Merge "Implement View.cancelDrag"

6 files changed, 61 insertions, 7 deletions

diff --git a/api/current.txt b/api/current.txt
index 620864060898..1a7139c08cd8 100644
--- a/api/current.txt
+++ b/api/current.txt
@@ -36238,6 +36238,7 @@ package android.view {
     method public boolean canResolveTextDirection();
     method public boolean canScrollHorizontally(int);
     method public boolean canScrollVertically(int);
+    method public final void cancelDrag();
     method public void cancelLongPress();
     method public final void cancelPendingInputEvents();
     method public boolean checkInputConnectionProxy(android.view.View);
diff --git a/api/system-current.txt b/api/system-current.txt
index fc11f34314b5..f27844101473 100644
--- a/api/system-current.txt
+++ b/api/system-current.txt
@@ -38559,6 +38559,7 @@ package android.view {
     method public boolean canResolveTextDirection();
     method public boolean canScrollHorizontally(int);
     method public boolean canScrollVertically(int);
+    method public final void cancelDrag();
     method public void cancelLongPress();
     method public final void cancelPendingInputEvents();
     method public boolean checkInputConnectionProxy(android.view.View);
diff --git a/core/java/android/view/IWindowSession.aidl b/core/java/android/view/IWindowSession.aidl
index 3fc70cc3b4d9..f81b5d01671a 100644
--- a/core/java/android/view/IWindowSession.aidl
+++ b/core/java/android/view/IWindowSession.aidl
@@ -186,6 +186,11 @@ interface IWindowSession {
 	void reportDropResult(IWindow window, boolean consumed);
 
     /**
+     * Cancel a drag operation.
+     */
+    void cancelDrag(IBinder dragToken);
+
+    /**
      * Tell the OS that we've just dragged into a View that is willing to accept the drop
      */
     void dragRecipientEntered(IWindow window);
diff --git a/core/java/android/view/View.java b/core/java/android/view/View.java
index de4d43990ea0..30408c6d4d46 100644
--- a/core/java/android/view/View.java
+++ b/core/java/android/view/View.java
@@ -19905,11 +19905,11 @@ public class View implements Drawable.Callback, KeyEvent.Callback,
         }
         Surface surface = new Surface();
         try {
-            IBinder token = mAttachInfo.mSession.prepareDrag(mAttachInfo.mWindow,
+            mAttachInfo.mDragToken = mAttachInfo.mSession.prepareDrag(mAttachInfo.mWindow,
                     flags, shadowSize.x, shadowSize.y, surface);
-            if (ViewDebug.DEBUG_DRAG) Log.d(VIEW_LOG_TAG, "prepareDrag returned token=" + token
-                    + " surface=" + surface);
-            if (token != null) {
+            if (ViewDebug.DEBUG_DRAG) Log.d(VIEW_LOG_TAG, "prepareDrag returned token="
+                    + mAttachInfo.mDragToken + " surface=" + surface);
+            if (mAttachInfo.mDragToken != null) {
                 Canvas canvas = surface.lockCanvas(null);
                 try {
                     canvas.drawColor(0, PorterDuff.Mode.CLEAR);
@@ -19926,7 +19926,7 @@ public class View implements Drawable.Callback, KeyEvent.Callback,
                 // repurpose 'shadowSize' for the last touch point
                 root.getLastTouchPoint(shadowSize);
 
-                okay = mAttachInfo.mSession.performDrag(mAttachInfo.mWindow, token,
+                okay = mAttachInfo.mSession.performDrag(mAttachInfo.mWindow, mAttachInfo.mDragToken,
                         shadowSize.x, shadowSize.y,
                         shadowTouchPoint.x, shadowTouchPoint.y, data);
                 if (ViewDebug.DEBUG_DRAG) Log.d(VIEW_LOG_TAG, "performDrag returned " + okay);
@@ -19943,6 +19943,22 @@ public class View implements Drawable.Callback, KeyEvent.Callback,
         return okay;
     }
 
+    public final void cancelDrag() {
+        if (ViewDebug.DEBUG_DRAG) {
+            Log.d(VIEW_LOG_TAG, "cancelDrag");
+        }
+        if (mAttachInfo.mDragToken != null) {
+            try {
+                mAttachInfo.mSession.cancelDrag(mAttachInfo.mDragToken);
+            } catch (Exception e) {
+                Log.e(VIEW_LOG_TAG, "Unable to cancel drag", e);
+            }
+            mAttachInfo.mDragToken = null;
+        } else {
+            Log.e(VIEW_LOG_TAG, "No active drag to cancel");
+        }
+    }
+
     /**
      * Starts a move from {startX, startY}, the amount of the movement will be the offset
      * between {startX, startY} and the new cursor positon.
@@ -22221,6 +22237,11 @@ public class View implements Drawable.Callback, KeyEvent.Callback,
         View mViewRequestingLayout;
 
         /**
+         * Used to track the identity of the current drag operation.
+         */
+        IBinder mDragToken;
+
+        /**
          * Creates a new set of attachment information with the specified
          * events handler and thread.
          *
diff --git a/core/java/android/view/ViewRootImpl.java b/core/java/android/view/ViewRootImpl.java
index cd9dd97468b3..f1d9f1ab1b45 100644
--- a/core/java/android/view/ViewRootImpl.java
+++ b/core/java/android/view/ViewRootImpl.java
@@ -5307,10 +5307,10 @@ public final class ViewRootImpl implements ViewParent,
                     }
                 }
 
-                // When the drag operation ends, release any local state object
-                // that may have been in use
+                // When the drag operation ends, reset drag-related state
                 if (what == DragEvent.ACTION_DRAG_ENDED) {
                     setLocalDragState(null);
+                    mAttachInfo.mDragToken = null;
                 }
             }
         }
diff --git a/services/core/java/com/android/server/wm/Session.java b/services/core/java/com/android/server/wm/Session.java
index 1caeca09238d..b85a6923d7f3 100644
--- a/services/core/java/com/android/server/wm/Session.java
+++ b/services/core/java/com/android/server/wm/Session.java
@@ -401,6 +401,32 @@ final class Session extends IWindowSession.Stub
         }
     }
 
+    public void cancelDrag(IBinder dragToken) {
+        if (WindowManagerService.DEBUG_DRAG) {
+            Slog.d(WindowManagerService.TAG, "cancel drag");
+        }
+
+        synchronized (mService.mWindowMap) {
+            long ident = Binder.clearCallingIdentity();
+            try {
+                if (mService.mDragState == null) {
+                    Slog.w(WindowManagerService.TAG, "cancelDrag() without prepareDrag()");
+                    throw new IllegalStateException("cancelDrag() without prepareDrag()");
+                }
+
+                if (mService.mDragState.mToken != dragToken) {
+                    Slog.w(WindowManagerService.TAG, "cancelDrag() does not match prepareDrag()");
+                    throw new IllegalStateException("cancelDrag() does not match prepareDrag()");
+                }
+
+                mService.mDragState.mDragResult = false;
+                mService.mDragState.endDragLw();
+            } finally {
+                Binder.restoreCallingIdentity(ident);
+            }
+        }
+    }
+
     public void dragRecipientEntered(IWindow window) {
         if (WindowManagerService.DEBUG_DRAG) {
             Slog.d(WindowManagerService.TAG, "Drag into new candidate view @ " + window.asBinder());