// ----------------------------------------------------------------------------
// -                        Open3D: www.open3d.org                            -
// ----------------------------------------------------------------------------
// Copyright (c) 2018-2023 www.open3d.org
// SPDX-License-Identifier: MIT
// ----------------------------------------------------------------------------

#pragma once

#include "open3d/visualization/gui/MenuBase.h"

namespace open3d {
namespace visualization {
namespace gui {

struct DrawContext;
struct Theme;

/// The menu item action is handled by Window, rather than by registering a
/// a callback function with (non-existent) Menu::SetOnClicked(). This is
/// because on macOS the menubar is global over all application windows, so any
/// callback would need to go find the data object corresponding to the active
/// window.
class Menu : public MenuBase {
    friend class Application;

public:
    Menu();
    virtual ~Menu();

    void AddItem(const char* name,
                 ItemId item_id = NO_ITEM,
                 KeyName key = KEY_NONE) override;
    void AddMenu(const char* name, std::shared_ptr<MenuBase> submenu) override;
    void AddSeparator() override;

    void InsertItem(int index,
                    const char* name,
                    ItemId item_id = NO_ITEM,
                    KeyName key = KEY_NONE) override;
    void InsertMenu(int index,
                    const char* name,
                    std::shared_ptr<MenuBase> submenu) override;
    void InsertSeparator(int index) override;

    int GetNumberOfItems() const override;

    /// Searches the menu hierarchy down from this menu to find the item
    /// and returns true if the item is enabled.
    bool IsEnabled(ItemId item_id) const override;
    /// Searches the menu hierarchy down from this menu to find the item
    /// and set it enabled according to \p enabled.
    void SetEnabled(ItemId item_id, bool enabled) override;

    bool IsChecked(ItemId item_id) const override;
    void SetChecked(ItemId item_id, bool checked) override;

    int CalcHeight(const Theme& theme) const override;

    /// Returns true if submenu visibility changed on last call to DrawMenuBar
    bool CheckVisibilityChange() const override;

    ItemId DrawMenuBar(const DrawContext& context, bool is_enabled) override;
    ItemId Draw(const DrawContext& context,
                const char* name,
                bool is_enabled) override;

    void* GetNativePointer() override;  // nullptr if not using native menus

private:
    struct Impl;
    std::unique_ptr<Impl> impl_;
};

}  // namespace gui
}  // namespace visualization
}  // namespace open3d