1// Copyright 2013 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/win/imm32_manager.h"
6
7#include <msctf.h>
8
9#include "base/basictypes.h"
10#include "base/memory/scoped_ptr.h"
11#include "base/strings/string16.h"
12#include "base/strings/string_util.h"
13#include "base/strings/utf_string_conversions.h"
14#include "base/win/scoped_comptr.h"
15#include "third_party/skia/include/core/SkColor.h"
16#include "ui/base/ime/composition_text.h"
17
18// "imm32.lib" is required by IMM32 APIs used in this file.
19// NOTE(hbono): To comply with a comment from Darin, I have added
20// this #pragma directive instead of adding "imm32.lib" to a project file.
21#pragma comment(lib, "imm32.lib")
22
23// Following code requires wchar_t to be same as char16. It should always be
24// true on Windows.
25COMPILE_ASSERT(sizeof(wchar_t) == sizeof(base::char16), wchar_t__char16_diff);
26
27///////////////////////////////////////////////////////////////////////////////
28// IMM32Manager
29
30namespace {
31
32// Determines whether or not the given attribute represents a target
33// (a.k.a. a selection).
34bool IsTargetAttribute(char attribute) {
35  return (attribute == ATTR_TARGET_CONVERTED ||
36          attribute == ATTR_TARGET_NOTCONVERTED);
37}
38
39// Helper function for IMM32Manager::GetCompositionInfo() method, to get the
40// target range that's selected by the user in the current composition string.
41void GetCompositionTargetRange(HIMC imm_context, int* target_start,
42                               int* target_end) {
43  int attribute_size = ::ImmGetCompositionString(imm_context, GCS_COMPATTR,
44                                                 NULL, 0);
45  if (attribute_size > 0) {
46    int start = 0;
47    int end = 0;
48    scoped_ptr<char[]> attribute_data(new char[attribute_size]);
49    if (attribute_data.get()) {
50      ::ImmGetCompositionString(imm_context, GCS_COMPATTR,
51                                attribute_data.get(), attribute_size);
52      for (start = 0; start < attribute_size; ++start) {
53        if (IsTargetAttribute(attribute_data[start]))
54          break;
55      }
56      for (end = start; end < attribute_size; ++end) {
57        if (!IsTargetAttribute(attribute_data[end]))
58          break;
59      }
60    }
61    *target_start = start;
62    *target_end = end;
63  }
64}
65
66// Helper function for IMM32Manager::GetCompositionInfo() method, to get
67// underlines information of the current composition string.
68void GetCompositionUnderlines(HIMC imm_context,
69                              int target_start,
70                              int target_end,
71                              ui::CompositionUnderlines* underlines) {
72  int clause_size = ::ImmGetCompositionString(imm_context, GCS_COMPCLAUSE,
73                                              NULL, 0);
74  int clause_length = clause_size / sizeof(uint32);
75  if (clause_length) {
76    scoped_ptr<uint32[]> clause_data(new uint32[clause_length]);
77    if (clause_data.get()) {
78      ::ImmGetCompositionString(imm_context, GCS_COMPCLAUSE,
79                                clause_data.get(), clause_size);
80      for (int i = 0; i < clause_length - 1; ++i) {
81        ui::CompositionUnderline underline;
82        underline.start_offset = clause_data[i];
83        underline.end_offset = clause_data[i+1];
84        underline.color = SK_ColorBLACK;
85        underline.thick = false;
86        underline.background_color = SK_ColorTRANSPARENT;
87
88        // Use thick underline for the target clause.
89        if (underline.start_offset >= static_cast<uint32>(target_start) &&
90            underline.end_offset <= static_cast<uint32>(target_end)) {
91          underline.thick = true;
92        }
93        underlines->push_back(underline);
94      }
95    }
96  }
97}
98
99// Checks if a given primary language ID is a RTL language.
