1. Added Date Picker Fragment for selecting date.

Author: amitjangid80

app/src/main/java/com/amit/views/DatePickerFragment.java

@@ -0,0 +1,101 @@
+package com.amit.views;
+
+import android.app.Activity;
+import android.app.DatePickerDialog;
+import android.app.Dialog;
+import android.app.DialogFragment;
+import android.content.Context;
+import android.os.Bundle;
+import android.support.annotation.NonNull;
+import android.util.Log;
+import android.widget.DatePicker;
+
+import java.text.SimpleDateFormat;
+import java.util.Calendar;
+import java.util.Locale;
+
+/**
+ * Created by AMIT JANGID on 24-Oct-18.
+ *
+ * this class will display a date picker dialog
+ * it will return selected date in the format defined
+**/
+@SuppressWarnings("unused")
+public class DatePickerFragment extends DialogFragment implements DatePickerDialog.OnDateSetListener
+{
+    private static final String TAG = DatePickerFragment.class.getSimpleName();
+
+    private Calendar calendar;
+    private SelectedDate mSelectedDate;
+
+    private static boolean mIsCurrentDateMin;
+    private static String mSelectedDateFormat;
+
+    public void showDatePickerDialog(@NonNull Context context, @NonNull SelectedDate selectedDate,
+                                     @NonNull String selectedDateFormat, boolean isCurrentDateMin)
+    {
+        mIsCurrentDateMin = isCurrentDateMin;
+        mSelectedDateFormat = selectedDateFormat;
+
+        DatePickerFragment datePickerFragment = new DatePickerFragment();
+        datePickerFragment.initializeInterface(selectedDate);
+        datePickerFragment.show(((Activity) context).getFragmentManager(), "DatePicker");
+    }
+
+    @Override
+    public Dialog onCreateDialog(Bundle savedInstanceState)
+    {
+        // Use the current date as the default date in the picker
+        calendar = Calendar.getInstance();
+
+        int year = calendar.get(Calendar.YEAR);
+        int month = calendar.get(Calendar.MONTH);
+        int day = calendar.get(Calendar.DAY_OF_MONTH);
+
+        // Create a new instance of DatePickerDialog and return it
+        DatePickerDialog datePickerDialog = new DatePickerDialog(getActivity(), this, year, month, day);
+
+        if (mIsCurrentDateMin)
+        {
+            datePickerDialog.getDatePicker().setMinDate(System.currentTimeMillis() - 1000);
+        }
+
+        return datePickerDialog;
+    }
+
+    @Override
+    public void onDateSet(DatePicker view, int year, int month, int dayOfMonth)
+    {
+        calendar.set(year, month, dayOfMonth);
+        SimpleDateFormat sdf = new SimpleDateFormat(mSelectedDateFormat, Locale.getDefault());
+
+        String selectedDate = sdf.format(calendar.getTime());
+        Log.e(TAG, "onDateSet: selected date is: " + selectedDate);
+
+        if (mSelectedDate != null)
+        {
+            mSelectedDate.selectedDate(selectedDate);
+        }
+    }
+
+    private void initializeInterface(SelectedDate selectedDate)
+    {
+        this.mSelectedDate = selectedDate;
+    }
+
+    public interface SelectedDate
+    {
+        void selectedDate(String selectedDate);
+    }
+
+    private class InvalidDateFormatException extends RuntimeException
+    {
+        String message;
+
+        private InvalidDateFormatException(String message)
+        {
+            super(message);
+            this.message = message;
+        }
+    }
+}