Sync with latext SVG-Edit

Subpath tool.

Also make the itex tool a little more selective
(only applies to <foreignObject>s with a <math> firstChild.

public/svg-edit/editor/extensions/ext-helloworld.js

@@ -0,0 +1,80 @@
+/*
+ * ext-helloworld.js
+ *
+ * Licensed under the Apache License, Version 2
+ *
+ * Copyright(c) 2010 Alexis Deveria
+ *
+ */
+ 
+/* 
+	This is a very basic SVG-Edit extension. It adds a "Hello World" button in
+	the left panel. Clicking on the button, and then the canvas will show the
+ 	user the point on the canvas that was clicked on.
+*/
+ 
+$(function() {
+	svgCanvas.addExtension("Hello World", function() {
+
+		return {
+			name: "Hello World",
+			// For more notes on how to make an icon file, see the source of
+			// the hellorworld-icon.xml
+			svgicons: "extensions/helloworld-icon.xml",
+			
+			// Multiple buttons can be added in this array
+			buttons: [{
+				// Must match the icon ID in helloworld-icon.xml
+				id: "hello_world", 
+				
+				// This indicates that the button will be added to the "mode"
+				// button panel on the left side
+				type: "mode", 
+				
+				// Tooltip text
+				title: "Say 'Hello World'", 
+				
+				// Events
+				events: {
+					'click': function() {
+						// The action taken when the button is clicked on.
+						// For "mode" buttons, any other button will 
+						// automatically be de-pressed.
+						svgCanvas.setMode("hello_world");
+					}
+				}
+			}],
+			// This is triggered when the main mouse button is pressed down 
+			// on the editor canvas (not the tool panels)
+			mouseDown: function() {
+				// Check the mode on mousedown
+				if(svgCanvas.getMode() == "hello_world") {
+				
+					// The returned object must include "started" with 
+					// a value of true in order for mouseUp to be triggered
+					return {started: true};
+				}
+			},
+			
+			// This is triggered from anywhere, but "started" must have been set
+			// to true (see above). Note that "opts" is an object with event info
+			mouseUp: function(opts) {
+				// Check the mode on mouseup
+				if(svgCanvas.getMode() == "hello_world") {
+					var zoom = svgCanvas.getZoom();
+					
+					// Get the actual coordinate by dividing by the zoom value
+					var x = opts.mouse_x / zoom;
+					var y = opts.mouse_y / zoom;
+					
+					var text = "Hello World!\n\nYou clicked here: " 
+						+ x + ", " + y;
+						
+					// Show the text using the custom alert function
+					$.alert(text);
+				}
+			}
+		};
+	});
+});
+