100bool IsRTLPrimaryLangID(LANGID lang) {
101  switch (lang) {
102    case LANG_ARABIC:
103    case LANG_HEBREW:
104    case LANG_PERSIAN:
105    case LANG_SYRIAC:
106    case LANG_UIGHUR:
107    case LANG_URDU:
108      return true;
109    default:
110      return false;
111  }
112}
113
114}  // namespace
115
116namespace ui {
117
118IMM32Manager::IMM32Manager()
119    : ime_status_(false),
120      input_language_id_(LANG_USER_DEFAULT),
121      is_composing_(false),
122      system_caret_(false),
123      caret_rect_(-1, -1, 0, 0),
124      use_composition_window_(false) {
125}
126
127IMM32Manager::~IMM32Manager() {
128}
129
130bool IMM32Manager::SetInputLanguage() {
131  // Retrieve the current keyboard layout from Windows and determine whether
132  // or not the current input context has IMEs.
133  // Also save its input language for language-specific operations required
134  // while composing a text.
135  HKL keyboard_layout = ::GetKeyboardLayout(0);
136  input_language_id_ = reinterpret_cast<LANGID>(keyboard_layout);
137
138  // Check TSF Input Processor first.
139  // If the active profile is TSF INPUTPROCESSOR, this is IME.
140  base::win::ScopedComPtr<ITfInputProcessorProfileMgr> prof_mgr;
141  TF_INPUTPROCESSORPROFILE prof;
142  if (SUCCEEDED(prof_mgr.CreateInstance(CLSID_TF_InputProcessorProfiles)) &&
143      SUCCEEDED(prof_mgr->GetActiveProfile(GUID_TFCAT_TIP_KEYBOARD, &prof)) &&
144      prof.hkl == NULL &&
145      prof.dwProfileType == TF_PROFILETYPE_INPUTPROCESSOR) {
146      ime_status_ = true;
147  } else {
148    // If the curent language is not using TSF, check IMM32 based IMEs.
149    // As ImmIsIME always returns non-0 value on Vista+, use ImmGetIMEFileName
150    // instead to check if this HKL has any associated IME file.
151    ime_status_ = (ImmGetIMEFileName(keyboard_layout, NULL, 0) != 0);
152  }
153
154  return ime_status_;
155}
156
157void IMM32Manager::CreateImeWindow(HWND window_handle) {
158  // When a user disables TSF (Text Service Framework) and CUAS (Cicero
159  // Unaware Application Support), Chinese IMEs somehow ignore function calls
160  // to ::ImmSetCandidateWindow(), i.e. they do not move their candidate
161  // window to the position given as its parameters, and use the position
162  // of the current system caret instead, i.e. it uses ::GetCaretPos() to
163  // retrieve the position of their IME candidate window.
164  // Therefore, we create a temporary system caret for Chinese IMEs and use
165  // it during this input context.
166  // Since some third-party Japanese IME also uses ::GetCaretPos() to determine
167  // their window position, we also create a caret for Japanese IMEs.
168  if (PRIMARYLANGID(input_language_id_) == LANG_CHINESE ||
169      PRIMARYLANGID(input_language_id_) == LANG_JAPANESE) {
170    if (!system_caret_) {
171      if (::CreateCaret(window_handle, NULL, 1, 1)) {
172        system_caret_ = true;
173      }
174    }
175  }
176  // Restore the positions of the IME windows.
177  UpdateImeWindow(window_handle);
178}
179
180LRESULT IMM32Manager::SetImeWindowStyle(HWND window_handle, UINT message,
181                                    WPARAM wparam, LPARAM lparam,
182                                    BOOL* handled) {
183  // To prevent the IMM (Input Method Manager) from displaying the IME
184  // composition window, Update the styles of the IME windows and EXPLICITLY
185  // call ::DefWindowProc() here.
186  // NOTE(hbono): We can NEVER let WTL call ::DefWindowProc() when we update
187  // the styles of IME windows because the 'lparam' variable is a local one
188  // and all its updates disappear in returning from this function, i.e. WTL
189  // does not call ::DefWindowProc() with our updated 'lparam' value but call
190  // the function with its original value and over-writes our window styles.
