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1 /*
2  * Copyright (C) 2007 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 package android.view;
18 
19 import android.annotation.Nullable;
20 import android.compat.annotation.UnsupportedAppUsage;
21 import android.hardware.input.InputManager;
22 import android.os.Build;
23 import android.os.Parcel;
24 import android.os.Parcelable;
25 import android.text.method.MetaKeyKeyListener;
26 import android.util.AndroidRuntimeException;
27 import android.util.SparseIntArray;
28 
29 import com.android.internal.annotations.VisibleForTesting;
30 
31 import java.text.Normalizer;
32 
33 /**
34  * Describes the keys provided by a keyboard device and their associated labels.
35  */
36 public class KeyCharacterMap implements Parcelable {
37     /**
38      * The id of the device's primary built in keyboard is always 0.
39      *
40      * @deprecated This constant should no longer be used because there is no
41      * guarantee that a device has a built-in keyboard that can be used for
42      * typing text.  There might not be a built-in keyboard, the built-in keyboard
43      * might be a {@link #NUMERIC} or {@link #SPECIAL_FUNCTION} keyboard, or there
44      * might be multiple keyboards installed including external keyboards.
45      * When interpreting key presses received from the framework, applications should
46      * use the device id specified in the {@link KeyEvent} received.
47      * When synthesizing key presses for delivery elsewhere or when translating key presses
48      * from unknown keyboards, applications should use the special {@link #VIRTUAL_KEYBOARD}
49      * device id.
50      */
51     @Deprecated
52     public static final int BUILT_IN_KEYBOARD = 0;
53 
54     /**
55      * The id of a generic virtual keyboard with a full layout that can be used to
56      * synthesize key events.  Typically used with {@link #getEvents}.
57      */
58     public static final int VIRTUAL_KEYBOARD = -1;
59 
60     /**
61      * A numeric (12-key) keyboard.
62      * <p>
63      * A numeric keyboard supports text entry using a multi-tap approach.
64      * It may be necessary to tap a key multiple times to generate the desired letter
65      * or symbol.
66      * </p><p>
67      * This type of keyboard is generally designed for thumb typing.
68      * </p>
69      */
70     public static final int NUMERIC = 1;
71 
72     /**
73      * A keyboard with all the letters, but with more than one letter per key.
74      * <p>
75      * This type of keyboard is generally designed for thumb typing.
76      * </p>
77      */
78     public static final int PREDICTIVE = 2;
79 
80     /**
81      * A keyboard with all the letters, and maybe some numbers.
82      * <p>
83      * An alphabetic keyboard supports text entry directly but may have a condensed
84      * layout with a small form factor.  In contrast to a {@link #FULL full keyboard}, some
85      * symbols may only be accessible using special on-screen character pickers.
86      * In addition, to improve typing speed and accuracy, the framework provides
87      * special affordances for alphabetic keyboards such as auto-capitalization
88      * and toggled / locked shift and alt keys.
89      * </p><p>
90      * This type of keyboard is generally designed for thumb typing.
91      * </p>
92      */
93     public static final int ALPHA = 3;
94 
95     /**
96      * A full PC-style keyboard.
97      * <p>
98      * A full keyboard behaves like a PC keyboard.  All symbols are accessed directly
99      * by pressing keys on the keyboard without on-screen support or affordances such
100      * as auto-capitalization.
101      * </p><p>
102      * This type of keyboard is generally designed for full two hand typing.
103      * </p>
104      */
105     public static final int FULL = 4;
106 
107     /**
108      * A keyboard that is only used to control special functions rather than for typing.
109      * <p>
110      * A special function keyboard consists only of non-printing keys such as
111      * HOME and POWER that are not actually used for typing.
112      * </p>
113      */
114     public static final int SPECIAL_FUNCTION = 5;
115 
116     /**
117      * This private-use character is used to trigger Unicode character
118      * input by hex digits.
119      */
120     public static final char HEX_INPUT = '\uEF00';
121 
122     /**
123      * This private-use character is used to bring up a character picker for
124      * miscellaneous symbols.
125      */
126     public static final char PICKER_DIALOG_INPUT = '\uEF01';
127 
128     /**
129      * Modifier keys may be chorded with character keys.
130      *
131      * @see #getModifierBehavior()
132      */
133     public static final int MODIFIER_BEHAVIOR_CHORDED = 0;
134 
135     /**
136      * Modifier keys may be chorded with character keys or they may toggle
137      * into latched or locked states when pressed independently.
