Limit capabilities of a11y gesture dispatch. am: a8918f23c7 (3d40beac) · Commits · e / os / android_frameworks_base

core/java/android/accessibilityservice/AccessibilityService.java

+4 −4

Original line number	Diff line number	Diff line
		@@ -628,8 +628,8 @@ public abstract class AccessibilityService extends Service {
		if (connection == null) {
		return false;
		}
		List<MotionEvent> events = MotionEventGenerator.getMotionEventsFromGestureDescription(
		gesture, 100);
		List<GestureDescription.GestureStep> steps =
		MotionEventGenerator.getGestureStepsFromGestureDescription(gesture, 100);
		try {
		synchronized (mLock) {
		mGestureStatusCallbackSequence++;
		@@ -641,8 +641,8 @@ public abstract class AccessibilityService extends Service {
		callback, handler);
		mGestureStatusCallbackInfos.put(mGestureStatusCallbackSequence, callbackInfo);
		}
		connection.sendMotionEvents(mGestureStatusCallbackSequence,
		new ParceledListSlice<>(events));
		connection.sendGesture(mGestureStatusCallbackSequence,
		new ParceledListSlice<>(steps));
		}
		} catch (RemoteException re) {
		throw new RuntimeException(re);

core/java/android/accessibilityservice/GestureDescription.java

+141 −19

Original line number	Diff line number	Diff line
		@@ -21,6 +21,8 @@ import android.annotation.NonNull;
		import android.graphics.Path;
		import android.graphics.PathMeasure;
		import android.graphics.RectF;
		import android.os.Parcel;
		import android.os.Parcelable;
		import android.view.InputDevice;
		import android.view.MotionEvent;
		import android.view.MotionEvent.PointerCoords;
		@@ -303,13 +305,37 @@ public final class GestureDescription {
		}
		}

		private static class TouchPoint {
		/**
		* The location of a finger for gesture dispatch
		*
		* @hide
		*/
		public static class TouchPoint implements Parcelable {
		private static final int FLAG_IS_START_OF_PATH = 0x01;
		private static final int FLAG_IS_END_OF_PATH = 0x02;

		int mPathIndex;
		boolean mIsStartOfPath;
		boolean mIsEndOfPath;
		float mX;
		float mY;

		public TouchPoint() {
		}

		public TouchPoint(TouchPoint pointToCopy) {
		copyFrom(pointToCopy);
		}

		public TouchPoint(Parcel parcel) {
		mPathIndex = parcel.readInt();
		int startEnd = parcel.readInt();
		mIsStartOfPath = (startEnd & FLAG_IS_START_OF_PATH) != 0;
		mIsEndOfPath = (startEnd & FLAG_IS_END_OF_PATH) != 0;
		mX = parcel.readFloat();
		mY = parcel.readFloat();
		}

		void copyFrom(TouchPoint other) {
		mPathIndex = other.mPathIndex;
		mIsStartOfPath = other.mIsStartOfPath;
		@@ -317,12 +343,94 @@ public final class GestureDescription {
		mX = other.mX;
		mY = other.mY;
		}

		@Override
		public int describeContents() {
		return 0;
		}

		@Override
		public void writeToParcel(Parcel dest, int flags) {
		dest.writeInt(mPathIndex);
		int startEnd = mIsStartOfPath ? FLAG_IS_START_OF_PATH : 0;
		startEnd \|= mIsEndOfPath ? FLAG_IS_END_OF_PATH : 0;
		dest.writeInt(startEnd);
		dest.writeFloat(mX);
		dest.writeFloat(mY);
		}

		public static final Parcelable.Creator<TouchPoint> CREATOR
		= new Parcelable.Creator<TouchPoint>() {
		public TouchPoint createFromParcel(Parcel in) {
		return new TouchPoint(in);
		}

		public TouchPoint[] newArray(int size) {
		return new TouchPoint[size];
		}
		};
		}

