com/android/server/wm/DragDropController.java - platform/prebuilts/fullsdk/sources/android-28 - Git at Google

 /*
  * Copyright (C) 2017 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 package com.android.server.wm;

 import static com.android.server.wm.WindowManagerDebugConfig.DEBUG_DRAG;
 import static com.android.server.wm.WindowManagerDebugConfig.SHOW_LIGHT_TRANSACTIONS;
 import static com.android.server.wm.WindowManagerDebugConfig.SHOW_TRANSACTIONS;
 import static com.android.server.wm.WindowManagerDebugConfig.TAG_WM;

 import android.annotation.NonNull;
 import android.content.ClipData;
 import android.graphics.PixelFormat;
 import android.os.Binder;
 import android.os.Handler;
 import android.os.IBinder;
 import android.os.Looper;
 import android.os.Message;
 import android.util.Slog;
 import android.view.Display;
 import android.view.IWindow;
 import android.view.Surface;
 import android.view.SurfaceControl;
 import android.view.SurfaceSession;
 import android.view.View;
 import android.view.WindowManagerInternal.IDragDropCallback;
 import com.android.internal.util.Preconditions;
 import com.android.server.input.InputWindowHandle;

 /**
  * Managing drag and drop operations initiated by View#startDragAndDrop.
  */
 class DragDropController {
     private static final float DRAG_SHADOW_ALPHA_TRANSPARENT = .7071f;
     private static final long DRAG_TIMEOUT_MS = 5000;

     // Messages for Handler.
     private static final int MSG_DRAG_START_TIMEOUT = 0;
     static final int MSG_DRAG_END_TIMEOUT = 1;
     static final int MSG_TEAR_DOWN_DRAG_AND_DROP_INPUT = 2;
     static final int MSG_ANIMATION_END = 3;

     /**
      * Drag state per operation.
      * Needs a lock of {@code WindowManagerService#mWindowMap} to read this. Needs both locks of
      * {@code mWriteLock} and {@code WindowManagerService#mWindowMap} to update this.
      * The variable is cleared by {@code #onDragStateClosedLocked} which is invoked by DragState
      * itself, thus the variable can be null after calling DragState's methods.
      */
     private DragState mDragState;

     private WindowManagerService mService;
     private final Handler mHandler;

     /**
      * Lock to preserve the order of state updates.
      * The lock is used to process drag and drop state updates in order without having the window
      * manager lock.
      *
      * Suppose DragDropController invokes a callback method A, then processes the following update
      * A'. Same for a callback method B and the following update B'. The callback wants
      * DragDropController to processes the updates in the order of  A' then B'.
      *
      * Without mWriteLock: the following race can happen.
      *
      * 1. Thread a calls A.
      * 2. Thread b calls B.
      * 3. Thread b acquires the window manager lock
      * 4. thread b processes the update B'
      * 5. Thread a acquires the window manager lock
      * 6. thread a processes the update A'
      *
      * With mWriteLock we can ensure the order of A' and B'
      *
      * 1. Thread a acquire mWriteLock
      * 2. Thread a calls A
      * 3. Thread a acquire the window manager lock
      * 4. Thread a processes A'
      * 5. Thread b acquire mWriteLock
      * 6. Thread b calls B
      * 7. Thread b acquire the window manager lock
      * 8. Thread b processes B'
      *
      * Don't acquire the lock while holding the window manager lock, otherwise it causes a deadlock.
      */
     private final Object mWriteLock = new Object();

     /**
      * Callback which is used to sync drag state with the vendor-specific code.
      */
     @NonNull private IDragDropCallback mCallback = new IDragDropCallback() {};

     boolean dragDropActiveLocked() {
         return mDragState != null;
     }

     InputWindowHandle getInputWindowHandleLocked() {
         return mDragState.getInputWindowHandle();
     }

     void registerCallback(IDragDropCallback callback) {
         Preconditions.checkNotNull(callback);
         synchronized (mWriteLock) {
             mCallback = callback;
         }
     }

