GestureStrokeRecognitionPoints.java revision f80f09c7eed430827ae8294a5b0f33d5f21cee60
1f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka/* 2f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka * Copyright (C) 2012 The Android Open Source Project 3f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka * 4f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except 5f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka * in compliance with the License. You may obtain a copy of the License at 6f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka * 7f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka * http://www.apache.org/licenses/LICENSE-2.0 8f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka * 9f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka * Unless required by applicable law or agreed to in writing, software distributed under the License 10f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express 11f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka * or implied. See the License for the specific language governing permissions and limitations under 12f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka * the License. 13f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka */ 14f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka 15f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaokapackage com.android.inputmethod.keyboard.internal; 16f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka 17f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaokaimport com.android.inputmethod.latin.InputPointers; 187519091f7c15c50a9a1e50d82fa92400335852ecTadashi G. Takaokaimport com.android.inputmethod.latin.ResizableIntArray; 19f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka 20f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaokapublic class GestureStroke { 2157f7de0ba664187e13bcea5adff7f5f65eddd823Tadashi G. Takaoka public static final int DEFAULT_CAPACITY = 128; 2257f7de0ba664187e13bcea5adff7f5f65eddd823Tadashi G. Takaoka 23f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka private final int mPointerId; 247519091f7c15c50a9a1e50d82fa92400335852ecTadashi G. Takaoka private final ResizableIntArray mEventTimes = new ResizableIntArray(DEFAULT_CAPACITY); 257519091f7c15c50a9a1e50d82fa92400335852ecTadashi G. Takaoka private final ResizableIntArray mXCoordinates = new ResizableIntArray(DEFAULT_CAPACITY); 267519091f7c15c50a9a1e50d82fa92400335852ecTadashi G. Takaoka private final ResizableIntArray mYCoordinates = new ResizableIntArray(DEFAULT_CAPACITY); 27f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka private float mLength; 281e6f39a9f994e21b749a1cbae55a3adbfb5640e9Tadashi G. Takaoka private int mIncrementalRecognitionSize; 290c5f72e2bf22df48af051827f97ab6052026d531Tom Ouyang private int mLastIncrementalBatchSize; 30f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka private long mLastPointTime; 31f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka private int mLastPointX; 32f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka private int mLastPointY; 33f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka 34f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka private int mMinGestureLength; 35f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka private int mMinGestureSampleLength; 36f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka 371e6f39a9f994e21b749a1cbae55a3adbfb5640e9Tadashi G. Takaoka // TODO: Move some of these to resource. 38708cc94a354ad96294126a6ba954bf8be5bd5a06Tadashi G. Takaoka private static final float MIN_GESTURE_LENGTH_RATIO_TO_KEY_WIDTH = 0.75f; 39f80f09c7eed430827ae8294a5b0f33d5f21cee60Tadashi G. Takaoka private static final int MIN_GESTURE_START_DURATION = 100; // msec 40f80f09c7eed430827ae8294a5b0f33d5f21cee60Tadashi G. Takaoka private static final int MIN_GESTURE_RECOGNITION_TIME = 100; // msec 4174d0bb09c700aec91afd120688c56498d93e3110Tadashi G. Takaoka private static final float MIN_GESTURE_SAMPLING_RATIO_TO_KEY_WIDTH = 1.0f / 6.0f; 42f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka private static final float GESTURE_RECOG_SPEED_THRESHOLD = 0.4f; // dip/msec 43f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka 44f80f09c7eed430827ae8294a5b0f33d5f21cee60Tadashi G. Takaoka public static final boolean