Chromium Code Reviews
chromiumcodereview-hr@appspot.gserviceaccount.com (chromiumcodereview-hr) | Please choose your nickname with Settings | Help | Chromium Project | Gerrit Changes | Sign out
(290)

Side by Side Diff: ui/base/ime/character_composer.cc

Issue 105103003: Move ui/base/ime/character_composer* to ui/base/ime/chromeos/ (Closed) Base URL: svn://svn.chromium.org/chrome/trunk/src
Patch Set: Created 7 years ago
Use n/p to move between diff chunks; N/P to move between comments. Draft comments are only viewable by you.
Jump to:
View unified diff | Download patch | Annotate | Revision Log
OLDNEW
(Empty)
1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #include "ui/base/ime/character_composer.h"
6
7 #include <X11/Xlib.h>
8 #include <X11/Xutil.h>
9
10 #include <algorithm>
11 #include <iterator>
12
13 #include "base/strings/utf_string_conversions.h"
14 #include "base/third_party/icu/icu_utf.h"
15 // Note for Gtk removal: gdkkeysyms.h only contains a set of
16 // '#define GDK_KeyName 0xNNNN' macros and does not #include any Gtk headers.
17 #include "third_party/gtk+/gdk/gdkkeysyms.h"
18 #include "ui/base/glib/glib_integers.h"
19 #include "ui/events/event.h"
20 #include "ui/events/event_constants.h"
21 #include "ui/gfx/x/x11_types.h"
22
23 // Note for Gtk removal: gtkimcontextsimpleseqs.h does not #include any Gtk
24 // headers and only contains one big guint16 array |gtk_compose_seqs_compact|
25 // which defines the main compose table. The table has internal linkage.
26 // The order of header inclusion is out of order because
27 // gtkimcontextsimpleseqs.h depends on guint16, which is defined in
28 // "ui/base/glib/glib_integers.h".
29 #include "third_party/gtk+/gtk/gtkimcontextsimpleseqs.h"
30
31 namespace {
32
33 // A black list for not composing dead keys. Once the key combination is listed
34 // below, the dead key won't work even when this is listed in
35 // gtkimcontextsimpleseqs.h. This only supports two keyevent sequenses.
36 // TODO(nona): Remove this hack.
37 const struct BlackListedDeadKey {
38 uint32 first_key; // target first key event.
39 uint32 second_key; // target second key event.
40 uint32 output_char; // the character to be inserted if the filter is matched.
41 bool consume; // true if the original key event will be consumed.
42 } kBlackListedDeadKeys[] = {
43 { GDK_KEY_dead_acute, GDK_KEY_m, GDK_KEY_apostrophe, false },
44 { GDK_KEY_dead_acute, GDK_KEY_s, GDK_KEY_apostrophe, false },
45 { GDK_KEY_dead_acute, GDK_KEY_t, GDK_KEY_apostrophe, false },
46 { GDK_KEY_dead_acute, GDK_KEY_v, GDK_KEY_apostrophe, false },
47 { GDK_KEY_dead_acute, GDK_KEY_dead_acute, GDK_KEY_apostrophe, true },
48 };
49
50 typedef std::vector<unsigned int> ComposeBufferType;
51
52 // An iterator class to apply std::lower_bound for composition table.
53 class SequenceIterator
54 : public std::iterator<std::random_access_iterator_tag, const uint16*> {
55 public:
56 SequenceIterator() : ptr_(NULL), stride_(0) {}
57 SequenceIterator(const uint16* ptr, int stride)
58 : ptr_(ptr), stride_(stride) {}
59
60 const uint16* ptr() const {return ptr_;}
61 int stride() const {return stride_;}
62
63 SequenceIterator& operator++() {
64 ptr_ += stride_;
65 return *this;
66 }
67 SequenceIterator& operator+=(int n) {
68 ptr_ += stride_*n;
69 return *this;
70 }
71
72 const uint16* operator*() const {return ptr_;}
73
74 private:
75 const uint16* ptr_;
76 int stride_;
77 };
78
79 inline SequenceIterator operator+(const SequenceIterator& l, int r) {
80 return SequenceIterator(l) += r;
81 }
82
83 inline int operator-(const SequenceIterator& l, const SequenceIterator& r) {
84 const int d = l.ptr() - r.ptr();
85 DCHECK(l.stride() == r.stride() && l.stride() > 0 && d%l.stride() == 0);
86 return d/l.stride();
87 }
88
89 inline bool operator==(const SequenceIterator& l, const SequenceIterator& r) {
90 DCHECK(l.stride() == r.stride());
91 return l.ptr() == r.ptr();
92 }
93
94 inline bool operator!=(const SequenceIterator& l, const SequenceIterator& r) {
95 return !(l == r);
96 }
97
98 // A function to compare key value.
