Draw solid or dashed polylines on Google Maps.

KMPolyline.js

/*!
 * KMPolyline - Draw solid or dashed polylines.
 *
 * Extended Google's GPolyline class.
 *
 * Rewritten Bill Chadwick's BDCCPolyline.js script.
 * http://www.bdcc.co.uk/Gmaps/BdccGmapBits.htm
 *
 * Non-solid polylines only if drawing is performed using VML or SVG.
 *
 * Prototype.js v1.6+ required - http://prototypejs.org/
 *
 * Downloaded from: Martin Milesich - http://milesich.com/
 *
 * Free for any use.
 */

var KMPolylineCounter = 0;

// Constructor
function KMPolyline(points, color, weight, opacity, tooltip, dash)
{
    ++KMPolylineCounter;

    this.points    = points  || [];
    this.color     = color   || "#000000";
    this.weight    = weight  || 1;
    this.tooltip   = tooltip || "";
    this.dash      = dash    || "solid";
    this.elemId    = "KMPolylineId" + KMPolylineCounter.toString();
    this.opacity   = Math.abs(opacity - (KMPolylineCounter + 1) / 10000);
    this.usesVml   = Prototype.Browser.IE;

    GPolyline.call(this, this.points, this.color, this.weight, this.opacity, {"clickable": false}); //call parent constructor
}

KMPolyline.prototype = new GPolyline([new GLatLng(0,0)]);

KMPolyline.prototype.copy = function()
{
    return new KMPolyline(this.points, this.color, this.weight, this.opacity, this.tooltip, this.dash);
}

KMPolyline.prototype.redraw = function(force)
{
   GPolyline.prototype.redraw.call(this, force); //call parent

   var elem = null;

   if (this.usesVml) {
   // VML
       var shps = $$('shape');

       for (i = 0; i < shps.length; i++) {
           if (shps[i].stroke.opacity.toFixed(4) == this.opacity) {
               elem = shps[i];
               break;
           }
       }
   } else {
   // SVG
       elem = $$('path[stroke-opacity="'+this.opacity+'"]').first();

        if (elem != null) {
            Element.writeAttribute(elem, "pointer-events", "stroke");
        }
   }

   if (elem != null) {
       if (this.tooltip != "") {
           elem.style.cursor = "help";
           Element.writeAttribute(elem, 'title', this.tooltip);
       }

       Element.writeAttribute(elem, 'id', this.elemId);

       this.setDash(this.dash);

       var eClick = GEvent.callback(this, this.onClick);
       var eOver  = GEvent.callback(this, this.onOver);
       var eOut   = GEvent.callback(this, this.onOut);

       GEvent.clearInstanceListeners(elem);

       GEvent.addDomListener(elem, "click",     function() {eClick()});
       GEvent.addDomListener(elem, "mouseover", function() {eOver()});
       GEvent.addDomListener(elem, "mouseout",  function() {eOut()});
   }
}

// event handlers
KMPolyline.prototype.onClick = function() {GEvent.trigger(this, "click")}
KMPolyline.prototype.onOver  = function() {GEvent.trigger(this, "mouseover")}
KMPolyline.prototype.onOut   = function() {GEvent.trigger(this, "mouseout")}

// getX functions
KMPolyline.prototype.getDash   = function() {return this.dash}
KMPolyline.prototype.getWeight = function() {return this.weight}
KMPolyline.prototype.getColor  = function() {return this.color}

// setX functions
KMPolyline.prototype.setDash = function(dash)
{
    this.dash = dash;

    var elem = $(this.elemId);

    if (!elem) return;

    if (this.usesVml) {
        switch (this.dash) {
            case "dash" : elem.stroke.dashstyle = "dash";
                break;
            case "dot"  : elem.stroke.dashstyle = "dot";
                break;
            default     : elem.stroke.dashstyle = "";
        }
    } else {
        switch (this.dash) {
            case "dash" : Element.writeAttribute(elem, "stroke-dasharray", "10,10");
                break;
            case "dot"  : Element.writeAttribute(elem, "stroke-dasharray", "3,17");
                break;
            default     : Element.writeAttribute(elem, "stroke-dasharray", null); // remove attribute
        }
    }
}

KMPolyline.prototype.setWeight = function(weight)
{
    this.weight = weight;

    var elem = $(this.elemId);

    if (!elem) return;

    if (this.usesVml) {
        elem.stroke.weight = this.weight.toString() + "px";
    } else {
        Element.writeAttribute(elem, "stroke-width", this.weight.toString() + "px");
    }
}

KMPolyline.prototype.setColor = function(color)
{
    this.color = color;

    var elem = $(this.elemId);

    if (!elem) return;

    if (this.usesVml) {
        elem.stroke.color = this.color;
    } else {
        Element.writeAttribute(elem, "stroke", this.color);
    }
}