191  *handled = TRUE;
192  lparam &= ~ISC_SHOWUICOMPOSITIONWINDOW;
193  return ::DefWindowProc(window_handle, message, wparam, lparam);
194}
195
196void IMM32Manager::DestroyImeWindow(HWND window_handle) {
197  // Destroy the system caret if we have created for this IME input context.
198  if (system_caret_) {
199    ::DestroyCaret();
200    system_caret_ = false;
201  }
202}
203
204void IMM32Manager::MoveImeWindow(HWND window_handle, HIMC imm_context) {
205  // Does nothing when the target window has no input focus. This is important
206  // because the renderer may issue SelectionBoundsChanged event even when it
207  // has no input focus. (e.g. the page update caused by incremental search.)
208  // So this event should be ignored when the |window_handle| no longer has the
209  // input focus.
210  if (GetFocus() != window_handle)
211    return;
212
213  int x = caret_rect_.x();
214  int y = caret_rect_.y();
215
216  const int kCaretMargin = 1;
217  if (!use_composition_window_ &&
218      PRIMARYLANGID(input_language_id_) == LANG_CHINESE) {
219    // As written in a comment in IMM32Manager::CreateImeWindow(),
220    // Chinese IMEs ignore function calls to ::ImmSetCandidateWindow()
221    // when a user disables TSF (Text Service Framework) and CUAS (Cicero
222    // Unaware Application Support).
223    // On the other hand, when a user enables TSF and CUAS, Chinese IMEs
224    // ignore the position of the current system caret and uses the
225    // parameters given to ::ImmSetCandidateWindow() with its 'dwStyle'
226    // parameter CFS_CANDIDATEPOS.
227    // Therefore, we do not only call ::ImmSetCandidateWindow() but also
228    // set the positions of the temporary system caret if it exists.
229    CANDIDATEFORM candidate_position = {0, CFS_CANDIDATEPOS, {x, y},
230                                        {0, 0, 0, 0}};
231    ::ImmSetCandidateWindow(imm_context, &candidate_position);
232  }
233  if (system_caret_) {
234    switch (PRIMARYLANGID(input_language_id_)) {
235      case LANG_JAPANESE:
236        ::SetCaretPos(x, y + caret_rect_.height());
237        break;
238      default:
239        ::SetCaretPos(x, y);
240        break;
241    }
242  }
243  if (use_composition_window_) {
244    // Moves the composition text window.
245    COMPOSITIONFORM cf = {CFS_POINT, {x, y}};
246    ::ImmSetCompositionWindow(imm_context, &cf);
247    // Don't need to set the position of candidate window.
248    return;
249  }
250
251  if (PRIMARYLANGID(input_language_id_) == LANG_KOREAN) {
252    // Chinese IMEs and Japanese IMEs require the upper-left corner of
253    // the caret to move the position of their candidate windows.
254    // On the other hand, Korean IMEs require the lower-left corner of the
255    // caret to move their candidate windows.
256    y += kCaretMargin;
257  }
258  // Japanese IMEs and Korean IMEs also use the rectangle given to
259  // ::ImmSetCandidateWindow() with its 'dwStyle' parameter CFS_EXCLUDE
260  // to move their candidate windows when a user disables TSF and CUAS.
261  // Therefore, we also set this parameter here.
262  CANDIDATEFORM exclude_rectangle = {0, CFS_EXCLUDE, {x, y},
263      {x, y, x + caret_rect_.width(), y + caret_rect_.height()}};
264  ::ImmSetCandidateWindow(imm_context, &exclude_rectangle);
265}
266
267void IMM32Manager::UpdateImeWindow(HWND window_handle) {
268  // Just move the IME window attached to the given window.
