Save display preference when all display configuration changes has been completed.

ash/display/display_manager.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/display/display_manager.h"
 
 #include <set>
 #include <string>
 #include <vector>
 
@@ skipping 161 matching lines @@
 }
 
 void DisplayManager::SetDisplayRotation(int64 display_id,
                                         gfx::Display::Rotation rotation) {
   if (!IsDisplayRotationEnabled())
     return;
   DisplayInfoList display_info_list;
   for (DisplayList::const_iterator iter = displays_.begin();
        iter != displays_.end(); ++iter) {
     DisplayInfo info = GetDisplayInfo(*iter);
-    if (info.id() == display_id)
+    if (info.id() == display_id) {
+      if (info.rotation() == rotation)
+        return;
       info.set_rotation(rotation);
+    }
     display_info_list.push_back(info);
   }
   UpdateDisplays(display_info_list);
 }
 
 void DisplayManager::SetDisplayUIScale(int64 display_id,
                                        float ui_scale) {
   if (!IsDisplayUIScalingEnabled())
     return;
   DisplayInfoList display_info_list;
   for (DisplayList::const_iterator iter = displays_.begin();
        iter != displays_.end(); ++iter) {
     DisplayInfo info = GetDisplayInfo(*iter);
-    if (info.id() == display_id)
+    if (info.id() == display_id) {
+      if (info.ui_scale() == ui_scale)
+        return;
       info.set_ui_scale(ui_scale);
+    }
     display_info_list.push_back(info);
   }
   UpdateDisplays(display_info_list);
 }
 
 
 bool DisplayManager::IsDisplayRotationEnabled() const {
   static bool enabled = !CommandLine::ForCurrentProcess()->
       HasSwitch(switches::kAshDisableDisplayRotation);
   return enabled;
 }
 
 bool DisplayManager::IsDisplayUIScalingEnabled() const {
   static bool enabled = !CommandLine::ForCurrentProcess()->
       HasSwitch(switches::kAshDisableUIScaling);
   if (!enabled)
     return false;
   // UI Scaling is effective only when the internal display has
   // 2x density (currently Pixel).
   int64 display_id = gfx::Display::InternalDisplayId();
 #if defined(OS_CHROMEOS)
-  // On linux desktop, allow ui scaling on the first dislpay.
-  if (!base::chromeos::IsRunningOnChromeOS())
+  // On linux desktop, allow ui scaling on the first dislpay if an internal
+  // display isn't specified.
+  if (display_id == gfx::Display::kInvalidDisplayID &&
+      !base::chromeos::IsRunningOnChromeOS()) {
     display_id = Shell::GetInstance()->display_manager()->first_display_id();
+  }
 #endif
   return GetDisplayForId(display_id).device_scale_factor() == 2.0f;
 }
 
 gfx::Insets DisplayManager::GetOverscanInsets(int64 display_id) const {
   std::map<int64, DisplayInfo>::const_iterator it =
       display_info_.find(display_id);
   return (it != display_info_.end()) ?
       it->second.overscan_insets_in_dip() : gfx::Insets();
 }
@@ skipping 131 matching lines @@
       removed_displays.empty()) {
     return;
   }
 
   displays_ = new_displays;
 
   // Temporarily add displays to be removed because display object
   // being removed are accessed during shutting down the root.
   displays_.insert(displays_.end(), removed_displays.begin(),
                    removed_displays.end());
+  DisplayController* display_controller =
+      Shell::GetInstance()->display_controller();
+  // |display_controller| is NULL during the bootstrap.
+  if (display_controller)
+    display_controller->NotifyDisplayConfigurationChanging();
+
   for (DisplayList::const_reverse_iterator iter = removed_displays.rbegin();
        iter != removed_displays.rend(); ++iter) {
     Shell::GetInstance()->screen()->NotifyDisplayRemoved(displays_.back());
     displays_.pop_back();
   }
   for (std::vector<size_t>::iterator iter = added_display_indices.begin();
        iter != added_display_indices.end(); ++iter) {
     Shell::GetInstance()->screen()->NotifyDisplayAdded(displays_[*iter]);
   }
   for (std::vector<size_t>::iterator iter = changed_display_indices.begin();
        iter != changed_display_indices.end(); ++iter) {
     Shell::GetInstance()->screen()->NotifyBoundsChanged(displays_[*iter]);
   }
+  if (display_controller)
+    display_controller->NotifyDisplayConfigurationChanged();
+
   EnsurePointerInDisplays();
-
 #if defined(USE_X11) && defined(OS_CHROMEOS)
   if (!changed_display_indices.empty() && base::chromeos::IsRunningOnChromeOS())
     ui::ClearX11DefaultRootWindow();
 #endif
 }
 
 gfx::Display* DisplayManager::GetDisplayAt(size_t index) {
   return index < displays_.size() ? &displays_[index] : NULL;
 }
 
@@ skipping 246 matching lines @@
   // always (0,0) and the secondary display's bounds will be updated
   // by |DisplayController::UpdateDisplayBoundsForLayout|.
   new_display.SetScaleAndBounds(
       display_info.device_scale_factor(), gfx::Rect(bounds_in_pixel.size()));
   new_display.set_rotation(display_info.rotation());
   return new_display;
 }
 
 }  // namespace internal
 }  // namespace ash