Fix gesture start detection algorithm (02a67200) · Commits · e / os / android_packages_inputmethods_LatinIME

java/src/com/android/inputmethod/keyboard/PointerTracker.java

+5 −5

Original line number	Diff line number	Diff line
		@@ -688,7 +688,7 @@ public class PointerTracker implements PointerTrackerQueue.Element {
		mIsDetectingGesture = true;
		final int elapsedTimeFromFirstDown = (int)(eventTime - sGestureFirstDownTime);
		mGestureStrokeWithPreviewPoints.addPoint(x, y, elapsedTimeFromFirstDown,
		false /* isHistorical */);
		true /* isMajorEvent */);
		}

		private void onDownEventInternal(final int x, final int y, final long eventTime) {
		@@ -724,10 +724,10 @@ public class PointerTracker implements PointerTrackerQueue.Element {
		}

		private void onGestureMoveEvent(final int x, final int y, final long eventTime,
		final boolean isHistorical, final Key key) {
		final boolean isMajorEvent, final Key key) {
		final int gestureTime = (int)(eventTime - sGestureFirstDownTime);
		if (mIsDetectingGesture) {
		mGestureStrokeWithPreviewPoints.addPoint(x, y, gestureTime, isHistorical);
		mGestureStrokeWithPreviewPoints.addPoint(x, y, gestureTime, isMajorEvent);
		mayStartBatchInput();
		if (sInGesture && key != null) {
		updateBatchInput(eventTime);
		@@ -752,7 +752,7 @@ public class PointerTracker implements PointerTrackerQueue.Element {
		final int historicalY = (int)me.getHistoricalY(pointerIndex, h);
		final long historicalTime = me.getHistoricalEventTime(h);
		onGestureMoveEvent(historicalX, historicalY, historicalTime,
		true /* isHistorical */, null);
		false /* isMajorEvent */, null);
		}
		}

		@@ -767,7 +767,7 @@ public class PointerTracker implements PointerTrackerQueue.Element {

		if (sShouldHandleGesture) {
		// Register move event on gesture tracker.
		onGestureMoveEvent(x, y, eventTime, false /* isHistorical */, key);
		onGestureMoveEvent(x, y, eventTime, true /* isMajorEvent */, key);
		if (sInGesture) {
		mIgnoreModifierKey = true;
		mTimerProxy.cancelLongPressTimer();

java/src/com/android/inputmethod/keyboard/internal/GestureStroke.java

+114 −47

Original line number	Diff line number	Diff line
		@@ -14,34 +14,45 @@

		package com.android.inputmethod.keyboard.internal;

		import android.util.Log;

		import com.android.inputmethod.latin.InputPointers;
		import com.android.inputmethod.latin.ResizableIntArray;

		public class GestureStroke {
		private static final String TAG = GestureStroke.class.getSimpleName();
		private static final boolean DEBUG = false;

		public static final int DEFAULT_CAPACITY = 128;

		private final int mPointerId;
		private final ResizableIntArray mEventTimes = new ResizableIntArray(DEFAULT_CAPACITY);
		private final ResizableIntArray mXCoordinates = new ResizableIntArray(DEFAULT_CAPACITY);
		private final ResizableIntArray mYCoordinates = new ResizableIntArray(DEFAULT_CAPACITY);
		private float mLength;
		private int mIncrementalRecognitionSize;
		private int mLastIncrementalBatchSize;
		private long mLastPointTime;
		private int mLastPointX;
		private int mLastPointY;

		private int mMinGestureLength; // pixel
		private int mMinGestureSampleLength; // pixel
		private int mGestureRecognitionThreshold; // pixel / sec
		private long mLastMajorEventTime;
		private int mLastMajorEventX;
		private int mLastMajorEventY;

		private int mKeyWidth;
		private int mStartGestureLengthThreshold; // pixel
		private int mMinGestureSamplingLength; // pixel
		private int mGestureRecognitionSpeedThreshold; // pixel / sec
		private int mDetectFastMoveSpeedThreshold; // pixel /sec
		private int mDetectFastMoveTime;
		private int mDetectFastMoveX;
		private int mDetectFastMoveY;

		// TODO: Move some of these to resource.
		private static final float MIN_GESTURE_LENGTH_RATIO_TO_KEY_WIDTH = 0.75f;
		private static final int MIN_GESTURE_START_DURATION = 100; // msec
		private static final float START_GESTURE_LENGTH_THRESHOLD_RATIO_TO_KEY_WIDTH = 0.75f;
		private static final int START_GESTURE_DURATION_THRESHOLD = 70; // msec
		private static final int MIN_GESTURE_RECOGNITION_TIME = 100; // msec
		private static final float MIN_GESTURE_SAMPLING_RATIO_TO_KEY_WIDTH = 1.0f / 6.0f;
		private static final float GESTURE_RECOGNITION_SPEED_THRESHOLD_RATIO_TO_KEY_WIDTH =
		5.5f; // keyWidth / sec
		private static final float DETECT_FAST_MOVE_SPEED_THRESHOLD_RATIO_TO_KEY_WIDTH =
		5.0f; // keyWidth / sec
		private static final int MSEC_PER_SEC = 1000;