99 inline int CompareSequenceValue(unsigned int l, unsigned int r) {
100 return (l > r) ? 1 : ((l < r) ? -1 : 0);
101 }
102
103 // A template to make |CompareFunc| work like operator<.
104 // |CompareFunc| is required to implement a member function,
105 // int operator()(const ComposeBufferType& l, const uint16* r) const.
106 template<typename CompareFunc>
107 struct ComparatorAdoptor {
108 bool operator()(const ComposeBufferType& l, const uint16* r) const {
109 return CompareFunc()(l, r) == -1;
110 }
111 bool operator()(const uint16* l, const ComposeBufferType& r) const {
112 return CompareFunc()(r, l) == 1;
113 }
114 };
115
116 class ComposeChecker {
117 public:
118 // This class does not take the ownership of |data|, |data| should be alive
119 // for the lifetime of the object.
120 // |data| is a pointer to the head of an array of
121 // length (|max_sequence_length| + 2)*|n_sequences|.
122 // Every (|max_sequence_length| + 2) elements of |data| represent an entry.
123 // First |max_sequence_length| elements of an entry is the sequecne which
124 // composes the character represented by the last two elements of the entry.
125 ComposeChecker(const uint16* data, int max_sequence_length, int n_sequences);
126 bool CheckSequence(const ComposeBufferType& sequence,
127 uint32* composed_character) const;
128
129 private:
130 struct CompareSequence {
131 int operator()(const ComposeBufferType& l, const uint16* r) const;
132 };
133
134 // This class does not take the ownership of |data_|,
135 // the dtor does not delete |data_|.
136 const uint16* data_;
137 int max_sequence_length_;
138 int n_sequences_;
139 int row_stride_;
140
141 DISALLOW_COPY_AND_ASSIGN(ComposeChecker);
142 };
143
144 ComposeChecker::ComposeChecker(const uint16* data,
145 int max_sequence_length,
146 int n_sequences)
147 : data_(data),
148 max_sequence_length_(max_sequence_length),
149 n_sequences_(n_sequences),
150 row_stride_(max_sequence_length + 2) {
151 }
152
153 bool ComposeChecker::CheckSequence(const ComposeBufferType& sequence,
154 uint32* composed_character) const {
155 const int sequence_length = sequence.size();
156 if (sequence_length > max_sequence_length_)
157 return false;
158 // Find sequence in the table.
159 const SequenceIterator begin(data_, row_stride_);
160 const SequenceIterator end = begin + n_sequences_;
161 const SequenceIterator found = std::lower_bound(
162 begin, end, sequence, ComparatorAdoptor<CompareSequence>());
163 if (found == end || CompareSequence()(sequence, *found) != 0)
164 return false;
165
166 if (sequence_length == max_sequence_length_ ||
167 (*found)[sequence_length] == 0) {
168 // |found| is not partially matching. It's fully matching.
169 if (found + 1 == end ||
170 CompareSequence()(sequence, *(found + 1)) != 0) {
171 // There is no composition longer than |found| which matches to
172 // |sequence|.
