Merge "[Magnifier-25] Fix race condition after #dismiss" (24257520) · Commits · e / os / android_frameworks_base

core/java/android/widget/Magnifier.java

+26 −14

Original line number	Diff line number	Diff line
		@@ -89,6 +89,9 @@ public final class Magnifier {
		NONEXISTENT_PREVIOUS_CONFIG_VALUE, NONEXISTENT_PREVIOUS_CONFIG_VALUE);
		// Rectangle defining the view surface area we pixel copy content from.
		private final Rect mPixelCopyRequestRect = new Rect();
		// Lock to synchronize between the UI thread and the thread that handles pixel copy results.
		// Only sync mWindow writes from UI thread with mWindow reads from sPixelCopyHandlerThread.
		private final Object mLock = new Object();

		/**
		* Initializes a magnifier.
		@@ -170,9 +173,12 @@ public final class Magnifier {

		if (xPosInView != mPrevPosInView.x \|\| yPosInView != mPrevPosInView.y) {
		if (mWindow == null) {
		synchronized (mLock) {
		mWindow = new InternalPopupWindow(mView.getContext(), mView.getDisplay(),
		getValidViewSurface(), mWindowWidth, mWindowHeight, mWindowElevation,
		Handler.getMain() /* draw the magnifier on the UI thread */, mCallback);
		Handler.getMain() /* draw the magnifier on the UI thread */, mLock,
		mCallback);
		}
		}
		performPixelCopy(startX, startY, true /* update window position */);
		mPrevPosInView.x = xPosInView;
		@@ -200,10 +206,12 @@ public final class Magnifier {
		*/
		public void dismiss() {
		if (mWindow != null) {
		synchronized (mLock) {
		mWindow.destroy();
		mWindow = null;
		}
		}
		}

		/**
		* Forces the magnifier to update its content. It uses the previous coordinates passed to
		@@ -281,20 +289,23 @@ public final class Magnifier {
		clampedStartYInSurface + mBitmapHeight);
		final int windowCoordsX = mWindowCoords.x;
		final int windowCoordsY = mWindowCoords.y;
		final InternalPopupWindow currentWindowInstance = mWindow;

		final Bitmap bitmap =
		Bitmap.createBitmap(mBitmapWidth, mBitmapHeight, Bitmap.Config.ARGB_8888);
		PixelCopy.request(surface, mPixelCopyRequestRect, bitmap,
		result -> {
		synchronized (mWindow.mLock) {
		if (mWindow != null) {
		synchronized (mLock) {
		if (mWindow != currentWindowInstance) {
		// The magnifier was dismissed (and maybe shown again) in the meantime.
		return;
		}
		if (updateWindowPosition) {
		// TODO: pull the position update outside #performPixelCopy
		mWindow.setContentPositionForNextDraw(windowCoordsX, windowCoordsY);
		}
		mWindow.updateContent(bitmap);
		}
		}
		},
		sPixelCopyHandlerThread.getThreadHandler());
		mPrevStartCoordsInSurface.x = startXInSurface;
		@@ -337,7 +348,7 @@ public final class Magnifier {
		// Members below describe the state of the magnifier. Reads/writes to them
		// have to be synchronized between the UI thread and the thread that handles
		// the pixel copy results. This is the purpose of mLock.
		private final Object mLock = new Object();
		private final Object mLock;
		// Whether a magnifier frame draw is currently pending in the UI thread queue.
		private boolean mFrameDrawScheduled;
		// The content bitmap.
		@@ -353,8 +364,9 @@ public final class Magnifier {
		InternalPopupWindow(final Context context, final Display display,
		final Surface parentSurface,
		final int width, final int height, final float elevation,
		final Handler handler, final Callback callback) {
		final Handler handler, final Object lock, final Callback callback) {
		mDisplay = display;
		mLock = lock;
		mCallback = callback;

		mContentWidth = width;