Scrolled window is created to access other widget of area larger than parent window. Some widgets like TreeView and TextView of native support for scrolling. For others such as Label or Table, a Viewport should be provided.
The following syntax is used for the constructor of the gtk.ScrolledWindow class −
sw = gtk.ScrolledWindow(hadj, vadj)
The following are the methods of the gtk.ScrolledWindow class −
ScrolledWindow.set_hadjustment() − This sets the horizontal adjustment to a gtk.Adjustment object
ScrolledWindow.set_vadjustment() − This sets the vertical adjustment to a gtk.Adjustment object
ScrolledWindow.set_Policy (hpolicy, vpolicy) − This sets the "hscrollbar_policy" and "vscrollbar_policy" properties. One of the following predefined constants are used −
gtk.POLICY_ALWAYS − The scrollbar is always present
gtk.POLICY_AUTOMATIC − The scrollbar is present only if needed i.e. the contents are larget than the window
gtk.POLICY_NEVER − The scrollbar is never present
ScrolledWindow.add_with_viewport(child) − This method is used to add a widget (specified by child) without native scrolling capabilities to the scrolled window. This is a convenience function that is equivalent to adding child to a gtk.Viewport, then adding the viewport to the scrolled window.
The following code adds a scrolled window around a gtk.Table object with 10 by 10 dimensions. Since a Table object doesn't support adjustments automatically, it is added in a Viewport.
sw = gtk.ScrolledWindow() table = gtk.Table(10,10)
Two nested loops are used to add 10 rows of 10 columns each. A gtk.Button widget is placed in each cell.
for i in range(1,11): for j in range(1,11): caption = "Btn"+str(j)+str(i) btn = gtk.Button(caption) table.attach(btn, i, i+1, j, j+1)
This large enough table is now added in the scrolled window along with a viewport.
Observe the following code −
import gtk class PyApp(gtk.Window): def __init__(self): super(PyApp, self).__init__() self.set_title("ScrolledWindow and Viewport") self.set_size_request(400,300) self.set_position(gtk.WIN_POS_CENTER) sw = gtk.ScrolledWindow() table = gtk.Table(10,10) table.set_row_spacings(10) table.set_col_spacings(10) for i in range(1,11): for j in range(1,11): caption = "Btn"+str(j)+str(i) btn = gtk.Button(caption) table.attach(btn, i, i+1, j, j+1) sw.add_with_viewport(table) self.add(sw) self.connect("destroy", gtk.main_quit) self.show_all() PyApp() gtk.main()
The above code will generate the following output −