chrome/browser/chromeos/ui/focus_ring_layer.cc

   1 // Copyright 2013 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 "chrome/browser/chromeos/ui/focus_ring_layer.h"
   6
   7 #include "ash/system/tray/actionable_view.h"
   8 #include "ash/system/tray/tray_background_view.h"
   9 #include "ash/system/tray/tray_popup_header_button.h"
  10 #include "base/bind.h"
  11 #include "ui/aura/window.h"
  12 #include "ui/compositor/layer.h"
  13 #include "ui/gfx/canvas.h"
  14 #include "ui/views/controls/button/label_button.h"
  15 #include "ui/views/view.h"
  16 #include "ui/views/widget/widget.h"
  17
  18 namespace chromeos {
  19
  20 namespace {
  21
  22 const int kShadowRadius = 10;
  23 const int kShadowAlpha = 90;
  24 const SkColor kShadowColor = SkColorSetRGB(77, 144, 254);
  25
  26 }  // namespace
  27
  28 FocusRingLayer::FocusRingLayer()
  29     : window_(NULL),
  30       root_window_(NULL) {
  31 }
  32
  33 FocusRingLayer::~FocusRingLayer() {}
  34
  35 void FocusRingLayer::Update() {
  36   if (!window_)
  37     return;
  38
  39   aura::Window* root_window = window_->GetRootWindow();
  40   if (!layer_ || root_window != root_window_) {
  41     root_window_ = root_window;
  42     ui::Layer* root_layer = root_window->layer();
  43     layer_.reset(new ui::Layer(ui::LAYER_TEXTURED));
  44     layer_->set_name("FocusRing");
  45     layer_->set_delegate(this);
  46     layer_->SetFillsBoundsOpaquely(false);
  47     root_layer->Add(layer_.get());
  48   }
  49
  50   // Keep moving it to the top in case new layers have been added
  51   // since we created this layer.
  52   layer_->parent()->StackAtTop(layer_.get());
  53
  54   // Translate native window coordinates to root window coordinates.
  55   gfx::Point origin = focus_ring_.origin();
  56   aura::Window::ConvertPointToTarget(window_, root_window_, &origin);
  57   gfx::Rect layer_bounds = focus_ring_;
  58   layer_bounds.set_origin(origin);
  59   int inset = -(kShadowRadius + 2);
  60   layer_bounds.Inset(inset, inset, inset, inset);
  61   layer_->SetBounds(layer_bounds);
  62 }
  63
  64 void FocusRingLayer::SetForView(views::View* view) {
  65   if (!view) {
  66     if (layer_ && !focus_ring_.IsEmpty())
  67       layer_->SchedulePaint(focus_ring_);
  68     focus_ring_ = gfx::Rect();
  69     return;
  70   }
  71
  72   DCHECK(view->GetWidget());
  73   window_ = view->GetWidget()->GetNativeWindow();
  74
  75   gfx::Rect view_bounds = view->GetContentsBounds();
  76
  77   // Workarounds that attempts to pick a better bounds.
  78   if (view->GetClassName() == views::LabelButton::kViewClassName) {
  79     view_bounds = view->GetLocalBounds();
  80     view_bounds.Inset(2, 2, 2, 2);
  81   }
  82
  83   // Workarounds for system tray items that have customized focus borders.  The
  84   // insets here must be consistent with the ones used by those classes.
  85   if (view->GetClassName() == ash::ActionableView::kViewClassName) {
  86     view_bounds = view->GetLocalBounds();
  87     view_bounds.Inset(1, 1, 3, 3);
  88   } else if (view->GetClassName() == ash::TrayBackgroundView::kViewClassName) {
  89     view_bounds.Inset(1, 1, 3, 3);
  90   } else if (view->GetClassName() ==
  91              ash::TrayPopupHeaderButton::kViewClassName) {
  92     view_bounds = view->GetLocalBounds();
  93     view_bounds.Inset(2, 1, 2, 2);
  94   }
  95
  96   focus_ring_ = view->ConvertRectToWidget(view_bounds);
  97   Update();
  98 }
  99
 100 void FocusRingLayer::OnPaintLayer(gfx::Canvas* canvas) {
 101   if (focus_ring_.IsEmpty())
 102     return;
 103
 104   // Convert the focus ring from native-window-relative coordinates to
 105   // layer-relative coordinates.
 106   gfx::Point origin = focus_ring_.origin();
 107   aura::Window::ConvertPointToTarget(window_, root_window_, &origin);
 108   origin -= layer_->bounds().OffsetFromOrigin();
 109   gfx::Rect bounds = focus_ring_;
 110   bounds.set_origin(origin);
 111
 112   SkPaint paint;
 113   paint.setColor(kShadowColor);
 114   paint.setFlags(SkPaint::kAntiAlias_Flag);
 115   paint.setStyle(SkPaint::kStroke_Style);
 116   paint.setStrokeWidth(2);
 117   int r = kShadowRadius;
 118   for (int i = 0; i < r; i++) {
 119     // Fade out alpha quadratically.
 120     paint.setAlpha((kShadowAlpha * (r - i) * (r - i)) / (r * r));
 121     gfx::Rect outsetRect = bounds;
 122     outsetRect.Inset(-i, -i, -i, -i);
 123     canvas->DrawRect(outsetRect, paint);
 124   }
 125 }
 126
 127 void FocusRingLayer::OnDeviceScaleFactorChanged(float device_scale_factor) {
 128   Update();
 129 }
 130
 131 base::Closure FocusRingLayer::PrepareForLayerBoundsChange() {
 132   return base::Bind(&base::DoNothing);
 133 }
 134
 135 }  // namespace chromeos