ui/wm/core/shadow.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 "ui/wm/core/shadow.h"
   6
   7 #include "third_party/skia/include/core/SkBitmap.h"
   8 #include "ui/base/resource/resource_bundle.h"
   9 #include "ui/compositor/layer.h"
  10 #include "ui/compositor/scoped_layer_animation_settings.h"
  11 #include "ui/resources/grit/ui_resources.h"
  12
  13 namespace {
  14
  15 // Shadow opacity for different styles.
  16 const float kActiveShadowOpacity = 1.0f;
  17 const float kInactiveShadowOpacity = 0.2f;
  18 const float kSmallShadowOpacity = 1.0f;
  19
  20 // Shadow aperture for different styles.
  21 // Note that this may be greater than interior inset to allow shadows with
  22 // curved corners that extend inwards beyond a window's borders.
  23 const int kActiveInteriorAperture = 134;
  24 const int kInactiveInteriorAperture = 134;
  25 const int kSmallInteriorAperture = 9;
  26
  27 // Interior inset for different styles.
  28 const int kActiveInteriorInset = 64;
  29 const int kInactiveInteriorInset = 64;
  30 const int kSmallInteriorInset = 4;
  31
  32 // Duration for opacity animation in milliseconds.
  33 const int kShadowAnimationDurationMs = 100;
  34
  35 float GetOpacityForStyle(wm::Shadow::Style style) {
  36   switch (style) {
  37     case wm::Shadow::STYLE_ACTIVE:
  38       return kActiveShadowOpacity;
  39     case wm::Shadow::STYLE_INACTIVE:
  40       return kInactiveShadowOpacity;
  41     case wm::Shadow::STYLE_SMALL:
  42       return kSmallShadowOpacity;
  43   }
  44   return 1.0f;
  45 }
  46
  47 int GetShadowApertureForStyle(wm::Shadow::Style style) {
  48   switch (style) {
  49     case wm::Shadow::STYLE_ACTIVE:
  50       return kActiveInteriorAperture;
  51     case wm::Shadow::STYLE_INACTIVE:
  52       return kInactiveInteriorAperture;
  53     case wm::Shadow::STYLE_SMALL:
  54       return kSmallInteriorAperture;
  55   }
  56   return 0;
  57 }
  58
  59 int GetInteriorInsetForStyle(wm::Shadow::Style style) {
  60   switch (style) {
  61     case wm::Shadow::STYLE_ACTIVE:
  62       return kActiveInteriorInset;
  63     case wm::Shadow::STYLE_INACTIVE:
  64       return kInactiveInteriorInset;
  65     case wm::Shadow::STYLE_SMALL:
  66       return kSmallInteriorInset;
  67   }
  68   return 0;
  69 }
  70
  71 }  // namespace
  72
  73 namespace wm {
  74
  75 Shadow::Shadow() : style_(STYLE_ACTIVE), interior_inset_(0) {
  76 }
  77
  78 Shadow::~Shadow() {
  79 }
  80
  81 void Shadow::Init(Style style) {
  82   style_ = style;
  83
  84   layer_.reset(new ui::Layer(ui::LAYER_NOT_DRAWN));
  85   shadow_layer_.reset(new ui::Layer(ui::LAYER_NINE_PATCH));
  86   layer()->Add(shadow_layer_.get());
  87
  88   UpdateImagesForStyle();
  89   shadow_layer_->set_name("Shadow");
  90   shadow_layer_->SetVisible(true);
  91   shadow_layer_->SetFillsBoundsOpaquely(false);
  92   shadow_layer_->SetOpacity(GetOpacityForStyle(style_));
  93 }
  94
  95 void Shadow::SetContentBounds(const gfx::Rect& content_bounds) {
  96   content_bounds_ = content_bounds;
  97   UpdateLayerBounds();
  98 }
  99
 100 void Shadow::SetStyle(Style style) {
 101   if (style_ == style)
 102     return;
 103
 104   Style old_style = style_;
 105   style_ = style;
 106
 107   // Stop waiting for any as yet unfinished implicit animations.
 108   StopObservingImplicitAnimations();
 109
 110   // If we're switching to or from the small style, don't bother with
 111   // animations.
