src/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/gfx/image/canvas_image_source.h"
  15 #include "ui/gfx/shadow_value.h"
  16 #include "ui/gfx/skia_util.h"
  17 #include "ui/views/controls/button/label_button.h"
  18 #include "ui/views/painter.h"
  19 #include "ui/views/view.h"
  20 #include "ui/views/widget/widget.h"
  21
  22 namespace chromeos {
  23
  24 namespace {
  25
  26 const int kShadowRadius = 23;
  27 const int kCenterBlockSize = 2 * kShadowRadius;
  28 const int kFocusRingImageSize = kShadowRadius * 2 + kCenterBlockSize;
  29 const SkColor kShadowColor = SkColorSetRGB(77, 144, 254);
  30
  31 // FocusRingImageSource generates a base image that could be used by
  32 // ImagePainter to paint a focus ring around a rect. The base image is a
  33 // transparent square block of kCenterBlockSize pixels with blue halo around.
  34 class FocusRingImageSource : public gfx::CanvasImageSource {
  35  public:
  36   FocusRingImageSource()
  37       : CanvasImageSource(gfx::Size(kFocusRingImageSize, kFocusRingImageSize),
  38                           false) {
  39     shadows_.push_back(
  40         gfx::ShadowValue(gfx::Point(), kShadowRadius, kShadowColor));
  41   }
  42
  43   virtual void Draw(gfx::Canvas* canvas) OVERRIDE {
  44     SkPaint paint;
  45     paint.setColor(kShadowColor);
  46
  47     skia::RefPtr<SkDrawLooper> looper = CreateShadowDrawLooper(shadows_);
  48     paint.setLooper(looper.get());
  49
  50     const gfx::Rect rect(kShadowRadius, kShadowRadius,
  51                          kCenterBlockSize, kCenterBlockSize);
  52     canvas->DrawRect(rect, paint);
  53     canvas->FillRect(rect, SK_ColorTRANSPARENT, SkXfermode::kSrc_Mode);
  54   }
  55
  56  private:
  57   gfx::ShadowValues shadows_;
  58
  59   DISALLOW_COPY_AND_ASSIGN(FocusRingImageSource);
  60 };
  61
  62 }  // namespace
  63
  64 FocusRingLayer::FocusRingLayer() {
  65   gfx::ImageSkia ring_image(
  66       new FocusRingImageSource,
  67       gfx::Size(kFocusRingImageSize, kFocusRingImageSize));
  68   ring_painter_.reset(views::Painter::CreateImagePainter(
  69       ring_image,
  70       gfx::Insets(kShadowRadius, kShadowRadius, kShadowRadius, kShadowRadius)));
  71 }
  72
  73 FocusRingLayer::~FocusRingLayer() {}
  74
  75 void FocusRingLayer::SetForView(views::View* view) {
  76   if (!view ||
  77       !view->GetWidget() ||
  78       !view->GetWidget()->GetNativeWindow() ||
  79       !view->GetWidget()->GetNativeWindow()->layer()) {
  80     layer_.reset();
  81     return;
  82   }
  83
  84   if (!layer_) {
  85     layer_.reset(new ui::Layer(ui::LAYER_TEXTURED));
  86     layer_->set_name("FocusRing");
  87     layer_->set_delegate(this);
  88     layer_->SetFillsBoundsOpaquely(false);
  89   }
  90
  91   // Puts the focus ring layer as a sibling layer of the widget layer so that
  92   // it does not clip at the widget's boundary.
  93   ui::Layer* widget_layer = view->GetWidget()->GetNativeWindow()->layer();
  94   widget_layer->parent()->Add(layer_.get());
  95
  96   // Workarounds that attempts to pick a better bounds.
  97   gfx::Rect view_bounds = view->GetContentsBounds();
  98   if (view->GetClassName() == views::LabelButton::kViewClassName) {
  99     view_bounds = view->GetLocalBounds();
 100     view_bounds.Inset(2, 2, 2, 2);
 101   }
 102
 103   // Workarounds for system tray items that has a customized OnPaintFocusBorder.
 104   // The insets here must be consistent with the ones used in OnPaintFocusBorder
 105   // and DrawBorder.
 106   if (view->GetClassName() ==
 107              ash::internal::ActionableView::kViewClassName) {
 108     view_bounds = view->GetLocalBounds();
 109     view_bounds.Inset(1, 1, 3, 3);
 110   } else if (view->GetClassName() ==
 111              ash::internal::TrayBackgroundView::kViewClassName) {
 112     view_bounds.Inset(1, 1, 3, 3);
 113   } else if (view->GetClassName() ==
 114              ash::internal::TrayPopupHeaderButton::kViewClassName) {
 115     view_bounds = view->GetLocalBounds();
 116     view_bounds.Inset(2, 1, 2, 2);
 117   }
 118
 119   // Note the bounds calculation below assumes no transformation and ignores
 120   // animations.
 121   const gfx::Rect widget_bounds = widget_layer->GetTargetBounds();
 122   gfx::Rect bounds = view->ConvertRectToWidget(view_bounds);
 123   bounds.Offset(widget_bounds.OffsetFromOrigin());
 124   bounds.Inset(-kShadowRadius, -kShadowRadius, -kShadowRadius, -kShadowRadius);
 125   layer_->SetBounds(bounds);
 126 }
 127
 128 void FocusRingLayer::OnPaintLayer(gfx::Canvas* canvas) {
 129   ring_painter_->Paint(canvas, layer_->bounds().size());
 130 }
 131
 132 void FocusRingLayer::OnDeviceScaleFactorChanged(float device_scale_factor) {
 133 }
 134
 135 base::Closure FocusRingLayer::PrepareForLayerBoundsChange() {
 136   return base::Bind(&base::DoNothing);
 137 }
 138
 139 }  // namespace chromeos