MainActivity.java

package com.nitinranjan.callingapp;

import android.app.Activity;
import android.content.Intent;
import android.net.Uri;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.EditText;


public class MainActivity extends Activity {
    EditText call_number;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        call_number = (EditText)findViewById(R.id.number_edit);
        }



    //************ this function is called when any button is prased in our activity****************
    public void input(View view){
        switch (view.getId()){
            case R.id.text_0:
                call_number.setText(call_number.getText().toString() + '0');
                break;
            case R.id.text_1:
                call_number.setText(call_number.getText().toString()+'1');
                break;
            case R.id.text_2:
                call_number.setText(call_number.getText().toString()+'2');
                break;
            case R.id.text_3:
                call_number.setText(call_number.getText().toString()+'3');
                break;
            case R.id.text_4:
                call_number.setText(call_number.getText().toString()+'4');
                break;
            case R.id.text_5:
                call_number.setText(call_number.getText().toString()+'5');
                break;
            case R.id.text_6:
                call_number.setText(call_number.getText().toString()+'6');
                break;
            case R.id.text_7:
                call_number.setText(call_number.getText().toString()+'7');
                break;
            case R.id.text_8:
                call_number.setText(call_number.getText().toString()+'8');
                break;
            case R.id.text_9:
                call_number.setText(call_number.getText().toString()+'9');
                break;
            case R.id.text_cross:
                call_number.setText(call_number.getText().toString()+"*");
                break;
            case R.id.text_backspace:
                String s =    call_number.getText().toString();
                if(s.length()>0)
                    s = s.subSequence(0,s.length()-1).toString();
                call_number.setText(s);
                break;
            case R.id.text_CALL:
                String number =    call_number.getText().toString();
                Intent intent=new Intent(Intent.ACTION_CALL); //making intent for calling
                intent.setData(Uri.parse("tel:"+number));
                    startActivity(intent);
                break;
        }


    }



}