Copy rectangles with APIs in DnD

This commit enforces the usage of Rectangle.clone and Rectangle.of
while copying a rectangle from an existing rectangle and creating a
rectangle from a Point making sure the internal state of the source
resources are copied to the new resource.

contributes to
eclipse-platform/eclipse.platform.swt#62 and
eclipse-platform/eclipse.platform.swt#128

Author: amartya4256

bundles/org.eclipse.e4.ui.workbench.addons.swt/META-INF/MANIFEST.MF

@@ -1,7 +1,7 @@
 Manifest-Version: 1.0
 Bundle-ManifestVersion: 2
 Bundle-SymbolicName: org.eclipse.e4.ui.workbench.addons.swt;singleton:=true
-Bundle-Version: 1.5.700.qualifier
+Bundle-Version: 1.5.800.qualifier
 Bundle-Name: %pluginName
 Bundle-Vendor: %providerName
 Bundle-Localization: plugin
@@ -12,7 +12,7 @@ Require-Bundle: org.eclipse.e4.ui.model.workbench;bundle-version="1.0.0",
  org.eclipse.e4.core.services;bundle-version="0.9.1",
  org.eclipse.e4.ui.workbench.renderers.swt;bundle-version="0.9.1",
  org.eclipse.e4.ui.widgets;bundle-version="0.11.0",
- org.eclipse.swt;bundle-version="[3.7.0,4.0.0)",
+ org.eclipse.swt;bundle-version="[3.131.0,4.0.0)",
  org.eclipse.jface;bundle-version="[3.7.0,4.0.0)",
  org.eclipse.core.runtime;bundle-version="[3.29.0,4.0.0)",
  org.eclipse.e4.ui.di;bundle-version="0.10.0",

bundles/org.eclipse.e4.ui.workbench.addons.swt/src/org/eclipse/e4/ui/workbench/addons/dndaddon/DetachedDropAgent.java

@@ -94,8 +94,9 @@ public Rectangle getRectangle(MUIElement dragElement) {
 		}
 
 		Point cp = Display.getCurrent().getCursorLocation();
-		curRect.x = cp.x - 15;
-		curRect.y = cp.y - 15;
+		cp.x -= 15;
+		cp.y -= 15;
+		curRect = Rectangle.of(cp, curRect.width, curRect.height);
 
 		return curRect;
 	}

bundles/org.eclipse.e4.ui.workbench.addons.swt/src/org/eclipse/e4/ui/workbench/addons/dndaddon/DnDManager.java

@@ -464,8 +464,11 @@ private Rectangle getOverlayBounds() {
 		Rectangle bounds = null;
 		for (Rectangle fr : frames) {
 			if (fr.width > 6) {
-				Rectangle outerBounds = new Rectangle(fr.x - 3, fr.y - 3, fr.width + 6,
-						fr.height + 6);
+				Rectangle outerBounds = fr.clone();
+				outerBounds.x -= 3;
+				outerBounds.y -= 3;
+				outerBounds.width += 6;
+				outerBounds.height += 6;
 				if (bounds == null) {
 					bounds = outerBounds;
 				}