Android Application Development Cookbook: 93 Recipes for Building Winning Apps

Recipe 7.2 Zooming in and out of Google Maps

Android Versions

Level 1 and above

Permissions

android.permission.INTERNET

Source Code to Download from Wrox.com

Maps-Zoom.zip

You want to zoom in and out of Google Maps.

Solution

To zoom in and out of Google Maps, you have three options:

• Pinch the map directly on the device. This option is only available on real devices, as the Android emulator does not support multi-touch.
• Display the zoom controls on the map so that the user can tap (or click on the emulator) on the zoom controls to zoom in or out of the map.
• Programmatically zoom in or out of the map.

To display the zoom control, you first get an instance of the MapView on your activity’s UI, like this:

package net.learn2develop.maps;

import android.os.Bundle;

import com.google.android.maps.MapActivity;
import com.google.android.maps.MapView;

public class MainActivity extends MapActivity {
    MapView mapView;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mapView = (MapView) findViewById(R.id.mapView);
        mapView.setBuiltInZoomControls(true);
    }

    @Override
    protected boolean isRouteDisplayed() {
        return false;
    }

}

You then call its setBuiltInZoomControls() method to display the zoom controls for the map. Figure 7-6 shows what the zoom controls look like.

Figure 7-6

NOTE The ...