Adding support for drag and drop for requestPinItem.

On long pressing, the confirmation activity starts a system
drag-n-drop and focuses the launcher activity. We then drive
the launcher drag controller using the system drag event

Caveats:
> We use a transparent preview for system drag and drop and use
  a view inside launcher for actual preview. This gives us better
  control over various animations.
> The parameters for drag operation are passed to the Launcher
  activity using the intent. Since onNewIntent and onDragEvent
  come at different times and are not associated, a random uuid
  is used as mime-type to match the drag event with intent params
> If the workspace is locked (eg, loader is running) the drag
  operation is simply dropped. Will be imporved in follow up cls

Bug: 33584624
Change-Id: I0bb5b25b690f86b6af31a14e11beb669fcb3a281

1 files changed, 27 insertions, 0 deletions

diff --git a/src/com/android/launcher3/dragndrop/FlingToDeleteHelper.java b/src/com/android/launcher3/dragndrop/FlingToDeleteHelper.java
index a2aa27d17..e79474483 100644
--- a/src/com/android/launcher3/dragndrop/FlingToDeleteHelper.java
+++ b/src/com/android/launcher3/dragndrop/FlingToDeleteHelper.java
@@ -17,6 +17,8 @@
 package com.android.launcher3.dragndrop;
 
 import android.graphics.PointF;
+import android.os.SystemClock;
+import android.view.DragEvent;
 import android.view.MotionEvent;
 import android.view.VelocityTracker;
 import android.view.ViewConfiguration;
@@ -53,6 +55,31 @@ public class FlingToDeleteHelper {
         mVelocityTracker.addMovement(ev);
     }
 
+    /**
+     * Same as {@link #recordMotionEvent}. It creates a temporary {@link MotionEvent} object
+     * using {@param event} for tracking velocity.
+     */
+    public void recordDragEvent(long dragStartTime, DragEvent event) {
+        final int motionAction;
+        switch (event.getAction()) {
+            case DragEvent.ACTION_DRAG_STARTED:
+                motionAction = MotionEvent.ACTION_DOWN;
+                break;
+            case DragEvent.ACTION_DRAG_LOCATION:
+                motionAction = MotionEvent.ACTION_MOVE;
+                break;
+            case DragEvent.ACTION_DRAG_ENDED:
+                motionAction = MotionEvent.ACTION_UP;
+                break;
+            default:
+                return;
+        }
+        MotionEvent emulatedEvent = MotionEvent.obtain(dragStartTime, SystemClock.uptimeMillis(),
+                motionAction, event.getX(), event.getY(), 0);
+        recordMotionEvent(emulatedEvent);
+        emulatedEvent.recycle();
+    }
+
     public void releaseVelocityTracker() {
         if (mVelocityTracker != null) {
             mVelocityTracker.recycle();