ash/wm_mode/pie_menu_view.h - chromium/src - Git at Google

 // Copyright 2022 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_WM_MODE_PIE_MENU_VIEW_H_
 #define ASH_WM_MODE_PIE_MENU_VIEW_H_

 #include <stack>
 #include <string>
 #include <vector>

 #include "ash/ash_export.h"
 #include "base/containers/flat_map.h"
 #include "base/memory/raw_ptr.h"
 #include "ui/base/metadata/metadata_header_macros.h"
 #include "ui/views/view.h"

 namespace gfx {
 struct VectorIcon;
 }  // namespace gfx

 namespace views {
 class ImageButton;
 }  // namespace views

 namespace ash {

 class PieMenuButton;
 class PieMenuView;

 // -----------------------------------------------------------------------------
 // PieSubMenuContainerView:

 // Defines a container for buttons representing menu items in a pie menu.
 class ASH_EXPORT PieSubMenuContainerView : public views::View {
  public:
   METADATA_HEADER(PieSubMenuContainerView);

   PieSubMenuContainerView(const PieSubMenuContainerView&) = delete;
   PieSubMenuContainerView& operator=(const PieSubMenuContainerView&) = delete;
   ~PieSubMenuContainerView() override;

   size_t button_count() const { return buttons_.size(); }

   // Adds a new menu item button with the given `button_id`,
   // `button_label_text`, and an optional `icon` (if non-null). The `button_id`
   // must be unique among all the IDs of the current existing buttons hosted by
   // parent `PieMenuView` and all its sub menus.
   // Returns a pointer to the newly added button.
   views::View* AddMenuButton(int button_id,
                              const std::u16string& button_label_text,
                              const gfx::VectorIcon* icon);

   // Removes all the currently added buttons in this container. This can be used
   // to rebuild the contents of this sub menu from scratch.
   void RemoveAllButtons();

  private:
   friend class PieMenuView;

   explicit PieSubMenuContainerView(PieMenuView* owner_menu_view);

   // The parent owner pie menu that hosts this container. Not null.
   const raw_ptr<PieMenuView> owner_menu_view_;

   // The buttons on this container, which will be painted as slices of a circle
   // in their same order in this vector.
   std::vector<raw_ptr<PieMenuButton, VectorExperimental>> buttons_;
 };

 // -----------------------------------------------------------------------------
 // PieMenuView:

 // Defines a pie menu that lists its menu items as radial slices of a circle.
 // Each menu item button can open its sub menu with its own buttons, replacing
 // the current content of this pie view. A back button is then shown to go back
 // to the previous sub menu in the stack. There is always a main menu container
 // at all times.
 class ASH_EXPORT PieMenuView : public views::View {
  public:
   METADATA_HEADER(PieMenuView);

   // Defines an interface for the delegate of this class which will be informed
   // when a button on this pie view is pressed.
   class Delegate {
    public:
     // Called when the button with the given `button_id` is pressed.
     virtual void OnPieMenuButtonPressed(int button_id) = 0;

    protected:
     virtual ~Delegate() = default;
   };

   explicit PieMenuView(Delegate* delegate);
   PieMenuView(const PieMenuView&) = delete;
   PieMenuView& operator=(const PieMenuView&) = delete;
   ~PieMenuView() override;

   PieSubMenuContainerView* main_menu_container() {
     return main_menu_container_;
   }

   // Returns the `PieSubMenuContainerView` that the button whose ID is
   // `button_id` opens when pressed if any, or creates one for it and associates
   // it with that button. A button with `button_id` must exist in this pie menu.
   PieSubMenuContainerView* GetOrAddSubMenuForButton(int button_id);

   // Sets the label of the button whose ID is `button_id` to the given `text`.
   // A button with `button_id` must exist in this pie menu.
   void SetButtonLabelText(int button_id, const std::u16string& text);

   // Pops all the sub menus (if any) and shows the main menu.
   void ReturnToMainMenu();

   // Similar to `GetButtonById()` below but returns the button as a
   // `views::View`. This prevents the need for exposing the actual type of
   // `PieMenuButton`.
   views::View* GetButtonByIdAsView(int button_id) const;

   // Gets the center point in screen coordinates of the contents of the button
   // whose ID is `button_id`. If no such button is found, an empty point is
   // returned.
   gfx::Point GetButtonContentsCenterInScreen(int button_id) const;

   // views::View:
   void Layout(PassKey) override;
   void AddedToWidget() override;
   void OnThemeChanged() override;

  private:
   friend class PieSubMenuContainerView;

