preferenceswindow.cc

Developing with Gnome一书examples例子代码

#include "PreferencesWindow.h"
#include <iostream>

using namespace std;

static bool
do_nothing(GdkEventAny* event)
{
  // Return true to signify that this event has been fully handled
  return true;
}

PreferencesWindow::PreferencesWindow(
  BaseObjectType* base_object,
  const Glib::RefPtr<Gnome::Glade::Xml>& glade_xml)
  : Gtk::Window(base_object)
{
  //
  // FIRST, get the widgets I want to track
  //

  // Get the widgets I'm interested in
  glade_xml->get_widget("ColorSelection", d_color_sel);
  glade_xml->get_widget("FontSelection",  d_font_sel);
  glade_xml->get_widget("ConfirmClose",   d_confirm_close);
  glade_xml->get_widget("InfoLabel",      d_warning_label);
  // Initialize the color and location to "not-yet-known" values
  d_location = "undefined";
  d_color.set_rgb(0,0,0);


  //
  // SECOND, we handle setting up defaults and connect callbacks for
  // the confirmation window.
  //

  // Have the confirm-closing window's delete event (window close) do nothing
  d_confirm_close->signal_delete_event().connect(sigc::ptr_fun(&do_nothing));

  // Have the cancel button hide the confirmation window
  Gtk::Button* cancel_button;
  glade_xml->get_widget("CancelButton", cancel_button);
  cancel_button->signal_clicked().connect(
    sigc::mem_fun(*this, &PreferencesWindow::cancel_button_pressed) );

  // Have the "Exit anyway" button hide the Preferences window (which has the
  // result of closing everything
  Gtk::Button* exit_button;
  glade_xml->get_widget("ExitButton", exit_button);
  exit_button->signal_clicked().connect(
    sigc::mem_fun(*this, &Gtk::Widget::hide));

  // Make the confirm-closing window start hidden
  d_confirm_close->hide();


  //
  // THIRD, we handle setting up defaults and connect callbacks for
  // the preferences window.
  //

  // Keep track of when the location changes
  Gtk::CheckButton* here = 
    dynamic_cast<Gtk::CheckButton*>(glade_xml->get_widget("Here"));
  here->signal_toggled().connect(
    sigc::bind<Glib::ustring>(
      sigc::mem_fun(*this, &PreferencesWindow::new_location_selected),
      "Here")
    );
  Gtk::CheckButton* there = 
    dynamic_cast<Gtk::CheckButton*>(glade_xml->get_widget("There"));
  there->signal_toggled().connect(
    sigc::bind<Glib::ustring>(
      sigc::mem_fun(*this, &PreferencesWindow::new_location_selected),
      "There")
    );

  // Make 'There' be the default; note this also emits the toggled signal
  there->set_active();

  // Keep track of when the color changes
  d_color_sel->signal_color_changed().connect(
    sigc::mem_fun(*this, &PreferencesWindow::new_color_selected));
  // Set the default to whatever the ColorSelection widget defaults to
  d_color = d_color_sel->get_current_color();  
  // Turn off the opacity slider
  d_color_sel->set_has_opacity_control(false);

  // Have the quit button show the confirmation window
  Gtk::Button* quit_button =
    dynamic_cast<Gtk::Button*>(glade_xml->get_widget("QuitButton"));
  quit_button->signal_clicked().connect(
    sigc::mem_fun(*this, &PreferencesWindow::time_to_quit));

  // Delete event taken care of by overriding the on_delete_event function...  
  // Destroy even taken care of by destructor...
}

PreferencesWindow::~PreferencesWindow()
{
}

void
PreferencesWindow::cancel_button_pressed()
{
  d_confirm_close->hide();
}

void
PreferencesWindow::new_location_selected(Glib::ustring location)
{
  d_location = location;
}

void
PreferencesWindow::new_color_selected()
{
  d_color = d_color_sel->get_current_color();  
}

// This simple helper function which converts an RGB triplet (which is
// part of a GdkColor) into a "#RRGGBB" string.
static Glib::ustring
convert_color_to_string (Gdk::Color & color)
{
  char color_string[8];

  color_string[0] = '#';

  // Gdk::Color stores its red, green, and blue as 0..65536 instead of 0..256
  sprintf(&color_string[1], "%.2X", color.get_red()  /256);
  sprintf(&color_string[3], "%.2X", color.get_green()/256);
  sprintf(&color_string[5], "%.2X", color.get_blue() /256);

  return color_string;
}

void
PreferencesWindow::time_to_quit()
{
  // Create a color string of the form #RRGGBB, where R, G, & B are hex digits
  Glib::ustring color = convert_color_to_string(d_color);

  // Get the warning message, and find where we want to modify it
  Glib::ustring message = d_warning_label->get_label();
  Glib::ustring::size_type end_span = message.rfind("span");
  Glib::ustring::size_type beg_span = message.rfind("span", end_span-1);

  // Set up the replacement text.  Note that we basically found the two
  // places where the letter 's' in span was in a string of the form 
  //   <span bla bla bla...>yadda yadda yadda...</span>
  // Now, we are just replacing all the stuff between those two s's.
  // (And yeah, I should really check out the String Composition)
  // (Library at  http://www.cs.auc.dk/~olau/compose/   but I'm )
  // (lazy and will use sprintf for now.                        )
  char replacement_text[500];
  sprintf(replacement_text, "span font_desc=\"%s\" foreground=\"%s\">%s</",
          d_font_sel->get_font_name().c_str(),
          color.c_str(),
          d_location.c_str());

  // Make the new message and update the label
  message.replace(beg_span, end_span-beg_span, replacement_text);
  d_warning_label->set_label(message);

  // Make sure the confirmation window is shown
  d_confirm_close->show();
}

bool
PreferencesWindow::on_delete_event(GdkEventAny* event)
{
  time_to_quit();

  // No other handlers need be called...
  return true;
}