Add ol.control.MouseWheelZoom

2012-07-18 14:07:59 +02:00
parent c6343ed2bc
commit 4754ed1cc2
4 changed files with 51 additions and 0 deletions
@@ -0,0 +1,39 @@
+goog.provide('ol.control.MouseWheelZoom');
+
+goog.require('goog.events.MouseWheelEvent');
+goog.require('goog.events.MouseWheelHandler.EventType');
+goog.require('ol.MapBrowserEvent');
+
+
+
+/**
+ * @constructor
+ * @extends {ol.Control}
+ */
+ol.control.MouseWheelZoom = function() {
+  goog.base(this);
+};
+goog.inherits(ol.control.MouseWheelZoom, ol.Control);
+
+
+/**
+ * @inheritDoc
+ */
+ol.control.MouseWheelZoom.prototype.handleMapBrowserEvent = function(event) {
+  if (event.type == goog.events.MouseWheelHandler.EventType.MOUSEWHEEL) {
+    var map = event.map;
+    var mouseWheelEvent = /** @type {goog.events.MouseWheelEvent} */
+        event.getBrowserEventObject();
+    goog.asserts.assert(mouseWheelEvent instanceof goog.events.MouseWheelEvent);
+    if (mouseWheelEvent.deltaY !== 0) {
+      map.whileFrozen(function() {
+        // FIXME compute correct center for zoom
+        map.setCenter(event.getCoordinate());
+        var scale = mouseWheelEvent.deltaY < 0 ? 0.5 : 2;
+        map.setResolution(scale * map.getResolution());
+      });
+      event.preventDefault();
+      mouseWheelEvent.preventDefault();
+    }
+  }
+};