| /* |
| * Copyright (C) 2013 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package com.android.inputmethod.event; |
| |
| import android.text.TextUtils; |
| import android.view.KeyCharacterMap; |
| |
| import com.android.inputmethod.latin.Constants; |
| |
| /** |
| * A combiner that handles dead keys. |
| */ |
| public class DeadKeyCombiner implements Combiner { |
| final StringBuilder mDeadSequence = new StringBuilder(); |
| |
| @Override |
| public Event combine(final Event event) { |
| if (null == event) return null; // Just in case some combiner is broken |
| if (TextUtils.isEmpty(mDeadSequence)) { |
| if (event.isDead()) { |
| mDeadSequence.appendCodePoint(event.mCodePoint); |
| } |
| return event; |
| } else { |
| // TODO: Allow combining for several dead chars rather than only the first one. |
| // The framework doesn't know how to do this now. |
| final int deadCodePoint = mDeadSequence.codePointAt(0); |
| mDeadSequence.setLength(0); |
| final int resultingCodePoint = |
| KeyCharacterMap.getDeadChar(deadCodePoint, event.mCodePoint); |
| if (0 == resultingCodePoint) { |
| // We can't combine both characters. We need to commit the dead key as a committable |
| // character, and the next char too unless it's a space (because as a special case, |
| // dead key + space should result in only the dead key being committed - that's |
| // how dead keys work). |
| // If the event is a space, we should commit the dead char alone, but if it's |
| // not, we need to commit both. |
| return Event.createCommittableEvent(deadCodePoint, |
| Constants.CODE_SPACE == event.mCodePoint ? null : event /* next */); |
| } else { |
| // We could combine the characters. |
| return Event.createCommittableEvent(resultingCodePoint, null /* next */); |
| } |
| } |
| } |
| |
| } |