     DragDropController(WindowManagerService service, Looper looper) {
         mService = service;
         mHandler = new DragHandler(service, looper);
     }

     void sendDragStartedIfNeededLocked(WindowState window) {
         mDragState.sendDragStartedIfNeededLocked(window);
     }

     IBinder prepareDrag(SurfaceSession session, int callerPid,
             int callerUid, IWindow window, int flags, int width, int height, Surface outSurface) {
         if (DEBUG_DRAG) {
             Slog.d(TAG_WM, "prepare drag surface: w=" + width + " h=" + height
                     + " flags=" + Integer.toHexString(flags) + " win=" + window
                     + " asbinder=" + window.asBinder());
         }

         synchronized (mWriteLock) {
             synchronized (mService.mWindowMap) {
                 if (dragDropActiveLocked()) {
                     Slog.w(TAG_WM, "Drag already in progress");
                     return null;
                 }

                 // TODO(multi-display): support other displays
                 final DisplayContent displayContent =
                         mService.getDefaultDisplayContentLocked();
                 final Display display = displayContent.getDisplay();

                 final SurfaceControl surface = new SurfaceControl.Builder(session)
                         .setName("drag surface")
                         .setSize(width, height)
                         .setFormat(PixelFormat.TRANSLUCENT)
                         .build();
                 surface.setLayerStack(display.getLayerStack());
                 float alpha = 1;
                 if ((flags & View.DRAG_FLAG_OPAQUE) == 0) {
                     alpha = DRAG_SHADOW_ALPHA_TRANSPARENT;
                 }
                 surface.setAlpha(alpha);

                 if (SHOW_TRANSACTIONS)
                     Slog.i(TAG_WM, "  DRAG " + surface + ": CREATE");
                 outSurface.copyFrom(surface);
                 final IBinder winBinder = window.asBinder();
                 IBinder token = new Binder();
                 mDragState = new DragState(mService, token, surface, flags, winBinder);
                 mDragState.mPid = callerPid;
                 mDragState.mUid = callerUid;
                 mDragState.mOriginalAlpha = alpha;
                 token = mDragState.mToken = new Binder();

                 // 5 second timeout for this window to actually begin the drag
                 sendTimeoutMessage(MSG_DRAG_START_TIMEOUT, winBinder);
                 return token;
             }
         }
     }

     boolean performDrag(IWindow window, IBinder dragToken,
             int touchSource, float touchX, float touchY, float thumbCenterX, float thumbCenterY,
             ClipData data) {
         if (DEBUG_DRAG) {
             Slog.d(TAG_WM, "perform drag: win=" + window + " data=" + data);
         }

         synchronized (mWriteLock) {
             if (!mCallback.performDrag(window, dragToken, touchSource, touchX, touchY, thumbCenterX,
                     thumbCenterY, data)) {
                 return false;
             }
             synchronized (mService.mWindowMap) {
                 if (mDragState == null) {
                     Slog.w(TAG_WM, "No drag prepared");
                     throw new IllegalStateException("performDrag() without prepareDrag()");
                 }

                 if (dragToken != mDragState.mToken) {
                     Slog.w(TAG_WM, "Performing mismatched drag");
                     throw new IllegalStateException("performDrag() does not match prepareDrag()");
                 }

                 final WindowState callingWin = mService.windowForClientLocked(null, window, false);
                 if (callingWin == null) {
                     Slog.w(TAG_WM, "Bad requesting window " + window);
                     return false;  // !!! TODO: throw here?
                 }

                 // !!! TODO: if input is not still focused on the initiating window, fail
                 // the drag initiation (e.g. an alarm window popped up just as the application
                 // called performDrag()

                 mHandler.removeMessages(MSG_DRAG_START_TIMEOUT, window.asBinder());

                 // !!! TODO: extract the current touch (x, y) in screen coordinates.  That
                 // will let us eliminate the (touchX,touchY) parameters from the API.

