Add setStyle and getStyle to ol.Feature

As with vector layers and feature overlays, feature style can be set by calling
setStyle.  Calling getStyle returns what was passed to setStyle.  Internally, we call getStyleFunction.

src/ol/feature.exports

@@ -3,3 +3,5 @@
 @exportProperty ol.Feature.prototype.setGeometryName
 @exportProperty ol.Feature.prototype.getId
 @exportProperty ol.Feature.prototype.setId
+@exportProperty ol.Feature.prototype.getStyle
+@exportProperty ol.Feature.prototype.setStyle

src/ol/feature.js

@@ -34,6 +34,14 @@ ol.Feature = function(opt_geometryOrValues) {
    */
   this.geometryName_ = 'geometry';
 
+  /**
+   * User provided style.
+   * @private
+   * @type {ol.style.Style|Array.<ol.style.Style>|
+   *     ol.feature.FeatureStyleFunction}
+   */
+  this.style_ = null;
+
   /**
    * @private
    * @type {ol.feature.FeatureStyleFunction|undefined}
@@ -98,6 +106,16 @@ ol.Feature.prototype.getGeometryName = function() {
 };
 
 
+/**
+ * @return {ol.style.Style|Array.<ol.style.Style>|
+ *     ol.feature.FeatureStyleFunction} User provided style.
+ * @todo stability experimental
+ */
+ol.Feature.prototype.getStyle = function() {
+  return this.style_;
+};
+
+
 /**
  * @return {ol.feature.FeatureStyleFunction|undefined} Style function.
  * @todo stability experimental
@@ -146,12 +164,13 @@ goog.exportProperty(
 
 
 /**
- * @param {ol.feature.FeatureStyleFunction|undefined} styleFunction Style
- *     function.
+ * @param {ol.style.Style|Array.<ol.style.Style>|
+ *     ol.feature.FeatureStyleFunction} style Feature style.
  * @todo stability experimental
  */
-ol.Feature.prototype.setStyleFunction = function(styleFunction) {
-  this.styleFunction_ = styleFunction;
+ol.Feature.prototype.setStyle = function(style) {
+  this.style_ = style;
+  this.styleFunction_ = ol.feature.createFeatureStyleFunction(style);
   this.dispatchChangeEvent();
 };
 
@@ -219,6 +238,42 @@ ol.feature.defaultStyleFunction = function(feature, resolution) {
 };
 
 
+/**
+ * Convert the provided object into a feature style function.  Functions passed
+ * through unchanged.  Arrays of ol.style.Style or single style objects wrapped
+ * in a new feature style function.
+ * @param {ol.feature.FeatureStyleFunction|Array.<ol.style.Style>|
+ *     ol.style.Style} obj A feature style function, a single style, or an array
+ *     of styles.
+ * @return {ol.feature.FeatureStyleFunction} A style function.
+ */
+ol.feature.createFeatureStyleFunction = function(obj) {
+  /**
+   * @type {ol.feature.FeatureStyleFunction}
+   */
+  var styleFunction;
+
+  if (goog.isFunction(obj)) {
+    styleFunction = /** @type {ol.feature.FeatureStyleFunction} */ (obj);
+  } else {
+    /**
+     * @type {Array.<ol.style.Style>}
+     */
+    var styles;
+    if (goog.isArray(obj)) {
+      styles = obj;
+    } else {
+      goog.asserts.assertInstanceof(obj, ol.style.Style);
+      styles = [obj];
+    }
+    styleFunction = function(resolution) {
+      return styles;
+    };
+  }
+  return styleFunction;
+};
+
+
 /**
  * Convert the provided object into a style function.  Functions passed through
  * unchanged.  Arrays of ol.style.Style or single style objects wrapped in a

src/ol/format/kmlformat.js

@@ -1448,7 +1448,7 @@ ol.format.KML.prototype.readPlacemark_ = function(node, objectStack) {
   } else {
     featureStyleFunction = ol.format.KML.makeFeatureStyleFunction_(style);
   }
-  feature.setStyleFunction(featureStyleFunction);
+  feature.setStyle(featureStyleFunction);
   return feature;
 };