Add reminder to default Calender from our Application

MainActivity.java

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import android.app.Activity;
import android.app.AlarmManager;
import android.app.DatePickerDialog;
import android.app.Dialog;
import android.app.PendingIntent;
import android.app.TimePickerDialog;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.text.Editable;
import android.text.TextWatcher;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.DatePicker;
import android.widget.EditText;
import android.widget.TimePicker;
import android.widget.Toast;

/**
 * To display the given data as notification at particular date and time
 *
 * @author Harshal Kalavadiya
 */

public class TaskReminderActivity extends Activity {
    /** Called when the activity is first created. */

    private int mYear;
    private int mMonth;
    private int mDay;
    private int mHour;
    private int mMinute;
    static final int DATE_DIALOG_ID = 1;
    static final int TIME_DIALOG_ID = 0;
    private Calendar c;  
    private EditText nameEdit;
    private EditText descEdit;
    private Context mContext;  
    private boolean dateFlag = false;
    private boolean timeFlag = false;
    private String time;
    private String contentTitle;
    private String contentText;
    public static int notificationCount;
    public Button dateButton;
    public Button timeButton;
    public Button reminButton;
    public TextListener textListener;
 
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);      
        mContext = this;
        textListener = new TextListener();
        dateButton= (Button)findViewById(R.id.dateButton);
        timeButton= (Button)findViewById(R.id.timeButton);
        reminButton= (Button)findViewById(R.id.reminderButton);
        dateButton.setEnabled(false);
  timeButton.setEnabled(false);
  reminButton.setEnabled(false);
        nameEdit = (EditText)findViewById(R.id.nameEditText);
        nameEdit.addTextChangedListener(textListener);
        descEdit = (EditText)findViewById(R.id.DescEditText);
        descEdit.addTextChangedListener(textListener);  
        c = Calendar.getInstance();
        mYear = c.get(Calendar.YEAR);
        mMonth = c.get(Calendar.MONTH);
        mDay = c.get(Calendar.DAY_OF_MONTH);
        mHour = c.get(Calendar.HOUR_OF_DAY);
        mMinute = c.get(Calendar.MINUTE);
    }
 
    public class TextListener implements TextWatcher{

   @Override
  public void afterTextChanged(Editable s) {
   // TODO Auto-generated method stub
  }

   @Override
  public void beforeTextChanged(CharSequence s, int start, int count,
    int after) {
   // TODO Auto-generated method stub
  }

   @Override
  public void onTextChanged(CharSequence s, int start, int before,
    int count) {
   // TODO Auto-generated method stub
   if(descEdit.getText().length()==0 | nameEdit.getText().length()==0){
    dateButton.setEnabled(false);
    timeButton.setEnabled(false);
    reminButton.setEnabled(false);
   }
   else if(descEdit.getText().length()>0 & nameEdit.getText().length()>0){
    dateButton.setEnabled(true);
    timeButton.setEnabled(true);
    reminButton.setEnabled(true);
   }
  }  
    }
 
    public void onReminderClicked(View view){      
     if(dateFlag & timeFlag == true){
      notificationCount  = notificationCount+1;
      dateFlag = false;
      timeFlag = false;
      time = mYear+"-"+mMonth+"-"+mDay+" "+mHour+"-"+mMinute;                              
            SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd hh-mm");
            Date dt = null;
   try {
    dt = df.parse(time);
   } catch (ParseException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
   }                                      
            long when = dt.getTime();              
            contentTitle = nameEdit.getText().toString();
            contentText = descEdit.getText().toString();      
         AlarmManager mgr = (AlarmManager) mContext.getSystemService(Context.ALARM_SERVICE);
         Intent notificationIntent = new Intent(mContext, ReminderAlarm.class);
         notificationIntent.putExtra("Name",contentTitle );
            notificationIntent.putExtra("Description",contentText );
            notificationIntent.putExtra("NotifyCount",notificationCount );
         PendingIntent pi = PendingIntent.getBroadcast(mContext, notificationCount, notificationIntent, PendingIntent.FLAG_UPDATE_CURRENT);
         mgr.set(AlarmManager.RTC_WAKEUP,when, pi);
         Toast.makeText(mContext, "Your Reminder Activated", Toast.LENGTH_LONG).show();
            contentTitle = "";
         contentText = "";
         descEdit.setText("");
         nameEdit.setText("");
     }
     else if(dateFlag == false | timeFlag == false){
      Toast.makeText(mContext, "Please choose Date & Time", Toast.LENGTH_SHORT).show();
     }
    }
 
    public void onTimeClicked(View view){  
     showDialog(TIME_DIALOG_ID);
    }
    public void onDateClicked(View view){  
     showDialog(DATE_DIALOG_ID);  
    }
 
