slider.hpp

#ifndef LIBWTK_SDL2_SLIDER_HPP
#define LIBWTK_SDL2_SLIDER_HPP

#include <functional>

#include "selectable.hpp"

struct slider : selectable
{
    slider(int start, int end, int num_steps, std::function<void(int)> value_callback);

    slider(int start, int end, std::function<void(int)> value_callback);
    ~slider() override;

    void on_draw(draw_context & dc, selection_context const & sc) const override;
    void on_mouse_up_event(mouse_up_event const & e) override;
    void on_mouse_down_event(mouse_down_event const & e) override;
    void on_mouse_move_event(mouse_move_event const & e) override;
    void on_key_event(key_event const & e) override;

    void on_box_allocated() override;

    size_hint get_size_hint(int width, int height) const override;

    void set_step_interval(int n);
    int get_step_interval() const;

    int get_value() const;

    private:

    void refresh_knob_box();
    int get_step_with_abs_pos(int abs_pos);
    void set_step(int step);
    void emit_value_callback(int step);

    int _start;
    int _end;
    int _step;

    int _num_steps;

    int _current_step;

    int _pressed_step;

    SDL_Rect _knob_box;
    int _step_width;
    int _step_width_rems;

    std::function<void(int)> _value_callback;
};

#endif