Android Google map with inset overview when zoomed in

Question

I am developing an android application using Google maps with clustering of markers. The application works fine however once you zoom into a specific area and all the clusters expand to individual markers I would like to also show a small view that represents the entire map, where you are, and where all the markers are, to enable the user to navigate round the map while zoomed in. Ive Googled and searched SO, but not found anything. Is there any "off the shelf" solution? Or am I going to have to code this all myself? The type of solution I am looking for is the type of small window that many games use to show an overview of where the player is and all the points of interest are within the current level.

Answer 1

I haven't seen any "off the shelf" solutions, but here is what I would do here:

1) Create an additional fragment of the map. Place it in one of corners like games do

2) Here is where all the magic should happen. You need to synchronize these 2 maps. Map's Projection lets you to translate geo coordinates into XY coordinates within the view. That's being said you can get lat/lng of your top-left and bottom-right corners on the main map and translate these 2 corners into top-left and bottom-right XY coordinates of the mini-map's view. Now, when you have XY coordinates, the only thing you need to do - is to draw a rect on top of the mini map.

There is even easier and more native solution - since you have top-left and bottom-right lat/lng coordinates - you can draw a set of polylines on a minimap to get a rect. But in this case it will be hard to move it around (with your finger) in case you want to change current main map location using mini-map