# $Id: OnCalleeProxy.xotcl,v 1.4 2005/09/09 21:09:01 neumann Exp $

package provide xotcl::pattern::onCalleeProxy 0.8
package require XOTcl

namespace eval ::xotcl::pattern::onCalleeProxy {
    namespace import ::xotcl::*

    Class OnCalleeProxy -superclass Class  

    @ @File {
	description {
	    Simple proxy pattern implementation enhanced with the ability to adapt
	    calls solely for specified calling objects
	    for each calling obj there may be a different delegator obj
	}
    }

    OnCalleeProxy instproc onCalleeProxyFilter args { 
	set o [string trimleft [self callingobject] :]
	my instvar callee
	#puts stderr "[self class]: checking $o -- [self] -- [self calledproc] "
	if {[info exists callee($o)]} {
	    return [::eval [set callee($o)] [self calledproc] $args]
	} else {
	    next
	}
    }

    OnCalleeProxy instproc init args {
	my instfilter add onCalleeProxyFilter
	next
	my instproc setCallee {callingObj a} {
	    my set callee([string trimleft $callingObj :]) $a
	}
    }

    namespace export OnCalleeProxy
}

namespace import ::xotcl::pattern::onCalleeProxy::*