title: Validating "from date" and "to date" in android
body: <p>I an application in which user has to choose two dates namely- <strong>from date</strong> and <strong>to date</strong>.Both the fields should not accept any date less than current date.I have gone through some posts in this website and achieved this functionality by using single datepicker dialog and single ondatesetListener.</p>
  
  <p>my problem is that i am unable to validate the condition that <strong>to date</strong> should be always greater than or equal to <strong>from date</strong>.please help me.I am unable to capture the <strong>from date</strong> as the active date is <strong>overide by the active end date</strong> Thanks in advance.Following is the code:</p>
  
  <pre><code>public class Leave_form extends Activity 
  {       
      private static EditText tvDislpayResult;
      private Button startPickDate;
      private Button endPickDate;
      private Calendar startDate;
      private Calendar endDate;
      //private EditText startDateDisplay;
      //private EditText endDateDisplay;
      static final int DATE_DIALOG_ID = 0;
      private TextView startDateDisplay;
      private TextView endDateDisplay;
      private TextView activeDateDisplay;
      private Calendar activeDate;
      private Calendar currentDate;
      private Calendar fromDate;
  
      protected void onCreate(Bundle savedInstanceState) 
      {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.activity_leave_form);
  
          /*  capture our View elements for the start date function   */
          startDateDisplay = (EditText) findViewById(R.id.e_from_date);
          startPickDate = (Button) findViewById(R.id.Set_date1);
  
          /*get tday date  */   
  
          currentDate=Calendar.getInstance();
          Log.d("currentDate ",""+(currentDate.get(Calendar.DAY_OF_MONTH))+(currentDate.get(Calendar.MONTH)+1)+(currentDate.get(Calendar.YEAR)));
  
          /* get the current date */
          startDate = Calendar.getInstance();
          Log.d("startdate ",""+(startDate.get(Calendar.DAY_OF_MONTH))+(startDate.get(Calendar.MONTH)+1)+(startDate.get(Calendar.YEAR)));
  
          /* add a click listener to the button   */
          startPickDate.setOnClickListener(new View.OnClickListener()
          {
              public void onClick(View v) 
              {
                  showDateDialog(startDateDisplay, startDate);
                  Log.d("startDate-on click ",""+(startDate.get(Calendar.DAY_OF_MONTH))+(startDate.get(Calendar.MONTH)+1)+(startDate.get(Calendar.YEAR)));
  
              }
          });
  
          /* capture our View elements for the end date function */
          endDateDisplay = (EditText) findViewById(R.id.e_to_date);
          endPickDate = (Button) findViewById(R.id.Set_date2);
  
          /* get the current date */
          endDate = Calendar.getInstance();
          Log.d("endDate ",""+(endDate.get(Calendar.DAY_OF_MONTH))+(endDate.get(Calendar.MONTH)+1)+(endDate.get(Calendar.YEAR)));
  
          /* add a click listener to the button   */
          endPickDate.setOnClickListener(new View.OnClickListener()
          {
              public void onClick(View v)
              {
                  showDateDialog(endDateDisplay, endDate);
                  Log.d("endDate -on click",""+(endDate.get(Calendar.DAY_OF_MONTH))+(endDate.get(Calendar.MONTH)+1)+(endDate.get(Calendar.YEAR)));
              }
          });
  
          /* display the current date (this method is below)  */
         // updateDisplay(startDateDisplay, startDate);
         // updateDisplay(endDateDisplay, endDate);
      }
  
      private void updateDisplay(TextView dateDisplay, Calendar date) 
      {
          dateDisplay.setText(
                  new StringBuilder()
                      // Month is 0 based so add 1
                      .append(date.get(Calendar.DAY_OF_MONTH) ).append("-")
                      .append(date.get(Calendar.MONTH)+1).append("-")
                      .append(date.get(Calendar.YEAR)).append(" "));
  