138      *
139      * @see #getModifierBehavior()
140      */
141     public static final int MODIFIER_BEHAVIOR_CHORDED_OR_TOGGLED = 1;
142 
143     /*
144      * This bit will be set in the return value of {@link #get(int, int)} if the
145      * key is a "dead key."
146      */
147     public static final int COMBINING_ACCENT = 0x80000000;
148 
149     /**
150      * Mask the return value from {@link #get(int, int)} with this value to get
151      * a printable representation of the accent character of a "dead key."
152      */
153     public static final int COMBINING_ACCENT_MASK = 0x7FFFFFFF;
154 
155     /* Characters used to display placeholders for dead keys. */
156     private static final int ACCENT_ACUTE = '\u00B4';
157     private static final int ACCENT_BREVE = '\u02D8';
158     private static final int ACCENT_CARON = '\u02C7';
159     private static final int ACCENT_CEDILLA = '\u00B8';
160     private static final int ACCENT_CIRCUMFLEX = '\u02C6';
161     private static final int ACCENT_COMMA_ABOVE = '\u1FBD';
162     private static final int ACCENT_COMMA_ABOVE_RIGHT = '\u02BC';
163     private static final int ACCENT_DOT_ABOVE = '\u02D9';
164     private static final int ACCENT_DOT_BELOW = '.'; // approximate
165     private static final int ACCENT_DOUBLE_ACUTE = '\u02DD';
166     private static final int ACCENT_GRAVE = '\u02CB';
167     private static final int ACCENT_HOOK_ABOVE = '\u02C0';
168     private static final int ACCENT_HORN = '\''; // approximate
169     private static final int ACCENT_MACRON = '\u00AF';
170     private static final int ACCENT_MACRON_BELOW = '\u02CD';
171     private static final int ACCENT_OGONEK = '\u02DB';
172     private static final int ACCENT_REVERSED_COMMA_ABOVE = '\u02BD';
173     private static final int ACCENT_RING_ABOVE = '\u02DA';
174     private static final int ACCENT_STROKE = '-'; // approximate
175     private static final int ACCENT_TILDE = '\u02DC';
176     private static final int ACCENT_TURNED_COMMA_ABOVE = '\u02BB';
177     private static final int ACCENT_UMLAUT = '\u00A8';
178     private static final int ACCENT_VERTICAL_LINE_ABOVE = '\u02C8';
179     private static final int ACCENT_VERTICAL_LINE_BELOW = '\u02CC';
180 
181     /* Legacy dead key display characters used in previous versions of the API.
182      * We still support these characters by mapping them to their non-legacy version. */
183     private static final int ACCENT_GRAVE_LEGACY = '`';
184     private static final int ACCENT_CIRCUMFLEX_LEGACY = '^';
185     private static final int ACCENT_TILDE_LEGACY = '~';
186 
187     private static final int CHAR_SPACE = ' ';
188 
189     /**
190      * Maps Unicode combining diacritical to display-form dead key.
191      */
192     private static final SparseIntArray sCombiningToAccent = new SparseIntArray();
193     private static final SparseIntArray sAccentToCombining = new SparseIntArray();
194     static {
195         addCombining('\u0300', ACCENT_GRAVE);
196         addCombining('\u0301', ACCENT_ACUTE);
197         addCombining('\u0302', ACCENT_CIRCUMFLEX);
198         addCombining('\u0303', ACCENT_TILDE);
199         addCombining('\u0304', ACCENT_MACRON);
200         addCombining('\u0306', ACCENT_BREVE);
201         addCombining('\u0307', ACCENT_DOT_ABOVE);
202         addCombining('\u0308', ACCENT_UMLAUT);
203         addCombining('\u0309', ACCENT_HOOK_ABOVE);
204         addCombining('\u030A', ACCENT_RING_ABOVE);
205         addCombining('\u030B', ACCENT_DOUBLE_ACUTE);
206         addCombining('\u030C', ACCENT_CARON);
207         addCombining('\u030D', ACCENT_VERTICAL_LINE_ABOVE);
208         //addCombining('\u030E', ACCENT_DOUBLE_VERTICAL_LINE_ABOVE);
209         //addCombining('\u030F', ACCENT_DOUBLE_GRAVE);
210         //addCombining('\u0310', ACCENT_CANDRABINDU);
211         //addCombining('\u0311', ACCENT_INVERTED_BREVE);
212         addCombining('\u0312', ACCENT_TURNED_COMMA_ABOVE);
213         addCombining('\u0313', ACCENT_COMMA_ABOVE);
214         addCombining('\u0314', ACCENT_REVERSED_COMMA_ABOVE);
215         addCombining('\u0315', ACCENT_COMMA_ABOVE_RIGHT);
216         addCombining('\u031B', ACCENT_HORN);
217         addCombining('\u0323', ACCENT_DOT_BELOW);
218         //addCombining('\u0326', ACCENT_COMMA_BELOW);
219         addCombining('\u0327', ACCENT_CEDILLA);
220         addCombining('\u0328', ACCENT_OGONEK);
221         addCombining('\u0329', ACCENT_VERTICAL_LINE_BELOW);
222         addCombining('\u0331', ACCENT_MACRON_BELOW);
223         addCombining('\u0335', ACCENT_STROKE);
224         //addCombining('\u0342', ACCENT_PERISPOMENI);
225         //addCombining('\u0344', ACCENT_DIALYTIKA_TONOS);
226         //addCombining('\u0345', ACCENT_YPOGEGRAMMENI);
227 
228         // One-way mappings to equivalent preferred accents.
