# MessageDialog (Python)

Marta Maria Casetti
mmcasetti@gmail.com 2012
A message window
Mario Blättermann
mario.blaettermann@gmail.com 2011, 2013, 2016, 2018

# MessageDialog

A message dialog which prints messages on the terminal, depending on your choices.

# Code used to generate this example

from gi.repository import Gtk from gi.repository import Gio import sys

class MyWindow(Gtk.ApplicationWindow):

# constructor for a window (the parent window) with a label def __init__(self, app): Gtk.Window.__init__(self, title="GMenu Example", application=app) self.set_default_size(400, 200) label = Gtk.Label() label.set_text("This application goes boom!") self.add(label)

# create the message_action (a Gio.SimpleAction) - for the window message_action = Gio.SimpleAction.new("message", None) # connect the signal from the action to the function message_cb() message_action.connect("activate", self.message_cb) # add the action to the application app.add_action(message_action)

# callback function for the signal "activate" from the message_action # in the menu of the parent window def message_cb(self, action, parameter): # a Gtk.MessageDialog messagedialog = Gtk.MessageDialog(parent=self, flags=Gtk.DialogFlags.MODAL, type=Gtk.MessageType.WARNING, buttons=Gtk.ButtonsType.OK_CANCEL, message_format="This action will cause the universe to stop existing.") # connect the response (of the button clicked) to the function # dialog_response() messagedialog.connect("response", self.dialog_response) # show the messagedialog messagedialog.show()

def dialog_response(self, widget, response_id): # if the button clicked gives response OK (-5) if response_id == Gtk.ResponseType.OK: print("*boom*") # if the button clicked gives response CANCEL (-6) elif response_id == Gtk.ResponseType.CANCEL: print("good choice") # if the messagedialog is destroyed (by pressing ESC) elif response_id == Gtk.ResponseType.DELETE_EVENT: print("dialog closed or cancelled") # finally, destroy the messagedialog widget.destroy()

class MyApplication(Gtk.Application):

def __init__(self): Gtk.Application.__init__(self)

def do_activate(self): win = MyWindow(self) win.show_all()

def quit_cb(self, action, parameter): self.quit()

def do_startup(self): Gtk.Application.do_startup(self)

# create a menu (a Gio.Menu) menu = Gio.Menu() # append a menu item with label "Message" and action "app.message" menu.append("Message", "app.message") # append a menu item with label "Quit" and action "app.quit" menu.append("Quit", "app.quit") # set menu as the menu for the application self.set_app_menu(menu)

# a new simpleaction - for the application quit_action = Gio.SimpleAction.new("quit", None) quit_action.connect("activate", self.quit_cb) self.add_action(quit_action)

app = MyApplication() exit_status = app.run(sys.argv) sys.exit(exit_status)

# Useful methods for a MessageDialog widget

In line 18 the signal `"activate"` is connected to the callback function `message_cb()` using `widget.connect(signal, callback function)`. See for a more detailed explanation.

In the constructor of MessageDialog we could set flags as `Gtk.DialogFlags.DESTROY_WITH_PARENT` (to destroy the messagedialog window when its parent window is destroyed) or as `Gtk.DialogFlags.MODAL` (no interaction with other windows of the application).

In the constructor of MessageDialog we could set type as any of `Gtk.MessageType.INFO, Gtk.MessageType.WARNING, Gtk.MessageType.QUESTION, Gtk.MessageType.ERROR, Gtk.MessageType.OTHER` depending on what type of message we want.

In the constructor of MessageDialog we could set buttons as any of `Gtk.ButtonsType.NONE, Gtk.ButtonsType.OK, Gtk.ButtonsType.CLOSE, Gtk.ButtonsType.CANCEL, Gtk.ButtonsType.YES_NO, Gtk.ButtonsType.OK_CANCEL`, or any button using `add_button()` as in Gtk.Dialog.

We could substitute the default image of the MessageDialog with another image using

image = Gtk.Image() image.set_from_stock(Gtk.STOCK_CAPS_LOCK_WARNING, Gtk.IconSize.DIALOG) image.show() messagedialog.set_image(image)

where `Gtk.STOCK_CAPS_LOCK_WARNING` is any image from Stock Items. We could also set any image as in the Image widget, as `image.set_from_file("filename.png")`.

`format_secondary_text("some secondary message")` sets a secondary message. The primary text becomes bold.

# API-Referenzen

In this sample we used the following:

GtkMessageDialog

GtkDialog

GtkWindow

GSimpleAction

GActionMap

GMenu

GtkApplication