am 61dcaaf1: Use device independent parameter for gesture

* commit '61dcaaf17e4d1f9e941b961559a46823e6e25c99':
  Use device independent parameter for gesture
This commit is contained in:
Tadashi G. Takaoka 2012-09-20 06:10:25 -07:00 committed by Android Git Automerger
commit b474b60216

View file

@ -31,15 +31,18 @@ public class GestureStroke {
private int mLastPointX;
private int mLastPointY;
private int mMinGestureLength;
private int mMinGestureSampleLength;
private int mMinGestureLength; // pixel
private int mMinGestureSampleLength; // pixel
private int mGestureRecognitionThreshold; // pixel / sec
// 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 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_RECOG_SPEED_THRESHOLD = 0.4f; // dip/msec
private static final float GESTURE_RECOGNITION_SPEED_THRESHOLD_RATIO_TO_KEY_WIDTH =
5.5f; // keyWidth / sec
private static final int MSEC_PER_SEC = 1000;
public static final boolean hasRecognitionTimePast(
final long currentTime, final long lastRecognitionTime) {
@ -54,6 +57,8 @@ public class GestureStroke {
// 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 =
(int)(keyWidth * GESTURE_RECOGNITION_SPEED_THRESHOLD_RATIO_TO_KEY_WIDTH);
}
public boolean isStartOfAGesture() {
@ -72,47 +77,43 @@ public class GestureStroke {
mYCoordinates.setLength(0);
}
private void updateLastPoint(final int x, final int y, final int time) {
public void addPoint(final int x, final int y, final int time, final boolean isHistorical) {
final boolean needsSampling;
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;
}
if (needsSampling) {
mEventTimes.add(time);
mXCoordinates.add(x);
mYCoordinates.add(y);
}
if (!isHistorical) {
updateIncrementalRecognitionSize(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);
// Equivalent to (pixels / msecs < mGestureRecognitionThreshold / MSEC_PER_SEC)
if (pixels * MSEC_PER_SEC < mGestureRecognitionThreshold * msecs) {
mIncrementalRecognitionSize = mEventTimes.getLength();
}
}
mLastPointTime = time;
mLastPointX = x;
mLastPointY = y;
}
public void addPoint(final int x, final int y, final int time, final boolean isHistorical) {
final int size = mEventTimes.getLength();
if (size == 0) {
mEventTimes.add(time);
mXCoordinates.add(x);
mYCoordinates.add(y);
if (!isHistorical) {
updateLastPoint(x, y, time);
}
return;
}
final int lastX = mXCoordinates.get(size - 1);
final int lastY = mYCoordinates.get(size - 1);
final float dist = getDistance(lastX, lastY, x, y);
if (dist > mMinGestureSampleLength) {
mEventTimes.add(time);
mXCoordinates.add(x);
mYCoordinates.add(y);
mLength += dist;
}
if (!isHistorical) {
final int duration = (int)(time - mLastPointTime);
if (mLastPointTime != 0 && duration > 0) {
final float distance = getDistance(mLastPointX, mLastPointY, x, y);
final float speed = distance / duration;
if (speed < GESTURE_RECOG_SPEED_THRESHOLD) {
mIncrementalRecognitionSize = size;
}
}
updateLastPoint(x, y, time);
}
}
public void appendAllBatchPoints(final InputPointers out) {
appendBatchPoints(out, mEventTimes.getLength());
}