Perl/Tk Pocket Reference

3. Widget Scroll Commands 7

2. Perl/Tk Special Variables

$Tk::library

Directory containing library of Tk modules, widgets, and

scripts.

$Tk::patchLevel

Integer specifying current patch level for Tcl/Tk.

$Tk::strictMotif

When non-zero, Tk tries to adhere to Motif look-and-feel

as closely as possible.

$Tk::version

Current version of Tcl/Tk that Perl/Tk is based on, in

major.minor form.

$Tk::VERSION

Current version of Perl/Tk.

3. Widget Scroll Commands

The Canvas, Listbox, and Text widgets support the following

scrolling commands. The Entry widget supports the xview

command and the scan command with the y coordinate

dropped.

Refer to the section Perl/Tk Widgets and learn how the Perl/

Tk widget Scrolled greatly simplifies managing scrollbars.

$widget->scanMark(x, y);

Records x and y as widget’s current view anchor.

$widget->scanDragto(x, y);

Shifts the view by 10 times the difference between

the coordinates x and y and the current view anchor

coordinates.

$widget->xview;

Returns a two-element list specifying the fraction of the

horizontal span of the widget at the left and right edges

of the window.

8 Perl/Tk Pocket Reference

$widget->xviewMoveto(fraction);

Adjusts the view in the window so that fraction of the

total width of the widget is off-screen to the left.

$widget->xviewScroll(number

=> units| pages );

Shifts the ...