Line Dash offset

src/ol/style/stroke.js

@@ -36,6 +36,12 @@ ol.style.Stroke = function(opt_options) {
    */
   this.lineDash_ = options.lineDash !== undefined ? options.lineDash : null;
 
+  /**
+   * @private
+   * @type {number|undefined}
+   */
+  this.lineDashOffset_ = options.lineDashOffset;
+
   /**
    * @private
    * @type {string|undefined}
@@ -73,6 +79,7 @@ ol.style.Stroke.prototype.clone = function() {
     color: (color && color.slice) ? color.slice() : color || undefined,
     lineCap: this.getLineCap(),
     lineDash: this.getLineDash() ? this.getLineDash().slice() : undefined,
+    lineDashOffset: this.getLineDashOffset(),
     lineJoin: this.getLineJoin(),
     miterLimit: this.getMiterLimit(),
     width: this.getWidth()
@@ -110,6 +117,16 @@ ol.style.Stroke.prototype.getLineDash = function() {
 };
 
 
+/**
+ * Get the line dash offset for the stroke.
+ * @return {number|undefined} Line dash offset.
+ * @api
+ */
+ol.style.Stroke.prototype.getLineDashOffset = function() {
+  return this.lineDashOffset_;
+};
+
+
 /**
  * Get the line join type for the stroke.
  * @return {string|undefined} Line join.
@@ -182,6 +199,18 @@ ol.style.Stroke.prototype.setLineDash = function(lineDash) {
 };
 
 
+/**
+ * Set the line dash offset.
+ *
+ * @param {number|undefined} lineDashOffset Line dash offset.
+ * @api
+ */
+ol.style.Stroke.prototype.setLineDashOffset = function(lineDashOffset) {
+  this.lineDashOffset_ = lineDashOffset;
+  this.checksum_ = undefined;
+};
+
+
 /**
  * Set the line join.
  *
@@ -238,6 +267,8 @@ ol.style.Stroke.prototype.getChecksum = function() {
             this.lineCap_.toString() : '-') + ',' +
         (this.lineDash_ ?
             this.lineDash_.toString() : '-') + ',' +
+        (this.lineDashOffset_ !== undefined ?
+            this.lineDashOffset_ : '-') + ',' +
         (this.lineJoin_ !== undefined ?
             this.lineJoin_ : '-') + ',' +
         (this.miterLimit_ !== undefined ?