		public static final boolean hasRecognitionTimePast(
		@@ -54,65 +65,121 @@ public class GestureStroke {
		}

		public void setKeyboardGeometry(final int keyWidth) {
		mKeyWidth = keyWidth;
		// TODO: Find an appropriate base metric for these length. Maybe diagonal length of the key?
		mMinGestureLength = (int)(keyWidth * MIN_GESTURE_LENGTH_RATIO_TO_KEY_WIDTH);
		mMinGestureSampleLength = (int)(keyWidth * MIN_GESTURE_SAMPLING_RATIO_TO_KEY_WIDTH);
		mGestureRecognitionThreshold =
		mStartGestureLengthThreshold =
		(int)(keyWidth * START_GESTURE_LENGTH_THRESHOLD_RATIO_TO_KEY_WIDTH);
		mMinGestureSamplingLength = (int)(keyWidth * MIN_GESTURE_SAMPLING_RATIO_TO_KEY_WIDTH);
		mGestureRecognitionSpeedThreshold =
		(int)(keyWidth * GESTURE_RECOGNITION_SPEED_THRESHOLD_RATIO_TO_KEY_WIDTH);
		mDetectFastMoveSpeedThreshold =
		(int)(keyWidth * DETECT_FAST_MOVE_SPEED_THRESHOLD_RATIO_TO_KEY_WIDTH);
		if (DEBUG) {
		Log.d(TAG, "setKeyboardGeometry: keyWidth=" + keyWidth);
		}
		}

		public boolean isStartOfAGesture() {
		if (mDetectFastMoveTime == 0) {
		return false;
		}
		final int size = mEventTimes.getLength();
		final int downDuration = (size > 0) ? mEventTimes.get(size - 1) : 0;
		return downDuration > MIN_GESTURE_START_DURATION && mLength > mMinGestureLength;
		if (size <= 0) {
		return false;
		}
		final int lastIndex = size - 1;
		final int deltaTime = mEventTimes.get(lastIndex) - mDetectFastMoveTime;
		final int deltaLength = getDistance(
		mXCoordinates.get(lastIndex), mYCoordinates.get(lastIndex),
		mDetectFastMoveX, mDetectFastMoveY);
		final boolean isStartOfAGesture = deltaTime > START_GESTURE_DURATION_THRESHOLD
		&& deltaLength > mStartGestureLengthThreshold;
		if (DEBUG) {
		Log.d(TAG, "isStartOfAGesture: dT=" + deltaTime + " dL=" + deltaLength
		+ " points=" + size + (isStartOfAGesture ? " Detect start of a gesture" : ""));
		}
		return isStartOfAGesture;
		}

		public void reset() {
		mLength = 0;
		mIncrementalRecognitionSize = 0;
		mLastIncrementalBatchSize = 0;
		mLastPointTime = 0;
		mEventTimes.setLength(0);
		mXCoordinates.setLength(0);
		mYCoordinates.setLength(0);
		mLastMajorEventTime = 0;
		mDetectFastMoveTime = 0;
		}

		public void addPoint(final int x, final int y, final int time, final boolean isHistorical) {
		final boolean needsSampling;
		private void appendPoint(final int x, final int y, final int time) {
		mEventTimes.add(time);
		mXCoordinates.add(x);
		mYCoordinates.add(y);
		}

		private void updateMajorEvent(final int x, final int y, final int time) {
		mLastMajorEventTime = time;
		mLastMajorEventX = x;
		mLastMajorEventY = y;
		}

		private int detectFastMove(final int x, final int y, final int time) {
		final int size = mEventTimes.getLength();
		if (size == 0) {
		needsSampling = true;
		} else {
		final int lastIndex = size - 1;
		final int lastX = mXCoordinates.get(lastIndex);
		final int lastY = mYCoordinates.get(lastIndex);
		final float dist = getDistance(lastX, lastY, x, y);
		needsSampling = dist > mMinGestureSampleLength;
		mLength += dist;
		final int dist = getDistance(lastX, lastY, x, y);
		final int msecs = time - mEventTimes.get(lastIndex);
		if (msecs > 0) {
		final int pixels = getDistance(lastX, lastY, x, y);
		final int pixelsPerSec = pixels * MSEC_PER_SEC;
		if (DEBUG) {
		final float speed = (float)pixelsPerSec / msecs / mKeyWidth;
		Log.d(TAG, String.format("Speed=%.3f keyWidth/sec", speed));
		}
		// Equivalent to (pixels / msecs < mStartSpeedThreshold / MSEC_PER_SEC)
		if (mDetectFastMoveTime == 0 && pixelsPerSec > mDetectFastMoveSpeedThreshold * msecs) {
		if (DEBUG) {
		Log.d(TAG, "Detect fast move: T=" + time + " points = " + size);
		}
		mDetectFastMoveTime = time;
		mDetectFastMoveX = x;
		mDetectFastMoveY = y;
		}
		}
		return dist;
		}

