[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..258c05ee00602ff2cf4a8ed6a1f0a76b71d15b46
--- /dev/null
+++ b/content/browser/renderer_host/text_input_manager.cc
@@ -0,0 +1,115 @@
+// 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 the logic for other platforms (crbug.com/578168).
+  NOTREACHED();
+  return true;
+#endif
+}
+
+}  // namespace
+
+TextInputManager::TextInputManager() : active_view_(nullptr) {}
+
+TextInputManager::~TextInputManager() {
+  // If there is an active view, we should unregister it first so that the
+  // the tab's top-level RWHV will be notified about |TextInputState.type|
+  // resetting to none (i.e., we do not have an active RWHV anymore).
+  if (active_view_)
+    Unregister(active_view_);
+
+  // Unregister all the remaining views.
+  std::vector<RenderWidgetHostViewBase*> views;
+  for (auto pair : text_input_state_map_)
+    views.push_back(pair.first);
+
+  for (auto view : views)
+    Unregister(view);
+}
+
+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(IsRegistered(view));
+
+  // Since |view| is registgered, we already have a previous value for its
+  // TextInputState.
+  bool changed = AreDifferentTextInputStates(text_input_state_map_[view],
+                                             text_input_state);
+
+  text_input_state_map_[view] = text_input_state;
+
+  // |active_view_| is only updated when the state for |view| is not none.
+  if (text_input_state.type != ui::TEXT_INPUT_TYPE_NONE)
+    active_view_ = view;
+
+  // If the state for |active_view_| is none, then we no longer have an
+  // |active_view_|.
+  if (active_view_ == view && text_input_state.type == ui::TEXT_INPUT_TYPE_NONE)
+    active_view_ = nullptr;
+
+  NotifyObserversAboutInputStateUpdate(view, changed);
+}
+
+void TextInputManager::Register(RenderWidgetHostViewBase* view) {
+  DCHECK(!IsRegistered(view));
+
+  text_input_state_map_[view] = TextInputState();
+}
+
+void TextInputManager::Unregister(RenderWidgetHostViewBase* view) {
+  DCHECK(IsRegistered(view));
+
+  text_input_state_map_.erase(view);
+  if (active_view_ == view) {
+    active_view_ = nullptr;
+    NotifyObserversAboutInputStateUpdate(view, true);
+  }
+  view->DidUnregisterFromTextInputManager(this);
+}
+
+bool TextInputManager::IsRegistered(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::NotifyObserversAboutInputStateUpdate(
+    RenderWidgetHostViewBase* updated_view,
+    bool did_update_state) {
+  FOR_EACH_OBSERVER(
+      Observer, observer_list_,
+      OnUpdateTextInputStateCalled(this, updated_view, did_update_state));
+}
+
+}  // namespace content