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// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "chrome/browser/chromeos/ui/accessibility_focus_ring_layer.h"
#include "ash/display/window_tree_host_manager.h"
#include "ash/shell.h"
#include "base/bind.h"
#include "third_party/skia/include/core/SkPaint.h"
#include "third_party/skia/include/core/SkPath.h"
#include "ui/aura/window.h"
#include "ui/compositor/layer.h"
#include "ui/compositor/paint_recorder.h"
#include "ui/gfx/canvas.h"
namespace chromeos {
namespace {
// The number of pixels in the color gradient that fades to transparent.
const int kGradientWidth = 6;
// The color of the focus ring. In the future this might be a parameter.
const int kFocusRingColorRed = 247;
const int kFocusRingColorGreen = 152;
const int kFocusRingColorBlue = 58;
int sign(int x) {
return ((x > 0) ? 1 : (x == 0) ? 0 : -1);
}
SkPath MakePath(const AccessibilityFocusRing& input_ring,
int outset,
const gfx::Vector2d& offset) {
AccessibilityFocusRing ring = input_ring;
for (int i = 0; i < 36; i++) {
gfx::Point p = input_ring.points[i];
gfx::Point prev;
gfx::Point next;
int prev_index = i;
do {
prev_index = (prev_index + 35) % 36;
prev = input_ring.points[prev_index];
} while (prev.x() == p.x() && prev.y() == p.y() && prev_index != i);
int next_index = i;
do {
next_index = (next_index + 1) % 36;
next = input_ring.points[next_index];
} while (next.x() == p.x() && next.y() == p.y() && next_index != i);
gfx::Point delta0 = gfx::Point(sign(p.x() - prev.x()),
sign(p.y() - prev.y()));
gfx::Point delta1 = gfx::Point(sign(next.x() - p.x()),
sign(next.y() - p.y()));
if (delta0.x() == delta1.x() && delta0.y() == delta1.y()) {
ring.points[i] = gfx::Point(
input_ring.points[i].x() + outset * delta0.y(),
input_ring.points[i].y() - outset * delta0.x());
} else {
ring.points[i] = gfx::Point(
input_ring.points[i].x() + ((i + 13) % 36 >= 18 ? outset : -outset),
input_ring.points[i].y() + ((i + 4) % 36 >= 18 ? outset : -outset));
}
}
SkPath path;
gfx::Point p0 = ring.points[0] - offset;
path.moveTo(SkIntToScalar(p0.x()), SkIntToScalar(p0.y()));
for (int i = 0; i < 12; i++) {
int index0 = ((3 * i) + 1) % 36;
int index1 = ((3 * i) + 2) % 36;
int index2 = ((3 * i) + 3) % 36;
gfx::Point p0 = ring.points[index0] - offset;
gfx::Point p1 = ring.points[index1] - offset;
gfx::Point p2 = ring.points[index2] - offset;
path.lineTo(SkIntToScalar(p0.x()), SkIntToScalar(p0.y()));
path.quadTo(SkIntToScalar(p1.x()), SkIntToScalar(p1.y()),
SkIntToScalar(p2.x()), SkIntToScalar(p2.y()));
}
return path;
}
} // namespace
AccessibilityFocusRingLayer::AccessibilityFocusRingLayer(
FocusRingLayerDelegate* delegate)
: FocusRingLayer(delegate) {
}
AccessibilityFocusRingLayer::~AccessibilityFocusRingLayer() {}
void AccessibilityFocusRingLayer::Set(const AccessibilityFocusRing& ring) {
ring_ = ring;
gfx::Rect bounds = ring.GetBounds();
int inset = kGradientWidth;
bounds.Inset(-inset, -inset, -inset, -inset);
gfx::Display display =
gfx::Screen::GetNativeScreen()->GetDisplayMatching(bounds);
aura::Window* root_window = ash::Shell::GetInstance()
->window_tree_host_manager()
->GetRootWindowForDisplayId(display.id());
CreateOrUpdateLayer(root_window, "AccessibilityFocusRing");
// Update the layer bounds.
layer()->SetBounds(bounds);
}
void AccessibilityFocusRingLayer::OnPaintLayer(
const ui::PaintContext& context) {
ui::PaintRecorder recorder(context, layer()->size());
SkPaint paint;
paint.setFlags(SkPaint::kAntiAlias_Flag);
paint.setStyle(SkPaint::kStroke_Style);
paint.setStrokeWidth(2);
SkPath path;
gfx::Vector2d offset = layer()->bounds().OffsetFromOrigin();
const int w = kGradientWidth;
for (int i = 0; i < w; ++i) {
paint.setColor(
SkColorSetARGBMacro(
255 * (w - i) * (w - i) / (w * w),
kFocusRingColorRed, kFocusRingColorGreen, kFocusRingColorBlue));
path = MakePath(ring_, i, offset);
recorder.canvas()->DrawPath(path, paint);
}
}
} // namespace chromeos
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