269  if (caret_rect_.x() >= 0 && caret_rect_.y() >= 0) {
270    HIMC imm_context = ::ImmGetContext(window_handle);
271    if (imm_context) {
272      MoveImeWindow(window_handle, imm_context);
273      ::ImmReleaseContext(window_handle, imm_context);
274    }
275  }
276}
277
278void IMM32Manager::CleanupComposition(HWND window_handle) {
279  // Notify the IMM attached to the given window to complete the ongoing
280  // composition, (this case happens when the given window is de-activated
281  // while composing a text and re-activated), and reset the omposition status.
282  if (is_composing_) {
283    HIMC imm_context = ::ImmGetContext(window_handle);
284    if (imm_context) {
285      ::ImmNotifyIME(imm_context, NI_COMPOSITIONSTR, CPS_COMPLETE, 0);
286      ::ImmReleaseContext(window_handle, imm_context);
287    }
288    ResetComposition(window_handle);
289  }
290}
291
292void IMM32Manager::ResetComposition(HWND window_handle) {
293  // Currently, just reset the composition status.
294  is_composing_ = false;
295}
296
297void IMM32Manager::CompleteComposition(HWND window_handle, HIMC imm_context) {
298  // We have to confirm there is an ongoing composition before completing it.
299  // This is for preventing some IMEs from getting confused while completing an
300  // ongoing composition even if they do not have any ongoing compositions.)
301  if (is_composing_) {
302    ::ImmNotifyIME(imm_context, NI_COMPOSITIONSTR, CPS_COMPLETE, 0);
303    ResetComposition(window_handle);
304  }
305}
306
307void IMM32Manager::GetCompositionInfo(HIMC imm_context, LPARAM lparam,
308                                  CompositionText* composition) {
309  // We only care about GCS_COMPATTR, GCS_COMPCLAUSE and GCS_CURSORPOS, and
310  // convert them into underlines and selection range respectively.
311  composition->underlines.clear();
312
313  int length = static_cast<int>(composition->text.length());
314
315  // Find out the range selected by the user.
316  int target_start = length;
317  int target_end = length;
318  if (lparam & GCS_COMPATTR)
319    GetCompositionTargetRange(imm_context, &target_start, &target_end);
320
321  // Retrieve the selection range information. If CS_NOMOVECARET is specified,
322  // that means the cursor should not be moved, then we just place the caret at
323  // the beginning of the composition string. Otherwise we should honour the
324  // GCS_CURSORPOS value if it's available.
325  // TODO(suzhe): due to a bug of webkit, we currently can't use selection range
326  // with composition string. See: https://bugs.webkit.org/show_bug.cgi?id=40805
327  if (!(lparam & CS_NOMOVECARET) && (lparam & GCS_CURSORPOS)) {
328    // IMM32 does not support non-zero-width selection in a composition. So
329    // always use the caret position as selection range.
330    int cursor = ::ImmGetCompositionString(imm_context, GCS_CURSORPOS, NULL, 0);
331    composition->selection = gfx::Range(cursor);
332  } else {
333    composition->selection = gfx::Range(0);
334  }
335
336  // Retrieve the clause segmentations and convert them to underlines.
337  if (lparam & GCS_COMPCLAUSE) {
338    GetCompositionUnderlines(imm_context, target_start, target_end,
339                             &composition->underlines);
340  }
341
342  // Set default underlines in case there is no clause information.