                 // !!! FIXME: put all this heavy stuff onto the mHandler looper, as well as
                 // the actual drag event dispatch stuff in the dragstate

                 final DisplayContent displayContent = callingWin.getDisplayContent();
                 if (displayContent == null) {
                     return false;
                 }
                 Display display = displayContent.getDisplay();
                 mDragState.register(display);
                 if (!mService.mInputManager.transferTouchFocus(callingWin.mInputChannel,
                         mDragState.getInputChannel())) {
                     Slog.e(TAG_WM, "Unable to transfer touch focus");
                     mDragState.closeLocked();
                     return false;
                 }

                 mDragState.mDisplayContent = displayContent;
                 mDragState.mData = data;
                 mDragState.broadcastDragStartedLocked(touchX, touchY);
                 mDragState.overridePointerIconLocked(touchSource);

                 // remember the thumb offsets for later
                 mDragState.mThumbOffsetX = thumbCenterX;
                 mDragState.mThumbOffsetY = thumbCenterY;

                 // Make the surface visible at the proper location
                 final SurfaceControl surfaceControl = mDragState.mSurfaceControl;
                 if (SHOW_LIGHT_TRANSACTIONS) Slog.i(TAG_WM, ">>> OPEN TRANSACTION performDrag");
                 mService.openSurfaceTransaction();
                 try {
                     surfaceControl.setPosition(touchX - thumbCenterX,
                             touchY - thumbCenterY);
                     surfaceControl.setLayer(mDragState.getDragLayerLocked());
                     surfaceControl.setLayerStack(display.getLayerStack());
                     surfaceControl.show();
                 } finally {
                     mService.closeSurfaceTransaction("performDrag");
                     if (SHOW_LIGHT_TRANSACTIONS) {
                         Slog.i(TAG_WM, "<<< CLOSE TRANSACTION performDrag");
                     }
                 }

                 mDragState.notifyLocationLocked(touchX, touchY);
             }
         }

         return true;    // success!
     }

     void reportDropResult(IWindow window, boolean consumed) {
         IBinder token = window.asBinder();
         if (DEBUG_DRAG) {
             Slog.d(TAG_WM, "Drop result=" + consumed + " reported by " + token);
         }

         synchronized (mWriteLock) {
             mCallback.reportDropResult(window, consumed);
             synchronized (mService.mWindowMap) {
                 if (mDragState == null) {
                     // Most likely the drop recipient ANRed and we ended the drag
                     // out from under it.  Log the issue and move on.
                     Slog.w(TAG_WM, "Drop result given but no drag in progress");
                     return;
                 }

                 if (mDragState.mToken != token) {
                     // We're in a drag, but the wrong window has responded.
                     Slog.w(TAG_WM, "Invalid drop-result claim by " + window);
                     throw new IllegalStateException("reportDropResult() by non-recipient");
                 }

                 // The right window has responded, even if it's no longer around,
                 // so be sure to halt the timeout even if the later WindowState
                 // lookup fails.
                 mHandler.removeMessages(MSG_DRAG_END_TIMEOUT, window.asBinder());
                 WindowState callingWin = mService.windowForClientLocked(null, window, false);
                 if (callingWin == null) {
                     Slog.w(TAG_WM, "Bad result-reporting window " + window);
                     return;  // !!! TODO: throw here?
                 }


                 mDragState.mDragResult = consumed;
                 mDragState.endDragLocked();
             }
         }
     }

     void cancelDragAndDrop(IBinder dragToken) {
         if (DEBUG_DRAG) {
             Slog.d(TAG_WM, "cancelDragAndDrop");
         }

         synchronized (mWriteLock) {
             mCallback.cancelDragAndDrop(dragToken);
             synchronized (mService.mWindowMap) {
                 if (mDragState == null) {
                     Slog.w(TAG_WM, "cancelDragAndDrop() without prepareDrag()");
                     throw new IllegalStateException("cancelDragAndDrop() without prepareDrag()");
                 }

                 if (mDragState.mToken != dragToken) {
                     Slog.w(TAG_WM,
                             "cancelDragAndDrop() does not match prepareDrag()");
                     throw new IllegalStateException(
                             "cancelDragAndDrop() does not match prepareDrag()");
                 }

                 mDragState.mDragResult = false;
                 mDragState.cancelDragLocked();
             }
         }
     }

