 
 subsubsection3_4_5_2.html  subsectionstar3_4_5.html  subsectionstar3_4_5.html  tableofcontents3_1.html   Next: subsubsection3_4_5_2.html The SetBindings Method Up: subsectionstar3_4_5.html Chaining Methods  Previous: subsectionstar3_4_5.html Chaining Methods    The ConstructWidget Method 
The 
ConstructWidget method is used to create the components of a
widget instance. In the case of 
TixArrowButton, we want to create a
new button subwidget, whose name is 
button, and use a bitmap to
display an arrow on this button. Assuming the bitmap files are stored
in the files up.xbm, down.xbm, left.xbm and right.xbm, the string
substitution 
@$data(-direction).xbm will give us the appropriate
bitmap depending on the current direction option of the widget
instance.
proc tixArrowButton:ConstructWidget {w} {
    upvar #0 $w data
    tixChainMethod $w ConstructWidget
    set data(w:button) \
        [button $w.button \
        -bitmap @$data(-direction).xbm]
    pack $data(w:button) \
        -expand yes -fill both
}
The 
tixArrowButton:ConstructWidget method shown above sets the
variable 
data(w:button) to be the pathname of the button subwidget. As
a convention of the Tix Intrinsics, we must declare a public subwidget
swid by storing its pathname in the variable data(w:swid).
http://tix.sourceforge.nethttp://tix.sourceforge.net 