343  if (!composition->underlines.size()) {
344    CompositionUnderline underline;
345    underline.color = SK_ColorBLACK;
346    underline.background_color = SK_ColorTRANSPARENT;
347    if (target_start > 0) {
348      underline.start_offset = 0U;
349      underline.end_offset = static_cast<uint32>(target_start);
350      underline.thick = false;
351      composition->underlines.push_back(underline);
352    }
353    if (target_end > target_start) {
354      underline.start_offset = static_cast<uint32>(target_start);
355      underline.end_offset = static_cast<uint32>(target_end);
356      underline.thick = true;
357      composition->underlines.push_back(underline);
358    }
359    if (target_end < length) {
360      underline.start_offset = static_cast<uint32>(target_end);
361      underline.end_offset = static_cast<uint32>(length);
362      underline.thick = false;
363      composition->underlines.push_back(underline);
364    }
365  }
366}
367
368bool IMM32Manager::GetString(HIMC imm_context,
369                         WPARAM lparam,
370                         int type,
371                         base::string16* result) {
372  if (!(lparam & type))
373    return false;
374  LONG string_size = ::ImmGetCompositionString(imm_context, type, NULL, 0);
375  if (string_size <= 0)
376    return false;
377  DCHECK_EQ(0u, string_size % sizeof(wchar_t));
378  ::ImmGetCompositionString(imm_context, type,
379      WriteInto(result, (string_size / sizeof(wchar_t)) + 1), string_size);
380  return true;
381}
382
383bool IMM32Manager::GetResult(
384    HWND window_handle, LPARAM lparam, base::string16* result) {
385  bool ret = false;
386  HIMC imm_context = ::ImmGetContext(window_handle);
387  if (imm_context) {
388    ret = GetString(imm_context, lparam, GCS_RESULTSTR, result);
389    ::ImmReleaseContext(window_handle, imm_context);
390  }
391  return ret;
392}
393
394bool IMM32Manager::GetComposition(HWND window_handle, LPARAM lparam,
395                              CompositionText* composition) {
396  bool ret = false;
397  HIMC imm_context = ::ImmGetContext(window_handle);
398  if (imm_context) {
399    // Copy the composition string to the CompositionText object.
400    ret = GetString(imm_context, lparam, GCS_COMPSTR, &composition->text);
401
402    if (ret) {
403      // This is a dirty workaround for facebook. Facebook deletes the
404      // placeholder character (U+3000) used by Traditional-Chinese IMEs at the
405      // beginning of composition text. This prevents WebKit from replacing this
406      // placeholder character with a Traditional-Chinese character, i.e. we
407      // cannot input any characters in a comment box of facebook with
408      // Traditional-Chinese IMEs. As a workaround, we replace U+3000 at the
409      // beginning of composition text with U+FF3F, a placeholder character used
410      // by Japanese IMEs.
411      if (input_language_id_ == MAKELANGID(LANG_CHINESE,
412                                           SUBLANG_CHINESE_TRADITIONAL) &&
413          composition->text[0] == 0x3000) {
414        composition->text[0] = 0xFF3F;
415      }
416
417      // Retrieve the composition underlines and selection range information.
418      GetCompositionInfo(imm_context, lparam, composition);
419
420      // Mark that there is an ongoing composition.
421      is_composing_ = true;
422    }
423
424    ::ImmReleaseContext(window_handle, imm_context);
425  }
426  return ret;
427}
428
429void IMM32Manager::DisableIME(HWND window_handle) {
430  // A renderer process have moved its input focus to a password input
431  // when there is an ongoing composition, e.g. a user has clicked a
432  // mouse button and selected a password input while composing a text.
433  // For this case, we have to complete the ongoing composition and
434  // clean up the resources attached to this object BEFORE DISABLING THE IME.
435  CleanupComposition(window_handle);
436  ::ImmAssociateContextEx(window_handle, NULL, 0);
437}
438
439void IMM32Manager::CancelIME(HWND window_handle) {
440  if (is_composing_) {
441    HIMC imm_context = ::ImmGetContext(window_handle);
442    if (imm_context) {
443      ::ImmNotifyIME(imm_context, NI_COMPOSITIONSTR, CPS_CANCEL, 0);
444      ::ImmReleaseContext(window_handle, imm_context);
445    }
446    ResetComposition(window_handle);
447  }
448}
449
450void IMM32Manager::EnableIME(HWND window_handle) {
451  // Load the default IME context.
452  // NOTE(hbono)
453  //   IMM ignores this call if the IME context is loaded. Therefore, we do
454  //   not have to check whether or not the IME context is loaded.
455  ::ImmAssociateContextEx(window_handle, NULL, IACE_DEFAULT);
456}
457
458void IMM32Manager::UpdateCaretRect(HWND window_handle,
459                               const gfx::Rect& caret_rect) {
460  // Save the caret position, and Update the position of the IME window.
