Refactoring the ownership of ui::InputMethod.

ash/magnifier/magnification_controller.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 "ash/magnifier/magnification_controller.h"
 
 #include "ash/accelerators/accelerator_controller.h"
 #include "ash/accessibility_delegate.h"
 #include "ash/ash_switches.h"
 #include "ash/display/root_window_transformers.h"
@@ skipping 44 matching lines @@
 // view-port before the caret is completely out of sight.
 const int kCaretPanningMargin = 10;
 
 void MoveCursorTo(aura::WindowTreeHost* host, const gfx::Point& root_location) {
   gfx::Point3F host_location_3f(root_location);
   host->GetRootTransform().TransformPoint(&host_location_3f);
   host->MoveCursorToHostLocation(
       gfx::ToCeiledPoint(host_location_3f.AsPointF()));
 }
 
+ui::InputMethod* GetInputMethod(aura::Window* root_window) {
+  if (root_window->GetHost())
+    return root_window->GetHost()->GetInputMethod();
+  return NULL;

[James Cook, 2015/06/01 22:20:59]

nullptr

[Shu Chen, 2015/06/02 04:11:16]

Done.

+}
+
 }  // namespace
 
 namespace ash {
 
 ////////////////////////////////////////////////////////////////////////////////
 // MagnificationControllerImpl:
 
 class MagnificationControllerImpl : virtual public MagnificationController,
                                     public ui::EventHandler,
                                     public ui::ImplicitAnimationObserver,
@@ skipping 123 matching lines @@
   // Stores the last mouse cursor (or last touched) location. This value is
   // used on zooming to keep this location visible.
   gfx::Point point_of_interest_;
 
   // Current scale, origin (left-top) position of the magnification window.
   float scale_;
   gfx::PointF origin_;
 
   ScrollDirection scroll_direction_;
 
-  ui::InputMethod* input_method_;  // Not owned.
-
   DISALLOW_COPY_AND_ASSIGN(MagnificationControllerImpl);
 };
 
 ////////////////////////////////////////////////////////////////////////////////
 // MagnificationControllerImpl:
 
 MagnificationControllerImpl::MagnificationControllerImpl()
     : root_window_(Shell::GetPrimaryRootWindow()),
       is_on_animation_(false),
       is_enabled_(false),
       move_cursor_after_animation_(false),
       scale_(kNonMagnifiedScale),
-      scroll_direction_(SCROLL_NONE),
-      input_method_(NULL) {
+      scroll_direction_(SCROLL_NONE) {
   Shell::GetInstance()->AddPreTargetHandler(this);
   root_window_->AddObserver(this);
   point_of_interest_ = root_window_->bounds().CenterPoint();
 }
 
 MagnificationControllerImpl::~MagnificationControllerImpl() {
-  if (input_method_)
-    input_method_->RemoveObserver(this);
+  ui::InputMethod* input_method = GetInputMethod(root_window_);
+  if (input_method)
+    input_method->RemoveObserver(this);
 
   root_window_->RemoveObserver(this);
 
   Shell::GetInstance()->RemovePreTargetHandler(this);
 }
 
 void MagnificationControllerImpl::RedrawKeepingMousePosition(
     float scale, bool animate) {
   gfx::Point mouse_in_root = point_of_interest_;
 
@@ skipping 280 matching lines @@
 }
 
 void MagnificationControllerImpl::SetScrollDirection(
     ScrollDirection direction) {
   scroll_direction_ = direction;
   StartOrStopScrollIfNecessary();
 }
 
 void MagnificationControllerImpl::SetEnabled(bool enabled) {
   Shell* shell = Shell::GetInstance();
+  ui::InputMethod* input_method = GetInputMethod(root_window_);
   if (enabled) {
-    if (!input_method_) {
-      input_method_ =
-          root_window_->GetProperty(aura::client::kRootWindowInputMethodKey);
-      if (input_method_)
-        input_method_->AddObserver(this);
-    }
+    if (!is_enabled_ && input_method)
+      input_method->AddObserver(this);
 
     float scale =
         Shell::GetInstance()->accessibility_delegate()->
         GetSavedScreenMagnifierScale();
     if (scale <= 0.0f)
       scale = kInitialMagnifiedScale;
     ValidateScale(&scale);
 
     // Do nothing, if already enabled with same scale.
     if (is_enabled_ && scale == scale_)
       return;
 
     is_enabled_ = enabled;
     RedrawKeepingMousePosition(scale, true);
     shell->accessibility_delegate()->SaveScreenMagnifierScale(scale);
   } else {
     // Do nothing, if already disabled.
     if (!is_enabled_)
       return;
 
-    if (input_method_) {
-      input_method_->RemoveObserver(this);
-      input_method_ = NULL;
-    }
+    if (input_method)
+      input_method->RemoveObserver(this);
 
     RedrawKeepingMousePosition(kNonMagnifiedScale, true);
     is_enabled_ = enabled;
   }
 }
 
 bool MagnificationControllerImpl::IsEnabled() const {
   return is_enabled_;
 }
 
@@ skipping 165 matching lines @@
 
 ////////////////////////////////////////////////////////////////////////////////
 // MagnificationController:
 
 // static
 MagnificationController* MagnificationController::CreateInstance() {
   return new MagnificationControllerImpl();
 }
 
 }  // namespace ash