Add ol.render.FeaturesOverlay

src/ol/render/featuresoverlay.js

@@ -0,0 +1,199 @@
+goog.provide('ol.render.FeaturesOverlay');
+
+goog.require('goog.array');
+goog.require('goog.asserts');
+goog.require('goog.events');
+goog.require('goog.events.EventType');
+goog.require('goog.object');
+goog.require('ol.Collection');
+goog.require('ol.CollectionEventType');
+goog.require('ol.Feature');
+goog.require('ol.render.EventType');
+goog.require('ol.style.StyleFunction');
+
+
+
+/**
+ * @constructor
+ */
+ol.render.FeaturesOverlay = function() {
+
+  /**
+   * @private
+   * @type {ol.Collection}
+   */
+  this.features_ = null;
+
+  /**
+   * @private
+   * @type {Array.<goog.events.Key>}
+   */
+  this.featuresListenerKeys_ = null;
+
+  /**
+   * @private
+   * @type {Object.<string, goog.events.Key>}
+   */
+  this.featureChangeListenerKeys_ = null;
+
+  /**
+   * @private
+   * @type {ol.Map}
+   */
+  this.map_ = null;
+
+  /**
+   * @private
+   * @type {goog.events.Key}
+   */
+  this.postComposeListenerKey_ = null;
+
+  /**
+   * @private
+   * @type {ol.style.StyleFunction|undefined}
+   */
+  this.styleFunction_ = undefined;
+
+};
+
+
+/**
+ * @return {ol.Collection} Features collection.
+ */
+ol.render.FeaturesOverlay.prototype.getFeatures = function() {
+  return this.features_;
+};
+
+
+/**
+ * @private
+ */
+ol.render.FeaturesOverlay.prototype.handleFeatureChange_ = function() {
+  this.requestRenderFrame_();
+};
+
+
+/**
+ * @private
+ * @param {ol.CollectionEvent} collectionEvent Collection event.
+ */
+ol.render.FeaturesOverlay.prototype.handleFeaturesAdd_ =
+    function(collectionEvent) {
+  goog.asserts.assert(!goog.isNull(this.featureChangeListenerKeys_));
+  var feature = /** @type {ol.Feature} */ (collectionEvent.getElement());
+  this.featureChangeListenerKeys_[goog.getUid(feature).toString()] =
+      goog.events.listen(feature, goog.events.EventType.CHANGE,
+      this.handleFeatureChange_, false, this);
+  this.requestRenderFrame_();
+};
+
+
+/**
+ * @private
+ * @param {ol.CollectionEvent} collectionEvent Collection event.
+ */
+ol.render.FeaturesOverlay.prototype.handleFeaturesRemove_ =
+    function(collectionEvent) {
+  goog.asserts.assert(!goog.isNull(this.featureChangeListenerKeys_));
+  var feature = /** @type {ol.Feature} */ (collectionEvent.getElement());
+  var key = goog.getUid(feature).toString();
+  goog.events.unlistenByKey(this.featureChangeListenerKeys_[key]);
+  delete this.featureChangeListenerKeys_[key];
+  this.requestRenderFrame_();
+};
+
+
+/**
+ * @param {ol.render.Event} event Event.
+ * @private
+ */
+ol.render.FeaturesOverlay.prototype.handleMapPostCompose_ = function(event) {
+  if (goog.isNull(this.features_) || !goog.isDef(this.styleFunction_)) {
+    return;
+  }
+  var resolution = event.getFrameState().view2DState.resolution;
+  var render = event.getRender();
+  var i, ii, feature, styles;
+  this.features_.forEach(function(feature) {
+    styles = this.styleFunction_(feature, resolution);
+    ii = styles.length;
+    for (i = 0; i < ii; ++i) {
+      render.drawFeature(feature, styles[i]);
+    }
+  }, this);
+};
+
+
+/**
+ * @private
+ */
+ol.render.FeaturesOverlay.prototype.requestRenderFrame_ = function() {
+  if (!goog.isNull(this.map_)) {
+    this.map_.requestRenderFrame();
+  }
+};
+
+
+/**
+ * @param {ol.Collection} features Features collection.
+ */
+ol.render.FeaturesOverlay.prototype.setFeatures = function(features) {
+  if (!goog.isNull(this.featuresListenerKeys_)) {
+    goog.array.forEach(this.featuresListenerKeys_, goog.events.unlistenByKey);
+    this.featuresListenerKeys_ = null;
+  }
+  if (!goog.isNull(this.featureChangeListenerKeys_)) {
+    goog.array.forEach(
+        goog.object.getValues(this.featureChangeListenerKeys_),
+        goog.events.unlistenByKey);
+    this.featureChangeListenerKeys_ = null;
+  }
+  this.features_ = features;
+  if (!goog.isNull(features)) {
+    this.featuresListenerKeys_ = [
+      goog.events.listen(features, ol.CollectionEventType.ADD,
+          this.handleFeaturesAdd_, false, this),
+      goog.events.listen(features, ol.CollectionEventType.REMOVE,
+          this.handleFeaturesRemove_, false, this)
+    ];
+    this.featureChangeListenerKeys_ = {};
+    var featuresArray = features.getArray();
+    var i, ii = featuresArray.length;
+    var feature;
+    for (i = 0; i < ii; ++i) {
+      feature = featuresArray[i];
+      this.featureChangeListenerKeys_[goog.getUid(feature).toString()] =
+          goog.events.listen(feature, goog.events.EventType.CHANGE,
+          this.handleFeatureChange_, false, this);
+    }
+  }
+  this.requestRenderFrame_();
+};
+
+
+/**
+ * @param {ol.Map} map Map.
+ */
+ol.render.FeaturesOverlay.prototype.setMap = function(map) {
+  if (!goog.isNull(this.postComposeListenerKey_)) {
+    goog.events.unlistenByKey(this.postComposeListenerKey_);
+    this.postComposeListenerKey_ = null;
+  }
+  this.requestRenderFrame_();
+  this.map_ = map;
+  if (!goog.isNull(map)) {
+    this.postComposeListenerKey_ = goog.events.listen(
+        map, ol.render.EventType.POSTCOMPOSE, this.handleMapPostCompose_, false,
+        this);
+    map.requestRenderFrame();
+  }
+};
+
+
+/**
+ * @param {ol.style.StyleFunction} styleFunction Style function.
+ */
+ol.render.FeaturesOverlay.prototype.setStyleFunction = function(styleFunction) {
+  this.styleFunction_ = styleFunction;
+  this.requestRenderFrame_();
+};