18.9 The Scrollbar Widget (Perl in a Nutshell)

18.9 The Scrollbar Widget

Create a scrollbar with the Scrollbar method.

$parentwidget->Scrollbar (
options
)

The standard configuration options that apply to


Scrollbar

are:


-activebackground


-background

-bg


-borderwidth

-bd


-cursor


-highlightbackground


-highlightcolor


-highlightthickness


-relief


-takefocus

, and


-width

Other options are:

-activerelief => type: Changes how active elements (arrow1, arrow2, and the slider) in the scrollbar are drawn. Values for type are 'flat' , 'groove' , 'raised' , 'ridge' , and 'sunken' . The default is 'raised' .
-command => callback: Pointer to a function that will be called when the scrollbar is clicked on.
-elementborderwidth => amount: The width of the borders of the arrow1, arrow2, and slider elements.
-jump => boolean: Determines whether the scrollbar will jump scroll. Default is 0 (jump scroll disabled).
-orient => orientation: Determines the orientation of the scrollbar. Possible orientation s are 'horizontal' and 'vertical' (default).
-repeatdelay => milliseconds: Determines the number of milliseconds to hold down an arrow before it will auto-repeat. Default is 300.
-repeatinterval => milliseconds: Determines the number of milliseconds between auto-repeats once it is started. Default is 100.
-troughcolor => color: Changes the color of the trough.

18.9.1 Scrollbar Methods

In addition to configure and cget , the following methods are supported by the Scrollbar widget:

set

Changes the viewable portion of the data, with the two arguments being numbers between 0 and 1 representing the portions of the data to be visible.

$scrollbar->set(0.2,0.6);

get

Returns the latest arguments to set .

activate

With no arguments, returns the name of the current active element. With an argument of arrow1 , arrow2 , or slider , changes the color of the specified element to the active foreground color and relief type.

delta

Given a number of pixels in the first argument, returns the fractional change needed to move the slider that amount.

fraction

Given an x,y coordinate as the first and second arguments, returns a number between 0 and 1 representing what fraction of the scrollbar that coordinate would fall under.

identify

Given an x,y coordinate as the first and second arguments, returns the name of the element at those coordinates.