The ButtonBox class in gtk API serves as a base class for containers to hold multiple buttons either horizontally or vertically. Two subclasses HButtonBox and VButtonBox are derived from the ButtonBox class, which itself is a subclass of gtk.Box class.

A button box is used to provide a consistent layout of buttons throughout an application. It provides one default layout and a default spacing value that are persistent across all widgets.

The set_spacing() method of the gtk.Box class can be used to change the default spacing between buttons in the button box.

The default layout of buttons can be changed by the set_default() method. The possible values of the button layout are −

• gtk.BUTTONBOX_SPREAD

• gtk.BUTTONBOX_EDGE

• gtk.BUTTONBOX_START

• gtk.BUTTONBOX_END.

Example

In the following example, a VBox object inside the toplevel window internally contains one VButtonBox object and one HButtonBox object, each containing two buttons, arranged vertically and horizontally respectively.

Observe the code −

import gtk

class PyApp(gtk.Window):
   def __init__(self):
      super(PyApp, self).__init__()
      
	  self.set_title("Button Box demo")
      self.set_size_request(200,100)
      self.set_position(gtk.WIN_POS_CENTER)
	  vb = gtk.VBox()
      box1 = gtk.VButtonBox()
      btn1 = gtk.Button(stock = gtk.STOCK_OK)
      btn2 = gtk.Button(stock = gtk.STOCK_CANCEL)
		
      box1.pack_start(btn1, True, True, 0)
      box1.pack_start(btn2, True, True, 0)
      box1.set_border_width(5)
		
      vb.add(box1)
      box2 = gtk.HButtonBox()
      btn3 = gtk.Button(stock = gtk.STOCK_OK)
      btn4 = gtk.Button(stock = gtk.STOCK_CANCEL)
		
      ent = gtk.Entry()
      box2.pack_start(btn3, True, True, 0)
      box2.pack_start(btn4, True, True, 0)
      box1.set_border_width(5)
		
      vb.add(box2)
      self.add(vb)
      self.show_all()

PyApp()
gtk.main()

The above code generates the following output −