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<HEAD><TITLE> 9.8. How do I display a bitmap?</TITLE></HEAD>
<BODY><a name="A9.8"> 9.8. How do I display a bitmap?</a>
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You can display X bitmaps on your widgets with the <KBD>-bitmap</KBD>
configuration option. Typically <KBD>-bitmap</KBD>s are configured
into <KBD>Label</KBD>, <KBD>Frame</KBD>,
<KBD>Button</KBD>, <i>etc.</i> widgets (<KBD>Canvas</KBD> widgets are another
story however <a href="qna10.1.html">see question [10.1] below</a>).
In order to emphasize the bitmap option itself let us assume we were
specifying a bitmap for a <KBD>Label</KBD> with a call like:
<PRE>
$main->Label(-bitmap => '<i>bitmap-name</i>')->pack;
</PRE>
Where <KBD><i>bitmap-name</i></KBD> could be any of the built in Tk bitmaps:
<KBD>error</KBD>, <KBD>gray25</KBD>, <KBD>gray50</KBD>, <KBD>hourglass</KBD>,
<KBD>info</KBD>, <KBD>question</KBD>, <KBD>questhead</KBD>,
<KBD>warning</KBD> (see the <KBD>widget</KBD> demo for a full list).
<p>
In order to use some of the bitmaps in the <KBD>perl5/Tk/demos/images/</KBD>
directory you would specify a fuller path name like:
<PRE>
$main->Label(-bitmap => "\@$tk_library/demos/images/face")->pack;
</PRE>
Note the escaped <KBD>"\@"</KBD> on the directory specification (as
well as the use of the <KBD>$tk_library</KBD> variable imported by <KBD>use
Tk;</KBD>). If you wanted to specify a file called <KBD>foobar.xbm</KBD> in
the directory where you were running the script then either:
<PRE>
$main->Label(-bitmap => '@foobar.xbm')->pack;
#<i>or</i>
$main->Label(-bitmap => "\@foobar.xbm")->pack;
</PRE>
should work just fine. In another directory however that would be a problem.
So something like:
<PRE>
$main->Label(-bitmap => "\@$ENV{'HOME'}/img/foobar.xbm")->pack;
</PRE>
will help someone who has an <KBD>img/foobar.xbm</KBD> file in their $HOME
directory. If you don't mind the non-portability then hard-wiring in the full
path name will help as well. (Or if you have write access then put your files
in <KBD>Tk/demos/images/</KBD> <i>e.g.</i>)
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