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// Copyright 2017 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef ASH_ACCESSIBILITY_UI_ACCESSIBILITY_LAYER_H_
#define ASH_ACCESSIBILITY_UI_ACCESSIBILITY_LAYER_H_
#include <memory>
#include "base/memory/raw_ptr.h"
#include "base/time/time.h"
#include "ui/compositor/layer_delegate.h"
#include "ui/gfx/geometry/rect.h"
namespace aura {
class Window;
}
namespace ui {
class Layer;
} // namespace ui
namespace ash {
// A delegate interface implemented by the object that owns an
// AccessibilityLayer.
class AccessibilityLayerDelegate {
public:
virtual void OnDeviceScaleFactorChanged() = 0;
protected:
virtual ~AccessibilityLayerDelegate() {}
};
// AccessibilityLayer manages a global always-on-top layer used to
// highlight or annotate UI elements for accessibility.
class AccessibilityLayer : public ui::LayerDelegate {
public:
explicit AccessibilityLayer(AccessibilityLayerDelegate* delegate);
AccessibilityLayer(const AccessibilityLayer&) = delete;
AccessibilityLayer& operator=(const AccessibilityLayer&) = delete;
~AccessibilityLayer() override;
// Move the accessibility layer to the given bounds in the coordinates of
// the given root window.
void Set(aura::Window* root_window,
const gfx::Rect& bounds,
bool stack_at_top);
// Set the layer's opacity.
void SetOpacity(float opacity);
// Set the layer's offset from parent layer.
void SetSubpixelPositionOffset(const gfx::Vector2dF& offset);
// Gets the inset for this layer in DIPs. This is used to increase
// the bounding box to provide space for any margins or padding.
virtual int GetInset() const = 0;
ui::Layer* layer() { return layer_.get(); }
aura::Window* root_window() { return root_window_; }
protected:
// Updates |root_window_| and creates |layer_| if it doesn't exist,
// or if the root window has changed. Moves the layer to the top if
// |stack_at_top| is true, otherwise moves layer to the bottom.
void CreateOrUpdateLayer(aura::Window* root_window,
const char* layer_name,
const gfx::Rect& bounds,
bool stack_at_top);
// The current root window containing the focused object.
raw_ptr<aura::Window, DanglingUntriaged> root_window_ = nullptr;
// The current layer.
std::unique_ptr<ui::Layer> layer_;
// The bounding rectangle of the focused object, in |root_window_|
// coordinates.
gfx::Rect layer_rect_;
private:
// ui::LayerDelegate overrides:
void OnDeviceScaleFactorChanged(float old_device_scale_factor,
float new_device_scale_factor) override;
// The object that owns this layer.
raw_ptr<AccessibilityLayerDelegate> delegate_;
};
} // namespace ash
#endif // ASH_ACCESSIBILITY_UI_ACCESSIBILITY_LAYER_H_
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