   // Called when the given `button` is added on any of the sub menu containers
   // hosted by this view.
   void OnPieMenuButtonAdded(PieMenuButton* button);

   // Called when the given `button` is removed from any of the sub menu
   // containers hosted by this view.
   void OnPieMenuButtonRemoved(PieMenuButton* button);

   // Called when the given `button` is pressed. This will inform the `delegate_`
   // via the `OnPieMenuButtonPressed()` API.
   void OnPieMenuButtonPressed(PieMenuButton* button);

   // Opens the given `sub_menu` by making it the only visible sub menu container
   // which visually replaces the contents of this pie view with the buttons
   // hosted by the given `sub_menu`. The `back_button_` will be shown to allow
   // the user to go back to the previous sub menu in `active_sub_menus_stack_`
   // (if any) or to the `main_menu_container_`.
   void OpenSubMenu(PieSubMenuContainerView* sub_menu);

   // If there are active sub menus in `active_sub_menus_stack_`, this function
   // pops the top-most one such that the previous sub menu shows. Finally when
   // there are no more sub menus, the `main_menu_container_` will show, and the
   // `back_button_` will hide.
   void MaybePopSubMenu();

   // Returns the button whose ID is `button_id` or nullptr if it doesn't exist.
   PieMenuButton* GetButtonById(int button_id) const;

   // The delegate of this view which takes care of handling button presses. Not
   // null.
   const raw_ptr<Delegate, DanglingUntriaged> delegate_;

   // The container hosting the buttons on the main menu of this view. When this
   // is visible, `active_sub_menus_stack_` should be empty, and `back_button_`
   // should be hidden.
   const raw_ptr<PieSubMenuContainerView> main_menu_container_;

   // Since a button on a sub menu can open another sub menu and so on, we keep
   // a stack of currently active sub menus (other than the main menu), so that
   // pressing on `back_button_` pops the top-most sub menu to show the previous
   // one, until there are no more active sub menus, at which point
   // `main_menu_container_` shows up and `back_button_` hides.
   std::stack<PieSubMenuContainerView*> active_sub_menus_stack_;

   const raw_ptr<views::ImageButton> back_button_;

   // Maps all the buttons on all sub menu containers of this view by their IDs.
   base::flat_map</*button_id=*/int, PieMenuButton*> buttons_by_id_;
 };

 }  // namespace ash

 #endif  // ASH_WM_MODE_PIE_MENU_VIEW_H_
	// Copyright 2022 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_WM_MODE_PIE_MENU_VIEW_H_
	#define ASH_WM_MODE_PIE_MENU_VIEW_H_

	#include <stack>
	#include <string>
	#include <vector>

	#include "ash/ash_export.h"
	#include "base/containers/flat_map.h"
	#include "base/memory/raw_ptr.h"
	#include "ui/base/metadata/metadata_header_macros.h"
	#include "ui/views/view.h"

	namespace gfx {
	struct VectorIcon;
	} // namespace gfx

	namespace views {
	class ImageButton;
	} // namespace views

	namespace ash {

	class PieMenuButton;
	class PieMenuView;

	// -----------------------------------------------------------------------------
	// PieSubMenuContainerView:

	// Defines a container for buttons representing menu items in a pie menu.
	class ASH_EXPORT PieSubMenuContainerView : public views::View {
	public:
	METADATA_HEADER(PieSubMenuContainerView);

	PieSubMenuContainerView(const PieSubMenuContainerView&) = delete;
	PieSubMenuContainerView& operator=(const PieSubMenuContainerView&) = delete;
	~PieSubMenuContainerView() override;

	size_t button_count() const { return buttons_.size(); }

	// Adds a new menu item button with the given `button_id`,
	// `button_label_text`, and an optional `icon` (if non-null). The `button_id`
	// must be unique among all the IDs of the current existing buttons hosted by
	// parent `PieMenuView` and all its sub menus.
	// Returns a pointer to the newly added button.
	views::View* AddMenuButton(int button_id,
	const std::u16string& button_label_text,
	const gfx::VectorIcon* icon);

	// Removes all the currently added buttons in this container. This can be used
	// to rebuild the contents of this sub menu from scratch.
	void RemoveAllButtons();

	private:
	friend class PieMenuView;

	explicit PieSubMenuContainerView(PieMenuView* owner_menu_view);

	// The parent owner pie menu that hosts this container. Not null.
	const raw_ptr<PieMenuView> owner_menu_view_;

	// The buttons on this container, which will be painted as slices of a circle
	// in their same order in this vector.
	std::vector<raw_ptr<PieMenuButton, VectorExperimental>> buttons_;
	};

	// -----------------------------------------------------------------------------
	// PieMenuView:

