First pass of the Launcher Overlay interface / impl

-> Added simple reference launcher extension
-> Make launcher able to handle a null qsb

Change-Id: Ib1575243cac800a335e95bbf00cdc394bb4741c3

src/com/android/launcher3/DragLayer.java

@@ -89,6 +89,8 @@ public class DragLayer extends FrameLayout implements ViewGroup.OnHierarchyChang
     private Drawable mLeftHoverDrawableActive;
     private Drawable mRightHoverDrawableActive;
 
+    private boolean mBlockTouches = false;
+
     /**
      * Used to create a new DragLayer from XML.
      *
@@ -185,11 +187,19 @@ public class DragLayer extends FrameLayout implements ViewGroup.OnHierarchyChang
         return false;
     }
 
+    public void setBlockTouch(boolean block) {
+        mBlockTouches = block;
+    }
+
     private boolean handleTouchDown(MotionEvent ev, boolean intercept) {
         Rect hitRect = new Rect();
         int x = (int) ev.getX();
         int y = (int) ev.getY();
 
+        if (mBlockTouches) {
+            return true;
+        }
+
         for (AppWidgetResizeFrame child: mResizeFrames) {
             child.getHitRect(hitRect);
             if (hitRect.contains(x, y)) {
@@ -332,6 +342,10 @@ public class DragLayer extends FrameLayout implements ViewGroup.OnHierarchyChang
         int x = (int) ev.getX();
         int y = (int) ev.getY();
 
+        if (mBlockTouches) {
+            return true;
+        }
+
         if (action == MotionEvent.ACTION_DOWN) {
             if (handleTouchDown(ev, false)) {
                 return true;