229         sCombiningToAccent.append('\u0340', ACCENT_GRAVE);
230         sCombiningToAccent.append('\u0341', ACCENT_ACUTE);
231         sCombiningToAccent.append('\u0343', ACCENT_COMMA_ABOVE);
232 
233         // One-way legacy mappings to preserve compatibility with older applications.
sAccentToCombining.append(ACCENT_GRAVE_LEGACY, '\\u0300')234         sAccentToCombining.append(ACCENT_GRAVE_LEGACY, '\u0300');
sAccentToCombining.append(ACCENT_CIRCUMFLEX_LEGACY, '\\u0302')235         sAccentToCombining.append(ACCENT_CIRCUMFLEX_LEGACY, '\u0302');
sAccentToCombining.append(ACCENT_TILDE_LEGACY, '\\u0303')236         sAccentToCombining.append(ACCENT_TILDE_LEGACY, '\u0303');
237     }
238 
addCombining(int combining, int accent)239     private static void addCombining(int combining, int accent) {
240         sCombiningToAccent.append(combining, accent);
241         sAccentToCombining.append(accent, combining);
242     }
243 
244     /**
245      * Maps combinations of (display-form) combining key and second character
246      * to combined output character.
247      * These mappings are derived from the Unicode NFC tables as needed.
248      */
249     private static final SparseIntArray sDeadKeyCache = new SparseIntArray();
250     private static final StringBuilder sDeadKeyBuilder = new StringBuilder();
251     static {
252         // Non-standard decompositions.
253         // Stroke modifier for Finnish multilingual keyboard and others.
addDeadKey(ACCENT_STROKE, 'D', '\\u0110')254         addDeadKey(ACCENT_STROKE, 'D', '\u0110');
addDeadKey(ACCENT_STROKE, 'G', '\\u01e4')255         addDeadKey(ACCENT_STROKE, 'G', '\u01e4');
addDeadKey(ACCENT_STROKE, 'H', '\\u0126')256         addDeadKey(ACCENT_STROKE, 'H', '\u0126');
addDeadKey(ACCENT_STROKE, 'I', '\\u0197')257         addDeadKey(ACCENT_STROKE, 'I', '\u0197');
addDeadKey(ACCENT_STROKE, 'L', '\\u0141')258         addDeadKey(ACCENT_STROKE, 'L', '\u0141');
addDeadKey(ACCENT_STROKE, 'O', '\\u00d8')259         addDeadKey(ACCENT_STROKE, 'O', '\u00d8');
addDeadKey(ACCENT_STROKE, 'T', '\\u0166')260         addDeadKey(ACCENT_STROKE, 'T', '\u0166');
addDeadKey(ACCENT_STROKE, 'd', '\\u0111')261         addDeadKey(ACCENT_STROKE, 'd', '\u0111');
addDeadKey(ACCENT_STROKE, 'g', '\\u01e5')262         addDeadKey(ACCENT_STROKE, 'g', '\u01e5');
addDeadKey(ACCENT_STROKE, 'h', '\\u0127')263         addDeadKey(ACCENT_STROKE, 'h', '\u0127');
addDeadKey(ACCENT_STROKE, 'i', '\\u0268')264         addDeadKey(ACCENT_STROKE, 'i', '\u0268');
addDeadKey(ACCENT_STROKE, 'l', '\\u0142')265         addDeadKey(ACCENT_STROKE, 'l', '\u0142');
addDeadKey(ACCENT_STROKE, 'o', '\\u00f8')266         addDeadKey(ACCENT_STROKE, 'o', '\u00f8');
addDeadKey(ACCENT_STROKE, 't', '\\u0167')267         addDeadKey(ACCENT_STROKE, 't', '\u0167');
268     }
269 
addDeadKey(int accent, int c, int result)270     private static void addDeadKey(int accent, int c, int result) {
271         final int combining = sAccentToCombining.get(accent);
272         if (combining == 0) {
273             throw new IllegalStateException("Invalid dead key declaration.");
274         }
275         final int combination = (combining << 16) | c;
276         sDeadKeyCache.put(combination, result);
277     }
278 
279     public static final @android.annotation.NonNull Parcelable.Creator<KeyCharacterMap> CREATOR =
280             new Parcelable.Creator<KeyCharacterMap>() {
281         public KeyCharacterMap createFromParcel(Parcel in) {
282             return new KeyCharacterMap(in);
283         }
284         public KeyCharacterMap[] newArray(int size) {
285             return new KeyCharacterMap[size];
286         }
287     };
288 
289     private long mPtr;
290 
nativeReadFromParcel(Parcel in)291     private static native long nativeReadFromParcel(Parcel in);
