win8/metro_driver/ime/text_service.cc

   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 "win8/metro_driver/ime/text_service.h"
   6
   7 #include <msctf.h>
   8
   9 #include "base/logging.h"
  10 #include "base/win/scoped_variant.h"
  11 #include "ui/metro_viewer/ime_types.h"
  12 #include "win8/metro_driver/ime/text_service_delegate.h"
  13 #include "win8/metro_driver/ime/text_store.h"
  14 #include "win8/metro_driver/ime/text_store_delegate.h"
  15
  16 // Architecture overview of input method support on Ash mode:
  17 //
  18 // Overview:
  19 // On Ash mode, the system keyboard focus is owned by the metro_driver process
  20 // while most of event handling are still implemented in the browser process.
  21 // Thus the metro_driver basically works as a proxy that simply forwards
  22 // keyevents to the metro_driver process. IME support must be involved somewhere
  23 // in this flow.
  24 //
  25 // In short, we need to interact with an IME in the metro_driver process since
  26 // TSF (Text Services Framework) runtime wants to processes keyevents while
  27 // (and only while) the attached UI thread owns keyboard focus.
  28 //
  29 // Due to this limitation, we need to split IME handling into two parts, one
  30 // is in the metro_driver process and the other is in the browser process.
  31 // The metro_driver process is responsible for implementing the primary data
  32 // store for the composition text and wiring it up with an IME via TSF APIs.
  33 // On the other hand, the browser process is responsible for calculating
  34 // character position in the composition text whenever the composition text
  35 // is updated.
  36 //
  37 // IPC overview:
  38 // Fortunately, we don't need so many IPC messages to support IMEs. In fact,
  39 // only 4 messages are required to enable basic IME functionality.
  40 //
  41 //   metro_driver process -> browser process
  42 //     Message Type:
  43 //       - MetroViewerHostMsg_ImeCompositionChanged
  44 //       - MetroViewerHostMsg_ImeTextCommitted
  45 //     Message Routing:
  46 //       TextServiceImpl
  47 //         -> ChromeAppViewAsh
  48 //         -- (process boundary) --
  49 //         -> RemoteWindowTreeHostWin
  50 //         -> RemoteInputMethodWin
  51 //
  52 //   browser process -> metro_driver process
  53 //     Message Type:
  54 //       - MetroViewerHostMsg_ImeCancelComposition
  55 //       - MetroViewerHostMsg_ImeTextInputClientUpdated
  56 //     Message Routing:
  57 //       RemoteInputMethodWin
  58 //         -> RemoteWindowTreeHostWin
  59 //         -- (process boundary) --
  60 //         -> ChromeAppViewAsh
  61 //         -> TextServiceImpl
  62 //
  63 // Note that a keyevent may be forwarded through a different path. When a
  64 // keyevent is not handled by an IME, such keyevent and subsequent character
  65 // events will be sent from the metro_driver process to the browser process as
  66 // following IPC messages.
  67 //  - MetroViewerHostMsg_KeyDown
  68 //  - MetroViewerHostMsg_KeyUp
  69 //  - MetroViewerHostMsg_Character
  70 //
  71 // How TextServiceImpl works:
  72 // Here is the list of the major tasks that are handled in TextServiceImpl.
  73 //  - Manages a session object obtained from TSF runtime. We need them to call
  74 //    most of TSF APIs.
  75 //  - Handles OnDocumentChanged event. Whenever the document type is changed,
  76 //    TextServiceImpl destroyes the current document and initializes new one
  77 //    according to the given |input_scopes|.
  78 //  - Stores the |composition_character_bounds_| passed from OnDocumentChanged
  79 //    event so that an IME or on-screen keyboard can query the character
  80 //    position synchronously.
  81 // The most complicated part is the OnDocumentChanged handler. Since some IMEs
  82 // such as Japanese IMEs drastically change their behavior depending on
  83 // properties exposed from the virtual document, we need to set up a lot
  84 // properties carefully and correctly. See DocumentBinding class in this file
  85 // about what will be involved in this multi-phase construction. See also
  86 // text_store.cc and input_scope.cc for more underlying details.
  87
  88 namespace metro_driver {
  89 namespace {
  90
  91 // Japanese IME expects the default value of this compartment is
  92 // TF_SENTENCEMODE_PHRASEPREDICT to emulate IMM32 behavior. This value is
  93 // managed per thread, thus setting this value at once is sufficient. This
  94 // value never affects non-Japanese IMEs.
