Android: Numerous overlays slowing down map movement

Issue

I have numerous Overlays added to a MapView. When I move, zoom in, or zoom out of the MapView the overlays cause a significant lag before the map responds to the action. Is there any way I can minimize this delay?

I saw that someone else suggested combining all the overlays into one large overlay for a similar problem. If something like that would work, how would I combine my array of overlays into a single overlay?

I also saw that it may improve performance to draw all the lines specified in the overlays on a bitmap and then overlay the bitmap instead. If this is the best option, then how would I go about implementing it?

Any help would be greatly appreciated. If you need any more information or code, then please ask!

Solution

I have numerous Overlays added to a MapView. When I move, zoom in, or zoom out of the MapView the overlays cause a significant lag before the map responds to the action. Is there any way I can minimize this delay?

Have fewer and less-complicated overlays. Use Traceview to determine exactly where your problem is. If it is that one of your existing draw() methods is slow, you will need to fix that before worrying about combining overlays. If the excess time seems to be in overlay management in MapView, then consolidating your overlays into fewer overlays may have benefit.

how would I combine my array of overlays into a single overlay?

Refactor the code into a single overlay class. Beyond that, we cannot help you, since we do not know much of anything about your overlays, other than that they are "numerous".

If this is the best option, then how would I go about implementing it?

Create a bitmap-backed Canvas, draw your lines on it, then draw the resulting Bitmap in your overlay in draw(), I presume.

Answered By - CommonsWare