Don't allow drags to fully occupied home screens

Change-Id: Ib9f6732f2d1d35fc4496c3d2257397ddf1f7f367

src/com/android/launcher2/Workspace.java

@@ -1483,7 +1483,7 @@ public class Workspace extends SmoothPagedView
         // If it's an external drop (e.g. from All Apps), check if it should be accepted
         if (source != this) {
             // Don't accept the drop if we're not over a screen at time of drop
-            if (mDragTargetLayout == null) {
+            if (mDragTargetLayout == null || !mDragTargetLayout.getAcceptsDrops()) {
                 return false;
             }
 
@@ -1931,7 +1931,7 @@ public class Workspace extends SmoothPagedView
                         mDragTargetLayout.setHover(false);
                     }
                     mDragTargetLayout = layout;
-                    if (mDragTargetLayout != null) {
+                    if (mDragTargetLayout != null && mDragTargetLayout.getAcceptsDrops()) {
                         mDragTargetLayout.setHover(true);
                     }
                 }