  95 bool InitializeSentenceMode(ITfThreadMgr* thread_manager,
  96                             TfClientId client_id) {
  97   base::win::ScopedComPtr<ITfCompartmentMgr> thread_compartment_manager;
  98   HRESULT hr = thread_compartment_manager.QueryFrom(thread_manager);
  99   if (FAILED(hr)) {
 100     LOG(ERROR) << "QueryFrom failed. hr = " << hr;
 101     return false;
 102   }
 103   base::win::ScopedComPtr<ITfCompartment> sentence_compartment;
 104   hr = thread_compartment_manager->GetCompartment(
 105       GUID_COMPARTMENT_KEYBOARD_INPUTMODE_SENTENCE,
 106       sentence_compartment.Receive());
 107   if (FAILED(hr)) {
 108     LOG(ERROR) << "ITfCompartment::GetCompartment failed. hr = " << hr;
 109     return false;
 110   }
 111
 112   base::win::ScopedVariant sentence_variant;
 113   sentence_variant.Set(TF_SENTENCEMODE_PHRASEPREDICT);
 114   hr = sentence_compartment->SetValue(client_id, sentence_variant.ptr());
 115   if (FAILED(hr)) {
 116     LOG(ERROR) << "ITfCompartment::SetValue failed. hr = " << hr;
 117     return false;
 118   }
 119   return true;
 120 }
 121
 122 // Initializes |context| as disabled context where IMEs will be disabled.
 123 bool InitializeDisabledContext(ITfContext* context, TfClientId client_id) {
 124   base::win::ScopedComPtr<ITfCompartmentMgr> compartment_mgr;
 125   HRESULT hr = compartment_mgr.QueryFrom(context);
 126   if (FAILED(hr)) {
 127     LOG(ERROR) << "QueryFrom failed. hr = " << hr;
 128     return false;
 129   }
 130
 131   base::win::ScopedComPtr<ITfCompartment> disabled_compartment;
 132   hr = compartment_mgr->GetCompartment(GUID_COMPARTMENT_KEYBOARD_DISABLED,
 133                                        disabled_compartment.Receive());
 134   if (FAILED(hr)) {
 135     LOG(ERROR) << "ITfCompartment::GetCompartment failed. hr = " << hr;
 136     return false;
 137   }
 138
 139   base::win::ScopedVariant variant;
 140   variant.Set(1);
 141   hr = disabled_compartment->SetValue(client_id, variant.ptr());
 142   if (FAILED(hr)) {
 143     LOG(ERROR) << "ITfCompartment::SetValue failed. hr = " << hr;
 144     return false;
 145   }
 146
 147   base::win::ScopedComPtr<ITfCompartment> empty_context;
 148   hr = compartment_mgr->GetCompartment(GUID_COMPARTMENT_EMPTYCONTEXT,
 149                                        empty_context.Receive());
 150   if (FAILED(hr)) {
 151     LOG(ERROR) << "ITfCompartment::GetCompartment failed. hr = " << hr;
 152     return false;
 153   }
 154
 155   base::win::ScopedVariant empty_context_variant;
 156   empty_context_variant.Set(static_cast<int32>(1));
 157   hr = empty_context->SetValue(client_id, empty_context_variant.ptr());
 158   if (FAILED(hr)) {
 159     LOG(ERROR) << "ITfCompartment::SetValue failed. hr = " << hr;
 160     return false;
 161   }
 162
 163   return true;
 164 }
 165
 166 bool IsPasswordField(const std::vector<InputScope>& input_scopes) {
 167   return std::find(input_scopes.begin(), input_scopes.end(), IS_PASSWORD) !=
 168       input_scopes.end();
 169 }
 170
 171 // A class that manages the lifetime of the event callback registration. When
 172 // this object is destroyed, corresponding event callback will be unregistered.
