Merge pull request #2975 from fredj/mouseevent-offset

Use offsetX and offsetY if available

src/ol/control/mousepositioncontrol.js

@@ -6,7 +6,6 @@ goog.require('goog.dom');
 goog.require('goog.dom.TagName');
 goog.require('goog.events');
 goog.require('goog.events.EventType');
-goog.require('goog.style');
 goog.require('ol.CoordinateFormatType');
 goog.require('ol.Object');
 goog.require('ol.Pixel');
@@ -162,9 +161,7 @@ goog.exportProperty(
  */
 ol.control.MousePosition.prototype.handleMouseMove = function(browserEvent) {
   var map = this.getMap();
-  var eventPosition = goog.style.getRelativePosition(
+  this.lastMouseMovePixel_ = map.getEventPixel(browserEvent.getBrowserEvent());
-      browserEvent, map.getViewport());
-  this.lastMouseMovePixel_ = [eventPosition.x, eventPosition.y];
   this.updateHTML_(this.lastMouseMovePixel_);
 };
 

src/ol/map.js

@@ -592,18 +592,25 @@ ol.Map.prototype.getEventCoordinate = function(event) {
 
 
 /**
- * Returns the map pixel position for a browser event.
+ * Returns the map pixel position for a browser event relative to the viewport.
  * @param {Event} event Event.
  * @return {ol.Pixel} Pixel.
  * @api stable
  */
 ol.Map.prototype.getEventPixel = function(event) {
-  // goog.style.getRelativePosition is based on event.targetTouches,
+  // Use the offsetX and offsetY values if available.
-  // but touchend and touchcancel events have no targetTouches when
+  // See http://www.w3.org/TR/cssom-view/#dom-mouseevent-offsetx and
-  // the last finger is removed from the screen.
+  // http://www.w3.org/TR/cssom-view/#dom-mouseevent-offsety
-  // So we ourselves compute the position of touch events.
+  if (goog.isDef(event.offsetX) && goog.isDef(event.offsetY)) {
-  // See https://github.com/google/closure-library/pull/323
+    return [event.offsetX, event.offsetY];
-  if (goog.isDef(event.changedTouches)) {
+  } else if (goog.isDef(event.changedTouches)) {
+    // offsetX and offsetY are not defined for Touch Event
+    //
+    // goog.style.getRelativePosition is based on event.targetTouches,
+    // but touchend and touchcancel events have no targetTouches when
+    // the last finger is removed from the screen.
+    // So we ourselves compute the position of touch events.
+    // See https://github.com/google/closure-library/pull/323
     var touch = event.changedTouches[0];
     var viewportPosition = goog.style.getClientPosition(this.viewport_);
     return [
@@ -611,6 +618,8 @@ ol.Map.prototype.getEventPixel = function(event) {
       touch.clientY - viewportPosition.y
     ];
   } else {
+    // Compute offsetX and offsetY values for browsers that don't implement
+    // cssom-view specification
     var eventPosition = goog.style.getRelativePosition(event, this.viewport_);
     return [eventPosition.x, eventPosition.y];
   }