    @Override
    protected Dialog onCreateDialog(int id) {
     // TODO Auto-generated method stub
     switch (id) {
      case TIME_DIALOG_ID:
         return new TimePickerDialog(this,
              mTimeSetListener, mHour, mMinute, false);
      case DATE_DIALOG_ID:
          return new DatePickerDialog(this,
                      mDateSetListener,
                      mYear, mMonth, mDay);
      }
     return super.onCreateDialog(id);
    }
 
    private DatePickerDialog.OnDateSetListener mDateSetListener =
        new DatePickerDialog.OnDateSetListener() {
            public void onDateSet(DatePicker view, int year, int monthOfYear,
                    int dayOfMonth) {
                mYear = year;
                mMonth = monthOfYear+1;
                mDay = dayOfMonth;              
                dateFlag = true;
            }
    };
     
    private TimePickerDialog.OnTimeSetListener mTimeSetListener =
        new TimePickerDialog.OnTimeSetListener() {
            public void onTimeSet(TimePicker view, int hourOfDay, int minute) {
                mHour = hourOfDay;
                mMinute = minute;
                timeFlag = true;
            }
    };

}

ReminderAlarm.java

import android.app.Notification;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.widget.Toast;

/**
 * Trigger Status bar Notification alert at particular date and time
 *
 * @author Kumaresan Palanisamy
 */
public class ReminderAlarm  extends BroadcastReceiver{
 private NotificationManager mNotificationManager;
 private Notification notification;

  @Override
 public void onReceive(Context context, Intent intent) {
  // TODO Auto-generated method stub    
      mNotificationManager = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
      CharSequence from = intent.getStringExtra("Name");
      CharSequence message = intent.getStringExtra("Description");
      PendingIntent contentIntent = PendingIntent.getActivity(context, 0, new Intent(), 0);
      notification = new Notification(R.drawable.ic_launcher,"Notification", System.currentTimeMillis());
      notification.setLatestEventInfo(context, from, message, contentIntent);
      mNotificationManager.notify(Integer.parseInt(intent.getExtras().get("NotifyCount").toString()), notification);      
      Toast.makeText(context, "New Notification Received", Toast.LENGTH_LONG).show();
 }

}

main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical"    
     >
 <LinearLayout    
     android:layout_marginTop="20dp"
        android:layout_width="wrap_content"
       android:layout_height="wrap_content"
       android:id="@+id/nameLayout">
      <TextView
          android:layout_width="100dp"
          android:layout_height="wrap_content"
          android:text="@string/Name"/>  
      <EditText
          android:id="@+id/nameEditText"
          android:hint="Enter Name "              
          android:layout_height="45dp"        
          android:layout_width="200dp" />  
    </LinearLayout>  
 <LinearLayout  
     android:layout_marginTop="20dp"
        android:layout_width="wrap_content"
       android:layout_height="wrap_content"
       android:id="@+id/descLayout"
       android:layout_below="@id/nameLayout">
      <TextView
          android:layout_width="100dp"
          android:layout_height="wrap_content"
          android:text="@string/Desc"/>  
      <EditText
          android:id="@+id/DescEditText"
          android:hint="Enter Description"          
          android:layout_height="45dp"        
          android:layout_width="200dp" />  
    </LinearLayout>    
 <LinearLayout
     android:layout_marginTop="20dp"
     android:layout_width="fill_parent"
     android:layout_height="wrap_content"
     android:orientation="horizontal"
     android:layout_below="@id/descLayout"  
     android:gravity="center_horizontal"
     >  
  <Button
      android:id="@+id/dateButton"
      android:layout_width="100sp"
      android:layout_height="wrap_content"
      android:text="@string/Date"
      android:onClick="@string/DateClick"
      />
     <Button
         android:id="@+id/timeButton"
      android:layout_width="100sp"
       android:layout_height="wrap_content"
      android:text="@string/Time"
      android:onClick="@string/Timeclick"/>
     <Button
         android:id="@+id/reminderButton"
      android:layout_width="100sp"
      android:layout_height="wrap_content"
      android:text="@string/Reminder"
      android:onClick="@string/ReminderClick"/>
 </LinearLayout>

</RelativeLayout>