Introduce TsfEventRouter.

ui/base/win/tsf_event_router.cc

+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "ui/base/win/tsf_event_router.h"
+
+#include <msctf.h>
+#include <set>
+#include <utility>
+
+#include "base/bind.h"
+#include "base/win/scoped_comptr.h"
+#include "base/win/metro.h"
+
+namespace ui {
+
+class TsfEventRouterImpl : public TsfEventRouter,
+                           public ITfUIElementSink,
+                           public ITfTextEditSink {
+ public:
+  TsfEventRouterImpl()
+      : context_source_cookie_(TF_INVALID_COOKIE),
+        ui_source_cookie_(TF_INVALID_COOKIE),
+        ref_count_(0) {}
+
+  virtual ~TsfEventRouterImpl() {}
+
+  // ITfTextEditSink override.
+  virtual ULONG STDMETHODCALLTYPE AddRef() OVERRIDE {
+    return InterlockedIncrement(&ref_count_);
+  }
+
+  // ITfTextEditSink override.
+  virtual ULONG STDMETHODCALLTYPE Release() OVERRIDE {
+    const LONG count = InterlockedDecrement(&ref_count_);
+    if (!count) {
+      delete this;
+      return 0;
+    }
+    return static_cast<ULONG>(count);
+  }
+
+  // ITfTextEditSink override.
+  virtual STDMETHODIMP QueryInterface(REFIID iid, void** result) OVERRIDE {
+    if (!result)
+      return E_INVALIDARG;
+    if (iid == IID_IUnknown || iid == IID_ITfTextEditSink) {
+      *result = static_cast<ITfTextEditSink*>(this);
+    } else if (iid == IID_ITfUIElementSink) {
+      *result = static_cast<ITfUIElementSink*>(this);
+    } else {
+      *result = NULL;
+      return E_NOINTERFACE;
+    }
+    AddRef();
+    return S_OK;
+  }
+
+  // ITfTextEditSink override.
+  virtual STDMETHODIMP OnEndEdit(ITfContext* context,
+                                 TfEditCookie read_only_cookie,
+                                 ITfEditRecord* edit_record) OVERRIDE {
+    if (!edit_record || !context)
+      return E_INVALIDARG;
+    if (text_updated_callback_.is_null())
+      return S_OK;
+
+    // |edit_record| can be used to obtain updated ranges in terms of text
+    // contents and/or text attributes. Here we are interested only in text
+    // update so we use TF_GTP_INCL_TEXT and check if there is any range which
+    // contains updated text.
+    base::win::ScopedComPtr<IEnumTfRanges> ranges;
+    if (FAILED(edit_record->GetTextAndPropertyUpdates(TF_GTP_INCL_TEXT,
+                                                      NULL,
+                                                      0,
+                                                      ranges.Receive()))) {
+       return S_OK;  // don't care about failures.
+    }
+
+    ULONG fetched_count = 0;
+    base::win::ScopedComPtr<ITfRange> range;
+    if (FAILED(ranges->Next(1, range.Receive(), &fetched_count)))
+      return S_OK;  // don't care about failures.
+
+    // |fetched_count| != 0 means there is at least one range that contains
+    // updated texts.
+    if (fetched_count != 0)
+      text_updated_callback_.Run();
+    return S_OK;
+  }
+
+  // ITfUiElementSink override.
+  virtual STDMETHODIMP BeginUIElement(DWORD element_id, BOOL* is_show) {
+    if (is_show)
+      *is_show = TRUE;  // without this the UI element will not be shown.
+
+    if (!IsCandidateWindowInternal(element_id))
+      return S_OK;
+
+    std::pair<std::set<DWORD>::iterator, bool> insert_result =
+        open_candidate_window_ids_.insert(element_id);
+
+    if (candidat_window_count_changed_callback_.is_null())
+      return S_OK;
+
+    // Don't call if |element_id| is already handled.
+    if (!insert_result.second)
+      return S_OK;
+
+    candidat_window_count_changed_callback_.Run(
+        open_candidate_window_ids_.size());
+
+    return S_OK;
+  }
+
+  // ITfUiElementSink override.
+  virtual STDMETHODIMP UpdateUIElement(DWORD element_id) {
+    return S_OK;
+  }
+
+  // ITfUiElementSink override.
+  virtual STDMETHODIMP EndUIElement(DWORD element_id) {
+    if (open_candidate_window_ids_.erase(element_id) == 0)
+      return S_OK;
+
+    if (candidat_window_count_changed_callback_.is_null())
+      return S_OK;
+
+    candidat_window_count_changed_callback_.Run(
+        open_candidate_window_ids_.size());
+
+    return S_OK;
+  }
+
+  // TsfEventRouter override.
+  virtual void SetManager(ITfThreadMgr* manager) OVERRIDE {
+    EnsureDeassociated();
+    if (manager)
+      Associate(manager);
+  }
+
+  // TsfEventRouter override.
+  virtual bool IsImeComposing() OVERRIDE {
+    DCHECK(base::win::IsTsfAwareRequired())
+        << "Do not call without TSF environment.";
+    if (!context_)
+      return false;
+    return IsImeComposingInternal(context_);
+  }
+
+  // TsfEventRouter override.