 112   if (style == STYLE_SMALL || old_style == STYLE_SMALL) {
 113     UpdateImagesForStyle();
 114     shadow_layer_->SetOpacity(GetOpacityForStyle(style));
 115     return;
 116   }
 117
 118   // If we're becoming active, switch images now.  Because the inactive image
 119   // has a very low opacity the switch isn't noticeable and this approach
 120   // allows us to use only a single set of shadow images at a time.
 121   if (style == STYLE_ACTIVE) {
 122     UpdateImagesForStyle();
 123     // Opacity was baked into inactive image, start opacity low to match.
 124     shadow_layer_->SetOpacity(kInactiveShadowOpacity);
 125   }
 126
 127   {
 128     // Property sets within this scope will be implicitly animated.
 129     ui::ScopedLayerAnimationSettings settings(shadow_layer_->GetAnimator());
 130     settings.AddObserver(this);
 131     settings.SetTransitionDuration(
 132         base::TimeDelta::FromMilliseconds(kShadowAnimationDurationMs));
 133     switch (style_) {
 134       case STYLE_ACTIVE:
 135         shadow_layer_->SetOpacity(kActiveShadowOpacity);
 136         break;
 137       case STYLE_INACTIVE:
 138         shadow_layer_->SetOpacity(kInactiveShadowOpacity);
 139         break;
 140       default:
 141         NOTREACHED() << "Unhandled style " << style_;
 142         break;
 143     }
 144   }
 145 }
 146
 147 void Shadow::OnImplicitAnimationsCompleted() {
 148   // If we just finished going inactive, switch images.  This doesn't cause
 149   // a visual pop because the inactive image opacity is so low.
 150   if (style_ == STYLE_INACTIVE) {
 151     UpdateImagesForStyle();
 152     // Opacity is baked into inactive image, so set fully opaque.
 153     shadow_layer_->SetOpacity(1.0f);
 154   }
 155 }
 156
 157 void Shadow::UpdateImagesForStyle() {
 158   ResourceBundle& res = ResourceBundle::GetSharedInstance();
 159   gfx::Image image;
 160   switch (style_) {
 161     case STYLE_ACTIVE:
 162       image = res.GetImageNamed(IDR_AURA_SHADOW_ACTIVE);
 163       break;
 164     case STYLE_INACTIVE:
 165       image = res.GetImageNamed(IDR_AURA_SHADOW_INACTIVE);
 166       break;
 167     case STYLE_SMALL:
 168       image = res.GetImageNamed(IDR_WINDOW_BUBBLE_SHADOW_SMALL);
 169       break;
 170     default:
 171       NOTREACHED() << "Unhandled style " << style_;
 172       break;
 173   }
 174
 175   shadow_layer_->UpdateNinePatchLayerBitmap(image.AsBitmap());
 176   image_size_ = image.Size();
 177   interior_inset_ = GetInteriorInsetForStyle(style_);
 178
 179   // Image sizes may have changed.
 180   UpdateLayerBounds();
 181 }
 182
 183 void Shadow::UpdateLayerBounds() {
 184   // Update bounds based on content bounds and interior inset.
 185   gfx::Rect layer_bounds = content_bounds_;
 186   layer_bounds.Inset(-interior_inset_, -interior_inset_);
 187   layer()->SetBounds(layer_bounds);
 188   shadow_layer_->SetBounds(gfx::Rect(layer_bounds.size()));
 189
 190   // Update the shadow aperture and border for style. Note that border is in
 191   // layer space and it cannot exceed the bounds of the layer.
 192   int aperture = GetShadowApertureForStyle(style_);
 193   int aperture_x = std::min(aperture, layer_bounds.width() / 2);
 194   int aperture_y = std::min(aperture, layer_bounds.height() / 2);
 195   shadow_layer_->UpdateNinePatchLayerAperture(
 196       gfx::Rect(aperture_x, aperture_y,
 197                 image_size_.width() - aperture_x * 2,
 198                 image_size_.height() - aperture_y * 2));
 199   shadow_layer_->UpdateNinePatchLayerBorder(
 200       gfx::Rect(aperture_x, aperture_y, aperture_x * 2, aperture_y * 2));
 201 }
 202
 203 }  // namespace wm