     /**
      * Handles motion events.
      * @param keepHandling Whether if the drag operation is continuing or this is the last motion
      *          event.
      * @param newX X coordinate value in dp in the screen coordinate
      * @param newY Y coordinate value in dp in the screen coordinate
      */
     void handleMotionEvent(boolean keepHandling, float newX, float newY) {
         synchronized (mWriteLock) {
             synchronized (mService.mWindowMap) {
                 if (!dragDropActiveLocked()) {
                     // The drag has ended but the clean-up message has not been processed by
                     // window manager. Drop events that occur after this until window manager
                     // has a chance to clean-up the input handle.
                     return;
                 }

                 if (keepHandling) {
                     mDragState.notifyMoveLocked(newX, newY);
                 } else {
                     mDragState.notifyDropLocked(newX, newY);
                 }
             }
         }
     }

     void dragRecipientEntered(IWindow window) {
         if (DEBUG_DRAG) {
             Slog.d(TAG_WM, "Drag into new candidate view @ " + window.asBinder());
         }
     }

     void dragRecipientExited(IWindow window) {
         if (DEBUG_DRAG) {
             Slog.d(TAG_WM, "Drag from old candidate view @ " + window.asBinder());
         }
     }

     /**
      * Sends a message to the Handler managed by DragDropController.
      */
     void sendHandlerMessage(int what, Object arg) {
         mHandler.obtainMessage(what, arg).sendToTarget();
     }

     /**
      * Sends a timeout message to the Handler managed by DragDropController.
      */
     void sendTimeoutMessage(int what, Object arg) {
         mHandler.removeMessages(what, arg);
         final Message msg = mHandler.obtainMessage(what, arg);
         mHandler.sendMessageDelayed(msg, DRAG_TIMEOUT_MS);
     }

     /**
      * Notifies the current drag state is closed.
      */
     void onDragStateClosedLocked(DragState dragState) {
         if (mDragState != dragState) {
             Slog.wtf(TAG_WM, "Unknown drag state is closed");
             return;
         }
         mDragState = null;
     }

     private class DragHandler extends Handler {
         /**
          * Lock for window manager.
          */
         private final WindowManagerService mService;

         DragHandler(WindowManagerService service, Looper looper) {
             super(looper);
             mService = service;
         }

         @Override
         public void handleMessage(Message msg) {
             switch (msg.what) {
                 case MSG_DRAG_START_TIMEOUT: {
                     IBinder win = (IBinder) msg.obj;
                     if (DEBUG_DRAG) {
                         Slog.w(TAG_WM, "Timeout starting drag by win " + win);
                     }
                     synchronized (mWriteLock) {
                         synchronized (mService.mWindowMap) {
                             // !!! TODO: ANR the app that has failed to start the drag in time
                             if (mDragState != null) {
                                 mDragState.closeLocked();
                             }
                         }
                     }
                     break;
                 }

                 case MSG_DRAG_END_TIMEOUT: {
                     final IBinder win = (IBinder) msg.obj;
                     if (DEBUG_DRAG) {
                         Slog.w(TAG_WM, "Timeout ending drag to win " + win);
                     }
                     synchronized (mWriteLock) {
                         synchronized (mService.mWindowMap) {
                             // !!! TODO: ANR the drag-receiving app
                             if (mDragState != null) {
                                 mDragState.mDragResult = false;
                                 mDragState.endDragLocked();
                             }
                         }
                     }
                     break;
                 }

                 case MSG_TEAR_DOWN_DRAG_AND_DROP_INPUT: {
                     if (DEBUG_DRAG)
                         Slog.d(TAG_WM, "Drag ending; tearing down input channel");
                     final DragState.InputInterceptor interceptor =
                             (DragState.InputInterceptor) msg.obj;
                     if (interceptor == null) return;
                     synchronized (mService.mWindowMap) {
                         interceptor.tearDown();
                     }
                     break;
                 }