 173 class EventSink {
 174  public:
 175   EventSink(DWORD cookie, base::win::ScopedComPtr<ITfSource> source)
 176       : cookie_(cookie),
 177         source_(source) {}
 178   ~EventSink() {
 179     if (!source_.get() || cookie_ != TF_INVALID_COOKIE)
 180       return;
 181     source_->UnadviseSink(cookie_);
 182     cookie_ = TF_INVALID_COOKIE;
 183     source_.Release();
 184   }
 185
 186  private:
 187   DWORD cookie_;
 188   base::win::ScopedComPtr<ITfSource> source_;
 189   DISALLOW_COPY_AND_ASSIGN(EventSink);
 190 };
 191
 192 scoped_ptr<EventSink> CreateTextEditSink(ITfContext* context,
 193                                          ITfTextEditSink* text_store) {
 194   DCHECK(text_store);
 195   base::win::ScopedComPtr<ITfSource> source;
 196   DWORD cookie = TF_INVALID_EDIT_COOKIE;
 197   HRESULT hr = source.QueryFrom(context);
 198   if (FAILED(hr)) {
 199     LOG(ERROR) << "QueryFrom failed, hr = " << hr;
 200     return scoped_ptr<EventSink>();
 201   }
 202   hr = source->AdviseSink(IID_ITfTextEditSink, text_store, &cookie);
 203   if (FAILED(hr)) {
 204     LOG(ERROR) << "AdviseSink failed, hr = " << hr;
 205     return scoped_ptr<EventSink>();
 206   }
 207   return scoped_ptr<EventSink>(new EventSink(cookie, source));
 208 }
 209
 210 // A set of objects that should have the same lifetime. Following things
 211 // are maintained.
 212 //  - TextStore: a COM object that abstracts text buffer. This object is
 213 //      actually implemented by us in text_store.cc
 214 //  - ITfDocumentMgr: a focusable unit in TSF. This object is implemented by
 215 //      TSF runtime and works as a container of TextStore.
 216 //  - EventSink: an object that ensures that the event callback between
 217 //      TSF runtime and TextStore is unregistered when this object is destroyed.
 218 class DocumentBinding {
 219  public:
 220   ~DocumentBinding() {
 221     if (!document_manager_.get())
 222       return;
 223     document_manager_->Pop(TF_POPF_ALL);
 224   }
 225
 226   static scoped_ptr<DocumentBinding> Create(
 227       ITfThreadMgr* thread_manager,
 228       TfClientId client_id,
 229       const std::vector<InputScope>& input_scopes,
 230       HWND window_handle,
 231       TextStoreDelegate* delegate) {
 232     base::win::ScopedComPtr<ITfDocumentMgr> document_manager;
 233     HRESULT hr = thread_manager->CreateDocumentMgr(document_manager.Receive());
 234     if (FAILED(hr)) {
 235       LOG(ERROR) << "ITfThreadMgr::CreateDocumentMgr failed. hr = " << hr;
 236       return scoped_ptr<DocumentBinding>();
 237     }
 238
 239     // Note: In our IPC protocol, an empty |input_scopes| is used to indicate
 240     // that an IME must be disabled in this context. In such case, we need not
 241     // instantiate TextStore.
 242     const bool use_null_text_store = input_scopes.empty();
 243
 244     scoped_refptr<TextStore> text_store;
 245     if (!use_null_text_store) {
 246       text_store = TextStore::Create(window_handle, input_scopes, delegate);
 247       if (!text_store.get()) {
 248         LOG(ERROR) << "Failed to create TextStore.";
 249         return scoped_ptr<DocumentBinding>();
 250       }
 251     }
 252
 253     base::win::ScopedComPtr<ITfContext> context;
 254     DWORD edit_cookie = TF_INVALID_EDIT_COOKIE;
 255     hr = document_manager->CreateContext(
 256         client_id,
 257         0,
 258         static_cast<ITextStoreACP*>(text_store.get()),
 259         context.Receive(),
 260         &edit_cookie);
 261     if (FAILED(hr)) {
 262       LOG(ERROR) << "ITfDocumentMgr::CreateContext failed. hr = " << hr;
 263       return scoped_ptr<DocumentBinding>();
 264     }
 265
 266     // If null-TextStore is used or |input_scopes| looks like a password field,
 267     // set special properties to tell IMEs to be disabled.
