Merge pull request #6682 from ahocevar/mouseweel-typedef

Add example, docs and typedef for MouseWheelZoom's constrainResolution option

examples/mousewheel-zoom.html

@@ -0,0 +1,12 @@
+---
+layout: example.html
+title: Mousewheel/Trackpad Zoom
+shortdesc: Restrict wheel/trackpad zooming to integer zoom levels.
+docs: >
+  By default, the `ol.interaction.MouseWheelZoom` can leave the map at
+  fractional zoom levels. If instead you want to constrain wheel/trackpad
+  zooming to integer zoom levels, set <code>constrainResolution: true</code>
+  when constructing the interaction.
+tags: "trackpad, mousewheel, zoom, interaction"
+---
+<div id="map" class="map"></div>

examples/mousewheel-zoom.js

@@ -0,0 +1,25 @@
+goog.require('ol.Map');
+goog.require('ol.View');
+goog.require('ol.interaction');
+goog.require('ol.interaction.MouseWheelZoom');
+goog.require('ol.layer.Tile');
+goog.require('ol.source.OSM');
+
+
+var map = new ol.Map({
+  interactions: ol.interaction.defaults({mouseWheelZoom: false}).extend([
+    new ol.interaction.MouseWheelZoom({
+      constrainResolution: true // force zooming to a integer zoom
+    })
+  ]),
+  layers: [
+    new ol.layer.Tile({
+      source: new ol.source.OSM()
+    })
+  ],
+  target: 'map',
+  view: new ol.View({
+    center: [0, 0],
+    zoom: 2
+  })
+});

externs/olx.js

@@ -3087,7 +3087,8 @@ olx.interaction.ModifyOptions.prototype.wrapX;
 
 
 /**
- * @typedef {{duration: (number|undefined),
+ * @typedef {{constrainResolution: (boolean|undefined),
+ *     duration: (number|undefined),
  *     timeout: (number|undefined),
  *     useAnchor: (boolean|undefined)}}
  */
@@ -3111,7 +3112,8 @@ olx.interaction.MouseWheelZoomOptions.prototype.timeout;
 
 
 /**
- * Zoom to the closest integer zoom level after trackpad zoom ends. Default is `false`.
+ * Zoom to the closest integer zoom level after the wheel/trackpad gesture ends.
+ * Default is `false`.
  * @type {boolean|undefined}
  * @api
  */