173 const uint32 value = ((*found)[max_sequence_length_] << 16) |
174 (*found)[max_sequence_length_ + 1];
175 *composed_character = value;
176 }
177 }
178 return true;
179 }
180
181 int ComposeChecker::CompareSequence::operator()(const ComposeBufferType& l,
182 const uint16* r) const {
183 for(size_t i = 0; i < l.size(); ++i) {
184 const int compare_result = CompareSequenceValue(l[i], r[i]);
185 if(compare_result)
186 return compare_result;
187 }
188 return 0;
189 }
190
191
192 class ComposeCheckerWithCompactTable {
193 public:
194 // This class does not take the ownership of |data|, |data| should be alive
195 // for the lifetime of the object.
196 // First |index_size|*|index_stride| elements of |data| are an index table.
197 // Every |index_stride| elements of an index table are an index entry.
198 // If you are checking with a sequence of length N beginning with character C,
199 // you have to find an index entry whose first element is C, then get the N-th
200 // element of the index entry as the index.
201 // The index is pointing the element of |data| where the composition table for
202 // sequences of length N beginning with C is placed.
203
204 ComposeCheckerWithCompactTable(const uint16* data,
205 int max_sequence_length,
206 int index_size,
207 int index_stride);
208 bool CheckSequence(const ComposeBufferType& sequence,
209 uint32* composed_character) const;
210
211 private:
212 struct CompareSequenceFront {
213 int operator()(const ComposeBufferType& l, const uint16* r) const;
214 };
215 struct CompareSequenceSkipFront {
216 int operator()(const ComposeBufferType& l, const uint16* r) const;
217 };
218
219 // This class does not take the ownership of |data_|,
220 // the dtor does not delete |data_|.
221 const uint16* data_;
222 int max_sequence_length_;
223 int index_size_;
224 int index_stride_;
225 };
226
227 ComposeCheckerWithCompactTable::ComposeCheckerWithCompactTable(
228 const uint16* data,
229 int max_sequence_length,
230 int index_size,
231 int index_stride)
232 : data_(data),
233 max_sequence_length_(max_sequence_length),
234 index_size_(index_size),
235 index_stride_(index_stride) {
236 }
237
238 bool ComposeCheckerWithCompactTable::CheckSequence(
239 const ComposeBufferType& sequence,
240 uint32* composed_character) const {
241 const int compose_length = sequence.size();
242 if (compose_length > max_sequence_length_)
243 return false;
244 // Find corresponding index for the first keypress.
245 const SequenceIterator index_begin(data_, index_stride_);
246 const SequenceIterator index_end = index_begin + index_size_;
247 const SequenceIterator index =
248 std::lower_bound(index_begin, index_end, sequence,
249 ComparatorAdoptor<CompareSequenceFront>());
250 if (index == index_end || CompareSequenceFront()(sequence, *index) != 0)
251 return false;
252 if (compose_length == 1)
253 return true;
254 // Check for composition sequences.
255 for (int length = compose_length - 1; length < max_sequence_length_;
256 ++length) {
257 const uint16* table = data_ + (*index)[length];
258 const uint16* table_next = data_ + (*index)[length + 1];
259 if (table_next > table) {
260 // There are composition sequences for this |length|.
261 const int row_stride = length + 1;
262 const int n_sequences = (table_next - table)/row_stride;
263 const SequenceIterator table_begin(table, row_stride);
264 const SequenceIterator table_end = table_begin + n_sequences;
265 const SequenceIterator found =
266 std::lower_bound(table_begin, table_end, sequence,
267 ComparatorAdoptor<CompareSequenceSkipFront>());
268 if (found != table_end &&
269 CompareSequenceSkipFront()(sequence, *found) == 0) {
270 if (length == compose_length - 1) // Exact match.
271 *composed_character = (*found)[length];
272 return true;
273 }
274 }
275 }
276 return false;
277 }
278
279 int ComposeCheckerWithCompactTable::CompareSequenceFront::operator()(
280 const ComposeBufferType& l, const uint16* r) const {
281 return CompareSequenceValue(l[0], r[0]);
282 }
283
284 int ComposeCheckerWithCompactTable::CompareSequenceSkipFront::operator()(
285 const ComposeBufferType& l, const uint16* r) const {
286 for(size_t i = 1; i < l.size(); ++i) {
287 const int compare_result = CompareSequenceValue(l[i], r[i - 1]);
288 if(compare_result)
289 return compare_result;
290 }
291 return 0;
292 }
293
294
295 // Additional table.
