Merge "Do not prefetching accessibility nodes while a view is scrolling" into... (33374f1e) · Commits · e / os / android_frameworks_base

core/java/android/view/accessibility/AccessibilityInteractionClient.java

+73 −0

Original line number	Diff line number	Diff line
		@@ -31,7 +31,9 @@ import android.os.SystemClock;
		import android.util.Log;
		import android.util.LongSparseArray;
		import android.util.SparseArray;
		import android.util.SparseLongArray;
		import android.view.Display;
		import android.view.ViewConfiguration;

		import com.android.internal.annotations.VisibleForTesting;
		import com.android.internal.util.ArrayUtils;
		@@ -89,6 +91,9 @@ public final class AccessibilityInteractionClient

		private static final long TIMEOUT_INTERACTION_MILLIS = 5000;

		private static final long DISABLE_PREFETCHING_FOR_SCROLLING_MILLIS =
		(long) (ViewConfiguration.getSendRecurringAccessibilityEventsInterval() * 1.5);

		private static final Object sStaticLock = new Object();

		private static final LongSparseArray<AccessibilityInteractionClient> sClients =
		@@ -97,6 +102,10 @@ public final class AccessibilityInteractionClient
		private static final SparseArray<IAccessibilityServiceConnection> sConnectionCache =
		new SparseArray<>();

		/** List of timestamps which indicate the latest time an a11y service receives a scroll event
		from a window, mapping from windowId -> timestamp. */
		private static final SparseLongArray sScrollingWindows = new SparseLongArray();

		private static AccessibilityCache sAccessibilityCache =
		new AccessibilityCache(new AccessibilityCache.AccessibilityNodeRefresher());

		@@ -422,6 +431,14 @@ public final class AccessibilityInteractionClient
		Log.i(LOG_TAG, "Node cache miss for "
		+ idToString(accessibilityWindowId, accessibilityNodeId));
		}
		} else {
		// No need to prefech nodes in bypass cache case.
		prefetchFlags &= ~AccessibilityNodeInfo.FLAG_PREFETCH_MASK;
		}
		// Skip prefetching if window is scrolling.
		if ((prefetchFlags & AccessibilityNodeInfo.FLAG_PREFETCH_MASK) != 0
		&& isWindowScrolling(accessibilityWindowId)) {
		prefetchFlags &= ~AccessibilityNodeInfo.FLAG_PREFETCH_MASK;
		}
		final int interactionId = mInteractionIdCounter.getAndIncrement();
		final long identityToken = Binder.clearCallingIdentity();
		@@ -718,6 +735,18 @@ public final class AccessibilityInteractionClient
		}

		public void onAccessibilityEvent(AccessibilityEvent event) {
		switch (event.getEventType()) {
		case AccessibilityEvent.TYPE_VIEW_SCROLLED:
		updateScrollingWindow(event.getWindowId(), SystemClock.uptimeMillis());
		break;
		case AccessibilityEvent.TYPE_WINDOWS_CHANGED:
		if (event.getWindowChanges() == AccessibilityEvent.WINDOWS_CHANGE_REMOVED) {
		deleteScrollingWindow(event.getWindowId());
		}
		break;
		default:
		break;
		}
		sAccessibilityCache.onAccessibilityEvent(event);
		}

		@@ -986,4 +1015,48 @@ public final class AccessibilityInteractionClient
		Log.e(LOG_TAG, disconnectedCount + " Disconnected nodes.");
		}
		}

		/**
		* Update scroll event timestamp of a given window.
		*
		* @param windowId The window id.
		* @param uptimeMillis Device uptime millis.
		*/
		private void updateScrollingWindow(int windowId, long uptimeMillis) {
		synchronized (sScrollingWindows) {
		sScrollingWindows.put(windowId, uptimeMillis);
		}
		}

		/**
		* Remove a window from the scrolling windows list.
		*
		* @param windowId The window id.
		*/
		private void deleteScrollingWindow(int windowId) {
		synchronized (sScrollingWindows) {
		sScrollingWindows.delete(windowId);
		}
		}

		/**
		* Whether or not the window is scrolling.
		*
		* @param windowId
		* @return true if it's scrolling.
		*/
		private boolean isWindowScrolling(int windowId) {
		synchronized (sScrollingWindows) {
		final long latestScrollingTime = sScrollingWindows.get(windowId);
		if (latestScrollingTime == 0) {
		return false;
		}
		final long currentUptime = SystemClock.uptimeMillis();
		if (currentUptime > (latestScrollingTime + DISABLE_PREFETCHING_FOR_SCROLLING_MILLIS)) {
		sScrollingWindows.delete(windowId);
		return false;
		}
		}
		return true;
		}
		}

core/java/android/view/accessibility/AccessibilityNodeInfo.java

+3 −0

Original line number	Diff line number	Diff line
		@@ -137,6 +137,9 @@ public class AccessibilityNodeInfo implements Parcelable {
		/** @hide */
		public static final int FLAG_PREFETCH_DESCENDANTS = 0x00000004;

		/** @hide */
		public static final int FLAG_PREFETCH_MASK = 0x00000007;

		/** @hide */
		public static final int FLAG_INCLUDE_NOT_IMPORTANT_VIEWS = 0x00000008;