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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 #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/String8.h>
31 #include <utils/Unicode.h>
32 #include <utils/RefBase.h>
33 
34 // Maximum number of keys supported by KeyCharacterMaps
35 #define MAX_KEYS 8192
36 
37 namespace android {
38 
39 /**
40  * Describes a mapping from Android key codes to characters.
41  * Also specifies other functions of the keyboard such as the keyboard type
42  * and key modifier semantics.
43  *
44  * This object is immutable after it has been loaded.
45  */
46 class KeyCharacterMap : public RefBase {
47 public:
48     enum KeyboardType {
49         KEYBOARD_TYPE_UNKNOWN = 0,
50         KEYBOARD_TYPE_NUMERIC = 1,
51         KEYBOARD_TYPE_PREDICTIVE = 2,
52         KEYBOARD_TYPE_ALPHA = 3,
53         KEYBOARD_TYPE_FULL = 4,
54         KEYBOARD_TYPE_SPECIAL_FUNCTION = 5,
55         KEYBOARD_TYPE_OVERLAY = 6,
56     };
57 
58     enum Format {
59         // Base keyboard layout, may contain device-specific options, such as "type" declaration.
60         FORMAT_BASE = 0,
61         // Overlay keyboard layout, more restrictive, may be published by applications,
62         // cannot override device-specific options.
63         FORMAT_OVERLAY = 1,
64         // Either base or overlay layout ok.
65         FORMAT_ANY = 2,
66     };
67 
68     // Substitute key code and meta state for fallback action.
69     struct FallbackAction {
70         int32_t keyCode;
71         int32_t metaState;
72     };
73 
74     /* Loads a key character map from a file. */
75     static status_t load(const String8& filename, Format format, sp<KeyCharacterMap>* outMap);
76 
77     /* Loads a key character map from its string contents. */
78     static status_t loadContents(const String8& filename,
79             const char* contents, Format format, sp<KeyCharacterMap>* outMap);
80 
81     /* Combines a base key character map and an overlay. */
82     static sp<KeyCharacterMap> combine(const sp<KeyCharacterMap>& base,
83             const sp<KeyCharacterMap>& overlay);
84 
85     /* Returns an empty key character map. */
86     static sp<KeyCharacterMap> empty();
87 
88     /* Gets the keyboard type. */
89     int32_t getKeyboardType() const;
90 
91     /* Gets the primary character for this key as in the label physically printed on it.
92      * Returns 0 if none (eg. for non-printing keys). */
93     char16_t getDisplayLabel(int32_t keyCode) const;
94 
95     /* Gets the Unicode character for the number or symbol generated by the key
96      * when the keyboard is used as a dialing pad.
97      * Returns 0 if no number or symbol is generated.
98      */
99     char16_t getNumber(int32_t keyCode) const;
100 
101     /* Gets the Unicode character generated by the key and meta key modifiers.
102      * Returns 0 if no character is generated.
103      */
104     char16_t getCharacter(int32_t keyCode, int32_t metaState) const;
105 
106     /* Gets the fallback action to use by default if the application does not
107      * handle the specified key.
108      * Returns true if an action was available, false if none.
109      */
110     bool getFallbackAction(int32_t keyCode, int32_t metaState,
111             FallbackAction* outFallbackAction) const;
112 
113     /* Gets the first matching Unicode character that can be generated by the key,
114      * preferring the one with the specified meta key modifiers.
115      * Returns 0 if no matching character is generated.
116      */
117     char16_t getMatch(int32_t keyCode, const char16_t* chars,
118             size_t numChars, int32_t metaState) const;
119 
120     /* Gets a sequence of key events that could plausibly generate the specified
121      * character sequence.  Returns false if some of the characters cannot be generated.