461  // This update is used for moving an IME window when a renderer process
462  // resize/moves the input caret.
463  if (caret_rect_ != caret_rect) {
464    caret_rect_ = caret_rect;
465    // Move the IME windows.
466    HIMC imm_context = ::ImmGetContext(window_handle);
467    if (imm_context) {
468      MoveImeWindow(window_handle, imm_context);
469      ::ImmReleaseContext(window_handle, imm_context);
470    }
471  }
472}
473
474void IMM32Manager::SetUseCompositionWindow(bool use_composition_window) {
475  use_composition_window_ = use_composition_window;
476}
477
478std::string IMM32Manager::GetInputLanguageName() const {
479  const LCID locale_id = MAKELCID(input_language_id_, SORT_DEFAULT);
480  // max size for LOCALE_SISO639LANGNAME and LOCALE_SISO3166CTRYNAME is 9.
481  wchar_t buffer[9];
482
483  // Get language id.
484  int length = ::GetLocaleInfo(locale_id, LOCALE_SISO639LANGNAME, &buffer[0],
485                               arraysize(buffer));
486  if (length <= 1)
487    return std::string();
488
489  std::string language;
490  base::WideToUTF8(buffer, length - 1, &language);
491  if (SUBLANGID(input_language_id_) == SUBLANG_NEUTRAL)
492    return language;
493
494  // Get region id.
495  length = ::GetLocaleInfo(locale_id, LOCALE_SISO3166CTRYNAME, &buffer[0],
496                           arraysize(buffer));
497  if (length <= 1)
498    return language;
499
500  std::string region;
501  base::WideToUTF8(buffer, length - 1, &region);
502  return language.append(1, '-').append(region);
503}
504
505void IMM32Manager::SetTextInputMode(HWND window_handle,
506                                    TextInputMode input_mode) {
507  if (input_mode == ui::TEXT_INPUT_MODE_DEFAULT)
508    return;
509
510  const HIMC imm_context = ::ImmGetContext(window_handle);
511  if (!imm_context)
512    return;
513
514  DWORD conversion_mode = 0;
515  DWORD sentence_mode = 0;
516  if (::ImmGetConversionStatus(imm_context, &conversion_mode, &sentence_mode)
517      == FALSE) {
518    return;
519  }
520
521  BOOL open = FALSE;
522  ConvertInputModeToImmFlags(input_mode, conversion_mode, &open,
523                             &conversion_mode),
524
525  ::ImmSetOpenStatus(imm_context, open);
526  if (open)
527    ::ImmSetConversionStatus(imm_context, conversion_mode, sentence_mode);
528  ::ImmReleaseContext(window_handle, imm_context);
529}
530
531// static
532bool IMM32Manager::IsRTLKeyboardLayoutInstalled() {
533  static enum {
534    RTL_KEYBOARD_LAYOUT_NOT_INITIALIZED,
535    RTL_KEYBOARD_LAYOUT_INSTALLED,
536    RTL_KEYBOARD_LAYOUT_NOT_INSTALLED,
537    RTL_KEYBOARD_LAYOUT_ERROR,
538  } layout = RTL_KEYBOARD_LAYOUT_NOT_INITIALIZED;
539
540  // Cache the result value.
541  if (layout != RTL_KEYBOARD_LAYOUT_NOT_INITIALIZED)
542    return layout == RTL_KEYBOARD_LAYOUT_INSTALLED;
543
544  // Retrieve the number of layouts installed in this system.
545  int size = GetKeyboardLayoutList(0, NULL);
546  if (size <= 0) {
547    layout = RTL_KEYBOARD_LAYOUT_ERROR;
548    return false;
549  }
550
551  // Retrieve the keyboard layouts in an array and check if there is an RTL
552  // layout in it.
