Add insertVertexCondition to ol.interaction.Modify options

examples/modify-test.js

@@ -222,7 +222,13 @@ var select = new ol.interaction.Select({
 
 var modify = new ol.interaction.Modify({
   features: select.getFeatures(),
-  style: overlayStyle
+  style: overlayStyle,
+  insertVertexCondition: function() {
+    // prevent new vertices to be added to the polygons
+    return !this.features_.getArray().every(function(feature) {
+      return feature.getGeometry().getType().match(/Polygon/);
+    });
+  }
 });
 
 var map = new ol.Map({

externs/olx.js

@@ -3164,12 +3164,15 @@ olx.interaction.KeyboardZoomOptions.prototype.delta;
 
 
 /**
- * @typedef {{condition: (ol.EventsConditionType|undefined),
+ * @typedef {{
+ *     condition: (ol.EventsConditionType|undefined),
  *     deleteCondition: (ol.EventsConditionType|undefined),
+ *     insertVertexCondition: (ol.EventsConditionType|undefined),
  *     pixelTolerance: (number|undefined),
  *     style: (ol.style.Style|Array.<ol.style.Style>|ol.StyleFunction|undefined),
  *     features: ol.Collection.<ol.Feature>,
- *     wrapX: (boolean|undefined)}}
+ *     wrapX: (boolean|undefined)
+ * }}
  */
 olx.interaction.ModifyOptions;
 
@@ -3196,6 +3199,16 @@ olx.interaction.ModifyOptions.prototype.condition;
 olx.interaction.ModifyOptions.prototype.deleteCondition;
 
 
+/**
+ * A function that takes an {@link ol.MapBrowserEvent} and returns a boolean
+ * to indicate whether a new vertex can be added to the sketch features.
+ * Default is {@link ol.events.condition.always}
+ * @type {ol.EventsConditionType|undefined}
+ * @api
+ */
+olx.interaction.ModifyOptions.prototype.insertVertexCondition;
+
+
 /**
  * Pixel tolerance for considering the pointer close enough to a segment or
  * vertex for editing. Default is `10`.

src/ol/interaction/modify.js

@@ -67,6 +67,13 @@ ol.interaction.Modify = function(options) {
   this.deleteCondition_ = options.deleteCondition ?
       options.deleteCondition : this.defaultDeleteCondition_;
 
+  /**
+   * @type {ol.EventsConditionType}
+   * @private
+   */
+  this.insertVertexCondition_ = options.insertVertexCondition ?
+      options.insertVertexCondition : ol.events.condition.always;
+
   /**
    * Editing vertex.
    * @type {ol.Feature}
@@ -600,7 +607,7 @@ ol.interaction.Modify.handleDownEvent_ = function(evt) {
 
         this.dragSegments_.push([segmentDataMatch, 1]);
         componentSegments[uid][1] = segmentDataMatch;
-      } else if (ol.getUid(segment) in this.vertexSegments_ &&
+      } else if (this.insertVertexCondition_(evt) && ol.getUid(segment) in this.vertexSegments_ &&
           (!componentSegments[uid][0] && !componentSegments[uid][1])) {
         insertVertices.push([segmentDataMatch, vertex]);
       }

test/spec/ol/interaction/modify.test.js

@@ -559,6 +559,40 @@ describe('ol.interaction.Modify', function() {
     });
   });
 
+  describe('insertVertexCondition', function() {
+    it('calls the callback function', function() {
+      var listenerSpy = sinon.spy(function(event) {
+        return false;
+      });
+
+      var modify = new ol.interaction.Modify({
+        features: new ol.Collection(features),
+        insertVertexCondition: listenerSpy
+      });
+      map.addInteraction(modify);
+      var feature = features[0];
+
+      // move first vertex
+      simulateEvent('pointermove', 0, 0, false, 0);
+      simulateEvent('pointerdown', 0, 0, false, 0);
+      simulateEvent('pointermove', -10, -10, false, 0);
+      simulateEvent('pointerdrag', -10, -10, false, 0);
+      simulateEvent('pointerup', -10, -10, false, 0);
+
+      expect(listenerSpy.callCount).to.be(0);
+      expect(feature.getGeometry().getCoordinates()[0]).to.have.length(5);
+
+      // try to add vertex
+      simulateEvent('pointerdown', 40, -20, false, 0);
+      simulateEvent('pointerup', 40, -20, false, 0);
+      simulateEvent('click', 40, -20, false, 0);
+      simulateEvent('singleclick', 40, -20, false, 0);
+
+      expect(listenerSpy.callCount).to.be(1);
+      expect(feature.getGeometry().getCoordinates()[0]).to.have.length(5);
+    });
+  });
+
   describe('handle feature change', function() {
     var getListeners;