My app needs to show Google Maps directions from A to B, but I don't want to put the Google Maps into my application - instead, I want to launch it using an Intent. Is this possible? If yes, how?
You could use something like this:
Intent intent = new Intent(android.content.Intent.ACTION_VIEW,
Uri.parse("http://maps.google.com/maps?saddr=20.344,34.34&daddr=20.5666,45.345"));
startActivity(intent);
To start the navigation from the current location, remove the saddr
parameter and value.
You can use an actual street address instead of latitude and longitude. However this will give the user a dialog to choose between opening it via browser or Google Maps.
This will fire up Google Maps in navigation mode directly:
Intent intent = new Intent(android.content.Intent.ACTION_VIEW,
Uri.parse("google.navigation:q=an+address+city"));
UPDATE
In May 2017 Google launched the new API for universal, cross-platform Google Maps URLs:
https://developers.google.com/maps/documentation/urls/guide
You can use Intents with the new API as well.