nativeWriteToParcel(long ptr, Parcel out)292     private static native void nativeWriteToParcel(long ptr, Parcel out);
nativeDispose(long ptr)293     private static native void nativeDispose(long ptr);
294 
nativeGetCharacter(long ptr, int keyCode, int metaState)295     private static native char nativeGetCharacter(long ptr, int keyCode, int metaState);
nativeGetFallbackAction(long ptr, int keyCode, int metaState, FallbackAction outFallbackAction)296     private static native boolean nativeGetFallbackAction(long ptr, int keyCode, int metaState,
297             FallbackAction outFallbackAction);
nativeGetNumber(long ptr, int keyCode)298     private static native char nativeGetNumber(long ptr, int keyCode);
nativeGetMatch(long ptr, int keyCode, char[] chars, int metaState)299     private static native char nativeGetMatch(long ptr, int keyCode, char[] chars, int metaState);
nativeGetDisplayLabel(long ptr, int keyCode)300     private static native char nativeGetDisplayLabel(long ptr, int keyCode);
nativeGetKeyboardType(long ptr)301     private static native int nativeGetKeyboardType(long ptr);
nativeGetEvents(long ptr, char[] chars)302     private static native KeyEvent[] nativeGetEvents(long ptr, char[] chars);
nativeObtainEmptyKeyCharacterMap(int deviceId)303     private static native KeyCharacterMap nativeObtainEmptyKeyCharacterMap(int deviceId);
nativeEquals(long ptr1, long ptr2)304     private static native boolean nativeEquals(long ptr1, long ptr2);
305 
KeyCharacterMap(Parcel in)306     private KeyCharacterMap(Parcel in) {
307         if (in == null) {
308             throw new IllegalArgumentException("parcel must not be null");
309         }
310         mPtr = nativeReadFromParcel(in);
311         if (mPtr == 0) {
312             throw new RuntimeException("Could not read KeyCharacterMap from parcel.");
313         }
314     }
315 
316     // Called from native
317     @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553)
KeyCharacterMap(long ptr)318     private KeyCharacterMap(long ptr) {
319         mPtr = ptr;
320     }
321 
322     @Override
finalize()323     protected void finalize() throws Throwable {
324         if (mPtr != 0) {
325             nativeDispose(mPtr);
326             mPtr = 0;
327         }
328     }
329 
330     /**
331      * Obtain empty key character map
332      * @param deviceId The input device ID
333      * @return The KeyCharacterMap object
334      * @hide
335      */
336     @VisibleForTesting
337     @Nullable
obtainEmptyMap(int deviceId)338     public static KeyCharacterMap obtainEmptyMap(int deviceId) {
339         return nativeObtainEmptyKeyCharacterMap(deviceId);
340     }
341 
342     /**
343      * Loads the key character maps for the keyboard with the specified device id.
344      *
345      * @param deviceId The device id of the keyboard.
346      * @return The associated key character map.
347      * @throws {@link UnavailableException} if the key character map
348      * could not be loaded because it was malformed or the default key character map
349      * is missing from the system.
350      */
load(int deviceId)351     public static KeyCharacterMap load(int deviceId) {
352         final InputManager im = InputManager.getInstance();
353         InputDevice inputDevice = im.getInputDevice(deviceId);
354         if (inputDevice == null) {
355             inputDevice = im.getInputDevice(VIRTUAL_KEYBOARD);
356             if (inputDevice == null) {
357                 throw new UnavailableException(
358                         "Could not load key character map for device " + deviceId);
359             }
360         }
361         return inputDevice.getKeyCharacterMap();
362     }
363 
364     /**
365      * Gets the Unicode character generated by the specified key and meta
366      * key state combination.