                 case MSG_ANIMATION_END: {
                     synchronized (mWriteLock) {
                         synchronized (mService.mWindowMap) {
                             if (mDragState == null) {
                                 Slog.wtf(TAG_WM, "mDragState unexpectedly became null while " +
                                         "plyaing animation");
                                 return;
                             }
                             mDragState.closeLocked();
                         }
                     }
                     break;
                 }
             }
         }
     }
 }
	/*
	* Copyright (C) 2017 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	package com.android.server.wm;

	import static com.android.server.wm.WindowManagerDebugConfig.DEBUG_DRAG;
	import static com.android.server.wm.WindowManagerDebugConfig.SHOW_LIGHT_TRANSACTIONS;
	import static com.android.server.wm.WindowManagerDebugConfig.SHOW_TRANSACTIONS;
	import static com.android.server.wm.WindowManagerDebugConfig.TAG_WM;

	import android.annotation.NonNull;
	import android.content.ClipData;
	import android.graphics.PixelFormat;
	import android.os.Binder;
	import android.os.Handler;
	import android.os.IBinder;
	import android.os.Looper;
	import android.os.Message;
	import android.util.Slog;
	import android.view.Display;
	import android.view.IWindow;
	import android.view.Surface;
	import android.view.SurfaceControl;
	import android.view.SurfaceSession;
	import android.view.View;
	import android.view.WindowManagerInternal.IDragDropCallback;
	import com.android.internal.util.Preconditions;
	import com.android.server.input.InputWindowHandle;

	/**
	* Managing drag and drop operations initiated by View#startDragAndDrop.
	*/
	class DragDropController {
	private static final float DRAG_SHADOW_ALPHA_TRANSPARENT = .7071f;
	private static final long DRAG_TIMEOUT_MS = 5000;

	// Messages for Handler.
	private static final int MSG_DRAG_START_TIMEOUT = 0;
	static final int MSG_DRAG_END_TIMEOUT = 1;
	static final int MSG_TEAR_DOWN_DRAG_AND_DROP_INPUT = 2;
	static final int MSG_ANIMATION_END = 3;

	/**
	* Drag state per operation.
	* Needs a lock of {@code WindowManagerService#mWindowMap} to read this. Needs both locks of
	* {@code mWriteLock} and {@code WindowManagerService#mWindowMap} to update this.
	* The variable is cleared by {@code #onDragStateClosedLocked} which is invoked by DragState
	* itself, thus the variable can be null after calling DragState's methods.
	*/
	private DragState mDragState;

	private WindowManagerService mService;
	private final Handler mHandler;

	/**
	* Lock to preserve the order of state updates.
	* The lock is used to process drag and drop state updates in order without having the window
	* manager lock.
	*
	* Suppose DragDropController invokes a callback method A, then processes the following update
	* A'. Same for a callback method B and the following update B'. The callback wants
	* DragDropController to processes the updates in the order of A' then B'.
	*
	* Without mWriteLock: the following race can happen.
	*
	* 1. Thread a calls A.
	* 2. Thread b calls B.
	* 3. Thread b acquires the window manager lock
	* 4. thread b processes the update B'
	* 5. Thread a acquires the window manager lock
	* 6. thread a processes the update A'
	*
	* With mWriteLock we can ensure the order of A' and B'
	*
	* 1. Thread a acquire mWriteLock
	* 2. Thread a calls A
	* 3. Thread a acquire the window manager lock
	* 4. Thread a processes A'
	* 5. Thread b acquire mWriteLock
	* 6. Thread b calls B
	* 7. Thread b acquire the window manager lock
	* 8. Thread b processes B'
	*
	* Don't acquire the lock while holding the window manager lock, otherwise it causes a deadlock.
	*/
	private final Object mWriteLock = new Object();

	/**
	* Callback which is used to sync drag state with the vendor-specific code.
	*/
	@NonNull private IDragDropCallback mCallback = new IDragDropCallback() {};

	boolean dragDropActiveLocked() {
	return mDragState != null;
	}

	InputWindowHandle getInputWindowHandleLocked() {
	return mDragState.getInputWindowHandle();
	}

	void registerCallback(IDragDropCallback callback) {
	Preconditions.checkNotNull(callback);
	synchronized (mWriteLock) {
	mCallback = callback;
	}
	}

