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 17 package com.android.inputmethod.event; 18 19 import android.text.TextUtils; 20 import android.view.KeyCharacterMap; 21 22 import com.android.inputmethod.latin.Constants; 23 24 /** 25 * A combiner that handles dead keys. 26 */ 27 public class DeadKeyCombiner implements Combiner { 28 final StringBuilder mDeadSequence = new StringBuilder(); 29 30 @Override 31 public Event combine(final Event event) { 32 if (null == event) return null; // Just in case some combiner is broken 33 if (TextUtils.isEmpty(mDeadSequence)) { 34 if (event.isDead()) { 35 mDeadSequence.appendCodePoint(event.mCodePoint); 36 } 37 return event; 38 } else { 39 // TODO: Allow combining for several dead chars rather than only the first one. 40 // The framework doesn't know how to do this now. 41 final int deadCodePoint = mDeadSequence.codePointAt(0); 42 mDeadSequence.setLength(0); 43 final int resultingCodePoint = 44 KeyCharacterMap.getDeadChar(deadCodePoint, event.mCodePoint); 45 if (0 == resultingCodePoint) { 46 // We can't combine both characters. We need to commit the dead key as a committable 47 // character, and the next char too unless it's a space (because as a special case, 48 // dead key + space should result in only the dead key being committed - that's 49 // how dead keys work). 50 // If the event is a space, we should commit the dead char alone, but if it's 51 // not, we need to commit both. 52 return Event.createCommittableEvent(deadCodePoint, 53 Constants.CODE_SPACE == event.mCodePoint ? null : event /* next */); 54 } else { 55 // We could combine the characters. 56 return Event.createCommittableEvent(resultingCodePoint, null /* next */); 57 } 58 } 59 } 60 61 } 62