+  virtual void SetTextUpdatedCallback(
+    const TextUpdatedCallback& callback) OVERRIDE {
+    text_updated_callback_ = callback;
+  }
+
+  // TsfEventRouter override.
+  virtual void SetCandidateWindowStatusChangedCallback(
+    const CandidateWindowCountChangedCallback& callback) OVERRIDE {
+      candidat_window_count_changed_callback_ = callback;
+  }
+
+ private:
+  // Returns true if the given |context| is in composing.
+  static bool IsImeComposingInternal(ITfContext* context) {
+    DCHECK(base::win::IsTsfAwareRequired())
+        << "Do not call without TSF environment.";
+    DCHECK(context);
+    base::win::ScopedComPtr<ITfContextComposition> context_composition;
+    if (FAILED(context_composition.QueryFrom(context)))
+      return false;
+    base::win::ScopedComPtr<IEnumITfCompositionView> enum_composition_view;
+    if (FAILED(context_composition->EnumCompositions(
+            enum_composition_view.Receive())))
+      return false;
+    base::win::ScopedComPtr<ITfCompositionView> composition_view;
+    return enum_composition_view->Next(1, composition_view.Receive(),
+               NULL) == S_OK;
+  }
+
+  // Returns true if the given |element_id| represents candidate window.
+  bool IsCandidateWindowInternal(DWORD element_id) {
+    DCHECK(ui_element_manager_.get());
+    base::win::ScopedComPtr<ITfUIElement> ui_element;
+    if (FAILED(ui_element_manager_->GetUIElement(element_id,
+                                                 ui_element.Receive()))) {
+      return false;
+    }
+    base::win::ScopedComPtr<ITfCandidateListUIElement>
+        candidate_list_ui_element;
+    return SUCCEEDED(candidate_list_ui_element.QueryFrom(ui_element));
+  }
+
+  // Associates this class with specified |manager|.
+  void Associate(ITfThreadMgr* thread_manager) {
+    DCHECK(base::win::IsTsfAwareRequired())
+        << "Do not call without TSF environment.";
+    DCHECK(thread_manager);
+
+    base::win::ScopedComPtr<ITfDocumentMgr> document_manager;
+    if (FAILED(thread_manager->GetFocus(document_manager.Receive())))
+      return;
+
+    if (FAILED(document_manager->GetBase(context_.Receive())))
+      return;
+    if (FAILED(context_source_.QueryFrom(context_)))
+      return;
+    context_source_->AdviseSink(IID_ITfTextEditSink,
+                                static_cast<ITfTextEditSink*>(this),
+                                &context_source_cookie_);
+
+    if (FAILED(ui_element_manager_.QueryFrom(thread_manager)))
+      return;
+    if (FAILED(ui_source_.QueryFrom(ui_element_manager_)))
+      return;
+    ui_source_->AdviseSink(IID_ITfUIElementSink,
+                           static_cast<ITfUIElementSink*>(this),
+                           &ui_source_cookie_);
+  }
+
+  // Resets the association, this function is safe to call if there is no
+  // associated thread manager.
+  void EnsureDeassociated() {
+    DCHECK(base::win::IsTsfAwareRequired())
+        << "Do not call without TSF environment.";
+
+    context_.Release();
+
+    if (context_source_) {
+      context_source_->UnadviseSink(context_source_cookie_);
+      context_source_.Release();
+    }
+    context_source_cookie_ = TF_INVALID_COOKIE;
+
+    ui_element_manager_.Release();
+    if (ui_source_) {
+      ui_source_->UnadviseSink(ui_source_cookie_);
+      ui_source_.Release();
+    }
+    ui_source_cookie_ = TF_INVALID_COOKIE;
+  }
+
+  // Callback function fired when the text contents are updated.
+  TextUpdatedCallback text_updated_callback_;
+
+  CandidateWindowCountChangedCallback candidat_window_count_changed_callback_;
+
+  // A context associated with this class.
+  base::win::ScopedComPtr<ITfContext> context_;
+
+  // The ITfSource associated with |context_|.
+  base::win::ScopedComPtr<ITfSource> context_source_;
+
+  // The cookie for |context_source_|.
+  DWORD context_source_cookie_;
+
+  // A UiElementMgr associated with this class.
+  base::win::ScopedComPtr<ITfUIElementMgr> ui_element_manager_;
+
+  // The ITfSouce associated with |ui_element_manager_|.
+  base::win::ScopedComPtr<ITfSource> ui_source_;
+
+  // The cookie for |ui_source_|.
+  DWORD ui_source_cookie_;
+
+  // The set of currently opend candidate window ids.
+  std::set<DWORD> open_candidate_window_ids_;
+
+  // The reference count of this instance.
+  volatile LONG ref_count_;
+
+  DISALLOW_COPY_AND_ASSIGN(TsfEventRouterImpl);
+};
+
+///////////////////////////////////////////////////////////////////////////////
+// TsfEventRouter
+
+TsfEventRouter::TsfEventRouter() {
+}
+
+TsfEventRouter::~TsfEventRouter() {
+}
+
+TsfEventRouter* TsfEventRouter::Create() {
+  return new TsfEventRouterImpl();
+}
+
+}  // namespace ui