[GIS] `change:center` event not fired on drag animation

eventsopenlayers

I'm quite new in OpenLayers, and I want to act when the map is moved.

So simply listening to the change:center event of the map's view:

map.getView().on('change:center', function(evt){
   console.log(map.getView().getCenter());
}

But I've noticed the event is not fired after we finish the map panning with the mouse – and the map is still moving and slowing down until it stops completely.

Is there another way to know when the map extent is changed?

Best Answer

The moveend event on the Map instance should do what you need: http://openlayers.org/en/v3.4.0/apidoc/ol.MapEvent.html?unstable=true#event:moveend

Related Solutions

OpenLayers – Trigger Event Once Layer is Loaded

Currently, OpenLayers 3 doesn't provide a mechanism to know when sources/layers are loaded. This is planned, but not yet implemented.

In the mean time, you can use your own imageLoadFunction. In your case:

 var source = new ol.source.ImageStatic({
   url: '../cartes/img/' + newMapFileName,
   imageSize: [width, height],
   projection: pixelProjection,
   imageExtent: pixelProjection.getExtent(),
   imageLoadFunction: function(image, src) {
     var imageElement = image.getImage();
     imageElement.onload = function() {
       console.log('loaded');
     };
     imageElement.src = src;
   }
  });

I've never used this myself, and I'm hoping it works.

Note that a similar technique can also be used for tile sources. See this post on the OpenLayers 3 mailing list.

[GIS] Does an event get fired after a Layer has finished rendering in Openlayers 3

I found another question (register event "loadend" on layer) with one answer which lead me to the right event:

vectorLayer.on('postcompose', function(event) {
    if (vectorLayer.getVisible()) {
         doSomething();   
    }
});

The method doSomething(); is now called when the corresponding vector layer was completely rendered on the Canvas.

Best Answer

Related Solutions

OpenLayers – Trigger Event Once Layer is Loaded

[GIS] Does an event get fired after a Layer has finished rendering in Openlayers 3

Related Question