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 /** 20 * Class representing a generic input event as handled by Latin IME. 21 * 22 * This contains information about the origin of the event, but it is generalized and should 23 * represent a software keypress, hardware keypress, or d-pad move alike. 24 * Very importantly, this does not necessarily result in inputting one character, or even anything 25 * at all - it may be a dead key, it may be a partial input, it may be a special key on the 26 * keyboard, it may be a cancellation of a keypress (e.g. in a soft keyboard the finger of the 27 * user has slid out of the key), etc. It may also be a batch input from a gesture or handwriting 28 * for example. 29 * The combiner should figure out what to do with this. 30 */ 31 public class Event { 32 // Should the types below be represented by separate classes instead? It would be cleaner 33 // but probably a bit too much 34 // An event we don't handle in Latin IME, for example pressing Ctrl on a hardware keyboard. 35 final public static int EVENT_NOT_HANDLED = 0; 36 // A character that is already final, for example pressing an alphabetic character on a 37 // hardware qwerty keyboard. 38 final public static int EVENT_COMMITTABLE = 1; 39 // A dead key, which means a character that should combine with what is coming next. Examples 40 // include the "^" character on an azerty keyboard which combines with "e" to make "ê", or 41 // AltGr+' on a dvorak international keyboard which combines with "e" to make "é". This is 42 // true regardless of the language or combining mode, and should be seen as a property of the 43 // key - a dead key followed by another key with which it can combine should be regarded as if 44 // the keyboard actually had such a key. 45 final public static int EVENT_DEAD = 2; 46 // A toggle event is triggered by a key that affects the previous character. An example would 47 // be a numeric key on a 10-key keyboard, which would toggle between 1 - a - b - c with 48 // repeated presses. 49 final public static int EVENT_TOGGLE = 3; 50 // A mode event instructs the combiner to change modes. The canonical example would be the 51 // hankaku/zenkaku key on a Japanese keyboard, or even the caps lock key on a qwerty keyboard 52 // if handled at the combiner level. 53 final public static int EVENT_MODE_KEY = 4; 54 55 final private static int NOT_A_CODE_POINT = 0; 56 57 final private int mType; // The type of event - one of the constants above 58 // The code point associated with the event, if relevant. This is a unicode code point, and 59 // has nothing to do with other representations of the key. It is only relevant if this event 60 // is the right type: COMMITTABLE or DEAD or TOGGLE, but for a mode key like hankaku/zenkaku or 61 // ctrl, there is no code point associated so this should be NOT_A_CODE_POINT to avoid 62 // unintentional use of its value when it's not relevant. 63 final public int mCodePoint; 64 // The next event, if any. Null if there is no next event yet. 65 final public Event mNextEvent; 66 67 // This method is private - to create a new event, use one of the create* utility methods. Event(final int type, final int codePoint, final Event next)68 private Event(final int type, final int codePoint, final Event next) { 69 mType = type; 70 mCodePoint = codePoint; 71 mNextEvent = next; 72 } 73 createDeadEvent(final int codePoint, final Event next)74 public static Event createDeadEvent(final int codePoint, final Event next) { 75 return new Event(EVENT_DEAD, codePoint, next); 76 } 77 createCommittableEvent(final int codePoint, final Event next)78 public static Event createCommittableEvent(final int codePoint, final Event next) { 79 return new Event(EVENT_COMMITTABLE, codePoint, next); 80 } 81 createNotHandledEvent()82 public static Event createNotHandledEvent() { 83 return new Event(EVENT_NOT_HANDLED, NOT_A_CODE_POINT, null); 84 } 85 isCommittable()86 public boolean isCommittable() { 87 return EVENT_COMMITTABLE == mType; 88 } 89 isDead()90 public boolean isDead() { 91 return EVENT_DEAD == mType; 92 } 93 } 94