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 #ifdef __ANDROID__
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/Unicode.h>
31 #include <utils/RefBase.h>
32 
33 // Maximum number of keys supported by KeyCharacterMaps
34 #define MAX_KEYS 8192
35 
36 namespace android {
37 
38 /**
39  * Describes a mapping from Android key codes to characters.
40  * Also specifies other functions of the keyboard such as the keyboard type
41  * and key modifier semantics.
42  *
43  * This object is immutable after it has been loaded.
44  */
45 class KeyCharacterMap : public RefBase {
46 public:
47     enum KeyboardType {
48         KEYBOARD_TYPE_UNKNOWN = 0,
49         KEYBOARD_TYPE_NUMERIC = 1,
50         KEYBOARD_TYPE_PREDICTIVE = 2,
51         KEYBOARD_TYPE_ALPHA = 3,
52         KEYBOARD_TYPE_FULL = 4,
53         /**
54          * Deprecated. Set 'keyboard.specialFunction' to '1' in the device's IDC file instead.
55          */
56         KEYBOARD_TYPE_SPECIAL_FUNCTION = 5,
57         KEYBOARD_TYPE_OVERLAY = 6,
58     };
59 
60     enum Format {
61         // Base keyboard layout, may contain device-specific options, such as "type" declaration.
62         FORMAT_BASE = 0,
63         // Overlay keyboard layout, more restrictive, may be published by applications,
64         // cannot override device-specific options.
65         FORMAT_OVERLAY = 1,
66         // Either base or overlay layout ok.
67         FORMAT_ANY = 2,
68     };
69 
70     // Substitute key code and meta state for fallback action.
71     struct FallbackAction {
72         int32_t keyCode;
73         int32_t metaState;
74     };
75 
76     /* Loads a key character map from a file. */
77     static status_t load(const std::string& filename, Format format, sp<KeyCharacterMap>* outMap);
78 
79     /* Loads a key character map from its string contents. */
80     static status_t loadContents(const std::string& filename,
81             const char* contents, Format format, sp<KeyCharacterMap>* outMap);
82 
83     /* Combines a base key character map and an overlay. */
84     static sp<KeyCharacterMap> combine(const sp<KeyCharacterMap>& base,
85             const sp<KeyCharacterMap>& overlay);
86 
87     /* Returns an empty key character map. */
88     static sp<KeyCharacterMap> empty();
89 
90     /* Gets the keyboard type. */
91     int32_t getKeyboardType() const;
92 
93     /* Gets the primary character for this key as in the label physically printed on it.
94      * Returns 0 if none (eg. for non-printing keys). */
95     char16_t getDisplayLabel(int32_t keyCode) const;
96 
97     /* Gets the Unicode character for the number or symbol generated by the key
98      * when the keyboard is used as a dialing pad.
99      * Returns 0 if no number or symbol is generated.
100      */
101     char16_t getNumber(int32_t keyCode) const;
102 
103     /* Gets the Unicode character generated by the key and meta key modifiers.
104      * Returns 0 if no character is generated.
105      */
106     char16_t getCharacter(int32_t keyCode, int32_t metaState) const;
107 
108     /* Gets the fallback action to use by default if the application does not
109      * handle the specified key.
110      * Returns true if an action was available, false if none.
111      */
112     bool getFallbackAction(int32_t keyCode, int32_t metaState,
113             FallbackAction* outFallbackAction) const;
114 
115     /* Gets the first matching Unicode character that can be generated by the key,
116      * preferring the one with the specified meta key modifiers.
117      * Returns 0 if no matching character is generated.
118      */
119     char16_t getMatch(int32_t keyCode, const char16_t* chars,
120             size_t numChars, int32_t metaState) const;
121 
122     /* Gets a sequence of key events that could plausibly generate the specified
123      * character sequence.  Returns false if some of the characters cannot be generated.
