ash/wm/screen_dimmer.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "ash/wm/screen_dimmer.h"
   6
   7 #include "ash/shell.h"
   8 #include "base/time/time.h"
   9 #include "ui/aura/window_event_dispatcher.h"
  10 #include "ui/compositor/layer.h"
  11 #include "ui/compositor/scoped_layer_animation_settings.h"
  12 #include "ui/gfx/rect.h"
  13 #include "ui/gfx/size.h"
  14
  15 namespace ash {
  16 namespace {
  17
  18 // Opacity for |dimming_layer_| when it's dimming the screen.
  19 const float kDimmingLayerOpacity = 0.4f;
  20
  21 // Duration for dimming animations, in milliseconds.
  22 const int kDimmingTransitionMs = 200;
  23
  24 }  // namespace
  25
  26 ScreenDimmer::ScreenDimmer(aura::Window* root_window)
  27     : root_window_(root_window),
  28       currently_dimming_(false) {
  29   root_window_->AddObserver(this);
  30 }
  31
  32 ScreenDimmer::~ScreenDimmer() {
  33   root_window_->RemoveObserver(this);
  34 }
  35
  36 void ScreenDimmer::SetDimming(bool should_dim) {
  37   if (should_dim == currently_dimming_)
  38     return;
  39
  40   if (!dimming_layer_) {
  41     dimming_layer_.reset(new ui::Layer(ui::LAYER_SOLID_COLOR));
  42     dimming_layer_->SetColor(SK_ColorBLACK);
  43     dimming_layer_->SetOpacity(0.0f);
  44     ui::Layer* root_layer = root_window_->layer();
  45     dimming_layer_->SetBounds(root_layer->bounds());
  46     root_layer->Add(dimming_layer_.get());
  47     root_layer->StackAtTop(dimming_layer_.get());
  48   }
  49
  50   currently_dimming_ = should_dim;
  51
  52   ui::ScopedLayerAnimationSettings scoped_settings(
  53       dimming_layer_->GetAnimator());
  54   scoped_settings.SetTransitionDuration(
  55       base::TimeDelta::FromMilliseconds(kDimmingTransitionMs));
  56   dimming_layer_->SetOpacity(should_dim ? kDimmingLayerOpacity : 0.0f);
  57 }
  58
  59 void ScreenDimmer::OnWindowBoundsChanged(aura::Window* root,
  60                                          const gfx::Rect& old_bounds,
  61                                          const gfx::Rect& new_bounds) {
  62   if (dimming_layer_)
  63     dimming_layer_->SetBounds(gfx::Rect(root->bounds().size()));
  64 }
  65
  66 }  // namespace ash