PyGTK - SpinButton Class

The SpinnButton widget, often called the Spinner is a gtk.Entry widget with up and down arrows on its right. A user can type in a numeric value directly in it or increment or decrement using up and down arrows. The gtk.SpinButton class is inherited from the gtk.Entry class. It uses a gtk.Adjustment object with which the range and step of the numeric value in the spinner can be restricted.

The SpinButton widget is created using the following constructor −

sp = gtk.SpinButton(adj, cpmb_rate, digits)

Here, adj represents the gtk.Adjustment object controlpng range, cpmb_rate is an acceleration factor and the number of decimals specified by digits.

The gtk.SpinButton class has the following methods −

SpinButton.set_adjustment() − This sets the "adjustment" property.

SpinButton.set_digits() − This sets the "digits" property to the value to determine the number of decimal places to be displayed by the spinbutton.

SpinButton.set_increments(step, page) − This sets the step value which has increment appped for each left mousebutton press and page value which is increment appped for each middle mousebutton press.

SpinButton.set_range() − This sets the minimum and maximum allowable values for spinbutton.

SpinButton.set_value() − This sets the spin button to a new value programmatically.

SpinButton.update_popcy() − The vapd values are gtk.UPDATE_ALWAYS and gtk.UPDATE_VALID

SpinButton.spin(direction, increment=1) − This increments or decrements Spinner s value in the specified direction.

The following are the predefined direction constants −

SpinButton.set_wrap() — If wrap is True, the spin button value wraps around to the opposite pmit when the upper or lower pmit of the range exceeds.

The gtk.SpinButton widget emits the following signals −

Example

The following example constructs a simple Date Selector by using three SpinButton widgets. The Day Selector is appped an Adjustment object to restrict value between 1—31. The second selector is for the number of months 1—12. The third selector selects the year range 2000—2020.

Observe the code −

import gtk

class PyApp(gtk.Window):
   
   def __init__(self):
      super(PyApp, self).__init__()
      self.set_title("SpinButton Demo")
      self.set_size_request(300, 200)
      self.set_position(gtk.WIN_POS_CENTER)
      self.set_border_width(20)
		
      vbox = gtk.VBox(False, 5)
      hbox = gtk.HBox(True, 3)
      lbl1 = gtk.Label("Date")
      hbox.add(lbl1)
		
      adj1 = gtk.Adjustment(1.0, 1.0, 31.0, 1.0, 5.0, 0.0)
      spin1 = gtk.SpinButton(adj1, 0, 0)
      spin1.set_wrap(True)
		
      hbox.add(spin1)
      lbl2 = gtk.Label("Month")
      hbox.add(lbl2)
		
      adj2 = gtk.Adjustment(1.0, 1.0, 12.0, 1.0, 5.0, 0.0)
      spin2 = gtk.SpinButton(adj2, 0, 0)
      spin2.set_wrap(True)
		
      hbox.add(spin2)
      lbl3 = gtk.Label("Year")
      hbox.add(lbl3)
		
      adj3 = gtk.Adjustment(1.0, 2000.0, 2020.0, 1.0, 5.0, 0.0)
      spin3 = gtk.SpinButton(adj3, 0, 0)
      spin3.set_wrap(True)
      hbox.add(spin3)
		
      frame = gtk.Frame()
      frame.add(hbox)
      frame.set_label("Date of Birth")
		
      vbox.add(frame)
      self.add(vbox)
      self.connect("destroy", gtk.main_quit)
      self.show_all()
PyApp()
gtk.main()

Upon execution, the above code will produce the following output −