 268     if ((use_null_text_store || IsPasswordField(input_scopes)) &&
 269         !InitializeDisabledContext(context.get(), client_id)) {
 270       LOG(ERROR) << "InitializeDisabledContext failed.";
 271       return scoped_ptr<DocumentBinding>();
 272     }
 273
 274     scoped_ptr<EventSink> text_edit_sink;
 275     if (!use_null_text_store) {
 276       text_edit_sink = CreateTextEditSink(context.get(), text_store.get());
 277       if (!text_edit_sink) {
 278         LOG(ERROR) << "CreateTextEditSink failed.";
 279         return scoped_ptr<DocumentBinding>();
 280       }
 281     }
 282     hr = document_manager->Push(context.get());
 283     if (FAILED(hr)) {
 284       LOG(ERROR) << "ITfDocumentMgr::Push failed. hr = " << hr;
 285       return scoped_ptr<DocumentBinding>();
 286     }
 287     return scoped_ptr<DocumentBinding>(
 288         new DocumentBinding(text_store,
 289                             document_manager,
 290                             text_edit_sink.Pass()));
 291   }
 292
 293   ITfDocumentMgr* document_manager() const { return document_manager_.get(); }
 294
 295   scoped_refptr<TextStore> text_store() const {
 296     return text_store_;
 297   }
 298
 299  private:
 300   DocumentBinding(scoped_refptr<TextStore> text_store,
 301                   base::win::ScopedComPtr<ITfDocumentMgr> document_manager,
 302                   scoped_ptr<EventSink> text_edit_sink)
 303       : text_store_(text_store),
 304         document_manager_(document_manager),
 305         text_edit_sink_(text_edit_sink.Pass()) {}
 306
 307   scoped_refptr<TextStore> text_store_;
 308   base::win::ScopedComPtr<ITfDocumentMgr> document_manager_;
 309   scoped_ptr<EventSink> text_edit_sink_;
 310
 311   DISALLOW_COPY_AND_ASSIGN(DocumentBinding);
 312 };
 313
 314 class TextServiceImpl : public TextService,
 315                         public TextStoreDelegate {
 316  public:
 317   TextServiceImpl(ITfThreadMgr* thread_manager,
 318                   TfClientId client_id,
 319                   HWND window_handle,
 320                   TextServiceDelegate* delegate)
 321       : client_id_(client_id),
 322         window_handle_(window_handle),
 323         delegate_(delegate),
 324         thread_manager_(thread_manager) {
 325     DCHECK_NE(TF_CLIENTID_NULL, client_id);
 326     DCHECK(window_handle != NULL);
 327     DCHECK(thread_manager_.get());
 328   }
 329   ~TextServiceImpl() override {
 330     thread_manager_->Deactivate();
 331   }
 332
 333  private:
 334   // TextService overrides:
 335   void CancelComposition() override {
 336     if (!current_document_) {
 337       VLOG(0) << "|current_document_| is NULL due to the previous error.";
 338       return;
 339     }
 340     scoped_refptr<TextStore> text_store = current_document_->text_store();
 341     if (!text_store.get())
 342       return;
 343     text_store->CancelComposition();
 344   }
 345
 346   void OnDocumentChanged(
 347       const std::vector<int32>& input_scopes,
 348       const std::vector<metro_viewer::CharacterBounds>& character_bounds)
 349       override {
 350     bool document_type_changed = input_scopes_ != input_scopes;
 351     input_scopes_ = input_scopes;
 352     composition_character_bounds_ = character_bounds;
 353     if (document_type_changed)
 354       OnDocumentTypeChanged(input_scopes);
 355   }
 356
 357   void OnWindowActivated() override {
 358     if (!current_document_) {
 359       VLOG(0) << "|current_document_| is NULL due to the previous error.";
 360       return;
 361     }
 362     ITfDocumentMgr* document_manager = current_document_->document_manager();
 363     if (!document_manager) {
 364       VLOG(0) << "|document_manager| is NULL due to the previous error.";
 365       return;
 366     }
 367     HRESULT hr = thread_manager_->SetFocus(document_manager);
 368     if (FAILED(hr)) {
 369       LOG(ERROR) << "ITfThreadMgr::SetFocus failed. hr = " << hr;
 370       return;
 371     }
 372   }
 373
 374   void OnCompositionChanged(
 375       const base::string16& text,
 376       int32 selection_start,
 377       int32 selection_end,
 378       const std::vector<metro_viewer::UnderlineInfo>& underlines) override {
 379     if (!delegate_)
 380       return;
 381     delegate_->OnCompositionChanged(text,
 382                                     selection_start,