hasRecognitionTimePast( 45f80f09c7eed430827ae8294a5b0f33d5f21cee60Tadashi G. Takaoka final long currentTime, final long lastRecognitionTime) { 46f80f09c7eed430827ae8294a5b0f33d5f21cee60Tadashi G. Takaoka return currentTime > lastRecognitionTime + MIN_GESTURE_RECOGNITION_TIME; 47f80f09c7eed430827ae8294a5b0f33d5f21cee60Tadashi G. Takaoka } 48f80f09c7eed430827ae8294a5b0f33d5f21cee60Tadashi G. Takaoka 49333a300586c3bedb3d51524642b542cefaa1a22dTadashi G. Takaoka public GestureStroke(final int pointerId) { 50f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka mPointerId = pointerId; 51f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka } 52f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka 53c7dc673cf0fb56015826079423ced659b9180febTadashi G. Takaoka public void setKeyboardGeometry(final int keyWidth) { 541e6f39a9f994e21b749a1cbae55a3adbfb5640e9Tadashi G. Takaoka // TODO: Find an appropriate base metric for these length. Maybe diagonal length of the key? 551e6f39a9f994e21b749a1cbae55a3adbfb5640e9Tadashi G. Takaoka mMinGestureLength = (int)(keyWidth * MIN_GESTURE_LENGTH_RATIO_TO_KEY_WIDTH); 5674d0bb09c700aec91afd120688c56498d93e3110Tadashi G. Takaoka mMinGestureSampleLength = (int)(keyWidth * MIN_GESTURE_SAMPLING_RATIO_TO_KEY_WIDTH); 57f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka } 58f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka 5974d0bb09c700aec91afd120688c56498d93e3110Tadashi G. Takaoka public boolean isStartOfAGesture() { 6074d0bb09c700aec91afd120688c56498d93e3110Tadashi G. Takaoka final int size = mEventTimes.getLength(); 6174d0bb09c700aec91afd120688c56498d93e3110Tadashi G. Takaoka final int downDuration = (size > 0) ? mEventTimes.get(size - 1) : 0; 62f80f09c7eed430827ae8294a5b0f33d5f21cee60Tadashi G. Takaoka return downDuration > MIN_GESTURE_START_DURATION && mLength > mMinGestureLength; 63f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka } 64f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka 65f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka public void reset() { 66f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka mLength = 0; 671e6f39a9f994e21b749a1cbae55a3adbfb5640e9Tadashi G. Takaoka mIncrementalRecognitionSize = 0; 680c5f72e2bf22df48af051827f97ab6052026d531Tom Ouyang mLastIncrementalBatchSize = 0; 69f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka mLastPointTime = 0; 707519091f7c15c50a9a1e50d82fa92400335852ecTadashi G. Takaoka mEventTimes.setLength(0); 717519091f7c15c50a9a1e50d82fa92400335852ecTadashi G. Takaoka mXCoordinates.setLength(0); 727519091f7c15c50a9a1e50d82fa92400335852ecTadashi G. Takaoka mYCoordinates.setLength(0); 73f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka } 74f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka 75f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka private void updateLastPoint(final int x, final int y, final int time) { 76f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka mLastPointTime = time; 77f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka mLastPointX = x; 78f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka mLastPointY = y; 79f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka } 80f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka 81f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka public void addPoint(final int x, final int y, final int time, final boolean isHistorical) { 827519091f7c15c50a9a1e50d82fa92400335852ecTadashi G. Takaoka final int size = mEventTimes.getLength(); 83f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka if (size == 0) { 847519091f7c15c50a9a1e50d82fa92400335852ecTadashi G. Takaoka mEventTimes.add(time); 857519091f7c15c50a9a1e50d82fa92400335852ecTadashi G. Takaoka mXCoordinates.add(x); 867519091f7c15c50a9a1e50d82fa92400335852ecTadashi G. Takaoka mYCoordinates.add(y); 87f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka if (!isHistorical) { 88f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka updateLastPoint(x, y, time); 89f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka } 90f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka return; 91f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka } 927519091f7c15c50a9a1e50d82fa92400335852ecTadashi G. Takaoka 937519091f7c15c50a9a1e50d82fa92400335852ecTadashi G. Takaoka final int lastX = mXCoordinates.get(size - 1); 947519091f7c15c50a9a1e50d82fa92400335852ecTadashi G. Takaoka final int lastY = mYCoordinates.get(size - 1); 95f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka final float dist = getDistance(lastX, lastY, x, y); 96f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka if (dist > mMinGestureSampleLength) { 977519091f7c15c50a9a1e50d82fa92400335852ecTadashi G. Takaoka mEventTimes.add(time); 987519091f7c15c50a9a1e50d82fa92400335852ecTadashi G. Takaoka mXCoordinates.add(x); 997519091f7c15c50a9a1e50d82fa92400335852ecTadashi G. Takaoka mYCoordinates.add(y); 100f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka mLength += dist; 101f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka } 102f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka 103f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka if (!isHistorical) { 104f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka final int duration = (int)(time - mLastPointTime); 105f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka if (mLastPointTime != 0 && duration > 0) { 106f80f09c7eed430827ae8294a5b0f33d5f21cee60Tadashi G. Takaoka final float distance = getDistance(mLastPointX, mLastPointY, x, y); 107f80f09c7eed430827ae8294a5b0f33d5f21cee60Tadashi G. Takaoka final float speed = distance / duration; 108f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka if (speed < GESTURE_RECOG_SPEED_THRESHOLD) { 1091e6f39a9f994e21b749a1cbae55a3adbfb5640e9Tadashi G. Takaoka mIncrementalRecognitionSize = size; 110f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka } 111f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka } 112f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka updateLastPoint(x, y, time); 113f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka } 114f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka } 115f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka 116f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka public void appendAllBatchPoints(final InputPointers out) { 1177519091f7c15c50a9a1e50d82fa92400335852ecTadashi G. Takaoka appendBatchPoints(out, mEventTimes.getLength()); 118f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka } 119f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka 120f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka public void appendIncrementalBatchPoints(final InputPointers out) { 1217519091f7c15c50a9a1e50d82fa92400335852ecTadashi G. Takaoka appendBatchPoints(out, mIncrementalRecognitionSize); 1227519091f7c15c50a9a1e50d82fa92400335852ecTadashi G. Takaoka } 1237519091f7c15c50a9a1e50d82fa92400335852ecTadashi G. Takaoka 1247519091f7c15c50a9a1e50d82fa92400335852ecTadashi G. Takaoka private void appendBatchPoints(final InputPointers out, final int size) { 1256c3304ea961fd4da0a1da01dc1fac4797c713bccTadashi G. Takaoka final int length = size - mLastIncrementalBatchSize; 1266c3304ea961fd4da0a1da01dc1fac4797c713bccTadashi G. Takaoka if (length <= 0) { 1276c3304ea961fd4da0a1da01dc1fac4797c713bccTadashi G. Takaoka return; 1286c3304ea961fd4da0a1da01dc1fac4797c713bccTadashi G. Takaoka } 1297519091f7c15c50a9a1e50d82fa92400335852ecTadashi G. Takaoka out.append(mPointerId, mEventTimes, mXCoordinates, mYCoordinates, 1306c3304ea961fd4da0a1da01dc1fac4797c713bccTadashi G. Takaoka mLastIncrementalBatchSize, length); 1317519091f7c15c50a9a1e50d82fa92400335852ecTadashi G. Takaoka mLastIncrementalBatchSize = size; 132f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka } 133f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka 1340fb950858e4dae7ea1602c27e741051f9421f9cbKen Wakasa private static float getDistance(final int x1, final int y1, final int x2, final int y2) { 1350fb950858e4dae7ea1602c27e741051f9421f9cbKen Wakasa final float dx = x1 - x2; 1360fb950858e4dae7ea1602c27e741051f9421f9cbKen Wakasa final float dy = y1 - y2; 137bcec82de66f52655593dc233346f11468f5077a0Ken Wakasa // Note that, in recent versions of Android, FloatMath is actually slower than 138bcec82de66f52655593dc233346f11468f5077a0Ken Wakasa // java.lang.Math due to the way the JIT optimizes java.lang.Math. 139bcec82de66f52655593dc233346f11468f5077a0Ken Wakasa return (float)Math.sqrt(dx * dx + dy * dy); 140f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka } 141f39fccbd0fd63647c52e8eabcb60df69f97492b5Tadashi G. Takaoka} 142