367      * <p>
368      * Returns the Unicode character that the specified key would produce
369      * when the specified meta bits (see {@link MetaKeyKeyListener})
370      * were active.
371      * </p><p>
372      * Returns 0 if the key is not one that is used to type Unicode
373      * characters.
374      * </p><p>
375      * If the return value has bit {@link #COMBINING_ACCENT} set, the
376      * key is a "dead key" that should be combined with another to
377      * actually produce a character -- see {@link #getDeadChar} --
378      * after masking with {@link #COMBINING_ACCENT_MASK}.
379      * </p>
380      *
381      * @param keyCode The key code.
382      * @param metaState The meta key modifier state.
383      * @return The associated character or combining accent, or 0 if none.
384      */
get(int keyCode, int metaState)385     public int get(int keyCode, int metaState) {
386         metaState = KeyEvent.normalizeMetaState(metaState);
387         char ch = nativeGetCharacter(mPtr, keyCode, metaState);
388 
389         int map = sCombiningToAccent.get(ch);
390         if (map != 0) {
391             return map | COMBINING_ACCENT;
392         } else {
393             return ch;
394         }
395     }
396 
397     /**
398      * Gets the fallback action to perform if the application does not
399      * handle the specified key.
400      * <p>
401      * When an application does not handle a particular key, the system may
402      * translate the key to an alternate fallback key (specified in the
403      * fallback action) and dispatch it to the application.
404      * The event containing the fallback key is flagged
405      * with {@link KeyEvent#FLAG_FALLBACK}.
406      * </p>
407      *
408      * @param keyCode The key code.
409      * @param metaState The meta key modifier state.
410      * @return The fallback action, or null if none.  Remember to recycle the fallback action.
411      *
412      * @hide
413      */
getFallbackAction(int keyCode, int metaState)414     public FallbackAction getFallbackAction(int keyCode, int metaState) {
415         FallbackAction action = FallbackAction.obtain();
416         metaState = KeyEvent.normalizeMetaState(metaState);
417         if (nativeGetFallbackAction(mPtr, keyCode, metaState, action)) {
418             action.metaState = KeyEvent.normalizeMetaState(action.metaState);
419             return action;
420         }
421         action.recycle();
422         return null;
423     }
424 
425     /**
426      * Gets the number or symbol associated with the key.
427      * <p>
428      * The character value is returned, not the numeric value.
429      * If the key is not a number, but is a symbol, the symbol is retuned.
430      * </p><p>
431      * This method is intended to to support dial pads and other numeric or
432      * symbolic entry on keyboards where certain keys serve dual function
433      * as alphabetic and symbolic keys.  This method returns the number
434      * or symbol associated with the key independent of whether the user
435      * has pressed the required modifier.
436      * </p><p>
437      * For example, on one particular keyboard the keys on the top QWERTY row generate
438      * numbers when ALT is pressed such that ALT-Q maps to '1'.  So for that keyboard
439      * when {@link #getNumber} is called with {@link KeyEvent#KEYCODE_Q} it returns '1'
440      * so that the user can type numbers without pressing ALT when it makes sense.
441      * </p>
442      *
443      * @param keyCode The key code.
444      * @return The associated numeric or symbolic character, or 0 if none.
445      */
getNumber(int keyCode)446     public char getNumber(int keyCode) {
447         return nativeGetNumber(mPtr, keyCode);
448     }
449 
450     /**
451      * Gets the first character in the character array that can be generated
452      * by the specified key code.
453      * <p>
454      * This is a convenience function that returns the same value as
455      * {@link #getMatch(int,char[],int) getMatch(keyCode, chars, 0)}.
456      * </p>
457      *
458      * @param keyCode The keycode.
459      * @param chars The array of matching characters to consider.
460      * @return The matching associated character, or 0 if none.
461      * @throws {@link IllegalArgumentException} if the passed array of characters is null.
462      */
getMatch(int keyCode, char[] chars)463     public char getMatch(int keyCode, char[] chars) {
464         return getMatch(keyCode, chars, 0);
465     }
466 
467     /**
468      * Gets the first character in the character array that can be generated
469      * by the specified key code.  If there are multiple choices, prefers
470      * the one that would be generated with the specified meta key modifier state.
471      *
472      * @param keyCode The key code.
473      * @param chars The array of matching characters to consider.
474      * @param metaState The preferred meta key modifier state.
475      * @return The matching associated character, or 0 if none.