 383                                     selection_end,
 384                                     underlines);
 385   }
 386
 387   void OnTextCommitted(const base::string16& text) override {
 388     if (!delegate_)
 389       return;
 390     delegate_->OnTextCommitted(text);
 391   }
 392
 393   RECT GetCaretBounds() override {
 394     if (composition_character_bounds_.empty()) {
 395       const RECT rect = {};
 396       return rect;
 397     }
 398     const metro_viewer::CharacterBounds& bounds =
 399         composition_character_bounds_[0];
 400     POINT left_top = { bounds.left, bounds.top };
 401     POINT right_bottom = { bounds.right, bounds.bottom };
 402     ClientToScreen(window_handle_, &left_top);
 403     ClientToScreen(window_handle_, &right_bottom);
 404     const RECT rect = {
 405       left_top.x,
 406       left_top.y,
 407       right_bottom.x,
 408       right_bottom.y,
 409     };
 410     return rect;
 411   }
 412
 413   bool GetCompositionCharacterBounds(uint32 index, RECT* rect) override {
 414     if (index >= composition_character_bounds_.size()) {
 415       return false;
 416     }
 417     const metro_viewer::CharacterBounds& bounds =
 418         composition_character_bounds_[index];
 419     POINT left_top = { bounds.left, bounds.top };
 420     POINT right_bottom = { bounds.right, bounds.bottom };
 421     ClientToScreen(window_handle_, &left_top);
 422     ClientToScreen(window_handle_, &right_bottom);
 423     SetRect(rect, left_top.x, left_top.y, right_bottom.x, right_bottom.y);
 424     return true;
 425   }
 426
 427   void OnDocumentTypeChanged(const std::vector<int32>& input_scopes) {
 428     std::vector<InputScope> native_input_scopes(input_scopes.size());
 429     for (size_t i = 0; i < input_scopes.size(); ++i)
 430       native_input_scopes[i] = static_cast<InputScope>(input_scopes[i]);
 431     scoped_ptr<DocumentBinding> new_document =
 432         DocumentBinding::Create(thread_manager_.get(),
 433                                 client_id_,
 434                                 native_input_scopes,
 435                                 window_handle_,
 436                                 this);
 437     LOG_IF(ERROR, !new_document) << "Failed to create a new document.";
 438     current_document_.swap(new_document);
 439     OnWindowActivated();
 440   }
 441
 442   TfClientId client_id_;
 443   HWND window_handle_;
 444   TextServiceDelegate* delegate_;
 445   scoped_ptr<DocumentBinding> current_document_;
 446   base::win::ScopedComPtr<ITfThreadMgr> thread_manager_;
 447
 448   // A vector of InputScope enumeration, which represents the document type of
 449   // the focused text field. Note that in our IPC message protocol, an empty
 450   // |input_scopes_| has special meaning that IMEs must be disabled on this
 451   // document.
 452   std::vector<int32> input_scopes_;
 453   // Character bounds of the composition. When there is no composition but this
 454   // vector is not empty, the first element contains the caret bounds.
 455   std::vector<metro_viewer::CharacterBounds> composition_character_bounds_;
 456
 457   DISALLOW_COPY_AND_ASSIGN(TextServiceImpl);
 458 };
 459
 460 }  // namespace
 461
 462 scoped_ptr<TextService>
 463 CreateTextService(TextServiceDelegate* delegate, HWND window_handle) {
 464   if (!delegate)
 465     return scoped_ptr<TextService>();
 466   base::win::ScopedComPtr<ITfThreadMgr> thread_manager;
 467   HRESULT hr = thread_manager.CreateInstance(CLSID_TF_ThreadMgr);
 468   if (FAILED(hr)) {
 469     LOG(ERROR) << "Failed to create instance of CLSID_TF_ThreadMgr. hr = "
 470                << hr;
 471     return scoped_ptr<TextService>();
 472   }
 473   TfClientId client_id = TF_CLIENTID_NULL;
 474   hr = thread_manager->Activate(&client_id);
 475   if (FAILED(hr)) {
 476     LOG(ERROR) << "ITfThreadMgr::Activate failed. hr = " << hr;
 477     return scoped_ptr<TextService>();
 478   }
 479   if (!InitializeSentenceMode(thread_manager.get(), client_id)) {
 480     LOG(ERROR) << "InitializeSentenceMode failed.";
 481     thread_manager->Deactivate();
 482     return scoped_ptr<TextService>();
 483   }
 484   return scoped_ptr<TextService>(new TextServiceImpl(
 485       thread_manager.get(), client_id, window_handle, delegate));
 486 }
 487
 488 }  // namespace metro_driver