	DragDropController(WindowManagerService service, Looper looper) {
	mService = service;
	mHandler = new DragHandler(service, looper);
	}

	void sendDragStartedIfNeededLocked(WindowState window) {
	mDragState.sendDragStartedIfNeededLocked(window);
	}

	IBinder prepareDrag(SurfaceSession session, int callerPid,
	int callerUid, IWindow window, int flags, int width, int height, Surface outSurface) {
	if (DEBUG_DRAG) {
	Slog.d(TAG_WM, "prepare drag surface: w=" + width + " h=" + height
	+ " flags=" + Integer.toHexString(flags) + " win=" + window
	+ " asbinder=" + window.asBinder());
	}

	synchronized (mWriteLock) {
	synchronized (mService.mWindowMap) {
	if (dragDropActiveLocked()) {
	Slog.w(TAG_WM, "Drag already in progress");
	return null;
	}

	// TODO(multi-display): support other displays
	final DisplayContent displayContent =
	mService.getDefaultDisplayContentLocked();
	final Display display = displayContent.getDisplay();

	final SurfaceControl surface = new SurfaceControl.Builder(session)
	.setName("drag surface")
	.setSize(width, height)
	.setFormat(PixelFormat.TRANSLUCENT)
	.build();
	surface.setLayerStack(display.getLayerStack());
	float alpha = 1;
	if ((flags & View.DRAG_FLAG_OPAQUE) == 0) {
	alpha = DRAG_SHADOW_ALPHA_TRANSPARENT;
	}
	surface.setAlpha(alpha);

	if (SHOW_TRANSACTIONS)
	Slog.i(TAG_WM, " DRAG " + surface + ": CREATE");
	outSurface.copyFrom(surface);
	final IBinder winBinder = window.asBinder();
	IBinder token = new Binder();
	mDragState = new DragState(mService, token, surface, flags, winBinder);
	mDragState.mPid = callerPid;
	mDragState.mUid = callerUid;
	mDragState.mOriginalAlpha = alpha;
	token = mDragState.mToken = new Binder();

	// 5 second timeout for this window to actually begin the drag
	sendTimeoutMessage(MSG_DRAG_START_TIMEOUT, winBinder);
	return token;
	}
	}
	}

	boolean performDrag(IWindow window, IBinder dragToken,
	int touchSource, float touchX, float touchY, float thumbCenterX, float thumbCenterY,
	ClipData data) {
	if (DEBUG_DRAG) {
	Slog.d(TAG_WM, "perform drag: win=" + window + " data=" + data);
	}

	synchronized (mWriteLock) {
	if (!mCallback.performDrag(window, dragToken, touchSource, touchX, touchY, thumbCenterX,
	thumbCenterY, data)) {
	return false;
	}
	synchronized (mService.mWindowMap) {
	if (mDragState == null) {
	Slog.w(TAG_WM, "No drag prepared");
	throw new IllegalStateException("performDrag() without prepareDrag()");
	}

	if (dragToken != mDragState.mToken) {
	Slog.w(TAG_WM, "Performing mismatched drag");
	throw new IllegalStateException("performDrag() does not match prepareDrag()");
	}

	final WindowState callingWin = mService.windowForClientLocked(null, window, false);
	if (callingWin == null) {
	Slog.w(TAG_WM, "Bad requesting window " + window);
	return false; // !!! TODO: throw here?
	}

	// !!! TODO: if input is not still focused on the initiating window, fail
	// the drag initiation (e.g. an alarm window popped up just as the application
	// called performDrag()

	mHandler.removeMessages(MSG_DRAG_START_TIMEOUT, window.asBinder());

	// !!! TODO: extract the current touch (x, y) in screen coordinates. That
	// will let us eliminate the (touchX,touchY) parameters from the API.