	// Defines a pie menu that lists its menu items as radial slices of a circle.
	// Each menu item button can open its sub menu with its own buttons, replacing
	// the current content of this pie view. A back button is then shown to go back
	// to the previous sub menu in the stack. There is always a main menu container
	// at all times.
	class ASH_EXPORT PieMenuView : public views::View {
	public:
	METADATA_HEADER(PieMenuView);

	// Defines an interface for the delegate of this class which will be informed
	// when a button on this pie view is pressed.
	class Delegate {
	public:
	// Called when the button with the given `button_id` is pressed.
	virtual void OnPieMenuButtonPressed(int button_id) = 0;

	protected:
	virtual ~Delegate() = default;
	};

	explicit PieMenuView(Delegate* delegate);
	PieMenuView(const PieMenuView&) = delete;
	PieMenuView& operator=(const PieMenuView&) = delete;
	~PieMenuView() override;

	PieSubMenuContainerView* main_menu_container() {
	return main_menu_container_;
	}

	// Returns the `PieSubMenuContainerView` that the button whose ID is
	// `button_id` opens when pressed if any, or creates one for it and associates
	// it with that button. A button with `button_id` must exist in this pie menu.
	PieSubMenuContainerView* GetOrAddSubMenuForButton(int button_id);

	// Sets the label of the button whose ID is `button_id` to the given `text`.
	// A button with `button_id` must exist in this pie menu.
	void SetButtonLabelText(int button_id, const std::u16string& text);

	// Pops all the sub menus (if any) and shows the main menu.
	void ReturnToMainMenu();

	// Similar to `GetButtonById()` below but returns the button as a
	// `views::View`. This prevents the need for exposing the actual type of
	// `PieMenuButton`.
	views::View* GetButtonByIdAsView(int button_id) const;

	// Gets the center point in screen coordinates of the contents of the button
	// whose ID is `button_id`. If no such button is found, an empty point is
	// returned.
	gfx::Point GetButtonContentsCenterInScreen(int button_id) const;

	// views::View:
	void Layout(PassKey) override;
	void AddedToWidget() override;
	void OnThemeChanged() override;

	private:
	friend class PieSubMenuContainerView;

	// Called when the given `button` is added on any of the sub menu containers
	// hosted by this view.
	void OnPieMenuButtonAdded(PieMenuButton* button);

	// Called when the given `button` is removed from any of the sub menu
	// containers hosted by this view.
	void OnPieMenuButtonRemoved(PieMenuButton* button);

	// Called when the given `button` is pressed. This will inform the `delegate_`
	// via the `OnPieMenuButtonPressed()` API.
	void OnPieMenuButtonPressed(PieMenuButton* button);

	// Opens the given `sub_menu` by making it the only visible sub menu container
	// which visually replaces the contents of this pie view with the buttons
	// hosted by the given `sub_menu`. The `back_button_` will be shown to allow
	// the user to go back to the previous sub menu in `active_sub_menus_stack_`
	// (if any) or to the `main_menu_container_`.
	void OpenSubMenu(PieSubMenuContainerView* sub_menu);

	// If there are active sub menus in `active_sub_menus_stack_`, this function
	// pops the top-most one such that the previous sub menu shows. Finally when
	// there are no more sub menus, the `main_menu_container_` will show, and the
	// `back_button_` will hide.
	void MaybePopSubMenu();

	// Returns the button whose ID is `button_id` or nullptr if it doesn't exist.
	PieMenuButton* GetButtonById(int button_id) const;

	// The delegate of this view which takes care of handling button presses. Not
	// null.
	const raw_ptr<Delegate, DanglingUntriaged> delegate_;

	// The container hosting the buttons on the main menu of this view. When this
	// is visible, `active_sub_menus_stack_` should be empty, and `back_button_`
	// should be hidden.
	const raw_ptr<PieSubMenuContainerView> main_menu_container_;

	// Since a button on a sub menu can open another sub menu and so on, we keep
	// a stack of currently active sub menus (other than the main menu), so that
	// pressing on `back_button_` pops the top-most sub menu to show the previous
	// one, until there are no more active sub menus, at which point
	// `main_menu_container_` shows up and `back_button_` hides.
	std::stack<PieSubMenuContainerView*> active_sub_menus_stack_;

	const raw_ptr<views::ImageButton> back_button_;

	// Maps all the buttons on all sub menu containers of this view by their IDs.
	base::flat_map</button_id=/int, PieMenuButton*> buttons_by_id_;
	};

	} // namespace ash

	#endif // ASH_WM_MODE_PIE_MENU_VIEW_H_