HI all,
 
I am new to GIS and specifically openlayers.
 
I have a fairly simple WMS app built on openlayers.
However due to performance I would like to make things seem as if they are 
performing faster. At the moment we have a tiled layer, and a single none tiled 
layer. The single layer is loaded first, then we catch a "moveend" then switch 
the base layer to a tiled one.
 
The initial load is quite quick but then switching to the tiled layer can take 
some time to satisfy the plethora of requests fired out.
 
What I would like to do is, show the single layer first, then in the back 
ground immediately fire off the requests for the tiled layer (without 
displaying it). When they scroll I would like to switch to the tiled layer, 
which should have hopefully started loading at this point.
 
When they change zoom , i would like to switch back to the single layer (as I 
think this gives the users something to look at the fastest) then again kick of 
the tiled layer to load in the background.
 
Is this a feasible and reasonable thing to want to achieve? At the moment I am 
using a movestart event to change the baselayer hopefully before a zoom. I am 
comparing the last zoom level with the current one to ascertain whether its 
been zoomed or not. So,is there anyway to start a tiled layer loading in the 
background? Is there anyway for a tiled layer to request the visible tiles 
first?  Whats the best way of controlling a switch between a single layer and a 
tiled layer (we can get quite a large tile for the single layer and dont want 
to switch immediately)?
 
Sorry for all the questions, it probably just demonstrated my lack of 
understanding.
 
Any advice greatly appreciated.
 
Thanks
 
Norman
 
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