/ime/latinime/src/com/googlecode/eyesfree/inputmethod/latin/ProximityKeyDetector.java

 1/*
 2 * Copyright (C) 2010 Google Inc.
 3 *
 4 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 5 * use this file except in compliance with the License. You may obtain a copy of
 6 * the License at
 7 *
 8 * http://www.apache.org/licenses/LICENSE-2.0
 9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
12 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
13 * License for the specific language governing permissions and limitations under
14 * the License.
15 */
16
17package com.googlecode.eyesfree.inputmethod.latin;
18
19import android.inputmethodservice.Keyboard.Key;
20
21import java.util.Arrays;
22
23class ProximityKeyDetector extends KeyDetector {
24    private static final int MAX_NEARBY_KEYS = 12;
25
26    // working area
27    private int[] mDistances = new int[MAX_NEARBY_KEYS];
28
29    @Override
30    protected int getMaxNearbyKeys() {
31        return MAX_NEARBY_KEYS;
32    }
33
34    @Override
35    public int getKeyIndexAndNearbyCodes(int x, int y, int[] allKeys) {
36        final Key[] keys = getKeys();
37        final int touchX = getTouchX(x);
38        final int touchY = getTouchY(y);
39        int primaryIndex = LatinKeyboardBaseView.NOT_A_KEY;
40        int closestKey = LatinKeyboardBaseView.NOT_A_KEY;
41        int closestKeyDist = mProximityThresholdSquare + 1;
42        int[] distances = mDistances;
43        Arrays.fill(distances, Integer.MAX_VALUE);
44        int [] nearestKeyIndices = mKeyboard.getNearestKeys(touchX, touchY);
45        final int keyCount = nearestKeyIndices.length;
46        for (int i = 0; i < keyCount; i++) {
47            final Key key = keys[nearestKeyIndices[i]];
48            int dist = 0;
49            boolean isInside = key.isInside(touchX, touchY);
50            if (isInside) {
51                primaryIndex = nearestKeyIndices[i];
52            }
53
54            if (((mProximityCorrectOn
55                    && (dist = key.squaredDistanceFrom(touchX, touchY)) < mProximityThresholdSquare)
56                    || isInside)
57                    && key.codes[0] > 32) {
58                // Find insertion point
59                final int nCodes = key.codes.length;
60                if (dist < closestKeyDist) {
61                    closestKeyDist = dist;
62                    closestKey = nearestKeyIndices[i];
63                }
64
65                if (allKeys == null) continue;
66
67                for (int j = 0; j < distances.length; j++) {
68                    if (distances[j] > dist) {
69                        // Make space for nCodes codes
70                        System.arraycopy(distances, j, distances, j + nCodes,
71                                distances.length - j - nCodes);
72                        System.arraycopy(allKeys, j, allKeys, j + nCodes,
73                                allKeys.length - j - nCodes);
74                        System.arraycopy(key.codes, 0, allKeys, j, nCodes);
75                        Arrays.fill(distances, j, j + nCodes, dist);
76                        break;
77                    }
78                }
79            }
80        }
81        if (primaryIndex == LatinKeyboardBaseView.NOT_A_KEY) {
82            primaryIndex = closestKey;
83        }
84        return primaryIndex;
85    }
86}