1 /* 2 * Copyright (C) 2012 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.util.SparseArray; 20 import android.view.KeyEvent; 21 22 import com.android.inputmethod.latin.Constants; 23 import com.android.inputmethod.latin.LatinIME; 24 import com.android.inputmethod.latin.utils.CollectionUtils; 25 26 import java.util.ArrayList; 27 28 /** 29 * This class implements the logic between receiving events and generating code points. 30 * 31 * Event sources are multiple. It may be a hardware keyboard, a D-PAD, a software keyboard, 32 * or any exotic input source. 33 * This class will orchestrate the decoding chain that starts with an event and ends up with 34 * a stream of code points + decoding state. 35 */ 36 public class EventInterpreter { 37 // TODO: Implement an object pool for events, as we'll create a lot of them 38 // TODO: Create a combiner 39 // TODO: Create an object type to represent input material + visual feedback + decoding state 40 // TODO: Create an interface to call back to Latin IME through the above object 41 42 final EventDecoderSpec mDecoderSpec; 43 final SparseArray<HardwareEventDecoder> mHardwareEventDecoders; 44 final SoftwareEventDecoder mSoftwareEventDecoder; 45 final LatinIME mLatinIme; 46 final ArrayList<Combiner> mCombiners; 47 48 /** 49 * Create a default interpreter. 50 * 51 * This creates a default interpreter that does nothing. A default interpreter should normally 52 * only be used for fallback purposes, when we really don't know what we want to do with input. 53 * 54 * @param latinIme a reference to the ime. 55 */ 56 public EventInterpreter(final LatinIME latinIme) { 57 this(null, latinIme); 58 } 59 60 /** 61 * Create an event interpreter according to a specification. 62 * 63 * The specification contains information about what to do with events. Typically, it will 64 * contain information about the type of keyboards - for example, if hardware keyboard(s) is/are 65 * attached, their type will be included here so that the decoder knows what to do with each 66 * keypress (a 10-key keyboard is not handled like a qwerty-ish keyboard). 67 * It also contains information for combining characters. For example, if the input language 68 * is Japanese, the specification will typically request kana conversion. 69 * Also note that the specification can be null. This means that we need to create a default 70 * interpreter that does no specific combining, and assumes the most common cases. 71 * 72 * @param specification the specification for event interpretation. null for default. 73 * @param latinIme a reference to the ime. 74 */ 75 public EventInterpreter(final EventDecoderSpec specification, final LatinIME latinIme) { 76 mDecoderSpec = null != specification ? specification : new EventDecoderSpec(); 77 // For both, we expect to have only one decoder in almost all cases, hence the default 78 // capacity of 1. 79 mHardwareEventDecoders = new SparseArray<HardwareEventDecoder>(1); 80 mSoftwareEventDecoder = new SoftwareKeyboardEventDecoder(); 81 mCombiners = CollectionUtils.newArrayList(); 82 mCombiners.add(new DeadKeyCombiner()); 83 mLatinIme = latinIme; 84 } 85 86 // Helper method to decode a hardware key event into a generic event, and execute any 87 // necessary action. 88 public boolean onHardwareKeyEvent(final KeyEvent hardwareKeyEvent) { 89 final Event decodedEvent = getHardwareKeyEventDecoder(hardwareKeyEvent.getDeviceId()) 90 .decodeHardwareKey(hardwareKeyEvent); 91 return onEvent(decodedEvent); 92 } 93 94 public boolean onSoftwareEvent() { 95 final Event decodedEvent = getSoftwareEventDecoder().decodeSoftwareEvent(); 96 return onEvent(decodedEvent); 97 } 98 99 private HardwareEventDecoder getHardwareKeyEventDecoder(final int deviceId) { 100 final HardwareEventDecoder decoder = mHardwareEventDecoders.get(deviceId); 101 if (null != decoder) return decoder; 102 // TODO: create the decoder according to the specification 103 final HardwareEventDecoder newDecoder = new HardwareKeyboardEventDecoder(deviceId); 104 mHardwareEventDecoders.put(deviceId, newDecoder); 105 return newDecoder; 106 } 107 108 private SoftwareEventDecoder getSoftwareEventDecoder() { 109 // Within the context of Latin IME, since we never present several software interfaces 110 // at the time, we should never need multiple software event decoders at a time. 111 return mSoftwareEventDecoder; 112 } 113 114 private boolean onEvent(final Event event) { 115 Event currentlyProcessingEvent = event; 116 boolean processed = false; 117 for (int i = 0; i < mCombiners.size(); ++i) { 118 currentlyProcessingEvent = mCombiners.get(i).combine(event); 119 } 120 while (null != currentlyProcessingEvent) { 121 if (currentlyProcessingEvent.isCommittable()) { 122 mLatinIme.onCodeInput(currentlyProcessingEvent.mCodePoint, 123 Constants.EXTERNAL_KEYBOARD_COORDINATE, 124 Constants.EXTERNAL_KEYBOARD_COORDINATE); 125 processed = true; 126 } else if (event.isDead()) { 127 processed = true; 128 } 129 currentlyProcessingEvent = currentlyProcessingEvent.mNextEvent; 130 } 131 return processed; 132 } 133 } 134
