利用iOS的本机指南针设备方向的Google Maps API

Question

If you open up Maps on the iPad and click the location arrow twice. You will notice that the map will rotate depending on the device's orientation. This is what I want my application's map to do in my iOS Native Web Application. It's a Google Maps mashup using iOS's Native Compass to point in the direction that I turn. I'm needing this to be done specifically with Javascript. If anyone can point me in the right direction I would really appreciate it.

Answer 1

Though this is technically possible by injecting javascript into a UIWebView , rotation of the map itself can be tricky.

I used to have a web app that I wrapped inside a UIWebView for a native iOS version. The only difference in the iOS version was that I tapped into the CLLocationManager to get heading from the iOS device, and then injected some javascript on each heading update which the webpage responded to be substituting one of 36 arrow icons (one for every 10 degrees) showing the user's current direction. Check out stringByEvaluatingJavascriptFromString on UIWebView .

When I did it, I only modified the user's current location icon though, rather than rotating the entire map. I do remember experimenting with rotation the entire map, but had issues where as soon as you rotate the map rectangle, you end up with white triangular areas on the screen that the map no longer covers. It should be possible somehow to oversize the map so that it bleeds off the screen when straight to an extent that it still covers the entire screen regardless of its rotation. I don't know whether this would mess with other aspects of Google Maps though.