Merge "Add pre/post callback to IDragDropCallback" (e6b8e7cf) · Commits · e / os / android_frameworks_base

services/core/java/com/android/server/wm/DragDropController.java

+83 −120

Original line number	Diff line number	Diff line
		@@ -40,6 +40,7 @@ import android.view.View;
		import com.android.internal.util.Preconditions;
		import com.android.server.input.InputWindowHandle;
		import com.android.server.wm.WindowManagerInternal.IDragDropCallback;
		import java.util.concurrent.atomic.AtomicReference;

		/**
		* Managing drag and drop operations initiated by View#startDragAndDrop.
		@@ -66,43 +67,11 @@ class DragDropController {
		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() {};
		@NonNull private AtomicReference<IDragDropCallback> mCallback = new AtomicReference<>(
		new IDragDropCallback() {});

		boolean dragDropActiveLocked() {
		return mDragState != null;
		@@ -114,9 +83,7 @@ class DragDropController {

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

		DragDropController(WindowManagerService service, Looper looper) {
		@@ -136,7 +103,6 @@ class DragDropController {
		+ " asbinder=" + window.asBinder());
		}

		synchronized (mWriteLock) {
		synchronized (mService.mWindowMap) {
		if (dragDropActiveLocked()) {
		Slog.w(TAG_WM, "Drag already in progress");
		@@ -176,7 +142,6 @@ class DragDropController {
		return token;
		}
		}
		}

		boolean performDrag(IWindow window, IBinder dragToken,
		int touchSource, float touchX, float touchY, float thumbCenterX, float thumbCenterY,
		@@ -185,11 +150,11 @@ class DragDropController {
		Slog.d(TAG_WM, "perform drag: win=" + window + " data=" + data);
		}

		synchronized (mWriteLock) {
		if (!mCallback.performDrag(window, dragToken, touchSource, touchX, touchY, thumbCenterX,
		if (!mCallback.get().prePerformDrag(window, dragToken, touchSource, touchX, touchY, thumbCenterX,
		thumbCenterY, data)) {
		return false;
		}
		try {
		synchronized (mService.mWindowMap) {
		if (mDragState == null) {
		Slog.w(TAG_WM, "No drag prepared");
		@@ -260,9 +225,10 @@ class DragDropController {

		mDragState.notifyLocationLocked(touchX, touchY);
		}
		}

		return true; // success!
		} finally {
		mCallback.get().postPerformDrag();
		}
		}

		void reportDropResult(IWindow window, boolean consumed) {
		@@ -271,8 +237,8 @@ class DragDropController {
		Slog.d(TAG_WM, "Drop result=" + consumed + " reported by " + token);
		}

		synchronized (mWriteLock) {
		mCallback.reportDropResult(window, consumed);
		mCallback.get().preReportDropResult(window, consumed);
		try {
		synchronized (mService.mWindowMap) {
		if (mDragState == null) {
		// Most likely the drop recipient ANRed and we ended the drag
		@@ -297,10 +263,11 @@ class DragDropController {
		return; // !!! TODO: throw here?
		}


		mDragState.mDragResult = consumed;
		mDragState.endDragLocked();
		}
		} finally {
		mCallback.get().postReportDropResult();
		}
		}

		@@ -309,8 +276,8 @@ class DragDropController {
		Slog.d(TAG_WM, "cancelDragAndDrop");
		}

		synchronized (mWriteLock) {
		mCallback.cancelDragAndDrop(dragToken);
		mCallback.get().preCancelDragAndDrop(dragToken);
		try {
		synchronized (mService.mWindowMap) {
		if (mDragState == null) {
		Slog.w(TAG_WM, "cancelDragAndDrop() without prepareDrag()");
		@@ -327,6 +294,8 @@ class DragDropController {
		mDragState.mDragResult = false;
		mDragState.cancelDragLocked();
		}
		} finally {
		mCallback.get().postCancelDragAndDrop();
		}
		}

		@@ -338,7 +307,6 @@ class DragDropController {
		* @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
		@@ -354,7 +322,6 @@ class DragDropController {
		}
		}
		}
		}

		void dragRecipientEntered(IWindow window) {
		if (DEBUG_DRAG) {
		@@ -414,14 +381,13 @@ class DragDropController {
		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;
		}

		@@ -430,7 +396,7 @@ class DragDropController {
		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) {
		@@ -438,7 +404,6 @@ class DragDropController {
		mDragState.endDragLocked();
		}
		}
		}
		break;
		}

		@@ -455,7 +420,6 @@ class DragDropController {
		}

		case MSG_ANIMATION_END: {
		synchronized (mWriteLock) {
		synchronized (mService.mWindowMap) {
		if (mDragState == null) {
		Slog.wtf(TAG_WM, "mDragState unexpectedly became null while " +
		@@ -464,7 +428,6 @@ class DragDropController {
		}
		mDragState.closeLocked();
		}
		}
		break;
		}
		}

services/core/java/com/android/server/wm/WindowManagerInternal.java

+21 −6

Original line number	Diff line number	Diff line
		@@ -151,23 +151,38 @@ public abstract class WindowManagerInternal {
		*/
		public interface IDragDropCallback {
		/**
		* Called when drag operation is started.
		* Called when drag operation is starting.
		*/
		default boolean performDrag(IWindow window, IBinder dragToken,
		default boolean prePerformDrag(IWindow window, IBinder dragToken,
		int touchSource, float touchX, float touchY, float thumbCenterX, float thumbCenterY,
		ClipData data) {
		return true;
		}

		/**
		* Called when drop result is reported.
		* Called when drag operation is started.
		*/
		default void postPerformDrag() {}

		/**
		* Called when drop result is being reported.
		*/
		default void preReportDropResult(IWindow window, boolean consumed) {}

		/**
		* Called when drop result was reported.
		*/
		default void postReportDropResult() {}

		/**
		* Called when drag operation is being cancelled.
		*/
		default void reportDropResult(IWindow window, boolean consumed) {}
		default void preCancelDragAndDrop(IBinder dragToken) {}

		/**
		* Called when drag operation is cancelled.
		* Called when drag operation was cancelled.
		*/
		default void cancelDragAndDrop(IBinder dragToken) {}
		default void postCancelDragAndDrop() {}
		}

		/**