Invoking a Built in Activity

In addition to the user defined activities, an android application contains a number of built-in activities such as browser, contacts, call_ dallier etc. In this part we are going to see how to call a built-in activity from your  own activity. Like the calling of user defined activities a built in activity is also called using the intent object. 

We will start with an example, for that create a new android project and named it as BuiltinApp. In this project the main.xml file contain two buttons, first one is for invoking the built-in activity browser and the other one is for dialing a particular number.

The main.xml file for the project is given below.

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

android:layout_width="fill_parent"

android:layout_height="fill_parent"

android:orientation="vertical" >

<TextView

 android:layout_width="fill_parent"

 android:layout_height="wrap_content"

 android:text="@string/hello" />

 <Button

 android:id="@+id/browser"

 android:layout_width="fill_parent"

 android:layout_height="wrap_content"

 android:text="Open Browser" />

<Button

 android:id="@+id/start_call"

 android:layout_width="fill_parent"

 android:layout_height="wrap_content"

 android:text="Make a Call" />

</LinearLayout>

The BuiltinAppActivity.java file is shown bellow.

package com.codeglympse;

import android.app.Activity;

import android.content.Intent;

import android.net.Uri;

import android.os.Bundle;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.Button;

public class BultinAppActivity extends Activity {

Button b1;

Button b2;

/** Called when the activity is first created. */

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.main);

b1 = (Button) findViewById(R.id.browser);

b2 = (Button) findViewById(R.id.start_call);

b1.setOnClickListener(new OnClickListener() 

{

@Override

public void onClick(View arg0) 

{

// TODO Auto-generated method stub

Intent i = new Intent(android.content.Intent.ACTION_VIEW,Uri.parse("http://www.google.com"));

startActivity(i);

}

});

b2.setOnClickListener(new OnClickListener()

 {

@Override

public void onClick(View v) {

// TODO Auto-generated method stub

Intent i = new Intent(android.content.Intent.ACTION_DIAL,Uri.parse("tel:+571894567"));

startActivity(i);

}

});

}

}

In the above example we call two built in activities, the  browser and dial. Here we also passing a data to the called activity by using the Uri.parse() method. That means here the intent object is an used as an action and data pair object.

Intent i = new Intent(android.content.Intent.ACTION_DIAL,Uri.parse("tel:+571894567"));

Intent i =new Intent(android.content.Intent.ACTION_VIEW,Uri.parse("http://www.google.com"));

For invoking the built in activities like browser, you have set the android permission in the androidmanifest.xml file.The permission is set within the <manifest>  </manifest> tag in AndroidManifest.xml file.

AndroidManifest,xml file is given bellow.

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.codeglympse"
    android:versionCode="1"
    android:versionName="1.0" >

 <uses-sdk android:minSdkVersion="8" />
 <application
   android:icon="@drawable/ic_launcher"
   android:label="@string/app_name" >
 <activity
   android:label="@string/app_name"
   android:name=".BultinAppActivity" >
 <intent-filter >
 <action android:name="android.intent.action.MAIN" />
 <category android:name="android.intent.category.LAUNCHER" />
 </intent-filter>
 </activity>
 </application>
<uses-permission android:name="android.permission.INTERNET" > </uses-permission>
<uses-permission android:name="android.permission.CALL_PHONE"> </uses-permission>
</manifest>

Output of the project is given bellow.