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 17 package com.android.inputmethod.latin; 18 19 import android.inputmethodservice.Keyboard; 20 import android.inputmethodservice.Keyboard.Key; 21 22 import java.util.Arrays; 23 import java.util.List; 24 25 abstract class KeyDetector { 26 protected Keyboard mKeyboard; 27 28 private Key[] mKeys; 29 30 protected int mCorrectionX; 31 32 protected int mCorrectionY; 33 34 protected boolean mProximityCorrectOn; 35 36 protected int mProximityThresholdSquare; 37 setKeyboard(Keyboard keyboard, float correctionX, float correctionY)38 public Key[] setKeyboard(Keyboard keyboard, float correctionX, float correctionY) { 39 if (keyboard == null) 40 throw new NullPointerException(); 41 mCorrectionX = (int)correctionX; 42 mCorrectionY = (int)correctionY; 43 mKeyboard = keyboard; 44 List<Key> keys = mKeyboard.getKeys(); 45 Key[] array = keys.toArray(new Key[keys.size()]); 46 mKeys = array; 47 return array; 48 } 49 getTouchX(int x)50 protected int getTouchX(int x) { 51 return x + mCorrectionX; 52 } 53 getTouchY(int y)54 protected int getTouchY(int y) { 55 return y + mCorrectionY; 56 } 57 getKeys()58 protected Key[] getKeys() { 59 if (mKeys == null) 60 throw new IllegalStateException("keyboard isn't set"); 61 // mKeyboard is guaranteed not to be null at setKeybaord() method if mKeys is not null 62 return mKeys; 63 } 64 setProximityCorrectionEnabled(boolean enabled)65 public void setProximityCorrectionEnabled(boolean enabled) { 66 mProximityCorrectOn = enabled; 67 } 68 isProximityCorrectionEnabled()69 public boolean isProximityCorrectionEnabled() { 70 return mProximityCorrectOn; 71 } 72 setProximityThreshold(int threshold)73 public void setProximityThreshold(int threshold) { 74 mProximityThresholdSquare = threshold * threshold; 75 } 76 77 /** 78 * Allocates array that can hold all key indices returned by {@link #getKeyIndexAndNearbyCodes} 79 * method. The maximum size of the array should be computed by {@link #getMaxNearbyKeys}. 80 * 81 * @return Allocates and returns an array that can hold all key indices returned by 82 * {@link #getKeyIndexAndNearbyCodes} method. All elements in the returned array are 83 * initialized by {@link com.android.inputmethod.latin.LatinKeyboardView.NOT_A_KEY} 84 * value. 85 */ newCodeArray()86 public int[] newCodeArray() { 87 int[] codes = new int[getMaxNearbyKeys()]; 88 Arrays.fill(codes, LatinKeyboardBaseView.NOT_A_KEY); 89 return codes; 90 } 91 92 /** 93 * Computes maximum size of the array that can contain all nearby key indices returned by 94 * {@link #getKeyIndexAndNearbyCodes}. 95 * 96 * @return Returns maximum size of the array that can contain all nearby key indices returned 97 * by {@link #getKeyIndexAndNearbyCodes}. 98 */ getMaxNearbyKeys()99 abstract protected int getMaxNearbyKeys(); 100 101 /** 102 * Finds all possible nearby key indices around a touch event point and returns the nearest key 103 * index. The algorithm to determine the nearby keys depends on the threshold set by 104 * {@link #setProximityThreshold(int)} and the mode set by 105 * {@link #setProximityCorrectionEnabled(boolean)}. 106 * 107 * @param x The x-coordinate of a touch point 108 * @param y The y-coordinate of a touch point 109 * @param allKeys All nearby key indices are returned in this array 110 * @return The nearest key index 111 */ getKeyIndexAndNearbyCodes(int x, int y, int[] allKeys)112 abstract public int getKeyIndexAndNearbyCodes(int x, int y, int[] allKeys); 113 } 114