553  scoped_ptr<HKL[]> layouts(new HKL[size]);
554  ::GetKeyboardLayoutList(size, layouts.get());
555  for (int i = 0; i < size; ++i) {
556    if (IsRTLPrimaryLangID(PRIMARYLANGID(layouts[i]))) {
557      layout = RTL_KEYBOARD_LAYOUT_INSTALLED;
558      return true;
559    }
560  }
561
562  layout = RTL_KEYBOARD_LAYOUT_NOT_INSTALLED;
563  return false;
564}
565
566bool IMM32Manager::IsCtrlShiftPressed(base::i18n::TextDirection* direction) {
567  uint8_t keystate[256];
568  if (!::GetKeyboardState(&keystate[0]))
569    return false;
570
571  // To check if a user is pressing only a control key and a right-shift key
572  // (or a left-shift key), we use the steps below:
573  // 1. Check if a user is pressing a control key and a right-shift key (or
574  //    a left-shift key).
575  // 2. If the condition 1 is true, we should check if there are any other
576  //    keys pressed at the same time.
577  //    To ignore the keys checked in 1, we set their status to 0 before
578  //    checking the key status.
579  const int kKeyDownMask = 0x80;
580  if ((keystate[VK_CONTROL] & kKeyDownMask) == 0)
581    return false;
582
583  if (keystate[VK_RSHIFT] & kKeyDownMask) {
584    keystate[VK_RSHIFT] = 0;
585    *direction = base::i18n::RIGHT_TO_LEFT;
586  } else if (keystate[VK_LSHIFT] & kKeyDownMask) {
587    keystate[VK_LSHIFT] = 0;
588    *direction = base::i18n::LEFT_TO_RIGHT;
589  } else {
590    return false;
591  }
592
593  // Scan the key status to find pressed keys. We should abandon changing the
594  // text direction when there are other pressed keys.
595  // This code is executed only when a user is pressing a control key and a
596  // right-shift key (or a left-shift key), i.e. we should ignore the status of
597  // the keys: VK_SHIFT, VK_CONTROL, VK_RCONTROL, and VK_LCONTROL.
598  // So, we reset their status to 0 and ignore them.
599  keystate[VK_SHIFT] = 0;
600  keystate[VK_CONTROL] = 0;
601  keystate[VK_RCONTROL] = 0;
602  keystate[VK_LCONTROL] = 0;
603  // Oddly, pressing F10 in another application seemingly breaks all subsequent
604  // calls to GetKeyboardState regarding the state of the F22 key. Perhaps this
605  // defect is limited to my keyboard driver, but ignoring F22 should be okay.
606  keystate[VK_F22] = 0;
607  for (int i = 0; i <= VK_PACKET; ++i) {
608    if (keystate[i] & kKeyDownMask)
609      return false;
610  }
611  return true;
612}
613
614void IMM32Manager::ConvertInputModeToImmFlags(TextInputMode input_mode,
615                                              DWORD initial_conversion_mode,
616                                              BOOL* open,
617                                              DWORD* new_conversion_mode) {
618  *open = TRUE;
619  *new_conversion_mode = initial_conversion_mode;
620  switch (input_mode) {
621    case ui::TEXT_INPUT_MODE_FULL_WIDTH_LATIN:
622      *new_conversion_mode |= IME_CMODE_FULLSHAPE;
623      *new_conversion_mode &= ~(IME_CMODE_NATIVE
624                              | IME_CMODE_KATAKANA);
625      break;
626    case ui::TEXT_INPUT_MODE_KANA:
627      *new_conversion_mode |= (IME_CMODE_NATIVE
628                             | IME_CMODE_FULLSHAPE);
629      *new_conversion_mode &= ~IME_CMODE_KATAKANA;
630      break;
631    case ui::TEXT_INPUT_MODE_KATAKANA:
632      *new_conversion_mode |= (IME_CMODE_NATIVE
633                             | IME_CMODE_KATAKANA
634                             | IME_CMODE_FULLSHAPE);
635      break;
636    default:
637      *open = FALSE;
638      break;
639  }
640}
641
642}  // namespace ui
643