// ----------------------------------------------------------------------------
// -                        Open3D: www.open3d.org                            -
// ----------------------------------------------------------------------------
// The MIT License (MIT)
//
// Copyright (c) 2018 www.open3d.org
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
// IN THE SOFTWARE.
// ----------------------------------------------------------------------------

#pragma once

#include <functional>

#include "Open3D/GUI/Widget.h"

namespace open3d {
namespace gui {

class Combobox : public Widget {
public:
    Combobox();
    explicit Combobox(const std::vector<const char*>& items);
    ~Combobox() override;

    void ClearItems();
    /// Adds an item to the combobox. Its index is the order in which it is
    /// added, so the first item's index is 0, the second is 1, etc.
    void AddItem(const char* name);
    const char* GetItem(int index) const;

    int GetSelectedIndex() const;
    /// Returns the text of the selected value, or "" if nothing is selected
    const char* GetSelectedValue() const;
    /// Sets the selected item by index. Does not call the onValueChanged
    /// callback.
    void SetSelectedIndex(int index);
    /// Sets the selected item by value. Does nothing if \param value is not an
    /// item. Does not call the onValueChanged callback
    void SetSelectedValue(const char* value);

    Size CalcPreferredSize(const Theme& theme) const override;

    DrawResult Draw(const DrawContext& context) override;

    /// Specifies a callback function which will be called when the value
    /// changes as a result of user action.
    void SetOnValueChanged(
            std::function<void(const char*, int)> on_value_changed);

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

}  // namespace gui
}  // namespace open3d