颜色选择器对话框(ColorChooserDialog)

ColorChooserDialog允许用户选择一个颜色。当ColorButton被点击的时会打开一个颜色选择对话框。

参考

15.3.1. 示例

Figure 15-3颜色选择器对话框(ColorChooserDialog)

源代码

File: examplewindow.h (For use with gtkmm 4)

#ifndef GTKMM_EXAMPLEWINDOW_H
#define GTKMM_EXAMPLEWINDOW_H

#include <gtkmm.h>
#include <memory>

class ExampleWindow : public Gtk::Window
{
public:
  ExampleWindow();
  virtual ~ExampleWindow();

protected:
  //Signal handlers:
  void on_color_button_color_set();
  void on_button_dialog_clicked();
  void on_dialog_response(int response_id);

  //Draw function:
  void on_drawing_area_draw(const Cairo::RefPtr<Cairo::Context>& cr, int width, int height);

  //Child widgets:
  Gtk::Box m_VBox;
  Gtk::ColorButton m_ColorButton;
  Gtk::Button m_Button_Dialog;
  Gtk::DrawingArea m_DrawingArea; //To show the color.

  std::unique_ptr<Gtk::ColorChooserDialog> m_pDialog;
  Gdk::RGBA m_Color;
};

#endif //GTKMM_EXAMPLEWINDOW_H

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);
}

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::ColorChooserDialog example");
  set_default_size(200, 200);

  set_child(m_VBox);

  m_VBox.append(m_ColorButton);
  m_ColorButton.signal_color_set().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_ColorButton.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_ColorButton.get_rgba();
  m_DrawingArea.queue_draw();
}

void ExampleWindow::on_button_dialog_clicked()
{
  if (!m_pDialog)
  {
    m_pDialog.reset(new Gtk::ColorChooserDialog("Please choose a color", *this));
    m_pDialog->set_modal(true);
    m_pDialog->set_hide_on_close(true);
    m_pDialog->signal_response().connect(
      sigc::mem_fun(*this, &ExampleWindow::on_dialog_response));
  }

  //Get the previously selected color:
  m_pDialog->set_rgba(m_Color);

  m_pDialog->show();
}

void ExampleWindow::on_dialog_response(int response_id)
{
  m_pDialog->hide();

  //Handle the response:
  switch (response_id)
  {
    case Gtk::ResponseType::OK:
    {
      //Store the chosen color:
      m_Color = m_pDialog->get_rgba();
      m_ColorButton.set_rgba(m_Color);
      m_DrawingArea.queue_draw();
      break;
    }
    case Gtk::ResponseType::CANCEL:
    {
      std::cout << "Cancel clicked." << std::endl;
      break;
    }
    default:
    {
      std::cout << "Unexpected button clicked: " << response_id << std::endl;
      break;
    }
  }
}

void ExampleWindow::on_drawing_area_draw(const Cairo::RefPtr<Cairo::Context>& cr, int, int)
{
  Gdk::Cairo::set_source_rgba(cr, m_Color);
  cr->paint();
}