MAPS IN ANDROID

By- Sumita Das

Created by Sumita Das

Android allows us to integrate Google maps in our application.

Customize the map according to your choices.

Introduction

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Several classes that are used to support Android maps:

MapView: User interface element that displays the map.

MapActivity: Base class used to create an Activity that can include

a Map View.

Overlay: Class used to annotate your maps

MapController: Used to control the map, and enables the user to set

the center location and zoom levels.

MyLocationOverlay: Can be used to display the current position

and orientation of the device.

Introducing Map View and Map Activity

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Obtain an API key from the Android developer website at

http://code.google.com/android/maps-api-signup.html.

To obtain a key, you need to specify the MD5 fingerprint of

the certificate used to sign your application. .

Getting Your Maps API Key

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To use maps- extend MapActivity.

The layout for the new class must then include a MapView to display a Google Maps interface element.

Android maps library - optional API. So it must be explicitly included in the application manifest

before it can be used.

Creating a Map-Based Activity

<uses-library android:name=”com.google.android.maps”/>

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Map View :-Downloads its map tiles on demand- Any application that features a Map View needs to include a

uses-permission for Internet access.

Add a uses-permission tag to your application manifest for INTERNET, as shown here:

After adding the library and configuring your permission, you’re ready to create your new map-based Activity.

Creating a Map-Based Activity

<uses-permission android:name=”android.permission.INTERNET”/>

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A map Activity layout resource<?xml version=”1.0” encoding=”utf-8”?> <LinearLayout xmlns:android=”http://schemas.android.com/apk/res/android” android:orientation=”vertical” android:layout_width=”fill_parent” android:layout_height=”fill_parent”> <com.google.android.maps.MapView android:id=”@+id/map_view” android:layout_width=”fill_parent” android:layout_height=”fill_parent” android:enabled=”true” android:clickable=”true” android:apiKey=”mymapapikey”/></LinearLayout>

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Framework for creating a new map-based Activity.

import com.google.android.maps.MapActivity; // import classesimport com.google.android.maps.MapController; import com.google.android.maps.MapView;import android.os.Bundle; public class MyMapActivity extends MapActivity {private MapView mapView;private MapController mapController;@Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.map_layout); mapView = (MapView)findViewById(R.id.map_view);}@Override protected boolean isRouteDisplayed() {// IMPORTANT: This method must return true if your Activity is displaying driving directions. Otherwise return false. return false;}}

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Example of a basic map-based Activity

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1. To display a satellite view and the expected traffic overlay:

mapView.setSatellite(true);mapView.setTraffic(true);

2. To find the current and maximum available zoom levels:

int maxZoom = mapView.getMaxZoomLevel();int currentZoom = mapView.getZoomLevel();

Configuring and Using Map Views

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3. To obtain center point and currently visible longitude and latitude span (in decimal degrees).

GeoPoint center = mapView.getMapCenter();int latSpan = mapView.getLatitudeSpan();int longSpan = mapView.getLongitudeSpan();

Created by Sumita Das

[1]Wei-Meng Lee, “Beginning Android Application Development”, Wiley Publishing Inc.