Learning Perl/Tk

16.8. Size of Widget

You can use the following methods to find out the size of a widget in several different ways.

16.8.1. Widget's Geometry

The geometry method returns the geometry string for the widget in the form of widthxheight+x+y.

$geom = $widget->geometry();

The geometry string was discussed in detail in Chapter 13. Geometry values are specified in pixels.

16.8.2. Requested Height

The height of the widget is returned by the reqheight method:

$height = $widget->reqheight();

The widget itself determines the appropriate height.

16.8.3. Requested Width

The width of the widget can be determined by using the reqwidth method:

$width = $widget->reqwidth();

16.8.4. Actual Width

To get the width of the widget as it currently is drawn, use the width method:

$cur_width = $widget->width();

When the widget is first created, width will return a 1 until the application has finished drawing everything. After that, it will return the actual width of the widget.

16.8.5. Actual Height

To get the current height, use the height method:

$h = $widget->height();

Just like the width method, height returns a 1 when the widget is first created. You can use the update or the afterIdle method to force everything else to happen and then call heightor widthto get the finished values.