DeadKeyCombiner.java revision 8e38b12e9ccc48bcb18b2eeec4d53d19cf7a29c9
1/* 2 * Copyright (C) 2013 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of 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, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17package com.android.inputmethod.event; 18 19import android.text.TextUtils; 20import android.view.KeyCharacterMap; 21 22import com.android.inputmethod.latin.Constants; 23 24import java.util.ArrayList; 25 26/** 27 * A combiner that handles dead keys. 28 */ 29public class DeadKeyCombiner implements Combiner { 30 // TODO: make this a list of events instead 31 final StringBuilder mDeadSequence = new StringBuilder(); 32 33 @Override 34 public Event processEvent(final ArrayList<Event> previousEvents, final Event event) { 35 if (TextUtils.isEmpty(mDeadSequence)) { 36 if (event.isDead()) { 37 mDeadSequence.appendCodePoint(event.mCodePoint); 38 } 39 return Event.createConsumedEvent(event); 40 } else { 41 // TODO: Allow combining for several dead chars rather than only the first one. 42 // The framework doesn't know how to do this now. 43 final int deadCodePoint = mDeadSequence.codePointAt(0); 44 mDeadSequence.setLength(0); 45 final int resultingCodePoint = 46 KeyCharacterMap.getDeadChar(deadCodePoint, event.mCodePoint); 47 if (0 == resultingCodePoint) { 48 // We can't combine both characters. We need to commit the dead key as a separate 49 // character, and the next char too unless it's a space (because as a special case, 50 // dead key + space should result in only the dead key being committed - that's 51 // how dead keys work). 52 // If the event is a space, we should commit the dead char alone, but if it's 53 // not, we need to commit both. 54 // TODO: this is not necessarily triggered by hardware key events, so it's not 55 // a good idea to masquerade as one. This should be typed as a software 56 // composite event or something. 57 return Event.createHardwareKeypressEvent(deadCodePoint, event.mKeyCode, 58 Constants.CODE_SPACE == event.mCodePoint ? null : event /* next */, 59 false /* isKeyRepeat */); 60 } else { 61 // We could combine the characters. 62 return Event.createHardwareKeypressEvent(resultingCodePoint, event.mKeyCode, 63 null /* next */, false /* isKeyRepeat */); 64 } 65 } 66 } 67 68 @Override 69 public void reset() { 70 mDeadSequence.setLength(0); 71 } 72 73 @Override 74 public CharSequence getCombiningStateFeedback() { 75 return mDeadSequence; 76 } 77} 78