122      */
123     bool getEvents(int32_t deviceId, const char16_t* chars, size_t numChars,
124             Vector<KeyEvent>& outEvents) const;
125 
126     /* Maps a scan code and usage code to a key code, in case this key map overrides
127      * the mapping in some way. */
128     status_t mapKey(int32_t scanCode, int32_t usageCode, int32_t* outKeyCode) const;
129 
130     /* Tries to find a replacement key code for a given key code and meta state
131      * in character map. */
132     void tryRemapKey(int32_t scanCode, int32_t metaState,
133             int32_t* outKeyCode, int32_t* outMetaState) const;
134 
135 #ifdef __ANDROID__
136     /* Reads a key map from a parcel. */
137     static sp<KeyCharacterMap> readFromParcel(Parcel* parcel);
138 
139     /* Writes a key map to a parcel. */
140     void writeToParcel(Parcel* parcel) const;
141 #endif
142 
143 protected:
144     virtual ~KeyCharacterMap();
145 
146 private:
147     struct Behavior {
148         Behavior();
149         Behavior(const Behavior& other);
150 
151         /* The next behavior in the list, or NULL if none. */
152         Behavior* next;
153 
154         /* The meta key modifiers for this behavior. */
155         int32_t metaState;
156 
157         /* The character to insert. */
158         char16_t character;
159 
160         /* The fallback keycode if the key is not handled. */
161         int32_t fallbackKeyCode;
162 
163         /* The replacement keycode if the key has to be replaced outright. */
164         int32_t replacementKeyCode;
165     };
166 
167     struct Key {
168         Key();
169         Key(const Key& other);
170         ~Key();
171 
172         /* The single character label printed on the key, or 0 if none. */
173         char16_t label;
174 
175         /* The number or symbol character generated by the key, or 0 if none. */
176         char16_t number;
177 
178         /* The list of key behaviors sorted from most specific to least specific
179          * meta key binding. */
180         Behavior* firstBehavior;
181     };
182 
183     class Parser {
184         enum State {
185             STATE_TOP = 0,
186             STATE_KEY = 1,
187         };
188 
189         enum {
190             PROPERTY_LABEL = 1,
191             PROPERTY_NUMBER = 2,
192             PROPERTY_META = 3,
193         };
194 
195         struct Property {
196             inline Property(int32_t property = 0, int32_t metaState = 0) :
propertyProperty197                     property(property), metaState(metaState) { }
198 
199             int32_t property;
200             int32_t metaState;
201         };
202 
203         KeyCharacterMap* mMap;
204         Tokenizer* mTokenizer;
205         Format mFormat;
206         State mState;
207         int32_t mKeyCode;
208 
209     public:
210         Parser(KeyCharacterMap* map, Tokenizer* tokenizer, Format format);
211         ~Parser();
212         status_t parse();
213 
214     private:
215         status_t parseType();
216         status_t parseMap();
217         status_t parseMapKey();
218         status_t parseKey();
219         status_t parseKeyProperty();
220         status_t finishKey(Key* key);
221         status_t parseModifier(const String8& token, int32_t* outMetaState);
222         status_t parseCharacterLiteral(char16_t* outCharacter);
223     };
224 
225     static sp<KeyCharacterMap> sEmpty;
226 
227     KeyedVector<int32_t, Key*> mKeys;
228     int mType;
229 
230     KeyedVector<int32_t, int32_t> mKeysByScanCode;
231     KeyedVector<int32_t, int32_t> mKeysByUsageCode;
232 
233     KeyCharacterMap();
234     KeyCharacterMap(const KeyCharacterMap& other);
235 
236     bool getKey(int32_t keyCode, const Key** outKey) const;
237     bool getKeyBehavior(int32_t keyCode, int32_t metaState,
238             const Key** outKey, const Behavior** outBehavior) const;
239     static bool matchesMetaState(int32_t eventMetaState, int32_t behaviorMetaState);
240 
241     bool findKey(char16_t ch, int32_t* outKeyCode, int32_t* outMetaState) const;
242 
243     static status_t load(Tokenizer* tokenizer, Format format, sp<KeyCharacterMap>* outMap);
244 
245     static void addKey(Vector<KeyEvent>& outEvents,
246             int32_t deviceId, int32_t keyCode, int32_t metaState, bool down, nsecs_t time);
247     static void addMetaKeys(Vector<KeyEvent>& outEvents,
248             int32_t deviceId, int32_t metaState, bool down, nsecs_t time,
249             int32_t* currentMetaState);
250     static bool addSingleEphemeralMetaKey(Vector<KeyEvent>& outEvents,
251             int32_t deviceId, int32_t metaState, bool down, nsecs_t time,
252             int32_t keyCode, int32_t keyMetaState,
253             int32_t* currentMetaState);
254     static void addDoubleEphemeralMetaKey(Vector<KeyEvent>& outEvents,
255             int32_t deviceId, int32_t metaState, bool down, nsecs_t time,
256             int32_t leftKeyCode, int32_t leftKeyMetaState,
257             int32_t rightKeyCode, int32_t rightKeyMetaState,
258             int32_t eitherKeyMetaState,
259             int32_t* currentMetaState);
260     static void addLockedMetaKey(Vector<KeyEvent>& outEvents,
261             int32_t deviceId, int32_t metaState, nsecs_t time,
262             int32_t keyCode, int32_t keyMetaState,
263             int32_t* currentMetaState);
264 };
265 
266 } // namespace android
267 
268 #endif // _LIBINPUT_KEY_CHARACTER_MAP_H
269