Browser Side TextInputState Tracking for Android

content/browser/renderer_host/text_input_manager.cc

 // 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 "base/strings/string16.h"
 #include "content/browser/renderer_host/render_widget_host_impl.h"
 #include "content/browser/renderer_host/render_widget_host_view_base.h"
 #include "content/common/view_messages.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/range/range.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;
 #elif defined(OS_MACOSX)
   return old_state.type != new_state.type ||
          old_state.can_compose_inline != new_state.can_compose_inline;
 #else
-  // TODO(ekaramad): Implement the logic for other platforms (crbug.com/578168).
-  NOTREACHED();
+  // On Android, TextInputState update is sent only if there is some change in
+  // the state. So the new state is always different.

[Charlie Reis, 2016/11/02 22:23:13]

nit: Comma, not period.  (Second sentence is not a sentence.)

Still, this behavior seems a bit unexpected.  Wouldn't this be confusing if
future code added a call to AreDifferentTextInputStates and it returns true for
two identical states?

[EhsanK, 2016/11/18 19:55:59]

Acknowledged...and good point. I believe what needs to be changed is the method
name. We only use this to determine if TextInputState should be updated (given
the old and new state).

   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
@@ skipping 10 matching lines @@
   for (auto* view : views)
     Unregister(view);
 }
 
 RenderWidgetHostImpl* TextInputManager::GetActiveWidget() const {
   return !!active_view_ ? static_cast<RenderWidgetHostImpl*>(
                               active_view_->GetRenderWidgetHost())
                         : nullptr;
 }
 
-const TextInputState* TextInputManager::GetTextInputState() const {
-  return !!active_view_ ? &text_input_state_map_.at(active_view_) : nullptr;
+const TextInputState* TextInputManager::GetTextInputState(
+    RenderWidgetHostViewBase* view) const {
+  DCHECK(!view || IsRegistered(view));
+  if (!view)
+    view = active_view_;
+  return !!view ? &text_input_state_map_.at(view) : nullptr;
 }
 
 const TextInputManager::SelectionRegion* TextInputManager::GetSelectionRegion(
     RenderWidgetHostViewBase* view) const {
   DCHECK(!view || IsRegistered(view));
   if (!view)
     view = active_view_;
   return view ? &selection_region_map_.at(view) : nullptr;
 }
 
@@ skipping 269 matching lines @@
                     "point exceeds text length).";
     return false;
   }
 
   selected_text->clear();
   selected_text->append(text.substr(pos, n));
   return true;
 }
 
 }  // namespace content