example-4.py

Developing with Gnome一书examples例子代码

#!/usr/bin/env python

# This program shows a preferences window, which contains
# RadioButtons, a color selection widget, and a font selection widget.
# It does manual signal connection the pygtk way (as opposed to either
# the autoconnect libglade method), pops up a (modal) window to
# confirm whether the user really wants to exit, and demonstrates how
# to use pango markup.

import gtk
import gtk.glade
import re

class PreferencesWindow:
  def __init__(self, glade_file):
    # Parse the glade file
    self.all_da_widgets = gtk.glade.XML(glade_file)

    #
    # FIRST, get the widgets I want to track
    #

    # Get the widgets I'm interested in
    self.preferences   = self.all_da_widgets.get_widget("MainWindow")
    self.color_sel     = self.all_da_widgets.get_widget("ColorSelection")
    self.font_sel      = self.all_da_widgets.get_widget("FontSelection")
    self.confirm_close = self.all_da_widgets.get_widget("ConfirmClose")
    self.warning_label = self.all_da_widgets.get_widget("InfoLabel")
    # Initialize the color and location to "not-yet-known" values
    self.location = "undefined"
    self.color = gtk.gdk.Color(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
    self.confirm_close.connect("delete_event", self.do_nothing);

    # Have the cancel button hide the confirmation window
    cancel_button = self.all_da_widgets.get_widget("CancelButton")
    cancel_button.connect("clicked", self.cancel_button_pressed)

    # Have the "Exit anyway" button close everything
    exit_button = self.all_da_widgets.get_widget("ExitButton")
    exit_button.connect("clicked", gtk.mainquit)

    # Make the confirm-closing window start hidden
    self.confirm_close.hide()

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

    # Keep track of when the location changes
    here = self.all_da_widgets.get_widget("Here")
    here.connect("toggled", self.new_location_selected, "Here")
    there = self.all_da_widgets.get_widget("There")
    there.connect("toggled", self.new_location_selected, "There")

    # Make 'There' be the default; note this also emits the toggled signal
    there.set_active(gtk.TRUE)

    # Keep track of when the color changes
    self.color_sel.connect("color_changed", self.new_color_selected)
    # Set the default to whatever the ColorSelection widget defaults to
    self.color = self.color_sel.get_current_color()
    # Turn off the opacity slider
    self.color_sel.set_has_opacity_control(gtk.FALSE)

    # Have the quit button show the confirmation window
    quit_button = self.all_da_widgets.get_widget("QuitButton")
    quit_button.connect("clicked", self.time_to_quit)

    # Delete event taken care of by overriding the on_delete_event function...
    self.preferences.connect("delete_event", self.call_time_to_quit)

  def do_nothing(self,confirmation_dialog,event):
    # Return true to signify that this event has been fully handled
    return gtk.TRUE

  def cancel_button_pressed(self, cancel_button):
    self.confirm_close.hide()

  def new_location_selected(self, radio_button, location):
    self.location = location

  def new_color_selected(self, color_selection_widget):
    self.color = self.color_sel.get_current_color()

  def convert_color_to_string(self, color):
    """
    This simple helper function which converts an RGB triplet (which is
    part of a Gdk.Color) into a "#RRGGBB" string.
    """
    color_string = "#%.2X%.2X%.2X" % \
                   (color.red/256,color.green/256,color.blue/256)
    return color_string

  def time_to_quit(self, ignored_widget):
    color_string = self.convert_color_to_string(self.color);

    # Get the warning message
    message = self.warning_label.get_label()

    # Set up the replacement text.
    replacement_text = '<span '                                \
      + 'font_desc="'  + self.font_sel.get_font_name() + '" '  \
      + 'foreground="' + color_string                  + '">'  \
      + self.location                                          \
      + '</span>'

    # Make the new message
    old_regex = re.compile(r'to <span.*<\/span>')
    message = old_regex.sub("to " + replacement_text, message)

    # Update the label
    self.warning_label.set_label(message)

    # Make sure the confirmation window is shown
    self.confirm_close.show()

  def call_time_to_quit(self, window, event):
    self.time_to_quit(window)

    # No other handlers need be called...
    return gtk.TRUE

# Create the PreferencesWindow
window = PreferencesWindow("example-4.glade")

# start the event loop
gtk.main()