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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         /**
     55          * Deprecated. Set 'keyboard.specialFunction' to '1' in the device's IDC file instead.
     56          */
     57         KEYBOARD_TYPE_SPECIAL_FUNCTION = 5,
     58         KEYBOARD_TYPE_OVERLAY = 6,
     59     };
     60 
     61     enum Format {
     62         // Base keyboard layout, may contain device-specific options, such as "type" declaration.
     63         FORMAT_BASE = 0,
     64         // Overlay keyboard layout, more restrictive, may be published by applications,
     65         // cannot override device-specific options.
     66         FORMAT_OVERLAY = 1,
     67         // Either base or overlay layout ok.
     68         FORMAT_ANY = 2,
     69     };
     70 
     71     // Substitute key code and meta state for fallback action.
     72     struct FallbackAction {
     73         int32_t keyCode;
     74         int32_t metaState;
     75     };
     76 
     77     /* Loads a key character map from a file. */
     78     static status_t load(const String8& filename, Format format, sp<KeyCharacterMap>* outMap);
     79 
     80     /* Loads a key character map from its string contents. */
     81     static status_t loadContents(const String8& filename,
     82             const char* contents, Format format, sp<KeyCharacterMap>* outMap);
     83 
     84     /* Combines a base key character map and an overlay. */
     85     static sp<KeyCharacterMap> combine(const sp<KeyCharacterMap>& base,
     86             const sp<KeyCharacterMap>& overlay);
     87 
     88     /* Returns an empty key character map. */
     89     static sp<KeyCharacterMap> empty();
     90 
     91     /* Gets the keyboard type. */
     92     int32_t getKeyboardType() const;
     93 
     94     /* Gets the primary character for this key as in the label physically printed on it.
     95      * Returns 0 if none (eg. for non-printing keys). */
     96     char16_t getDisplayLabel(int32_t keyCode) const;
     97 
     98     /* Gets the Unicode character for the number or symbol generated by the key
     99      * when the keyboard is used as a dialing pad.
    100      * Returns 0 if no number or symbol is generated.
    101      */
    102     char16_t getNumber(int32_t keyCode) const;
    103 
    104     /* Gets the Unicode character generated by the key and meta key modifiers.
    105      * Returns 0 if no character is generated.
    106      */
    107     char16_t getCharacter(int32_t keyCode, int32_t metaState) const;
    108 
    109     /* Gets the fallback action to use by default if the application does not
    110      * handle the specified key.
    111      * Returns true if an action was available, false if none.
    112      */
    113     bool getFallbackAction(int32_t keyCode, int32_t metaState,
    114             FallbackAction* outFallbackAction) const;
    115 
    116     /* Gets the first matching Unicode character that can be generated by the key,
    117      * preferring the one with the specified meta key modifiers.
    118      * Returns 0 if no matching character is generated.
    119      */
    120     char16_t getMatch(int32_t keyCode, const char16_t* chars,
    121             size_t numChars, int32_t metaState) const;
    122 
    123     /* Gets a sequence of key events that could plausibly generate the specified
    124      * character sequence.  Returns false if some of the characters cannot be generated.
    125      */
    126     bool getEvents(int32_t deviceId, const char16_t* chars, size_t numChars,
    127             Vector<KeyEvent>& outEvents) const;
    128 
    129     /* Maps a scan code and usage code to a key code, in case this key map overrides
    130      * the mapping in some way. */
    131     status_t mapKey(int32_t scanCode, int32_t usageCode, int32_t* outKeyCode) const;
    132 
    133     /* Tries to find a replacement key code for a given key code and meta state
    134      * in character map. */
    135     void tryRemapKey(int32_t scanCode, int32_t metaState,
    136             int32_t* outKeyCode, int32_t* outMetaState) const;
    137 
    138 #ifdef __ANDROID__
    139     /* Reads a key map from a parcel. */
    140     static sp<KeyCharacterMap> readFromParcel(Parcel* parcel);
    141 
    142     /* Writes a key map to a parcel. */
    143     void writeToParcel(Parcel* parcel) const;
    144 #endif
    145 
    146 protected:
    147     virtual ~KeyCharacterMap();
    148 
    149 private:
    150     struct Behavior {
    151         Behavior();
    152         Behavior(const Behavior& other);
    153 
    154         /* The next behavior in the list, or NULL if none. */
