How To Make A Simple Phone Call Application

Following on from yesterday’s post about adding a text function to your app, this time is how to make a simple phone call application. Is that important? Yes, It is. Imagine, you're in danger, and you don't know what to do. So, what should you do? Call emergency number? Do you remember that number? Or, if you get accident, can you type the number correctly? It's a simple task. But it'll be easier and simpler if you can call a number with one touch. Let's see how to do that.


Create a new android project. First thing we should do is to add user permission in AndroidManifest.xml file so we can make a phone call using our app. See the highlighted code below:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
 package="com.blogspot.juniantr.phonecallsample" android:versionCode="1"
 android:versionName="1.0">
 <application android:icon="@drawable/icon" android:label="@string/app_name"
  android:debuggable="true">
  <activity android:name=".PhoneCallSampleAct" android:label="@string/app_name">
   <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.CALL_PHONE" />
</manifest>


Next, open the main.xml file and we'll change the user

<?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">
 <Button android:layout_height="wrap_content" android:text="@string/call"
  android:layout_width="wrap_content" android:id="@+id/btnCall"></Button>
</LinearLayout>


Open your activity java file (in my project, it's PhoneCallSampleAct.java) and add this code:

private void phoneCall()
{
   String phoneCallUri = "tel:911";
   Intent phoneCallIntent = new Intent(Intent.ACTION_CALL);
   phoneCallIntent.setData(Uri.parse(phoneCallUri));
   startActivity(phoneCallIntent);
}

Finally, let's add the last touch so the app can running. Our scenario is simple. We just need press the button and it'll call 911. Here is the complete code:

package com.blogspot.juniantr.phonecallsample;
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;
public class PhoneCallSampleAct extends Activity implements OnClickListener{
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
       
        View callButton = findViewById(R.id.btnCall);
        callButton.setOnClickListener(this);
    }
   
    private void phoneCall()
    {
     String phoneCallUri = "tel:911";
     Intent phoneCallIntent = new Intent(Intent.ACTION_CALL);
     phoneCallIntent.setData(Uri.parse(phoneCallUri));
     startActivity(phoneCallIntent);
    }
 @Override
 public void onClick(View v) {
  // TODO Auto-generated method stub
  switch(v.getId())
  {
   case R.id.btnCall:
    phoneCall();
    break;
   default:
    break;
  }
 }
}


Here is a running sample:

 

How to implement Sending a SMS Message from an Android Application

Introduction

We often come across situations where we are required to send a text message from our Android app. In this article we will explore all possible ways to achieve this simple yet very useful task.

Background

There are two possible ways to send a text message from an Android app
1. The first way is to send it programmatically from your application.
2. The second way is to send it by invoking the built-in SMS application.
In this article we will explore both the scenarios one by one.

* If you are new to Android app development, do refer to the Demo Project section of this article for some useful tips.

1. Sending a SMS programmatically from your application

Include the following permission in your AndroidManifest.xml file -

 

<uses-permission android:name="android.permission.SEND_SMS" />

Import the package -

import android.telephony.SmsManager;

Code to send a SMS -

 

public void sendSMS() {
    String phoneNumber = "0123456789";
    String message = "Hello World!";

    SmsManager smsManager = SmsManager.getDefault();
    smsManager.sendTextMessage(phoneNumber, null, message, null, null);
}

The method sendTextMessage of class SmsManager sends a text based SMS.





Method Detail

 

public void sendTextMessage(String destinationAddress, String scAddress, String text, PendingIntent sentIntent, PendingIntent deliveryIntent)

Details about the parameters that the method accepts can be found here.
If you use the code above you will able to send messages with length less than or equal to 160 characters only.

Code to send a long SMS -

public void sendLongSMS() {
 
    String phoneNumber = "0123456789";
    String message = "Hello World! Now we are going to demonstrate " + 
            "how to send a message with more than 160 characters from your Android application.";

    SmsManager smsManager = SmsManager.getDefault();
    ArrayList<String> parts = smsManager.divideMessage(message); 
    smsManager.sendMultipartTextMessage(phoneNumber, null, parts, null, null);
}

The method sendMultipartTextMessage of class SmsManager sends a multi-part text based SMS


Method Detail

public void sendMultipartTextMessage(String destinationAddress, String scAddress, ArrayList<String> parts, ArrayList<PendingIntent> sentIntents, ArrayList<PendingIntent> deliveryIntents)

Details about the parameters that the method accepts can be found here



Note
The method divideMessage of class SmsManager divides the message text into several smaller fragments of size 160 characters or less.

* Refer to the Points of Interest section of this article for a useful tip.

2. Send a SMS by invoking the built-in SMS application using Intents.

To invoke the SMS application via intents we have to do the following:
- Set the action to ACTION_VIEW
- Set the mime type to vnd.android-dir/mms-sms
- Add the text to send by adding an extra String with the key sms_body
- Add the phone number of the recipient to whom you wish to send the message by adding an extra String with the key address
Note:
- The last two steps are optional, if you don't wish to specify the message text or the recipients you can ignore these steps.
- If you wish to set multiple recipients use semi-colon ';' as the separator in the string passed as theaddress

Code to send a SMS using Intents

    
public void invokeSMSApp() {
        Intent smsIntent = new Intent(Intent.ACTION_VIEW);

        smsIntent.putExtra("sms_body", "Hello World!"); 
        smsIntent.putExtra("address", "0123456789");
        smsIntent.setType("vnd.android-dir/mms-sms");

        startActivity(smsIntent);
}

Points of Interest

If you choose to send messages programmatically and wish to add the message sent from your application in the native 'Messages' application of Android in the 'Sent' folder, here is the code to achieve it using Content providers -

Code to save a SMS in 'Sent' folder of native 'Messages' application

Include the following permission in your AndroidManifest.xml file -

 

<uses-permission android:name="android.permission.WRITE_SMS" />
<uses-permission android:name="android.permission.READ_SMS" />

You will have to add both WRITE_SMS and READ_SMS permissions.

Add the following imports -

 

    import android.net.Uri;
    import android.content.ContentValues;

Insert the below code where you wish to perform the operation -

    ContentValues values = new ContentValues(); 
              
    values.put("address", "0123456789"); 
              
    values.put("body", "Hello World!"); 
              
    getContentResolver().insert(Uri.parse("content://sms/sent"), values);

Demo Project

This is a demo project which implements all the scenarios as discussed in this article.

It has used EditText widget for the Phone Number and Message input. Here I'd like to mention twoXML attributes that I have used -

• android:hint This string is displayed as a hint to the user when the field is empty. This will give your application a more native look and feel.
• android:inputType="phone" (for Phone Number field) This signals the input method (IME) that this field should accept only valid Phone Numbers. This will save you from validating user input.

Which way to go....

Both the ways have their own set of pros and cons. If you decide to use Intents to send text messages from your application then no additional permissions are required but it will become a two step process, for instance if the user presses any button in your app to send SMS the intent will be displayed where he/she will have to press send; whereas if you decide to do it programitically you might also have to check for the result.