          Log.d("msg","date:"+(date.get(Calendar.DAY_OF_MONTH))+(date.get(Calendar.MONTH)+1)+(date.get(Calendar.YEAR)));
  
          fromDate=date;
      }
  
      public void showDateDialog(TextView dateDisplay, Calendar date)
      {
          Log.d("SDD", dateDisplay.getText().toString());
          Log.d("startdate ",""+(currentDate.get(Calendar.DAY_OF_MONTH))+(currentDate.get(Calendar.MONTH)+1)+(currentDate.get(Calendar.YEAR)));
         activeDateDisplay = dateDisplay;
          activeDate = date;
          showDialog(DATE_DIALOG_ID);
      }
  
      private OnDateSetListener dateSetListener = new OnDateSetListener()
      {
          @SuppressWarnings("deprecation")
          @Override
          public void onDateSet(DatePicker view, int year, int monthOfYear, int dayOfMonth) {
              activeDate.set(Calendar.YEAR, year);
              activeDate.set(Calendar.MONTH, monthOfYear);
              activeDate.set(Calendar.DAY_OF_MONTH, dayOfMonth);
              Log.d("activeDate-on dateset ",""+(activeDate.get(Calendar.DAY_OF_MONTH))+(activeDate.get(Calendar.MONTH)+1)+(activeDate.get(Calendar.YEAR)));
  
              if(currentDate.after(activeDate)|(currentDate.equals(activeDate)))
              {
                  Toast toast=Toast.makeText(Leave_form.this, "Please select a valid date", Toast.LENGTH_LONG);
                  toast.setGravity(Gravity.CENTER, 0, 0);
                  toast.show();
  
  
              }
              else
              {
                  if((currentDate.after(activeDate)|(currentDate.equals(activeDate)))&amp;&amp;(startDateDisplay.getText().toString()!=null))
                  {
                      Log.d("startDate-on click ",""+(startDate.get(Calendar.DAY_OF_MONTH))+(startDate.get(Calendar.MONTH)+1)+(startDate.get(Calendar.YEAR)));
                      if(startDate.before(activeDate))
                      {
                          updateDisplay(activeDateDisplay, activeDate);
                      }
  
                      else
                      {
                          Toast.makeText(getApplicationContext(), "enter valid date", Toast.LENGTH_SHORT).show();
                          /*AlertDialog alertDialog=new AlertDialog.Builder(Leave_form.this).create();
  
                          alertDialog.setMessage("Choose a valid date");
  
                          alertDialog.setButton("OK", new DialogInterface.OnClickListener() {
  
                              @Override
                              public void onClick(DialogInterface dialog, int which) {
                                  // TODO Auto-generated method stub
  
                              }
                          });
                          alertDialog.show();*/
                      }
                  }
                  else
                  {
                      updateDisplay(activeDateDisplay, activeDate);
                  }
  
             }
  
              unregisterDateDisplay();
          }
      };
  
      private void unregisterDateDisplay() 
      {
          Log.d("startdate ",""+(currentDate.get(Calendar.DAY_OF_MONTH))+(currentDate.get(Calendar.MONTH)+1)+(currentDate.get(Calendar.YEAR)));
          Log.d("from date:","-"+activeDate.DAY_OF_MONTH+activeDate.MONTH+activeDate.YEAR);
          activeDateDisplay = null;
          activeDate = null;
      }
  
      @Override
      protected Dialog onCreateDialog(int id) {
          switch (id) {
  
              case DATE_DIALOG_ID:
                  Log.d("fromdate","msg");
                  Log.d("id",""+DATE_DIALOG_ID);
                  return new DatePickerDialog(this, dateSetListener, activeDate.get(Calendar.YEAR), activeDate.get(Calendar.MONTH), activeDate.get(Calendar.DAY_OF_MONTH));
          }
          return null;
      }
  
      @Override
      protected void onPrepareDialog(int id, Dialog dialog) {
          super.onPrepareDialog(id, dialog);
          switch (id) {
              case DATE_DIALOG_ID:
                  Log.d("id",""+DATE_DIALOG_ID);
                  ((DatePickerDialog) dialog).updateDate(activeDate.get(Calendar.YEAR), activeDate.get(Calendar.MONTH), activeDate.get(Calendar.DAY_OF_MONTH));
                  break;
          }
      }
  
      public void leave(View view)
      {
          Intent intent1=new Intent(this,Rough.class);
          setContentView(R.layout.activity_rough);
          startActivity(intent1);
      }
      public void logout(View view)
      {
          Intent intent2=new Intent (this,MainActivity.class);
          setContentView(R.layout.activity_main);
          startActivity(intent2);
      }
  }
  </code></pre>