    155         Behavior* next;
    156 
    157         /* The meta key modifiers for this behavior. */
    158         int32_t metaState;
    159 
    160         /* The character to insert. */
    161         char16_t character;
    162 
    163         /* The fallback keycode if the key is not handled. */
    164         int32_t fallbackKeyCode;
    165 
    166         /* The replacement keycode if the key has to be replaced outright. */
    167         int32_t replacementKeyCode;
    168     };
    169 
    170     struct Key {
    171         Key();
    172         Key(const Key& other);
    173         ~Key();
    174 
    175         /* The single character label printed on the key, or 0 if none. */
    176         char16_t label;
    177 
    178         /* The number or symbol character generated by the key, or 0 if none. */
    179         char16_t number;
    180 
    181         /* The list of key behaviors sorted from most specific to least specific
    182          * meta key binding. */
    183         Behavior* firstBehavior;
    184     };
    185 
    186     class Parser {
    187         enum State {
    188             STATE_TOP = 0,
    189             STATE_KEY = 1,
    190         };
    191 
    192         enum {
    193             PROPERTY_LABEL = 1,
    194             PROPERTY_NUMBER = 2,
    195             PROPERTY_META = 3,
    196         };
    197 
    198         struct Property {
    199             inline Property(int32_t property = 0, int32_t metaState = 0) :
    200                     property(property), metaState(metaState) { }
    201 
    202             int32_t property;
    203             int32_t metaState;
    204         };
    205 
    206         KeyCharacterMap* mMap;
    207         Tokenizer* mTokenizer;
    208         Format mFormat;
    209         State mState;
    210         int32_t mKeyCode;
    211 
    212     public:
    213         Parser(KeyCharacterMap* map, Tokenizer* tokenizer, Format format);
    214         ~Parser();
    215         status_t parse();
    216 
    217     private:
    218         status_t parseType();
    219         status_t parseMap();
    220         status_t parseMapKey();
    221         status_t parseKey();
    222         status_t parseKeyProperty();
    223         status_t finishKey(Key* key);
    224         status_t parseModifier(const String8& token, int32_t* outMetaState);
    225         status_t parseCharacterLiteral(char16_t* outCharacter);
    226     };
    227 
    228     static sp<KeyCharacterMap> sEmpty;
    229 
    230     KeyedVector<int32_t, Key*> mKeys;
    231     int mType;
    232 
    233     KeyedVector<int32_t, int32_t> mKeysByScanCode;
    234     KeyedVector<int32_t, int32_t> mKeysByUsageCode;
    235 
    236     KeyCharacterMap();
    237     KeyCharacterMap(const KeyCharacterMap& other);
    238 
    239     bool getKey(int32_t keyCode, const Key** outKey) const;
    240     bool getKeyBehavior(int32_t keyCode, int32_t metaState,
    241             const Key** outKey, const Behavior** outBehavior) const;
    242     static bool matchesMetaState(int32_t eventMetaState, int32_t behaviorMetaState);
    243 
    244     bool findKey(char16_t ch, int32_t* outKeyCode, int32_t* outMetaState) const;
    245 
    246     static status_t load(Tokenizer* tokenizer, Format format, sp<KeyCharacterMap>* outMap);
    247 
    248     static void addKey(Vector<KeyEvent>& outEvents,
    249             int32_t deviceId, int32_t keyCode, int32_t metaState, bool down, nsecs_t time);
    250     static void addMetaKeys(Vector<KeyEvent>& outEvents,
    251             int32_t deviceId, int32_t metaState, bool down, nsecs_t time,
    252             int32_t* currentMetaState);
    253     static bool addSingleEphemeralMetaKey(Vector<KeyEvent>& outEvents,
    254             int32_t deviceId, int32_t metaState, bool down, nsecs_t time,
    255             int32_t keyCode, int32_t keyMetaState,
    256             int32_t* currentMetaState);
    257     static void addDoubleEphemeralMetaKey(Vector<KeyEvent>& outEvents,
    258             int32_t deviceId, int32_t metaState, bool down, nsecs_t time,
    259             int32_t leftKeyCode, int32_t leftKeyMetaState,
    260             int32_t rightKeyCode, int32_t rightKeyMetaState,
    261             int32_t eitherKeyMetaState,
    262             int32_t* currentMetaState);
    263     static void addLockedMetaKey(Vector<KeyEvent>& outEvents,
    264             int32_t deviceId, int32_t metaState, nsecs_t time,
    265             int32_t keyCode, int32_t keyMetaState,
    266             int32_t* currentMetaState);
    267 };
    268 
    269 } // namespace android
    270 
    271 #endif // _LIBINPUT_KEY_CHARACTER_MAP_H
    272