	// !!! FIXME: put all this heavy stuff onto the mHandler looper, as well as
	// the actual drag event dispatch stuff in the dragstate

	final DisplayContent displayContent = callingWin.getDisplayContent();
	if (displayContent == null) {
	return false;
	}
	Display display = displayContent.getDisplay();
	mDragState.register(display);
	if (!mService.mInputManager.transferTouchFocus(callingWin.mInputChannel,
	mDragState.getInputChannel())) {
	Slog.e(TAG_WM, "Unable to transfer touch focus");
	mDragState.closeLocked();
	return false;
	}

	mDragState.mDisplayContent = displayContent;
	mDragState.mData = data;
	mDragState.broadcastDragStartedLocked(touchX, touchY);
	mDragState.overridePointerIconLocked(touchSource);

	// remember the thumb offsets for later
	mDragState.mThumbOffsetX = thumbCenterX;
	mDragState.mThumbOffsetY = thumbCenterY;

	// Make the surface visible at the proper location
	final SurfaceControl surfaceControl = mDragState.mSurfaceControl;
	if (SHOW_LIGHT_TRANSACTIONS) Slog.i(TAG_WM, ">>> OPEN TRANSACTION performDrag");
	mService.openSurfaceTransaction();
	try {
	surfaceControl.setPosition(touchX - thumbCenterX,
	touchY - thumbCenterY);
	surfaceControl.setLayer(mDragState.getDragLayerLocked());
	surfaceControl.setLayerStack(display.getLayerStack());
	surfaceControl.show();
	} finally {
	mService.closeSurfaceTransaction("performDrag");
	if (SHOW_LIGHT_TRANSACTIONS) {
	Slog.i(TAG_WM, "<<< CLOSE TRANSACTION performDrag");
	}
	}

	mDragState.notifyLocationLocked(touchX, touchY);
	}
	}

	return true; // success!
	}

	void reportDropResult(IWindow window, boolean consumed) {
	IBinder token = window.asBinder();
	if (DEBUG_DRAG) {
	Slog.d(TAG_WM, "Drop result=" + consumed + " reported by " + token);
	}

	synchronized (mWriteLock) {
	mCallback.reportDropResult(window, consumed);
	synchronized (mService.mWindowMap) {
	if (mDragState == null) {
	// Most likely the drop recipient ANRed and we ended the drag
	// out from under it. Log the issue and move on.
	Slog.w(TAG_WM, "Drop result given but no drag in progress");
	return;
	}

	if (mDragState.mToken != token) {
	// We're in a drag, but the wrong window has responded.
	Slog.w(TAG_WM, "Invalid drop-result claim by " + window);
	throw new IllegalStateException("reportDropResult() by non-recipient");
	}

	// The right window has responded, even if it's no longer around,
	// so be sure to halt the timeout even if the later WindowState
	// lookup fails.
	mHandler.removeMessages(MSG_DRAG_END_TIMEOUT, window.asBinder());
	WindowState callingWin = mService.windowForClientLocked(null, window, false);
	if (callingWin == null) {
	Slog.w(TAG_WM, "Bad result-reporting window " + window);
	return; // !!! TODO: throw here?
	}


	mDragState.mDragResult = consumed;
	mDragState.endDragLocked();
	}
	}
	}

	void cancelDragAndDrop(IBinder dragToken) {
	if (DEBUG_DRAG) {
	Slog.d(TAG_WM, "cancelDragAndDrop");
	}

	synchronized (mWriteLock) {
	mCallback.cancelDragAndDrop(dragToken);
	synchronized (mService.mWindowMap) {
	if (mDragState == null) {
	Slog.w(TAG_WM, "cancelDragAndDrop() without prepareDrag()");
	throw new IllegalStateException("cancelDragAndDrop() without prepareDrag()");
	}

	if (mDragState.mToken != dragToken) {
	Slog.w(TAG_WM,
	"cancelDragAndDrop() does not match prepareDrag()");
	throw new IllegalStateException(
	"cancelDragAndDrop() does not match prepareDrag()");
	}