476      * @throws {@link IllegalArgumentException} if the passed array of characters is null.
477      */
getMatch(int keyCode, char[] chars, int metaState)478     public char getMatch(int keyCode, char[] chars, int metaState) {
479         if (chars == null) {
480             throw new IllegalArgumentException("chars must not be null.");
481         }
482 
483         metaState = KeyEvent.normalizeMetaState(metaState);
484         return nativeGetMatch(mPtr, keyCode, chars, metaState);
485     }
486 
487     /**
488      * Gets the primary character for this key.
489      * In other words, the label that is physically printed on it.
490      *
491      * @param keyCode The key code.
492      * @return The display label character, or 0 if none (eg. for non-printing keys).
493      */
getDisplayLabel(int keyCode)494     public char getDisplayLabel(int keyCode) {
495         return nativeGetDisplayLabel(mPtr, keyCode);
496     }
497 
498     /**
499      * Get the character that is produced by combining the dead key producing accent
500      * with the key producing character c.
501      * For example, getDeadChar('`', 'e') returns &egrave;.
502      * getDeadChar('^', ' ') returns '^' and getDeadChar('^', '^') returns '^'.
503      *
504      * @param accent The accent character.  eg. '`'
505      * @param c The basic character.
506      * @return The combined character, or 0 if the characters cannot be combined.
507      */
getDeadChar(int accent, int c)508     public static int getDeadChar(int accent, int c) {
509         if (c == accent || CHAR_SPACE == c) {
510             // The same dead character typed twice or a dead character followed by a
511             // space should both produce the non-combining version of the combining char.
512             // In this case we don't even need to compute the combining character.
513             return accent;
514         }
515 
516         int combining = sAccentToCombining.get(accent);
517         if (combining == 0) {
518             return 0;
519         }
520 
521         final int combination = (combining << 16) | c;
522         int combined;
523         synchronized (sDeadKeyCache) {
524             combined = sDeadKeyCache.get(combination, -1);
525             if (combined == -1) {
526                 sDeadKeyBuilder.setLength(0);
527                 sDeadKeyBuilder.append((char)c);
528                 sDeadKeyBuilder.append((char)combining);
529                 String result = Normalizer.normalize(sDeadKeyBuilder, Normalizer.Form.NFC);
530                 combined = result.codePointCount(0, result.length()) == 1
531                         ? result.codePointAt(0) : 0;
532                 sDeadKeyCache.put(combination, combined);
533             }
534         }
535         return combined;
536     }
537 
538     /**
539      * Describes the character mappings associated with a key.
540      *
541      * @deprecated instead use {@link KeyCharacterMap#getDisplayLabel(int)},
542      * {@link KeyCharacterMap#getNumber(int)} and {@link KeyCharacterMap#get(int, int)}.
543      */
544     @Deprecated
545     public static class KeyData {
546         public static final int META_LENGTH = 4;
547 
548         /**
549          * The display label (see {@link #getDisplayLabel}).
550          */
551         public char displayLabel;
552         /**
553          * The "number" value (see {@link #getNumber}).
554          */
555         public char number;
556         /**
557          * The character that will be generated in various meta states
558          * (the same ones used for {@link #get} and defined as
559          * {@link KeyEvent#META_SHIFT_ON} and {@link KeyEvent#META_ALT_ON}).
560          *      <table>
561          *          <tr><th>Index</th><th align="left">Value</th></tr>
562          *          <tr><td>0</td><td>no modifiers</td></tr>
563          *          <tr><td>1</td><td>caps</td></tr>
564          *          <tr><td>2</td><td>alt</td></tr>
565          *          <tr><td>3</td><td>caps + alt</td></tr>
566          *      </table>
567          */
568         public char[] meta = new char[META_LENGTH];
569     }
570 
571     /**
572      * Get the character conversion data for a given key code.
573      *
574      * @param keyCode The keyCode to query.
575      * @param results A {@link KeyData} instance that will be filled with the results.
576      * @return True if the key was mapped.  If the key was not mapped, results is not modified.
577      *
578      * @deprecated instead use {@link KeyCharacterMap#getDisplayLabel(int)},
579      * {@link KeyCharacterMap#getNumber(int)} or {@link KeyCharacterMap#get(int, int)}.
