Added support for plugging in event handlers - will allow the wave gadget to receive state notifications without any wave specific code in the editor itself

git-svn-id: http://svg-edit.googlecode.com/svn/trunk@43 eee81c28-f429-11dd-99c0-75d572ba1ddd

editor/svgcanvas.js

@@ -32,12 +32,19 @@ function SvgCanvas(doc)
 	var freehand_min_y = null;
 	var freehand_max_y = null;
 	var selected = null;
+	var events = {};
 
 // private functions
 	var getId = function() {
 		return "svg_"+obj_num;
 	}
 
+	var call = function(event, arg) {
+		if (events[event]) {
+			return events[event](this,arg);
+		}
+	}
+
 	var assignAttributes = function(node, attrs) {
 		for (i in attrs) {
 			node.setAttributeNS(null, i, attrs[i]);
@@ -66,6 +73,7 @@ function SvgCanvas(doc)
 		assignAttributes(shape, data.attr);
 		cleanupElement(shape);
 		svgdoc.documentElement.appendChild(shape);
+		call("changed",shape);
 	}
 
 	var svgToString = function(elem, indent) {
@@ -393,6 +401,7 @@ function SvgCanvas(doc)
 		} else if (element != null) {
 			element.setAttribute("opacity", current_opacity);
 			cleanupElement(element);
+			call("changed",element);
 		}
 	}
 
@@ -482,6 +491,10 @@ function SvgCanvas(doc)
 		current_stroke_opacity = val;
 	}
 
+	this.bind = function(event, f) {
+		events[event] = f;
+	}
+
 	this.setup = function(evt) {
 		assignAttributes(svgroot, {
 			"onmouseup":   "svgcanvas.mouseUp(evt)",