296
297 // The difference between this and the default input method is the handling
298 // of C+acute - this method produces C WITH CEDILLA rather than C WITH ACUTE.
299 // For languages that use CCedilla and not acute, this is the preferred mapping,
300 // and is particularly important for pt_BR, where the us-intl keyboard is
301 // used extensively.
302
303 const uint16 cedilla_compose_seqs[] = {
304 // LATIN_CAPITAL_LETTER_C_WITH_CEDILLA
305 GDK_KEY_dead_acute, GDK_KEY_C, 0, 0, 0, 0x00C7,
306 // LATIN_SMALL_LETTER_C_WITH_CEDILLA
307 GDK_KEY_dead_acute, GDK_KEY_c, 0, 0, 0, 0x00E7,
308 // LATIN_CAPITAL_LETTER_C_WITH_CEDILLA
309 GDK_KEY_Multi_key, GDK_KEY_apostrophe, GDK_KEY_C, 0, 0, 0x00C7,
310 // LATIN_SMALL_LETTER_C_WITH_CEDILLA
311 GDK_KEY_Multi_key, GDK_KEY_apostrophe, GDK_KEY_c, 0, 0, 0x00E7,
312 // LATIN_CAPITAL_LETTER_C_WITH_CEDILLA
313 GDK_KEY_Multi_key, GDK_KEY_C, GDK_KEY_apostrophe, 0, 0, 0x00C7,
314 // LATIN_SMALL_LETTER_C_WITH_CEDILLA
315 GDK_KEY_Multi_key, GDK_KEY_c, GDK_KEY_apostrophe, 0, 0, 0x00E7,
316 };
317
318 bool KeypressShouldBeIgnored(unsigned int keyval) {
319 switch(keyval) {
320 case GDK_KEY_Shift_L:
321 case GDK_KEY_Shift_R:
322 case GDK_KEY_Control_L:
323 case GDK_KEY_Control_R:
324 case GDK_KEY_Caps_Lock:
325 case GDK_KEY_Shift_Lock:
326 case GDK_KEY_Meta_L:
327 case GDK_KEY_Meta_R:
328 case GDK_KEY_Alt_L:
329 case GDK_KEY_Alt_R:
330 case GDK_KEY_Super_L:
331 case GDK_KEY_Super_R:
332 case GDK_KEY_Hyper_L:
333 case GDK_KEY_Hyper_R:
334 case GDK_KEY_Mode_switch:
335 case GDK_KEY_ISO_Level3_Shift:
336 return true;
337 default:
338 return false;
339 }
340 }
341
342 bool CheckCharacterComposeTable(const ComposeBufferType& sequence,
343 uint32* composed_character) {
344 // Check cedilla compose table.
345 const ComposeChecker kCedillaComposeChecker(
346 cedilla_compose_seqs, 4, arraysize(cedilla_compose_seqs)/(4 + 2));
347 if (kCedillaComposeChecker.CheckSequence(sequence, composed_character))
348 return true;
349
350 // Check main compose table.
351 const ComposeCheckerWithCompactTable kMainComposeChecker(
352 gtk_compose_seqs_compact, 5, 24, 6);
353 if (kMainComposeChecker.CheckSequence(sequence, composed_character))
354 return true;
355
356 return false;
357 }
358
359 // Converts |character| to UTF16 string.
360 // Returns false when |character| is not a valid character.
361 bool UTF32CharacterToUTF16(uint32 character, string16* output) {
362 output->clear();
363 // Reject invalid character. (e.g. codepoint greater than 0x10ffff)
364 if (!CBU_IS_UNICODE_CHAR(character))
365 return false;
366 if (character) {
367 output->resize(CBU16_LENGTH(character));
368 size_t i = 0;
369 CBU16_APPEND_UNSAFE(&(*output)[0], i, character);
370 }
371 return true;
372 }
373
374 // Converts a X keycode to a X keysym with no modifiers.
