = new Dimension(req.getMoveDelta().x, req.getMoveDelta().y);
+			getHostFigure().translateToRelative(moveDelta);
 			if (getGuideEditPart().isHorizontal()) {
-				newPosition = getGuideEditPart().getZoomedPosition() + req.getMoveDelta().y;
+				newPosition = getGuideEditPart().getZoomedPosition() + moveDelta.height;
 			} else {
-				newPosition = getGuideEditPart().getZoomedPosition() + req.getMoveDelta().x;
+				newPosition = getGuideEditPart().getZoomedPosition() + moveDelta.width;
 			}
 			getHostFigure().setVisible(true);
 			getGuideEditPart().getGuideLineFigure().setVisible(true);

org.eclipse.gef/src/org/eclipse/gef/internal/ui/rulers/RulerRootEditPart.java

@@ -21,6 +21,7 @@
 import org.eclipse.draw2d.Viewport;
 import org.eclipse.draw2d.geometry.Dimension;
 import org.eclipse.draw2d.geometry.Insets;
+import org.eclipse.draw2d.geometry.Point;
 import org.eclipse.draw2d.geometry.Rectangle;
 
 import org.eclipse.gef.AutoexposeHelper;
@@ -246,6 +247,13 @@ public void setContents(IFigure figure) {
 			}
 		}
 
+		@Override
+		public Point getViewLocation() {
+			Point viewLocation = new Point(getHorizontalRangeModel().getValue(), getVerticalRangeModel().getValue());
+			getFigure().translateToRelative(viewLocation);
+			return viewLocation;
+		}
+
 		/**
 		 * RulerViewport uses local coordinates.
 		 *

org.eclipse.gef/src/org/eclipse/gef/ui/rulers/RulerComposite.java

@@ -34,10 +34,13 @@
 import org.eclipse.draw2d.FigureCanvas;
 import org.eclipse.draw2d.Graphics;
 import org.eclipse.draw2d.IFigure;
+import org.eclipse.draw2d.LightweightSystem;
 import org.eclipse.draw2d.PositionConstants;
 import org.eclipse.draw2d.RangeModel;
+import org.eclipse.draw2d.ScalableLightweightSystem;
 import org.eclipse.draw2d.Viewport;
 import org.eclipse.draw2d.geometry.Insets;
+import org.eclipse.draw2d.internal.InternalDraw2dUtils;
 
 import org.eclipse.gef.DragTracker;
 import org.eclipse.gef.EditDomain;
@@ -82,6 +85,7 @@ public class RulerComposite extends Composite {
 	private boolean isRulerVisible = true;
 	private boolean needToLayout = false;
 	private final Runnable runnable = () -> layout(false);
+	private double monitorScale = 1.0;
 
 	/**
 	 * Constructor
@@ -93,6 +97,7 @@ public class RulerComposite extends Composite {
 	 */
 	public RulerComposite(Composite parent, int style) {
 		super(parent, style);
+		InternalDraw2dUtils.configureForAutoscalingMode(this, scale -> monitorScale = scale);
 		addDisposeListener(e -> disposeResources());
 	}
 
@@ -242,14 +247,15 @@ public void doLayout() {
 		 * Motif) leave some trimming around some canvasses.
 		 */
 		Rectangle trim = calculateEditorTrim(editor);
+		// Positioning must compensate for the RulerBorder
+		int rulerBorder = (int) Math.floor(1 * monitorScale);
 		if (left != null) {
-			// The - 1 and + 1 are to compensate for the RulerBorder
-			left.getControl().setBounds(0, topHeight - trim.x + leftTrim.x - 1, leftWidth,
-					editorSize.height - trim.height + leftTrim.height + 1);
+			left.getControl().setBounds(0, topHeight - trim.x + leftTrim.x - rulerBorder, leftWidth,
+					editorSize.height - trim.height + leftTrim.height + rulerBorder);
 		}
 		if (top != null) {
-			top.getControl().setBounds(leftWidth - trim.y + topTrim.y - 1, 0,
-					editorSize.width - trim.width + topTrim.width + 1, topHeight);
+			top.getControl().setBounds(leftWidth - trim.y + topTrim.y - rulerBorder, 0,
+					editorSize.width - trim.width + topTrim.width + rulerBorder, topHeight);
 		}
 	}
 
@@ -458,6 +464,11 @@ public RulerViewer() {
 			init();
 		}
 
+		@Override
+		protected LightweightSystem createLightweightSystem() {
+			return InternalDraw2dUtils.isAutoScaleEnabled() ? new ScalableLightweightSystem() : new LightweightSystem();
+		}
+
 		/**
 		 * @see org.eclipse.gef.EditPartViewer#appendSelection(org.eclipse.gef.EditPart)
 		 */