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