375 KeySym XKeyCodeToXKeySym(unsigned int keycode) {
376 XDisplay* display = gfx::GetXDisplay();
377 if (!display)
378 return NoSymbol;
379
380 XKeyEvent x_key_event = {0};
381 x_key_event.type = KeyPress;
382 x_key_event.display = display;
383 x_key_event.keycode = keycode;
384 return ::XLookupKeysym(&x_key_event, 0);
385 }
386
387 // Returns an hexadecimal digit integer (0 to 15) corresponding to |keyval|.
388 // -1 is returned when |keyval| cannot be a hexadecimal digit.
389 int KeyvalToHexDigit(unsigned int keyval) {
390 if (GDK_KEY_0 <= keyval && keyval <= GDK_KEY_9)
391 return keyval - GDK_KEY_0;
392 if (GDK_KEY_a <= keyval && keyval <= GDK_KEY_f)
393 return keyval - GDK_KEY_a + 10;
394 if (GDK_KEY_A <= keyval && keyval <= GDK_KEY_F)
395 return keyval - GDK_KEY_A + 10;
396 return -1; // |keyval| cannot be a hexadecimal digit.
397 }
398
399 } // namespace
400
401 namespace ui {
402
403 CharacterComposer::CharacterComposer() : composition_mode_(KEY_SEQUENCE_MODE) {}
404
405 CharacterComposer::~CharacterComposer() {}
406
407 void CharacterComposer::Reset() {
408 compose_buffer_.clear();
409 composed_character_.clear();
410 preedit_string_.clear();
411 composition_mode_ = KEY_SEQUENCE_MODE;
412 }
413
414 bool CharacterComposer::FilterKeyPress(const ui::KeyEvent& event) {
415 if (!event.HasNativeEvent() ||
416 (event.type() != ET_KEY_PRESSED && event.type() != ET_KEY_RELEASED))
417 return false;
418
419 XEvent* xevent = event.native_event();
420 DCHECK(xevent);
421 KeySym keysym = NoSymbol;
422 ::XLookupString(&xevent->xkey, NULL, 0, &keysym, NULL);
423
424 return FilterKeyPressInternal(keysym, xevent->xkey.keycode, event.flags());
425 }
426
427
428 bool CharacterComposer::FilterKeyPressInternal(unsigned int keyval,
429 unsigned int keycode,
430 int flags) {
431 composed_character_.clear();
432 preedit_string_.clear();
433
434 // We don't care about modifier key presses.
435 if(KeypressShouldBeIgnored(keyval))
436 return false;
437
438 // When the user presses Ctrl+Shift+U, maybe switch to HEX_MODE.
439 // We don't care about other modifiers like Alt. When CapsLock is down, we
440 // do nothing because what we receive is Ctrl+Shift+u (not U).
441 if (keyval == GDK_KEY_U && (flags & EF_SHIFT_DOWN) &&
442 (flags & EF_CONTROL_DOWN)) {
443 if (composition_mode_ == KEY_SEQUENCE_MODE && compose_buffer_.empty()) {
444 // There is no ongoing composition. Let's switch to HEX_MODE.
445 composition_mode_ = HEX_MODE;
446 UpdatePreeditStringHexMode();
447 return true;
448 }
449 }
450
451 // Filter key press in an appropriate manner.
452 switch (composition_mode_) {
453 case KEY_SEQUENCE_MODE:
454 return FilterKeyPressSequenceMode(keyval, flags);
455 case HEX_MODE:
456 return FilterKeyPressHexMode(keyval, keycode, flags);
457 default:
458 NOTREACHED();
459 return false;
460 }
461 }
462
463 bool CharacterComposer::FilterKeyPressSequenceMode(unsigned int keyval,
464 int flags) {
465 DCHECK(composition_mode_ == KEY_SEQUENCE_MODE);
466 compose_buffer_.push_back(keyval);
467
468 if (compose_buffer_.size() == 2U) {
469 for (size_t i = 0; i < ARRAYSIZE_UNSAFE(kBlackListedDeadKeys); ++i) {
470 if (compose_buffer_[0] == kBlackListedDeadKeys[i].first_key &&
471 compose_buffer_[1] == kBlackListedDeadKeys[i].second_key ) {
472 Reset();
473 composed_character_.push_back(kBlackListedDeadKeys[i].output_char);
474 return kBlackListedDeadKeys[i].consume;
475 }
476 }
477 }
478
479 // Check compose table.