580      */
581     @Deprecated
getKeyData(int keyCode, KeyData results)582     public boolean getKeyData(int keyCode, KeyData results) {
583         if (results.meta.length < KeyData.META_LENGTH) {
584             throw new IndexOutOfBoundsException(
585                     "results.meta.length must be >= " + KeyData.META_LENGTH);
586         }
587 
588         char displayLabel = nativeGetDisplayLabel(mPtr, keyCode);
589         if (displayLabel == 0) {
590             return false;
591         }
592 
593         results.displayLabel = displayLabel;
594         results.number = nativeGetNumber(mPtr, keyCode);
595         results.meta[0] = nativeGetCharacter(mPtr, keyCode, 0);
596         results.meta[1] = nativeGetCharacter(mPtr, keyCode, KeyEvent.META_SHIFT_ON);
597         results.meta[2] = nativeGetCharacter(mPtr, keyCode, KeyEvent.META_ALT_ON);
598         results.meta[3] = nativeGetCharacter(mPtr, keyCode,
599                 KeyEvent.META_ALT_ON | KeyEvent.META_SHIFT_ON);
600         return true;
601     }
602 
603     /**
604      * Get an array of KeyEvent objects that if put into the input stream
605      * could plausibly generate the provided sequence of characters.  It is
606      * not guaranteed that the sequence is the only way to generate these
607      * events or that it is optimal.
608      * <p>
609      * This function is primarily offered for instrumentation and testing purposes.
610      * It may fail to map characters to key codes.  In particular, the key character
611      * map for the {@link #BUILT_IN_KEYBOARD built-in keyboard} device id may be empty.
612      * Consider using the key character map associated with the
613      * {@link #VIRTUAL_KEYBOARD virtual keyboard} device id instead.
614      * </p><p>
615      * For robust text entry, do not use this function.  Instead construct a
616      * {@link KeyEvent} with action code {@link KeyEvent#ACTION_MULTIPLE} that contains
617      * the desired string using {@link KeyEvent#KeyEvent(long, String, int, int)}.
618      * </p>
619      *
620      * @param chars The sequence of characters to generate.
621      * @return An array of {@link KeyEvent} objects, or null if the given char array
622      *         can not be generated using the current key character map.
623      * @throws {@link IllegalArgumentException} if the passed array of characters is null.
624      */
getEvents(char[] chars)625     public KeyEvent[] getEvents(char[] chars) {
626         if (chars == null) {
627             throw new IllegalArgumentException("chars must not be null.");
628         }
629         return nativeGetEvents(mPtr, chars);
630     }
631 
632     /**
633      * Returns true if the specified key produces a glyph.
634      *
635      * @param keyCode The key code.
636      * @return True if the key is a printing key.
637      */
isPrintingKey(int keyCode)638     public boolean isPrintingKey(int keyCode) {
639         int type = Character.getType(nativeGetDisplayLabel(mPtr, keyCode));
640 
641         switch (type)
642         {
643             case Character.SPACE_SEPARATOR:
644             case Character.LINE_SEPARATOR:
645             case Character.PARAGRAPH_SEPARATOR:
646             case Character.CONTROL:
647             case Character.FORMAT:
648                 return false;
649             default:
650                 return true;
651         }
652     }
653 
654     /**
655      * Gets the keyboard type.
656      * Returns {@link #NUMERIC}, {@link #PREDICTIVE}, {@link #ALPHA}, {@link #FULL}
657      * or {@link #SPECIAL_FUNCTION}.
658      * <p>
659      * Different keyboard types have different semantics.  Refer to the documentation
660      * associated with the keyboard type constants for details.
661      * </p>
662      *
663      * @return The keyboard type.
664      */
getKeyboardType()665     public int getKeyboardType() {
666         return nativeGetKeyboardType(mPtr);
667     }
668 
669     /**
670      * Gets a constant that describes the behavior of this keyboard's modifier keys
671      * such as {@link KeyEvent#KEYCODE_SHIFT_LEFT}.
672      * <p>
673      * Currently there are two behaviors that may be combined:
674      * </p>
675      * <ul>
676      * <li>Chorded behavior: When the modifier key is pressed together with one or more
677      * character keys, the keyboard inserts the modified keys and
678      * then resets the modifier state when the modifier key is released.</li>
679      * <li>Toggled behavior: When the modifier key is pressed and released on its own
680      * it first toggles into a latched state.  When latched, the modifier will apply
681      * to next character key that is pressed and will then reset itself to the initial state.
682      * If the modifier is already latched and the modifier key is pressed and release on
683      * its own again, then it toggles into a locked state.  When locked, the modifier will
684      * apply to all subsequent character keys that are pressed until unlocked by pressing
685      * the modifier key on its own one more time to reset it to the initial state.
686      * Toggled behavior is useful for small profile keyboards designed for thumb typing.
