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1 /*
2  * Copyright (C) 2008 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 #ifndef _LIBINPUT_KEY_CHARACTER_MAP_H
18 #define _LIBINPUT_KEY_CHARACTER_MAP_H
19 
20 #include <stdint.h>
21 
22 #if HAVE_ANDROID_OS
23 #include <binder/IBinder.h>
24 #endif
25 
26 #include <input/Input.h>
27 #include <utils/Errors.h>
28 #include <utils/KeyedVector.h>
29 #include <utils/Tokenizer.h>
30 #include <utils/String8.h>
31 #include <utils/Unicode.h>
32 #include <utils/RefBase.h>
33 
34 namespace android {
35 
36 /**
37  * Describes a mapping from Android key codes to characters.
38  * Also specifies other functions of the keyboard such as the keyboard type
39  * and key modifier semantics.
40  *
41  * This object is immutable after it has been loaded.
42  */
43 class KeyCharacterMap : public RefBase {
44 public:
45     enum KeyboardType {
46         KEYBOARD_TYPE_UNKNOWN = 0,
47         KEYBOARD_TYPE_NUMERIC = 1,
48         KEYBOARD_TYPE_PREDICTIVE = 2,
49         KEYBOARD_TYPE_ALPHA = 3,
50         KEYBOARD_TYPE_FULL = 4,
51         KEYBOARD_TYPE_SPECIAL_FUNCTION = 5,
52         KEYBOARD_TYPE_OVERLAY = 6,
53     };
54 
55     enum Format {
56         // Base keyboard layout, may contain device-specific options, such as "type" declaration.
57         FORMAT_BASE = 0,
58         // Overlay keyboard layout, more restrictive, may be published by applications,
59         // cannot override device-specific options.
60         FORMAT_OVERLAY = 1,
61         // Either base or overlay layout ok.
62         FORMAT_ANY = 2,
63     };
64 
65     // Substitute key code and meta state for fallback action.
66     struct FallbackAction {
67         int32_t keyCode;
68         int32_t metaState;
69     };
70 
71     /* Loads a key character map from a file. */
72     static status_t load(const String8& filename, Format format, sp<KeyCharacterMap>* outMap);
73 
74     /* Loads a key character map from its string contents. */
75     static status_t loadContents(const String8& filename,
76             const char* contents, Format format, sp<KeyCharacterMap>* outMap);
77 
78     /* Combines a base key character map and an overlay. */
79     static sp<KeyCharacterMap> combine(const sp<KeyCharacterMap>& base,
80             const sp<KeyCharacterMap>& overlay);
81 
82     /* Returns an empty key character map. */
83     static sp<KeyCharacterMap> empty();
84 
85     /* Gets the keyboard type. */
86     int32_t getKeyboardType() const;
87 
88     /* Gets the primary character for this key as in the label physically printed on it.
89      * Returns 0 if none (eg. for non-printing keys). */
90     char16_t getDisplayLabel(int32_t keyCode) const;
91 
92     /* Gets the Unicode character for the number or symbol generated by the key
93      * when the keyboard is used as a dialing pad.
94      * Returns 0 if no number or symbol is generated.
95      */
96     char16_t getNumber(int32_t keyCode) const;
97 
98     /* Gets the Unicode character generated by the key and meta key modifiers.
99      * Returns 0 if no character is generated.
100      */
101     char16_t getCharacter(int32_t keyCode, int32_t metaState) const;
102 
103     /* Gets the fallback action to use by default if the application does not
104      * handle the specified key.
105      * Returns true if an action was available, false if none.
106      */
107     bool getFallbackAction(int32_t keyCode, int32_t metaState,
108             FallbackAction* outFallbackAction) const;
109 
110     /* Gets the first matching Unicode character that can be generated by the key,
111      * preferring the one with the specified meta key modifiers.
112      * Returns 0 if no matching character is generated.
113      */
114     char16_t getMatch(int32_t keyCode, const char16_t* chars,
115             size_t numChars, int32_t metaState) const;
116 
117     /* Gets a sequence of key events that could plausibly generate the specified
118      * character sequence.  Returns false if some of the characters cannot be generated.