		public void addPoint(final int x, final int y, final int time, final boolean isMajorEvent) {
		final int size = mEventTimes.getLength();
		if (size <= 0) {
		// Down event
		appendPoint(x, y, time);
		updateMajorEvent(x, y, time);
		} else {
		final int dist = detectFastMove(x, y, time);
		if (dist > mMinGestureSamplingLength) {
		appendPoint(x, y, time);
		}
		if (needsSampling) {
		mEventTimes.add(time);
		mXCoordinates.add(x);
		mYCoordinates.add(y);
		}
		if (!isHistorical) {
		if (isMajorEvent) {
		updateIncrementalRecognitionSize(x, y, time);
		updateMajorEvent(x, y, time);
		}
		}

		private void updateIncrementalRecognitionSize(final int x, final int y, final int time) {
		final int msecs = (int)(time - mLastPointTime);
		if (msecs > 0) {
		final int pixels = (int)getDistance(mLastPointX, mLastPointY, x, y);
		final int msecs = (int)(time - mLastMajorEventTime);
		if (msecs <= 0) {
		return;
		}
		final int pixels = getDistance(mLastMajorEventX, mLastMajorEventY, x, y);
		final int pixelsPerSec = pixels * MSEC_PER_SEC;
		// Equivalent to (pixels / msecs < mGestureRecognitionThreshold / MSEC_PER_SEC)
		if (pixels * MSEC_PER_SEC < mGestureRecognitionThreshold * msecs) {
		if (pixelsPerSec < mGestureRecognitionSpeedThreshold * msecs) {
		mIncrementalRecognitionSize = mEventTimes.getLength();
		}
		}
		mLastPointTime = time;
		mLastPointX = x;
		mLastPointY = y;
		}

		public void appendAllBatchPoints(final InputPointers out) {
		appendBatchPoints(out, mEventTimes.getLength());
		@@ -132,11 +199,11 @@ public class GestureStroke {
		mLastIncrementalBatchSize = size;
		}

		private static float getDistance(final int x1, final int y1, final int x2, final int y2) {
		final float dx = x1 - x2;
		final float dy = y1 - y2;
		private static int getDistance(final int x1, final int y1, final int x2, final int y2) {
		final int dx = x1 - x2;
		final int dy = y1 - y2;
		// Note that, in recent versions of Android, FloatMath is actually slower than
		// java.lang.Math due to the way the JIT optimizes java.lang.Math.
		return (float)Math.sqrt(dx * dx + dy * dy);
		return (int)Math.sqrt(dx * dx + dy * dy);
		}
		}

java/src/com/android/inputmethod/keyboard/internal/GestureStrokeWithPreviewPoints.java

+6 −9

Original line number	Diff line number	Diff line
		@@ -65,21 +65,18 @@ public class GestureStrokeWithPreviewPoints extends GestureStroke {
		private boolean needsSampling(final int x, final int y) {
		final int dx = x - mLastX;
		final int dy = y - mLastY;
		final boolean needsSampling = (dx * dx + dy * dy >= mMinPreviewSampleLengthSquare);
		if (needsSampling) {
		mLastX = x;
		mLastY = y;
		}
		return needsSampling;
		return dx * dx + dy * dy >= mMinPreviewSampleLengthSquare;
		}

		@Override
		public void addPoint(final int x, final int y, final int time, final boolean isHistorical) {
		super.addPoint(x, y, time, isHistorical);
		if (mPreviewEventTimes.getLength() == 0 \|\| isHistorical \|\| needsSampling(x, y)) {
		public void addPoint(final int x, final int y, final int time, final boolean isMajorEvent) {
		super.addPoint(x, y, time, isMajorEvent);
		if (isMajorEvent \|\| needsSampling(x, y)) {
		mPreviewEventTimes.add(time);
		mPreviewXCoordinates.add(x);
		mPreviewYCoordinates.add(y);
		mLastX = x;
		mLastY = y;
		}
		}

java/src/com/android/inputmethod/latin/BinaryDictionary.java

+1 −1

Original line number	Diff line number	Diff line
		@@ -45,7 +45,7 @@ public class BinaryDictionary extends Dictionary {
		public static final int MAX_WORDS = 18;
		public static final int MAX_SPACES = 16;

		private static final String TAG = "BinaryDictionary";
		private static final String TAG = BinaryDictionary.class.getSimpleName();
		private static final int MAX_PREDICTIONS = 60;
		private static final int MAX_RESULTS = Math.max(MAX_PREDICTIONS, MAX_WORDS);

java/src/com/android/inputmethod/latin/UserHistoryDictionary.java

+1 −1

Original line number	Diff line number	Diff line
		@@ -42,7 +42,7 @@ import java.util.concurrent.locks.ReentrantLock;
		* cancellation or manual picks. This allows the keyboard to adapt to the typist over time.
		*/
		public class UserHistoryDictionary extends ExpandableDictionary {
		private static final String TAG = "UserHistoryDictionary";
		private static final String TAG = UserHistoryDictionary.class.getSimpleName();
		public static final boolean DBG_SAVE_RESTORE = false;
		public static final boolean DBG_STRESS_TEST = false;
		public static final boolean DBG_ALWAYS_WRITE = false;