Android - Update minDate and maxDate of a DatePicker many times

Question

I've 2 DatePicker, the first is the start date and the second is the end date. I'want that both have maxDate the current date (and this works with my code) and i want that when i change start date the minDate of second DatePicker will update to this date (and vice versa). With this listner i handle the action but second DatePicker doesn't refresh its minDate on layout.

private DatePicker.OnDateChangedListener startDataListener = new DatePicker.OnDateChangedListener() {

    public void onDateChanged(DatePicker view, int year, int monthOfYear,
            int dayOfMonth) { 
        Calendar c = Calendar.getInstance();
        c.set(year, monthOfYear, dayOfMonth);
        endDate.setMinDate(c.getTimeInMillis());
    }
};

private DatePicker.OnDateChangedListener endDateListener = new DatePicker.OnDateChangedListener() {

    public void onDateChanged(DatePicker view, int year, int monthOfYear,
            int dayOfMonth) {

        Calendar c = Calendar.getInstance();
        c.set(year, monthOfYear, dayOfMonth);
        startDate.setMaxDate(c.getTimeInMillis());
    }
};

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    startDate= (DatePicker)findViewById(***);
    endDate= (DatePicker)findViewById(***);

    startDate.setMaxDate(Calendar.getInstance().getTimeInMillis());
    startDate.init(year, month, day, startDateListener);

    endDate.setMinDate(c.getTimeInMillis()-1000);
    endDate.setMaxDate(c.getTimeInMillis());
    endDate.init(year, month, day, endDateListener);
}

Answer 1

Just initialize the DatePickerDialog object TWICE OR MULTIPLE times, every time you change the setMinDate(milisecs).

void yourListenerMethod() {
     datePickerDialog2 = new DatePickerDialog(getActivity(), date2, myCalendar
            .get(Calendar.YEAR), myCalendar.get(Calendar.MONTH),
            myCalendar.get(Calendar.DAY_OF_MONTH));
    datePickerDialog2.getDatePicker().setMaxDate(System.currentTimeMillis()-1000);
    datePickerDialog2.getDatePicker().setMinDate(date.getTime());
}  

Answer 2

It is because method setMinDate() has check

if (mTempDate.get(Calendar.YEAR) == mMinDate.get(Calendar.YEAR)
            && mTempDate.get(Calendar.DAY_OF_YEAR) != mMinDate.get(Calendar.DAY_OF_YEAR){
        return;}

Simply set

mPicker.setMinDate(0); 
//The Min date you wish to set.
mPicker.setMinDate(new LocalDate().minusWeeks(2)
                            .toDateTimeAtStartOfDay().getMillis());

By this the year has been changed for new Min Date and hence it will set the new date. This works for me

Answer 3

From https://stackoverflow.com/a/19722636

This happens because of this code of setMinDate() has check:

if (mTempDate.get(Calendar.YEAR) == mMinDate.get(Calendar.YEAR) && mTempDate.get(Calendar.DAY_OF_YEAR) != mMinDate.get(Calendar.DAY_OF_YEAR)
        return;

Simple workaround is to set min date with different year at first.

Using the suggested solution and avoiding listener execution when the solution is applied I came to this:

DatePicker startDate, endDate;
Calendar minDate = Calendar.getInstance(), maxDate = Calendar.getInstance();
boolean callFromStartDate = false, callFromEndDate = false;

private DatePicker.OnDateChangedListener startDateListener = new DatePicker.OnDateChangedListener() {
    public void onDateChanged(DatePicker view, int year, int monthOfYear, int dayOfMonth) {
        // Avoid listener execution when there's a forced updated on picker
        if(callFromEndDate){
            callFromEndDate = false;
            return;
        }

        callFromStartDate = true;

        // Force picker update
        minDate.set(year - 1, monthOfYear, dayOfMonth);
        endDate.setMinDate(minDate.getTimeInMillis());  // Calls onDateChange from the other picker

        callFromStartDate = true;

        // Update the picker to the desired date
        minDate.set(year, monthOfYear, dayOfMonth);
        endDate.setMinDate(minDate.getTimeInMillis());
    }
};

private DatePicker.OnDateChangedListener endDateListener = new DatePicker.OnDateChangedListener() {
    public void onDateChanged(DatePicker view, int year, int monthOfYear, int dayOfMonth) {
        if(callFromStartDate) {
            callFromStartDate = false;
            return;
        }

        callFromEndDate = true;

        maxDate.set(year + 1, monthOfYear, dayOfMonth);
        startDate.setMaxDate(maxDate.getTimeInMillis());

        callFromEndDate = true;

        maxDate.set(year, monthOfYear, dayOfMonth);
        startDate.setMaxDate(maxDate.getTimeInMillis());
    }
};

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setContentView(R.layout.activity_main);

    startDate = (DatePicker) findViewById(R.id.datePicker);
    endDate = (DatePicker) findViewById(R.id.datePicker2);

    Calendar c = Calendar.getInstance();
    int year = c.get(Calendar.YEAR);
    int month = c.get(Calendar.MONTH);
    int day = c.get(Calendar.DAY_OF_MONTH);
    long initialTimeInMillis = c.getTimeInMillis();

    startDate.setMinDate(initialTimeInMillis-2000000000);
    startDate.setMaxDate(initialTimeInMillis);
    startDate.init(year, month, day, startDateListener);

    endDate.setMinDate(initialTimeInMillis-2000000000);
    endDate.setMaxDate(initialTimeInMillis);
    endDate.init(year, month, day, endDateListener);
}