[qwaq] Add Listener and ListenerGroup delegates

Simple single parameter (caller) direct messages.

ruamoko/qwaq/Makefile.am

@@ -28,6 +28,7 @@ qwaq_app_dat_src= \
 	qwaq-draw.r \
 	qwaq-garray.r \
 	qwaq-group.r \
+	qwaq-listener.r \
 	qwaq-rect.r \
 	qwaq-screen.r \
 	qwaq-textcontext.r \

ruamoko/qwaq/qwaq-listener.h

@@ -0,0 +1,29 @@
+#ifndef __qwaq_listener_h
+#define __qwaq_listener_h
+
+#include <Object.h>
+
+@class Array;
+
+@interface Listener : Object
+{
+	id          responder;
+	SEL         message;
+	IMP         imp;
+}
+-initWithResponder: (id) responder message: (SEL) message;
+-(void) respond: (id) caller;
+-(BOOL) matchResponder: (id) responder message: (SEL) message;
+@end
+
+@interface ListenerGroup : Object
+{
+	Array      *listeners;
+}
+-init;
+-addListener: (id) responder message: (SEL) message;
+-removeListener: (id) responder message: (SEL) message;
+-(void) respond: (id) caller;
+@end
+
+#endif//__qwaq_listener_h

ruamoko/qwaq/qwaq-listener.r

@@ -0,0 +1,66 @@
+#include <Array.h>
+
+#include "qwaq-listener.h"
+
+@class Array;
+
+@implementation Listener
+-initWithResponder: (id) responder message: (SEL) message
+{
+	if (!(self = [super init])) {
+		return nil;
+	}
+	self.responder = responder;
+	self.message = message;
+	imp = [responder instanceMethodForSelector: message];
+	return self;
+}
+
+-(void)respond: (id) caller
+{
+	imp (responder, message, caller);
+}
+
+-(BOOL) matchResponder: (id) responder message: (SEL) message
+{
+	return self.responder == responder && self.message == message;
+}
+@end
+
+@implementation ListenerGroup : Object
+-init
+{
+	if (!(self = [super init])) {
+		return nil;
+	}
+	listeners = [[Array alloc] retain];
+	return self;
+}
+
+-addListener: (id) responder message: (SEL) message
+{
+	Listener   *listener = [[Listener alloc] initWithResponder: responder
+													   message: message];
+	if (listener) {
+		[listeners addObject: listener];
+	}
+	return self;
+}
+
+-removeListener: (id) responder message: (SEL) message
+{
+	for (int i = [listeners count]; i-- > 0; ) {
+		Listener   *l = [listeners objectAtIndex: i];
+		if ([l matchResponder: responder message: message]) {
+			[listeners removeObjectAtIndex: i];
+		}
+	}
+	return self;
+}
+
+-(void)respond: (id) caller
+{
+	[listeners makeObjectsPerformSelector: @selector (respond:)
+							   withObject: caller];
+}
+@end