/ime/latinime/src/com/googlecode/eyesfree/inputmethod/latin/MiniKeyboardKeyDetector.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
21class MiniKeyboardKeyDetector extends KeyDetector {
22    private static final int MAX_NEARBY_KEYS = 1;
23
24    private final int mSlideAllowanceSquare;
25    private final int mSlideAllowanceSquareTop;
26
27    public MiniKeyboardKeyDetector(float slideAllowance) {
28        super();
29        mSlideAllowanceSquare = (int)(slideAllowance * slideAllowance);
30        // Top slide allowance is slightly longer (sqrt(2) times) than other edges.
31        mSlideAllowanceSquareTop = mSlideAllowanceSquare * 2;
32    }
33
34    @Override
35    protected int getMaxNearbyKeys() {
36        return MAX_NEARBY_KEYS;
37    }
38
39    @Override
40    public int getKeyIndexAndNearbyCodes(int x, int y, int[] allKeys) {
41        final Key[] keys = getKeys();
42        final int touchX = getTouchX(x);
43        final int touchY = getTouchY(y);
44        int closestKeyIndex = LatinKeyboardBaseView.NOT_A_KEY;
45        int closestKeyDist = (y < 0) ? mSlideAllowanceSquareTop : mSlideAllowanceSquare;
46        final int keyCount = keys.length;
47        for (int i = 0; i < keyCount; i++) {
48            final Key key = keys[i];
49            int dist = key.squaredDistanceFrom(touchX, touchY);
50            if (dist < closestKeyDist) {
51                closestKeyIndex = i;
52                closestKeyDist = dist;
53            }
54        }
55        if (allKeys != null && closestKeyIndex != LatinKeyboardBaseView.NOT_A_KEY)
56            allKeys[0] = keys[closestKeyIndex].codes[0];
57        return closestKeyIndex;
58    }
59}