Classes which implement this interface provide methods
that deal with changes in state of <code>Shell</code>s.
<p>
After creating an instance of a class that :
this interface it can be added to a shell using the
<code>addShellListener</code> method and removed using
the <code>removeShellListener</code> method. When the
state of the shell changes, the appropriate method will
be invoked.
</p>
Classes which implement this interface provide methods that deal with changes in state of <code>Shell</code>s. <p> After creating an instance of a class that : this interface it can be added to a shell using the <code>addShellListener</code> method and removed using the <code>removeShellListener</code> method. When the state of the shell changes, the appropriate method will be invoked. </p>
@see ShellAdapter @see ShellEvent