| // 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_ |