Toggle buttons are derived from normal buttons and are very similar, except they will always be in one of two states, alternated by a click. They may be depressed, and when you click again, they will pop back up. Click again, and they will pop back down.
Toggle buttons are the basis for check buttons and radio buttons, as such, many of the calls used for toggle buttons are inherited by radio and check buttons. I will point these out when we come to them.
Creating a new toggle button:
toggle_button = gtk.ToggleButton(
As you can imagine, these work identically to the normal button widget calls. If no label is specified the button will be blank. The label text will be parsed for '_'-prefixed mnemonic characters.
To retrieve the state of the toggle widget, including radio and
check buttons, we use a construct as shown in our example below. This tests
the state of the toggle, by calling the
method of the toggle button object. The signal of interest to us that is
emitted by toggle buttons (the toggle button, check button, and radio button
widgets) is the "toggled" signal. To check the state of these buttons, set
up a signal handler to catch the toggled signal, and access the object
attributes to determine its state. The callback will look something
def toggle_button_callback(widget, data): if widget.get_active(): # If control reaches here, the toggle button is down else: # If control reaches here, the toggle button is up
To force the state of a toggle button, and its children, the radio and check buttons, use this method:
The above method can be used to set the state of the toggle
button, and its children the radio and check buttons. Specifying a
FALSE for the
is_active argument indicates whether the button
should be down (depressed) or up (released). When the toggle button is
created its default is up or
Note that when you use the
method, and the state is actually changed, it causes the "clicked" and
"toggled" signals to be emitted from the button.
This method returns the current state of the toggle button as a
The source code for the program is:
1 #!/usr/bin/env python 2 3 # example togglebutton.py 4 5 import pygtk 6 pygtk.require('2.0') 7 import gtk 8 9 class ToggleButton: 10 # Our callback. 11 # The data passed to this method is printed to stdout 12 def callback(self, widget, data=None): 13 print "%s was toggled %s" % (data, ("OFF", "ON")[widget.get_active()]) 14 15 # This callback quits the program 16 def delete_event(self, widget, event, data=None): 17 gtk.main_quit() 18 return False 19 20 def __init__(self): 21 # Create a new window 22 self.window = gtk.Window(gtk.WINDOW_TOPLEVEL) 23 24 # Set the window title 25 self.window.set_title("Toggle Button") 26 27 # Set a handler for delete_event that immediately 28 # exits GTK. 29 self.window.connect("delete_event", self.delete_event) 30 31 # Sets the border width of the window. 32 self.window.set_border_width(20) 33 34 # Create a vertical box 35 vbox = gtk.VBox(True, 2) 36 37 # Put the vbox in the main window 38 self.window.add(vbox) 39 40 # Create first button 41 button = gtk.ToggleButton("toggle button 1") 42 43 # When the button is toggled, we call the "callback" method 44 # with a pointer to "button" as its argument 45 button.connect("toggled", self.callback, "toggle button 1") 46 47 48 # Insert button 1 49 vbox.pack_start(button, True, True, 2) 50 51 button.show() 52 53 # Create second button 54 55 button = gtk.ToggleButton("toggle button 2") 56 57 # When the button is toggled, we call the "callback" method 58 # with a pointer to "button 2" as its argument 59 button.connect("toggled", self.callback, "toggle button 2") 60 # Insert button 2 61 vbox.pack_start(button, True, True, 2) 62 63 button.show() 64 65 # Create "Quit" button 66 button = gtk.Button("Quit") 67 68 # When the button is clicked, we call the main_quit function 69 # and the program exits 70 button.connect("clicked", lambda wid: gtk.main_quit()) 71 72 # Insert the quit button 73 vbox.pack_start(button, True, True, 2) 74 75 button.show() 76 vbox.show() 77 self.window.show() 78 79 def main(): 80 gtk.main() 81 return 0 82 83 if __name__ == "__main__": 84 ToggleButton() 85 main()
The interesting lines are 12-13 which define the
callback() method that prints the toggle button
label and its state when it is toggled. Lines 45 and 59 connect the
"toggled" signal of the toggle buttons to the