124      */
125     bool getEvents(int32_t deviceId, const char16_t* chars, size_t numChars,
126             Vector<KeyEvent>& outEvents) const;
127 
128     /* Maps a scan code and usage code to a key code, in case this key map overrides
129      * the mapping in some way. */
130     status_t mapKey(int32_t scanCode, int32_t usageCode, int32_t* outKeyCode) const;
131 
132     /* Tries to find a replacement key code for a given key code and meta state
133      * in character map. */
134     void tryRemapKey(int32_t scanCode, int32_t metaState,
135             int32_t* outKeyCode, int32_t* outMetaState) const;
136 
137 #ifdef __ANDROID__
138     /* Reads a key map from a parcel. */
139     static sp<KeyCharacterMap> readFromParcel(Parcel* parcel);
140 
141     /* Writes a key map to a parcel. */
142     void writeToParcel(Parcel* parcel) const;
143 #endif
144 
145 protected:
146     virtual ~KeyCharacterMap();
147 
148 private:
149     struct Behavior {
150         Behavior();
151         Behavior(const Behavior& other);
152 
153         /* The next behavior in the list, or NULL if none. */
154         Behavior* next;
155 
156         /* The meta key modifiers for this behavior. */
157         int32_t metaState;
158 
159         /* The character to insert. */
160         char16_t character;
161 
162         /* The fallback keycode if the key is not handled. */
163         int32_t fallbackKeyCode;
164 
165         /* The replacement keycode if the key has to be replaced outright. */
166         int32_t replacementKeyCode;
167     };
168 
169     struct Key {
170         Key();
171         Key(const Key& other);
172         ~Key();
173 
174         /* The single character label printed on the key, or 0 if none. */
175         char16_t label;
176 
177         /* The number or symbol character generated by the key, or 0 if none. */
178         char16_t number;
179 
180         /* The list of key behaviors sorted from most specific to least specific
181          * meta key binding. */
182         Behavior* firstBehavior;
183     };
184 
185     class Parser {
186         enum State {
187             STATE_TOP = 0,
188             STATE_KEY = 1,
189         };
190 
191         enum {
192             PROPERTY_LABEL = 1,
193             PROPERTY_NUMBER = 2,
194             PROPERTY_META = 3,
195         };
196 
197         struct Property {
198             inline explicit Property(int32_t property = 0, int32_t metaState = 0) :
propertyProperty199                     property(property), metaState(metaState) { }
200 
201             int32_t property;
202             int32_t metaState;
203         };
204 
205         KeyCharacterMap* mMap;
206         Tokenizer* mTokenizer;
207         Format mFormat;
208         State mState;
209         int32_t mKeyCode;
210 
211     public:
212         Parser(KeyCharacterMap* map, Tokenizer* tokenizer, Format format);
213         ~Parser();
214         status_t parse();
215 
216     private:
217         status_t parseType();
218         status_t parseMap();
219         status_t parseMapKey();
220         status_t parseKey();
221         status_t parseKeyProperty();
222         status_t finishKey(Key* key);
223         status_t parseModifier(const std::string& token, int32_t* outMetaState);
224         status_t parseCharacterLiteral(char16_t* outCharacter);
225     };
226 
227     static sp<KeyCharacterMap> sEmpty;
228 
229     KeyedVector<int32_t, Key*> mKeys;
230     int mType;
231 
232     KeyedVector<int32_t, int32_t> mKeysByScanCode;
233     KeyedVector<int32_t, int32_t> mKeysByUsageCode;
234 
235     KeyCharacterMap();
236     KeyCharacterMap(const KeyCharacterMap& other);
237 
238     bool getKey(int32_t keyCode, const Key** outKey) const;
239     bool getKeyBehavior(int32_t keyCode, int32_t metaState,
240             const Key** outKey, const Behavior** outBehavior) const;
241     static bool matchesMetaState(int32_t eventMetaState, int32_t behaviorMetaState);
242 
243     bool findKey(char16_t ch, int32_t* outKeyCode, int32_t* outMetaState) const;
244 
245     static status_t load(Tokenizer* tokenizer, Format format, sp<KeyCharacterMap>* outMap);
246 
247     static void addKey(Vector<KeyEvent>& outEvents,
248             int32_t deviceId, int32_t keyCode, int32_t metaState, bool down, nsecs_t time);
249     static void addMetaKeys(Vector<KeyEvent>& outEvents,
250             int32_t deviceId, int32_t metaState, bool down, nsecs_t time,
251             int32_t* currentMetaState);
252     static bool addSingleEphemeralMetaKey(Vector<KeyEvent>& outEvents,
253             int32_t deviceId, int32_t metaState, bool down, nsecs_t time,
254             int32_t keyCode, int32_t keyMetaState,
255             int32_t* currentMetaState);
256     static void addDoubleEphemeralMetaKey(Vector<KeyEvent>& outEvents,
257             int32_t deviceId, int32_t metaState, bool down, nsecs_t time,
258             int32_t leftKeyCode, int32_t leftKeyMetaState,
259             int32_t rightKeyCode, int32_t rightKeyMetaState,
260             int32_t eitherKeyMetaState,
261             int32_t* currentMetaState);
262     static void addLockedMetaKey(Vector<KeyEvent>& outEvents,
263             int32_t deviceId, int32_t metaState, nsecs_t time,
264             int32_t keyCode, int32_t keyMetaState,
265             int32_t* currentMetaState);
266 };
267 
268 } // namespace android
269 
270 #endif // _LIBINPUT_KEY_CHARACTER_MAP_H
271