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Diffstat (limited to 'java/src/com/android/inputmethod/event/EventInterpreter.java')
| -rw-r--r-- | java/src/com/android/inputmethod/event/EventInterpreter.java | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/java/src/com/android/inputmethod/event/EventInterpreter.java b/java/src/com/android/inputmethod/event/EventInterpreter.java new file mode 100644 index 000000000..6efe899bb --- /dev/null +++ b/java/src/com/android/inputmethod/event/EventInterpreter.java @@ -0,0 +1,133 @@ +/* + * Copyright (C) 2012 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.util.SparseArray; +import android.view.KeyEvent; + +import com.android.inputmethod.latin.CollectionUtils; +import com.android.inputmethod.latin.Constants; +import com.android.inputmethod.latin.LatinIME; + +import java.util.ArrayList; + +/** + * This class implements the logic between receiving events and generating code points. + * + * Event sources are multiple. It may be a hardware keyboard, a D-PAD, a software keyboard, + * or any exotic input source. + * This class will orchestrate the decoding chain that starts with an event and ends up with + * a stream of code points + decoding state. + */ +public class EventInterpreter { + // TODO: Implement an object pool for events, as we'll create a lot of them + // TODO: Create a combiner + // TODO: Create an object type to represent input material + visual feedback + decoding state + // TODO: Create an interface to call back to Latin IME through the above object + + final EventDecoderSpec mDecoderSpec; + final SparseArray<HardwareEventDecoder> mHardwareEventDecoders; + final SoftwareEventDecoder mSoftwareEventDecoder; + final LatinIME mLatinIme; + final ArrayList<Combiner> mCombiners; + + /** + * Create a default interpreter. + * + * This creates a default interpreter that does nothing. A default interpreter should normally + * only be used for fallback purposes, when we really don't know what we want to do with input. + * + * @param latinIme a reference to the ime. + */ + public EventInterpreter(final LatinIME latinIme) { + this(null, latinIme); + } + + /** + * Create an event interpreter according to a specification. + * + * The specification contains information about what to do with events. Typically, it will + * contain information about the type of keyboards - for example, if hardware keyboard(s) is/are + * attached, their type will be included here so that the decoder knows what to do with each + * keypress (a 10-key keyboard is not handled like a qwerty-ish keyboard). + * It also contains information for combining characters. For example, if the input language + * is Japanese, the specification will typically request kana conversion. + * Also note that the specification can be null. This means that we need to create a default + * interpreter that does no specific combining, and assumes the most common cases. + * + * @param specification the specification for event interpretation. null for default. + * @param latinIme a reference to the ime. + */ + public EventInterpreter(final EventDecoderSpec specification, final LatinIME latinIme) { + mDecoderSpec = null != specification ? specification : new EventDecoderSpec(); + // For both, we expect to have only one decoder in almost all cases, hence the default + // capacity of 1. + mHardwareEventDecoders = new SparseArray<HardwareEventDecoder>(1); + mSoftwareEventDecoder = new SoftwareKeyboardEventDecoder(); + mCombiners = CollectionUtils.newArrayList(); + mCombiners.add(new DeadKeyCombiner()); + mLatinIme = latinIme; + } + + // Helper method to decode a hardware key event into a generic event, and execute any + // necessary action. + public boolean onHardwareKeyEvent(final KeyEvent hardwareKeyEvent) { + final Event decodedEvent = getHardwareKeyEventDecoder(hardwareKeyEvent.getDeviceId()) + .decodeHardwareKey(hardwareKeyEvent); + return onEvent(decodedEvent); + } + + public boolean onSoftwareEvent() { + final Event decodedEvent = getSoftwareEventDecoder().decodeSoftwareEvent(); + return onEvent(decodedEvent); + } + + private HardwareEventDecoder getHardwareKeyEventDecoder(final int deviceId) { + final HardwareEventDecoder decoder = mHardwareEventDecoders.get(deviceId); + if (null != decoder) return decoder; + // TODO: create the decoder according to the specification + final HardwareEventDecoder newDecoder = new HardwareKeyboardEventDecoder(deviceId); + mHardwareEventDecoders.put(deviceId, newDecoder); + return newDecoder; + } + + private SoftwareEventDecoder getSoftwareEventDecoder() { + // Within the context of Latin IME, since we never present several software interfaces + // at the time, we should never need multiple software event decoders at a time. + return mSoftwareEventDecoder; + } + + private boolean onEvent(final Event event) { + Event currentlyProcessingEvent = event; + boolean processed = false; + for (int i = 0; i < mCombiners.size(); ++i) { + currentlyProcessingEvent = mCombiners.get(i).combine(event); + } + while (null != currentlyProcessingEvent) { + if (currentlyProcessingEvent.isCommittable()) { + mLatinIme.onCodeInput(currentlyProcessingEvent.mCodePoint, + Constants.EXTERNAL_KEYBOARD_COORDINATE, + Constants.EXTERNAL_KEYBOARD_COORDINATE); + processed = true; + } else if (event.isDead()) { + processed = true; + } + currentlyProcessingEvent = currentlyProcessingEvent.mNextEvent; + } + return processed; + } +} |