480 uint32 composed_character_utf32 = 0;
481 if (CheckCharacterComposeTable(compose_buffer_, &composed_character_utf32)) {
482 // Key press is recognized as a part of composition.
483 if (composed_character_utf32 != 0) {
484 // We get a composed character.
485 compose_buffer_.clear();
486 UTF32CharacterToUTF16(composed_character_utf32, &composed_character_);
487 }
488 return true;
489 }
490 // Key press is not a part of composition.
491 compose_buffer_.pop_back(); // Remove the keypress added this time.
492 if (!compose_buffer_.empty()) {
493 compose_buffer_.clear();
494 return true;
495 }
496 return false;
497 }
498
499 bool CharacterComposer::FilterKeyPressHexMode(unsigned int keyval,
500 unsigned int keycode,
501 int flags) {
502 DCHECK(composition_mode_ == HEX_MODE);
503 const size_t kMaxHexSequenceLength = 8;
504 int hex_digit = KeyvalToHexDigit(keyval);
505 if (hex_digit < 0) {
506 // With 101 keyboard, control + shift + 3 produces '#', but a user may
507 // have intended to type '3'. So, if a hexadecimal character was not found,
508 // suppose a user is holding shift key (and possibly control key, too) and
509 // try a character with modifier keys removed.
510 hex_digit = KeyvalToHexDigit(XKeyCodeToXKeySym(keycode));
511 }
512
513 if (keyval == GDK_KEY_Escape) {
514 // Cancel composition when ESC is pressed.
515 Reset();
516 } else if (keyval == GDK_KEY_Return || keyval == GDK_KEY_KP_Enter ||
517 keyval == GDK_KEY_ISO_Enter ||
518 keyval == GDK_KEY_space || keyval == GDK_KEY_KP_Space) {
519 // Commit the composed character when Enter or space is pressed.
520 CommitHex();
521 } else if (keyval == GDK_KEY_BackSpace) {
522 // Pop back the buffer when Backspace is pressed.
523 if (!compose_buffer_.empty()) {
524 compose_buffer_.pop_back();
525 } else {
526 // If there is no character in |compose_buffer_|, cancel composition.
527 Reset();
528 }
529 } else if (hex_digit >= 0 &&
530 compose_buffer_.size() < kMaxHexSequenceLength) {
531 // Add the key to the buffer if it is a hex digit.
532 compose_buffer_.push_back(hex_digit);
533 }
534
535 UpdatePreeditStringHexMode();
536
537 return true;
538 }
539
540 void CharacterComposer::CommitHex() {
541 DCHECK(composition_mode_ == HEX_MODE);
542 uint32 composed_character_utf32 = 0;
543 for (size_t i = 0; i != compose_buffer_.size(); ++i) {
544 const uint32 digit = compose_buffer_[i];
545 DCHECK(0 <= digit && digit < 16);
546 composed_character_utf32 <<= 4;
547 composed_character_utf32 |= digit;
548 }
549 Reset();
550 UTF32CharacterToUTF16(composed_character_utf32, &composed_character_);
551 }
552
553 void CharacterComposer::UpdatePreeditStringHexMode() {
554 if (composition_mode_ != HEX_MODE) {
555 preedit_string_.clear();
556 return;
557 }
558 std::string preedit_string_ascii("u");
559 for (size_t i = 0; i != compose_buffer_.size(); ++i) {
560 const int digit = compose_buffer_[i];
561 DCHECK(0 <= digit && digit < 16);
562 preedit_string_ascii += digit <= 9 ? ('0' + digit) : ('a' + (digit - 10));
563 }
564 preedit_string_ = ASCIIToUTF16(preedit_string_ascii);
565 }
566
567 } // namespace ui
OLDNEW

Powered by Google App Engine
This is Rietveld 408576698