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
37namespace 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 */
46class KeyCharacterMap : public RefBase {
47public:
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
143protected:
144    virtual ~KeyCharacterMap();
145
146private:
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) :
197                    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