Fixed page scroll event not being blocked when moving around in Network using arrow keys

HISTORY.md

@@ -18,6 +18,8 @@ http://visjs.org
 - Fixed physics solving stopping when a support node was not moving.
 - Added localization support.
 - Implemented option `activatable`.
+- Fixed page scroll event not being blocked when moving around in Network
+  using arrow keys.
 
 ### Graph2D
 

lib/network/mixins/NavigationMixin.js

@@ -65,6 +65,7 @@ exports._stopMovement = function() {
 exports._moveUp = function(event) {
   this.yIncrement = this.constants.keyboard.speed.y;
   this.start(); // if there is no node movement, the calculation wont be done
+  event.preventDefault();
 };
 
 
@@ -75,6 +76,7 @@ exports._moveUp = function(event) {
 exports._moveDown = function(event) {
   this.yIncrement = -this.constants.keyboard.speed.y;
   this.start(); // if there is no node movement, the calculation wont be done
+  event.preventDefault();
 };
 
 
@@ -85,6 +87,7 @@ exports._moveDown = function(event) {
 exports._moveLeft = function(event) {
   this.xIncrement = this.constants.keyboard.speed.x;
   this.start(); // if there is no node movement, the calculation wont be done
+  event.preventDefault();
 };
 
 
@@ -95,6 +98,7 @@ exports._moveLeft = function(event) {
 exports._moveRight = function(event) {
   this.xIncrement = -this.constants.keyboard.speed.y;
   this.start(); // if there is no node movement, the calculation wont be done
+  event.preventDefault();
 };
 
 
@@ -105,6 +109,7 @@ exports._moveRight = function(event) {
 exports._zoomIn = function(event) {
   this.zoomIncrement = this.constants.keyboard.speed.zoom;
   this.start(); // if there is no node movement, the calculation wont be done
+  event.preventDefault();
 };
 
 
@@ -112,10 +117,10 @@ exports._zoomIn = function(event) {
  * Zoom out
  * @private
  */
-exports._zoomOut = function() {
+exports._zoomOut = function(event) {
   this.zoomIncrement = -this.constants.keyboard.speed.zoom;
   this.start(); // if there is no node movement, the calculation wont be done
-  util.preventDefault(event);
+  event.preventDefault();
 };
 
 
@@ -123,8 +128,9 @@ exports._zoomOut = function() {
  * Stop zooming and unhighlight the zoom controls
  * @private
  */
-exports._stopZoom = function() {
+exports._stopZoom = function(event) {
   this.zoomIncrement = 0;
+  event && event.preventDefault();
 };
 
 
@@ -132,8 +138,9 @@ exports._stopZoom = function() {
  * Stop moving in the Y direction and unHighlight the up and down
  * @private
  */
-exports._yStopMoving = function() {
+exports._yStopMoving = function(event) {
   this.yIncrement = 0;
+  event && event.preventDefault();
 };
 
 
@@ -141,6 +148,7 @@ exports._yStopMoving = function() {
  * Stop moving in the X direction and unHighlight left and right.
  * @private
  */
-exports._xStopMoving = function() {
+exports._xStopMoving = function(event) {
   this.xIncrement = 0;
+  event && event.preventDefault();
 };