		/**
		* A step along a gesture. Contains all of the touch points at a particular time
		*
		* @hide
		*/
		public static class GestureStep implements Parcelable {
		public long timeSinceGestureStart;
		public int numTouchPoints;
		public TouchPoint[] touchPoints;

		public GestureStep(long timeSinceGestureStart, int numTouchPoints,
		TouchPoint[] touchPointsToCopy) {
		this.timeSinceGestureStart = timeSinceGestureStart;
		this.numTouchPoints = numTouchPoints;
		this.touchPoints = new TouchPoint[numTouchPoints];
		for (int i = 0; i < numTouchPoints; i++) {
		this.touchPoints[i] = new TouchPoint(touchPointsToCopy[i]);
		}
		}

		public GestureStep(Parcel parcel) {
		timeSinceGestureStart = parcel.readLong();
		Parcelable[] parcelables =
		parcel.readParcelableArray(TouchPoint.class.getClassLoader());
		numTouchPoints = (parcelables == null) ? 0 : parcelables.length;
		touchPoints = new TouchPoint[numTouchPoints];
		for (int i = 0; i < numTouchPoints; i++) {
		touchPoints[i] = (TouchPoint) parcelables[i];
		}
		}

		@Override
		public int describeContents() {
		return 0;
		}

		@Override
		public void writeToParcel(Parcel dest, int flags) {
		dest.writeLong(timeSinceGestureStart);
		dest.writeParcelableArray(touchPoints, flags);
		}

		public static final Parcelable.Creator<GestureStep> CREATOR
		= new Parcelable.Creator<GestureStep>() {
		public GestureStep createFromParcel(Parcel in) {
		return new GestureStep(in);
		}

		public GestureStep[] newArray(int size) {
		return new GestureStep[size];
		}
		};
		}

		/**
		* Class to convert a GestureDescription to a series of MotionEvents.
		*
		* @hide
		*/
		static class MotionEventGenerator {
		public static class MotionEventGenerator {
		/**
		* Constants used to initialize all MotionEvents
		*/
		@@ -341,38 +449,52 @@ public final class GestureDescription {
		private static PointerCoords[] sPointerCoords;
		private static PointerProperties[] sPointerProps;

		static List<MotionEvent> getMotionEventsFromGestureDescription(
		static List<GestureStep> getGestureStepsFromGestureDescription(
		GestureDescription description, int sampleTimeMs) {
		final List<MotionEvent> motionEvents = new ArrayList<>();
		final List<GestureStep> gestureSteps = new ArrayList<>();

		// Point data at each time we generate an event for
		final TouchPoint[] currentTouchPoints =
		getCurrentTouchPoints(description.getStrokeCount());
		// Point data sent in last touch event
		int lastTouchPointSize = 0;
		final TouchPoint[] lastTouchPoints =
		getLastTouchPoints(description.getStrokeCount());

		int currentTouchPointSize = 0;
		/* Loop through each time slice where there are touch points */
		long timeSinceGestureStart = 0;
		long nextKeyPointTime = description.getNextKeyPointAtLeast(timeSinceGestureStart);
		while (nextKeyPointTime >= 0) {
		timeSinceGestureStart = (lastTouchPointSize == 0) ? nextKeyPointTime
		timeSinceGestureStart = (currentTouchPointSize == 0) ? nextKeyPointTime
		: Math.min(nextKeyPointTime, timeSinceGestureStart + sampleTimeMs);
		int currentTouchPointSize = description.getPointsForTime(timeSinceGestureStart,
		currentTouchPointSize = description.getPointsForTime(timeSinceGestureStart,
		currentTouchPoints);
		gestureSteps.add(new GestureStep(timeSinceGestureStart, currentTouchPointSize,
		currentTouchPoints));

		/* Move to next time slice */
		nextKeyPointTime = description.getNextKeyPointAtLeast(timeSinceGestureStart + 1);
		}
		return gestureSteps;
		}

		public static List<MotionEvent> getMotionEventsFromGestureSteps(List<GestureStep> steps) {
		final List<MotionEvent> motionEvents = new ArrayList<>();

