<HTML>
<TITLE>
The java::event Command
</TITLE>
<BODY>
<HR>
<H3>
The java::event Command
</H3>
<HR>
<DL>
<H3>
Usage:
</H3>
<B>java::event </B>?<B>-index </B><I>num</I>? ?<I>propertyName</I>?<BR>
<P>
When a callback script is invoked due to the firing of a Java event,
some <I>event parameters</I> may be passed to the script to give
detailed description of the event. The <B>java::event</B> command is
used to query the values of these parameters. The <B>-index</B> option
specifies which event parameter to quety: <I>num</I> is equal to
<B>0</B> for the first parameter, <B>1</B> for the second parameter, and
so on. If the <B>-index</B> option is omitted, the first event
paramater is queried by default. In most cases, there is exactly one
event parameter passed to the callback script and the <B>-index</B>
may thus be safely omitted.
<P>
If <I>propertyName</I> is not given, <B>java::event</B> returns the
value of the specified event paramater. If the specified event
parameter is a Java object, then its object handle is returned. If
<I>propertyName</I> is given, and the specified event parameter is a
Java object, <B>java::event</B> returns the value of the given property
of the event parameter. The second form is used mainly for
convenience. For example, the following two statements are equivalent:
<P>
<code>
<pre>
java::bind $b keyTyped {
puts [java::prop [java::event] keyCode]
}
java::bind $b keyTyped {
puts [java::event keyCode]
}
</pre>
</code>
<P>
Event handling may be nested if the Tcl event loop is re-entered
during the execution of a callback script (e.g, when a callback script
executes the <B>update</B> command.) In that case, <B>java::event</B>
always returns the paramaters of the inner-most event whose callback
script is currently being executed.
<P>
If the <I>eventName</I> and <I>script</I> arguments are both omitted,
the <B>java::bind</B> command returns a Tcl list of the the full names
of all the events of <I>javaObj</I> that are currently associated with
callback scripts.
<P>
</DL>
<PRE>
<A HREF="../license.html">Copyright</A> © 1997-1998 Sun Microsystems, Inc.
</PRE>
</BODY>
</HTML>