The ColorChooserDialog
(deprecated since gtkmm 4.10) and
ColorDialog
(available since gtkmm 4.10) allow the user
to choose a color. The ColorButton
(deprecated since gtkmm 4.10)
and ColorDialogButton
(available since gtkmm 4.10) open
a color selection dialog when it is clicked.
File: examplewindow.h
(For use with gtkmm 4)
#ifndef GTKMM_EXAMPLEWINDOW_H
#define GTKMM_EXAMPLEWINDOW_H
#include <gtkmm.h>
class ExampleWindow : public Gtk::Window
{
public:
ExampleWindow();
~ExampleWindow() override;
protected:
//Signal handlers:
void on_color_button_color_set();
void on_button_dialog_clicked();
void on_dialog_finish(const Glib::RefPtr<Gio::AsyncResult>& result);
//Draw function:
void on_drawing_area_draw(const Cairo::RefPtr<Cairo::Context>& cr, int width, int height);
//Child widgets:
Gtk::Box m_VBox;
Gtk::ColorDialogButton m_ColorDialogButton;
Gtk::Button m_Button_Dialog;
Gtk::DrawingArea m_DrawingArea; //To show the color.
Glib::RefPtr<Gtk::ColorDialog> m_pDialog;
Gdk::RGBA m_Color;
};
#endif //GTKMM_EXAMPLEWINDOW_H
File: examplewindow.cc
(For use with gtkmm 4)
#include "examplewindow.h"
#include <iostream>
ExampleWindow::ExampleWindow()
: m_VBox(Gtk::Orientation::VERTICAL, 5),
m_Button_Dialog("Choose Color")
{
set_title("Gtk::ColorDialog example");
set_default_size(200, 200);
m_pDialog = Gtk::ColorDialog::create();
m_ColorDialogButton.set_dialog(m_pDialog);
set_child(m_VBox);
m_VBox.append(m_ColorDialogButton);
m_ColorDialogButton.property_rgba().signal_changed().connect(
sigc::mem_fun(*this, &ExampleWindow::on_color_button_color_set));
m_VBox.append(m_Button_Dialog);
m_Button_Dialog.signal_clicked().connect(sigc::mem_fun(*this,
&ExampleWindow::on_button_dialog_clicked) );
//Set start color:
m_Color.set_red(0.0);
m_Color.set_green(0.0);
m_Color.set_blue(1.0);
m_Color.set_alpha(1.0); //opaque
m_ColorDialogButton.set_rgba(m_Color);
m_VBox.append(m_DrawingArea);
m_DrawingArea.set_expand(true);
m_DrawingArea.set_draw_func(sigc::mem_fun(*this, &ExampleWindow::on_drawing_area_draw));
}
ExampleWindow::~ExampleWindow()
{
}
void ExampleWindow::on_color_button_color_set()
{
//Store the chosen color:
m_Color = m_ColorDialogButton.get_rgba();
m_DrawingArea.queue_draw();
}
void ExampleWindow::on_button_dialog_clicked()
{
m_pDialog->choose_rgba(*this, m_Color,
sigc::mem_fun(*this, &ExampleWindow::on_dialog_finish));
}
void ExampleWindow::on_dialog_finish(const Glib::RefPtr<Gio::AsyncResult>& result)
{
try
{
// If this call changes the color, it will trigger a call to
// on_color_button_color_set().
m_ColorDialogButton.set_rgba(m_pDialog->choose_rgba_finish(result));
// This is what you should do if m_ColorDialogButton and
// on_color_button_color_set() did not exist:
//m_Color = m_pDialog->choose_rgba_finish(result);
//m_DrawingArea.queue_draw();
}
catch (const Gtk::DialogError& err)
{
// Can be thrown by m_pDialog->choose_rgba_finish(result).
std::cout << "No color selected. " << err.what() << std::endl;
}
catch (const Glib::Error& err)
{
std::cout << "Unexpected exception. " << err.what() << std::endl;
}
}
void ExampleWindow::on_drawing_area_draw(const Cairo::RefPtr<Cairo::Context>& cr, int, int)
{
Gdk::Cairo::set_source_rgba(cr, m_Color);
cr->paint();
}
File: main.cc
(For use with gtkmm 4)
#include "examplewindow.h"
#include <gtkmm/application.h>
int main(int argc, char *argv[])
{
auto app = Gtk::Application::create("org.gtkmm.example");
//Shows the window and returns when it is closed.
return app->make_window_and_run<ExampleWindow>(argc, argv);
}