119      */
120     bool getEvents(int32_t deviceId, const char16_t* chars, size_t numChars,
121             Vector<KeyEvent>& outEvents) const;
122 
123     /* Maps a scan code and usage code to a key code, in case this key map overrides
124      * the mapping in some way. */
125     status_t mapKey(int32_t scanCode, int32_t usageCode, int32_t* outKeyCode) const;
126 
127 #if HAVE_ANDROID_OS
128     /* Reads a key map from a parcel. */
129     static sp<KeyCharacterMap> readFromParcel(Parcel* parcel);
130 
131     /* Writes a key map to a parcel. */
132     void writeToParcel(Parcel* parcel) const;
133 #endif
134 
135 protected:
136     virtual ~KeyCharacterMap();
137 
138 private:
139     struct Behavior {
140         Behavior();
141         Behavior(const Behavior& other);
142 
143         /* The next behavior in the list, or NULL if none. */
144         Behavior* next;
145 
146         /* The meta key modifiers for this behavior. */
147         int32_t metaState;
148 
149         /* The character to insert. */
150         char16_t character;
151 
152         /* The fallback keycode if the key is not handled. */
153         int32_t fallbackKeyCode;
154     };
155 
156     struct Key {
157         Key();
158         Key(const Key& other);
159         ~Key();
160 
161         /* The single character label printed on the key, or 0 if none. */
162         char16_t label;
163 
164         /* The number or symbol character generated by the key, or 0 if none. */
165         char16_t number;
166 
167         /* The list of key behaviors sorted from most specific to least specific
168          * meta key binding. */
169         Behavior* firstBehavior;
170     };
171 
172     class Parser {
173         enum State {
174             STATE_TOP = 0,
175             STATE_KEY = 1,
176         };
177 
178         enum {
179             PROPERTY_LABEL = 1,
180             PROPERTY_NUMBER = 2,
181             PROPERTY_META = 3,
182         };
183 
184         struct Property {
185             inline Property(int32_t property = 0, int32_t metaState = 0) :
propertyProperty186                     property(property), metaState(metaState) { }
187 
188             int32_t property;
189             int32_t metaState;
190         };
191 
192         KeyCharacterMap* mMap;
193         Tokenizer* mTokenizer;
194         Format mFormat;
195         State mState;
196         int32_t mKeyCode;
197 
198     public:
199         Parser(KeyCharacterMap* map, Tokenizer* tokenizer, Format format);
200         ~Parser();
201         status_t parse();
202 
203     private:
204         status_t parseType();
205         status_t parseMap();
206         status_t parseMapKey();
207         status_t parseKey();
208         status_t parseKeyProperty();
209         status_t finishKey(Key* key);
210         status_t parseModifier(const String8& token, int32_t* outMetaState);
211         status_t parseCharacterLiteral(char16_t* outCharacter);
212     };
213 
214     static sp<KeyCharacterMap> sEmpty;
215 
216     KeyedVector<int32_t, Key*> mKeys;
217     int mType;
218 
219     KeyedVector<int32_t, int32_t> mKeysByScanCode;
220     KeyedVector<int32_t, int32_t> mKeysByUsageCode;
221 
222     KeyCharacterMap();
223     KeyCharacterMap(const KeyCharacterMap& other);
224 
225     bool getKey(int32_t keyCode, const Key** outKey) const;
226     bool getKeyBehavior(int32_t keyCode, int32_t metaState,
227             const Key** outKey, const Behavior** outBehavior) const;
228     static bool matchesMetaState(int32_t eventMetaState, int32_t behaviorMetaState);
229 
230     bool findKey(char16_t ch, int32_t* outKeyCode, int32_t* outMetaState) const;
231 
232     static status_t load(Tokenizer* tokenizer, Format format, sp<KeyCharacterMap>* outMap);
233 
234     static void addKey(Vector<KeyEvent>& outEvents,
235             int32_t deviceId, int32_t keyCode, int32_t metaState, bool down, nsecs_t time);
236     static void addMetaKeys(Vector<KeyEvent>& outEvents,
237             int32_t deviceId, int32_t metaState, bool down, nsecs_t time,
238             int32_t* currentMetaState);
239     static bool addSingleEphemeralMetaKey(Vector<KeyEvent>& outEvents,
240             int32_t deviceId, int32_t metaState, bool down, nsecs_t time,
241             int32_t keyCode, int32_t keyMetaState,
242             int32_t* currentMetaState);
243     static void addDoubleEphemeralMetaKey(Vector<KeyEvent>& outEvents,
244             int32_t deviceId, int32_t metaState, bool down, nsecs_t time,
245             int32_t leftKeyCode, int32_t leftKeyMetaState,
246             int32_t rightKeyCode, int32_t rightKeyMetaState,
247             int32_t eitherKeyMetaState,
248             int32_t* currentMetaState);
249     static void addLockedMetaKey(Vector<KeyEvent>& outEvents,
250             int32_t deviceId, int32_t metaState, nsecs_t time,
251             int32_t keyCode, int32_t keyMetaState,
252             int32_t* currentMetaState);
253 };
254 
255 } // namespace android
256 
257 #endif // _LIBINPUT_KEY_CHARACTER_MAP_H
258