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 "base/bind.h"
8#include "ui/aura/window.h"
9#include "ui/compositor/layer.h"
10#include "ui/gfx/canvas.h"
11
12namespace chromeos {
13
14namespace {
15
16const int kShadowRadius = 10;
17const int kShadowAlpha = 90;
18const SkColor kShadowColor = SkColorSetRGB(77, 144, 254);
19
20}  // namespace
21
22FocusRingLayerDelegate::~FocusRingLayerDelegate() {}
23
24FocusRingLayer::FocusRingLayer(FocusRingLayerDelegate* delegate)
25    : delegate_(delegate),
26      root_window_(NULL) {
27}
28
29FocusRingLayer::~FocusRingLayer() {}
30
31void FocusRingLayer::Set(aura::Window* root_window, const gfx::Rect& bounds) {
32  focus_ring_ = bounds;
33  CreateOrUpdateLayer(root_window, "FocusRing");
34
35  // Update the layer bounds.
36  gfx::Rect layer_bounds = bounds;
37  int inset = -(kShadowRadius + 2);
38  layer_bounds.Inset(inset, inset, inset, inset);
39  layer_->SetBounds(layer_bounds);
40}
41
42void FocusRingLayer::CreateOrUpdateLayer(
43    aura::Window* root_window, const char* layer_name) {
44  if (!layer_ || root_window != root_window_) {
45    root_window_ = root_window;
46    ui::Layer* root_layer = root_window->layer();
47    layer_.reset(new ui::Layer(ui::LAYER_TEXTURED));
48    layer_->set_name(layer_name);
49    layer_->set_delegate(this);
50    layer_->SetFillsBoundsOpaquely(false);
51    root_layer->Add(layer_.get());
52  }
53
54  // Keep moving it to the top in case new layers have been added
55  // since we created this layer.
56  layer_->parent()->StackAtTop(layer_.get());
57}
58
59void FocusRingLayer::OnPaintLayer(gfx::Canvas* canvas) {
60  if (!root_window_ || focus_ring_.IsEmpty())
61    return;
62
63  gfx::Rect bounds = focus_ring_ - layer_->bounds().OffsetFromOrigin();
64  SkPaint paint;
65  paint.setColor(kShadowColor);
66  paint.setFlags(SkPaint::kAntiAlias_Flag);
67  paint.setStyle(SkPaint::kStroke_Style);
68  paint.setStrokeWidth(2);
69  int r = kShadowRadius;
70  for (int i = 0; i < r; i++) {
71    // Fade out alpha quadratically.
72    paint.setAlpha((kShadowAlpha * (r - i) * (r - i)) / (r * r));
73    gfx::Rect outsetRect = bounds;
74    outsetRect.Inset(-i, -i, -i, -i);
75    canvas->DrawRect(outsetRect, paint);
76  }
77}
78
79void FocusRingLayer::OnDelegatedFrameDamage(
80    const gfx::Rect& damage_rect_in_dip) {
81}
82
83void FocusRingLayer::OnDeviceScaleFactorChanged(float device_scale_factor) {
84  if (delegate_)
85    delegate_->OnDeviceScaleFactorChanged();
86}
87
88base::Closure FocusRingLayer::PrepareForLayerBoundsChange() {
89  return base::Bind(&base::DoNothing);
90}
91
92}  // namespace chromeos
93