theme_info.h

#pragma once
 
#include <cgv/media/color.h>
#include <cgv/signal/signal.h>
 
#include "lib_begin.h"
 
namespace cgv {
namespace gui {
 
#define DEF_COLOR_MEMBER_METHODS(FIELD) \
void FIELD(unsigned char r, unsigned char g, unsigned char b) { \
    FIELD##_col = rgb( \
        static_cast<float>(r) / 255.0f, \
        static_cast<float>(g) / 255.0f, \
        static_cast<float>(b) / 255.0f \
    ); \
} \
rgb FIELD() const { \
    return FIELD##_col; \
}\
std::string FIELD##_hex() const { \
    return cgv::media::to_hex(FIELD##_col); \
}
 
class CGV_API theme_info {
protected:
    int index_ = -1;
 
    // the spacing between user interface groups (usually a 1px wide border)
    int spacing_ = 1;
    // the scaling of user interface elements (used for DPI-adjustment); currently not supported by fltk controls
    float scaling_ = 1.0f;
 
    rgb background_col;
    rgb group_col;
    rgb control_col;
    rgb border_col;
    rgb text_col;
    rgb text_background_col;
    rgb selection_col;
    rgb highlight_col;
    rgb warning_col;
    rgb shadow_col;
 
public:
    static theme_info& instance();
 
    theme_info(const theme_info&) = delete;
    void operator=(const theme_info&) = delete;

    theme_info();
    ~theme_info() {}
 
    // general info
    void index(int index) { index_ = index; }
    int index() const { return index_; }
    bool is_dark() const;
 
    // layout variables
    int spacing() const { return spacing_; }
    void spacing(int i) { spacing_ = i; }
 
    float scaling() const { return scaling_; }
    void scaling(float f) { scaling_ = f; }
 
    // theme colors
    DEF_COLOR_MEMBER_METHODS(background);
    DEF_COLOR_MEMBER_METHODS(group);
    DEF_COLOR_MEMBER_METHODS(control);
    DEF_COLOR_MEMBER_METHODS(border);
    DEF_COLOR_MEMBER_METHODS(text);
    DEF_COLOR_MEMBER_METHODS(text_background);
    DEF_COLOR_MEMBER_METHODS(selection);
    DEF_COLOR_MEMBER_METHODS(highlight);
    DEF_COLOR_MEMBER_METHODS(warning);
    DEF_COLOR_MEMBER_METHODS(shadow);
 
    // calls the on_change signal to notify theme_observers upon theme changes
    void notify_observers() const;
 
    cgv::signal::signal<const theme_info&> on_change;
};
 
#undef DEF_COLOR_MEMBER_METHODS
 
// derive from this class to handle theme changes whenever theme_info::notify_changes is called
class CGV_API theme_observer : virtual public cgv::signal::tacker {
public:
    theme_observer() {
        cgv::gui::theme_info& theme = cgv::gui::theme_info::instance();
        cgv::signal::connect(theme.on_change, this, &theme_observer::handle_theme_change);
    }
 
    ~theme_observer() {
        cgv::gui::theme_info& theme = cgv::gui::theme_info::instance();
        cgv::signal::disconnect(theme.on_change, this, &theme_observer::handle_theme_change);
    }

    virtual void handle_theme_change(const cgv::gui::theme_info& theme) {}
};
 
}
}
 
#include <cgv/config/lib_end.h>