I'm trying to make a user controlled cross-layer animation in Leaflet. I have about 70 tileLayer.wms layers, that need to be preloaded on the map before animation can run.
The question is - is there a way to preload tiles before showing them? Ideally, I would like to have something like a progress bar, or a spinning clock icon, while this process takes place.
I don't know of any Leaflet-specific way to do this.
However, you could preload all images asynchronously and let the browser's cache handle everything for you.
All major JS libraries let you do asynchronous resource loading very easily, including binding the loads with whichever progress indicator you'd like. You'll just have to make sure your server is set up so that the images to load have proper Expires and Cache-control headers to leverage caching.