	mDragState.mDragResult = false;
	mDragState.cancelDragLocked();
	}
	}
	}

	/**
	* Handles motion events.
	* @param keepHandling Whether if the drag operation is continuing or this is the last motion
	* event.
	* @param newX X coordinate value in dp in the screen coordinate
	* @param newY Y coordinate value in dp in the screen coordinate
	*/
	void handleMotionEvent(boolean keepHandling, float newX, float newY) {
	synchronized (mWriteLock) {
	synchronized (mService.mWindowMap) {
	if (!dragDropActiveLocked()) {
	// The drag has ended but the clean-up message has not been processed by
	// window manager. Drop events that occur after this until window manager
	// has a chance to clean-up the input handle.
	return;
	}

	if (keepHandling) {
	mDragState.notifyMoveLocked(newX, newY);
	} else {
	mDragState.notifyDropLocked(newX, newY);
	}
	}
	}
	}

	void dragRecipientEntered(IWindow window) {
	if (DEBUG_DRAG) {
	Slog.d(TAG_WM, "Drag into new candidate view @ " + window.asBinder());
	}
	}

	void dragRecipientExited(IWindow window) {
	if (DEBUG_DRAG) {
	Slog.d(TAG_WM, "Drag from old candidate view @ " + window.asBinder());
	}
	}

	/**
	* Sends a message to the Handler managed by DragDropController.
	*/
	void sendHandlerMessage(int what, Object arg) {
	mHandler.obtainMessage(what, arg).sendToTarget();
	}

	/**
	* Sends a timeout message to the Handler managed by DragDropController.
	*/
	void sendTimeoutMessage(int what, Object arg) {
	mHandler.removeMessages(what, arg);
	final Message msg = mHandler.obtainMessage(what, arg);
	mHandler.sendMessageDelayed(msg, DRAG_TIMEOUT_MS);
	}

	/**
	* Notifies the current drag state is closed.
	*/
	void onDragStateClosedLocked(DragState dragState) {
	if (mDragState != dragState) {
	Slog.wtf(TAG_WM, "Unknown drag state is closed");
	return;
	}
	mDragState = null;
	}

	private class DragHandler extends Handler {
	/**
	* Lock for window manager.
	*/
	private final WindowManagerService mService;

	DragHandler(WindowManagerService service, Looper looper) {
	super(looper);
	mService = service;
	}

	@Override
	public void handleMessage(Message msg) {
	switch (msg.what) {
	case MSG_DRAG_START_TIMEOUT: {
	IBinder win = (IBinder) msg.obj;
	if (DEBUG_DRAG) {
	Slog.w(TAG_WM, "Timeout starting drag by win " + win);
	}
	synchronized (mWriteLock) {
	synchronized (mService.mWindowMap) {
	// !!! TODO: ANR the app that has failed to start the drag in time
	if (mDragState != null) {
	mDragState.closeLocked();
	}
	}
	}
	break;
	}

	case MSG_DRAG_END_TIMEOUT: {
	final IBinder win = (IBinder) msg.obj;
	if (DEBUG_DRAG) {
	Slog.w(TAG_WM, "Timeout ending drag to win " + win);
	}
	synchronized (mWriteLock) {
	synchronized (mService.mWindowMap) {
	// !!! TODO: ANR the drag-receiving app
	if (mDragState != null) {
	mDragState.mDragResult = false;
	mDragState.endDragLocked();
	}
	}
	}
	break;
	}

	case MSG_TEAR_DOWN_DRAG_AND_DROP_INPUT: {
	if (DEBUG_DRAG)
	Slog.d(TAG_WM, "Drag ending; tearing down input channel");
	final DragState.InputInterceptor interceptor =
	(DragState.InputInterceptor) msg.obj;
	if (interceptor == null) return;
	synchronized (mService.mWindowMap) {
	interceptor.tearDown();
	}
	break;
	}

	case MSG_ANIMATION_END: {
	synchronized (mWriteLock) {
	synchronized (mService.mWindowMap) {
	if (mDragState == null) {
	Slog.wtf(TAG_WM, "mDragState unexpectedly became null while " +
	"plyaing animation");
	return;
	}
	mDragState.closeLocked();
	}
	}
	break;
	}
	}
	}
	}
	}