3. Using a ScrolledList widget in your Tkinter application

3. Using a `ScrolledList` widget in your Tkinter application

Here is how you call the constructor for a ScrolledList widget.

s = ScrolledList ( master, width=W, height=H, vscroll=VS,
                   hscroll=HS, callback=c )

where:

s

The constructor returns a new ScrolledList widget that has not been registered. Be sure to register it with the .grid() method or it will not appear in your application.

master

The parent Frame widget in which the new ScrolledList widget is to be mastered.

width=W

The width of the Listbox in characters. The default value is 40.

height=H

The height of the Listbox in lines. The default value is 25.

vscroll=VS

By default, you will get a vertical scrollbar. If you don't want one, use “vscroll=0”.

hscroll=HS

By default, you will not get a horizontal scrollbar. If you do want one, use “hscroll=1”.

callback=c

If you want your application to react whenever a user clicks on a line in the Listbox, use this keyword argument to supply a function c, and that function will be called whenever the user clicks on a line. You should define your function like this:

def c ( lineNo ):
    ...

where the lineNo argument will be the index (starting at 0) of the line on which the user clicked. For example, if the user clicks on the third line, the ScrolledList widget will call your procedure with an argument 2.

3.1. Public attributes of a `ScrolledList`

These attributes of a ScrolledList widget are visible.

.width

The width of the listbox in characters when the widget was constructed.

.height

The height of the listbox in lines when the widget was constructed.

.listbox

The Tkinter Listbox widget inside the ScrolledList widget. If you want to change the appearance of the listbox, use this attribute's .configure() method.

For example, if you have a font object (tkFont.Font) named ttFont, and you would like to apply it to a ScrolledList widget named optionBox, this would do it:

    optionBox.listbox.configure(font=ttFont)

3.2. Methods on a `ScrolledList`

These methods are defined on a ScrolledList widget.

.count()

Returns the number of lines currently contained in the listbox.

.__getitem__(self, i)

To retrieve the text of the i^th line in the listbox, you can use the regular Python index operator. For example, if you have a ScrolledList object named optionBox, the expression “optionBox[2]” would return the contents of the third line.

.append(s)

Adds a string s as the next line in the listbox.

.insert(linex, s)

Inserts a string s as a new line before position linex. For example, to add a new first line containing “Merlin” to a ScrolledList widget named s:

 s.insert(0, 'Merlin')

.delete(linex)

Deletes a line from the listbox; linex is the index of the line, starting from 0.

.clear()

Removes all lines from the listbox.

ScrolledList: A Tkinter scrollable list widget