687      * </ul>
688      * <p>
689      * This function currently returns {@link #MODIFIER_BEHAVIOR_CHORDED} when the
690      * {@link #getKeyboardType() keyboard type} is {@link #FULL} or {@link #SPECIAL_FUNCTION} and
691      * {@link #MODIFIER_BEHAVIOR_CHORDED_OR_TOGGLED} otherwise.
692      * In the future, the function may also take into account global keyboard
693      * accessibility settings, other user preferences, or new device capabilities.
694      * </p>
695      *
696      * @return The modifier behavior for this keyboard.
697      *
698      * @see #MODIFIER_BEHAVIOR_CHORDED
699      * @see #MODIFIER_BEHAVIOR_CHORDED_OR_TOGGLED
700      */
getModifierBehavior()701     public int getModifierBehavior() {
702         switch (getKeyboardType()) {
703             case FULL:
704             case SPECIAL_FUNCTION:
705                 return MODIFIER_BEHAVIOR_CHORDED;
706             default:
707                 return MODIFIER_BEHAVIOR_CHORDED_OR_TOGGLED;
708         }
709     }
710 
711     /**
712      * Queries the framework about whether any physical keys exist on any currently attached input
713      * devices that are capable of producing the given key code.
714      *
715      * @param keyCode The key code to query.
716      * @return True if at least one attached keyboard supports the specified key code.
717      */
deviceHasKey(int keyCode)718     public static boolean deviceHasKey(int keyCode) {
719         return InputManager.getInstance().deviceHasKeys(new int[] { keyCode })[0];
720     }
721 
722     /**
723      * Queries the framework about whether any physical keys exist on any currently attached input
724      * devices that are capable of producing the given array of key codes.
725      *
726      * @param keyCodes The array of key codes to query.
727      * @return A new array of the same size as the key codes array whose elements
728      * are set to true if at least one attached keyboard supports the corresponding key code
729      * at the same index in the key codes array.
730      */
deviceHasKeys(int[] keyCodes)731     public static boolean[] deviceHasKeys(int[] keyCodes) {
732         return InputManager.getInstance().deviceHasKeys(keyCodes);
733     }
734 
735     @Override
writeToParcel(Parcel out, int flags)736     public void writeToParcel(Parcel out, int flags) {
737         if (out == null) {
738             throw new IllegalArgumentException("parcel must not be null");
739         }
740         nativeWriteToParcel(mPtr, out);
741     }
742 
743     @Override
describeContents()744     public int describeContents() {
745         return 0;
746     }
747 
748     @Override
equals(Object obj)749     public boolean equals(Object obj) {
750         if (obj == null || !(obj instanceof KeyCharacterMap)) {
751             return false;
752         }
753         KeyCharacterMap peer = (KeyCharacterMap) obj;
754         if (mPtr == 0 || peer.mPtr == 0) {
755             return mPtr == peer.mPtr;
756         }
757         return nativeEquals(mPtr, peer.mPtr);
758     }
759 
760     /**
761      * Thrown by {@link KeyCharacterMap#load} when a key character map could not be loaded.
762      */
763     public static class UnavailableException extends AndroidRuntimeException {
UnavailableException(String msg)764         public UnavailableException(String msg) {
765             super(msg);
766         }
767     }
768 
769     /**
770      * Specifies a substitute key code and meta state as a fallback action
771      * for an unhandled key.
772      * @hide
773      */
774     public static final class FallbackAction {
775         private static final int MAX_RECYCLED = 10;
776         private static final Object sRecycleLock = new Object();
777         private static FallbackAction sRecycleBin;
778         private static int sRecycledCount;
779 
780         private FallbackAction next;
781 
782         @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553)
783         public int keyCode;
784         @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553)
785         public int metaState;
786 
FallbackAction()787         private FallbackAction() {
788         }
789 
obtain()790         public static FallbackAction obtain() {
791             final FallbackAction target;
792             synchronized (sRecycleLock) {
793                 if (sRecycleBin == null) {
794                     target = new FallbackAction();
795                 } else {
796                     target = sRecycleBin;
797                     sRecycleBin = target.next;
798                     sRecycledCount--;
799                     target.next = null;
800                 }
801             }
802             return target;
803         }
804 
recycle()805         public void recycle() {
806             synchronized (sRecycleLock) {
807                 if (sRecycledCount < MAX_RECYCLED) {
808                     next = sRecycleBin;
809                     sRecycleBin = this;
810                     sRecycledCount += 1;
811                 } else {
812                     next = null;
813                 }
814             }
815         }
816     }
817 }
818