Tag Info

I can confirm that OL Canvas renderer redraws the whole layer when even a single feature needs to be redrawn. The exact point of the sources where this is implemented is this one in drawFeature. This has probably to do with the fact that the canvas is simply a bitmap so redrawing on top of it can produce artifacts if the new image is not perfectly placed on ...

I think the difference is likely due to the way that the Android phone with a GPS, and the iPhone using 3GS, are determining their location. I am not sure about all Android phones, but it is likely that they are all using similar GPS for location purposes. This could be verified if you provided the similar models that you tested with. Anyway, the point is ...

For the OpenLayers.Format.GeoJSON feature collection use an OpenLayers.Layer.Vector instance. Examples from the OpenLayers Examples Gallery: http://openlayers.org/dev/examples/geojson.html http://openlayers.org/dev/examples/vector-formats.html http://dev.openlayers.org/docs/files/OpenLayers/Layer/Vector-js.html Use a zoom based strategy for displaying ...

Did you do read the coordinates at the exact same time? Because if not, you should know that the location accuracy in these devices can be poor, certainly could be 20meters. That said, the location accuraccy and also your current location will change slightly over time if you stand on the same spot, because conditions such as gps signal quality change ...

OpenLayers doesn't have knowledge of what features might have interactions with other features on redraw. As a result, when selecting a feature, it is very likely that OpenLayers redraws all of the features. (For example, if you have multiple features stacked up, and redrew only one of them, you could get weird side effects where the drawing isn't the same ...

As @Sunil notes: for the tiles part, see the Tiles in local storage developer sample and for the feature layers see Local storage - experimental. Each sample is complete, in the sense that they're working demos, you'll still need to modify to suit your local circumstances.