		// Number of points in last touch event
		int lastTouchPointSize = 0;
		TouchPoint[] lastTouchPoints;

		for (int i = 0; i < steps.size(); i++) {
		GestureStep step = steps.get(i);
		int currentTouchPointSize = step.numTouchPoints;
		lastTouchPoints = getLastTouchPoints(
		Math.max(lastTouchPointSize, currentTouchPointSize));

		appendMoveEventIfNeeded(motionEvents, lastTouchPoints, lastTouchPointSize,
		currentTouchPoints, currentTouchPointSize, timeSinceGestureStart);
		step.touchPoints, currentTouchPointSize, step.timeSinceGestureStart);
		lastTouchPointSize = appendUpEvents(motionEvents, lastTouchPoints,
		lastTouchPointSize, currentTouchPoints, currentTouchPointSize,
		timeSinceGestureStart);
		lastTouchPointSize, step.touchPoints, currentTouchPointSize,
		step.timeSinceGestureStart);
		lastTouchPointSize = appendDownEvents(motionEvents, lastTouchPoints,
		lastTouchPointSize, currentTouchPoints, currentTouchPointSize,
		timeSinceGestureStart);

		/* Move to next time slice */
		nextKeyPointTime = description.getNextKeyPointAtLeast(timeSinceGestureStart + 1);
		lastTouchPointSize, step.touchPoints, currentTouchPointSize,
		step.timeSinceGestureStart);
		}
		return motionEvents;
		}

core/java/android/accessibilityservice/IAccessibilityServiceConnection.aidl

+1 −1

Original line number	Diff line number	Diff line
		@@ -88,5 +88,5 @@ interface IAccessibilityServiceConnection {

		void setSoftKeyboardCallbackEnabled(boolean enabled);

		void sendMotionEvents(int sequence, in ParceledListSlice events);
		void sendGesture(int sequence, in ParceledListSlice gestureSteps);
		}

services/accessibility/java/com/android/server/accessibility/AccessibilityManagerService.java

+12 −4

Original line number	Diff line number	Diff line
		@@ -21,6 +21,7 @@ import static android.accessibilityservice.AccessibilityServiceInfo.DEFAULT;
		import android.Manifest;
		import android.accessibilityservice.AccessibilityService;
		import android.accessibilityservice.AccessibilityServiceInfo;
		import android.accessibilityservice.GestureDescription;
		import android.accessibilityservice.IAccessibilityServiceClient;
		import android.accessibilityservice.IAccessibilityServiceConnection;
		import android.annotation.NonNull;
		@@ -2752,7 +2753,7 @@ public class AccessibilityManagerService extends IAccessibilityManager.Stub {
		}

		@Override
		public void sendMotionEvents(int sequence, ParceledListSlice events) {
		public void sendGesture(int sequence, ParceledListSlice gestureSteps) {
		synchronized (mLock) {
		if (mSecurityPolicy.canPerformGestures(this)) {
		final long endMillis =
		@@ -2766,9 +2767,16 @@ public class AccessibilityManagerService extends IAccessibilityManager.Stub {
		}
		}
		if (mMotionEventInjector != null) {
		mMotionEventInjector.injectEvents((List<MotionEvent>) events.getList(),
		mServiceInterface, sequence);
		List<GestureDescription.GestureStep> steps = gestureSteps.getList();
		List<MotionEvent> events = GestureDescription.MotionEventGenerator
		.getMotionEventsFromGestureSteps(steps);
		// Confirm that the motion events end with an UP event.
		if (events.get(events.size() - 1).getAction() == MotionEvent.ACTION_UP) {
		mMotionEventInjector.injectEvents(events, mServiceInterface, sequence);
		return;
		} else {
		Slog.e(LOG_TAG, "Gesture is not well-formed");
		}
		} else {
		Slog.e(LOG_TAG, "MotionEventInjector installation timed out");
		}