[reland] Browser Side Text Input State Tracking for OOPIF (Aura Only)

content/browser/renderer_host/text_input_manager.cc

Index: content/browser/renderer_host/text_input_manager.cc
diff --git a/content/browser/renderer_host/text_input_manager.cc b/content/browser/renderer_host/text_input_manager.cc
new file mode 100644
index 0000000000000000000000000000000000000000..80a37ca2230046aa4bd925be88491cd00bbaa3a9
--- /dev/null
+++ b/content/browser/renderer_host/text_input_manager.cc
@@ -0,0 +1,124 @@
+// Copyright 2016 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 "content/browser/renderer_host/text_input_manager.h"
+
+#include "content/browser/renderer_host/render_widget_host_view_base.h"
+
+namespace content {
+
+namespace {
+
+bool AreDifferentTextInputStates(const content::TextInputState& old_state,
+                                 const content::TextInputState& new_state) {
+#if defined(USE_AURA)
+  return old_state.type != new_state.type || old_state.mode != new_state.mode ||
+         old_state.flags != new_state.flags ||
+         old_state.can_compose_inline != new_state.can_compose_inline;
+#else
+  // TODO(ekaramad): Implement this logic for other platforms.
+  return true;
+#endif
+}
+
+}  // namespace
+
+TextInputManager::TextInputManager() : active_view_(nullptr) {}
+
+TextInputManager::~TextInputManager() {
+  // It is necessary and sufficient to remove the TextInputManager from
+  // all the registered views' observer lists.
+  std::vector<RenderWidgetHostViewBase*> tracked_views;
+  for (auto pair : text_input_state_map_)
+    tracked_views.push_back(pair.first);
+
+  for (RenderWidgetHostViewBase* view : tracked_views)
+    Unregister(view);
+
+  FOR_EACH_OBSERVER(Observer, observer_list_,
+                    OnTextInputManagerDestroyed(this));
+}
+
+const TextInputState* TextInputManager::GetTextInputState() {
+  return !!active_view_ ? &text_input_state_map_[active_view_] : nullptr;
+}
+
+RenderWidgetHostViewBase* TextInputManager::GetActiveView() const {
+  return active_view_;
+}
+
+void TextInputManager::UpdateTextInputState(
+    RenderWidgetHostViewBase* view,
+    const TextInputState& text_input_state) {
+  DCHECK(IsRegisteredView(view));
+
+  bool changed = AreDifferentTextInputStates(text_input_state_map_[view],
+                                             text_input_state);
+
+  text_input_state_map_[view] = text_input_state;
+
+  // Only change |active_view_| if this new text input state is not none.
+  if (text_input_state.type != ui::TEXT_INPUT_TYPE_NONE)
+    active_view_ = view;
+
+  // If the |active_view_| loses state, then there is no active sources.
+  if (active_view_ == view && text_input_state.type == ui::TEXT_INPUT_TYPE_NONE)
+    active_view_ = nullptr;
+
+  text_input_state_map_[view] = text_input_state;
+  NotifyObserversAboutInputStateUpdate(view, changed);
+}
+
+void TextInputManager::Register(RenderWidgetHostViewBase* view) {
+  DCHECK(!IsRegisteredView(view));
+
+  text_input_state_map_[view] = TextInputState();
+  view->AddObserver(this);
+}
+
+void TextInputManager::Unregister(RenderWidgetHostViewBase* view) {
+  DCHECK(IsRegisteredView(view));
+
+  text_input_state_map_.erase(view);
+  if (active_view_ == view) {
+    active_view_ = nullptr;
+    NotifyObserversAboutInputStateUpdate(view, true);
+  }
+  view->RemoveObserver(this);
+}
+
+bool TextInputManager::IsRegisteredView(RenderWidgetHostViewBase* view) const {
+  return text_input_state_map_.count(view) == 1;
+}
+
+void TextInputManager::AddObserver(Observer* observer) {
+  observer_list_.AddObserver(observer);
+}
+
+void TextInputManager::RemoveObserver(Observer* observer) {
+  observer_list_.RemoveObserver(observer);
+}
+
+void TextInputManager::OnRenderWidgetHostViewBaseDestroyed(
+    RenderWidgetHostViewBase* view) {
+  DCHECK(IsRegisteredView(view));
+
+  Unregister(view);
+
+  if (active_view_ == view) {
+    DCHECK(text_input_state_map_[active_view_].type !=
+           ui::TEXT_INPUT_TYPE_NONE);
+    active_view_ = nullptr;
+    NotifyObserversAboutInputStateUpdate(view, true);
+  }
+}
+
+void TextInputManager::NotifyObserversAboutInputStateUpdate(
+    RenderWidgetHostViewBase* updated_view,
+    bool changed) {
+  FOR_EACH_OBSERVER(Observer, observer_list_,
+                    OnTextInputStateUpdated(this, updated_view, changed));
+}
+
+}  // namespace content