add support for maxVertices in Hander.Path, p=me,r=erilem, thanks erilem for the updated patch and your great work on this (closes #2779)

git-svn-id: http://svn.openlayers.org/trunk/openlayers@11797 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Handler/Path.js

@@ -26,6 +26,15 @@ OpenLayers.Handler.Path = OpenLayers.Class(OpenLayers.Handler.Point, {
      */
     line: null,
 
+    /**
+     * APIProperty: maxVertices
+     * {Number} The maximum number of vertices which can be drawn by this
+     * handler. When the number of vertices reaches maxVertices, the
+     * geometry is automatically finalized. This property doesn't
+     * apply if freehand is set. Default is null.
+     */
+    maxVertices: null,
+
     /**
      * Property: freehand
      * {Boolean} In freehand mode, the handler starts the path on mouse down,
@@ -328,6 +337,9 @@ OpenLayers.Handler.Path = OpenLayers.Class(OpenLayers.Handler.Point, {
                     }
                     this.addPoint(evt.xy);
                     this.lastUp = evt.xy;
+                    if(this.line.geometry.components.length === this.maxVertices + 1) {
+                        this.finishGeometry();
+                    }
                 }
             }
         }