How to mask an EditText to show the dd/mm/yyyy date format

Question

How can I format an EditText to follow the \"dd/mm/yyyy\" format the same way that we can format using a TextWatcher to mask

Answer 1

a cleaner way to use the Juan Cortés's code is put it in a class:

public class DateInputMask implements TextWatcher {

private String current = "";
private String ddmmyyyy = "DDMMYYYY";
private Calendar cal = Calendar.getInstance();
private EditText input;

public DateInputMask(EditText input) {
    this.input = input;
    this.input.addTextChangedListener(this);
}

@Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {

}

@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
    if (s.toString().equals(current)) {
        return;
    }

    String clean = s.toString().replaceAll("[^\\d.]|\\.", "");
    String cleanC = current.replaceAll("[^\\d.]|\\.", "");

    int cl = clean.length();
    int sel = cl;
    for (int i = 2; i <= cl && i < 6; i += 2) {
        sel++;
    }
    //Fix for pressing delete next to a forward slash
    if (clean.equals(cleanC)) sel--;

    if (clean.length() < 8){
        clean = clean + ddmmyyyy.substring(clean.length());
    }else{
        //This part makes sure that when we finish entering numbers
        //the date is correct, fixing it otherwise
        int day  = Integer.parseInt(clean.substring(0,2));
        int mon  = Integer.parseInt(clean.substring(2,4));
        int year = Integer.parseInt(clean.substring(4,8));

        mon = mon < 1 ? 1 : mon > 12 ? 12 : mon;
        cal.set(Calendar.MONTH, mon-1);
        year = (year<1900)?1900:(year>2100)?2100:year;
        cal.set(Calendar.YEAR, year);
        // ^ first set year for the line below to work correctly
        //with leap years - otherwise, date e.g. 29/02/2012
        //would be automatically corrected to 28/02/2012

        day = (day > cal.getActualMaximum(Calendar.DATE))? cal.getActualMaximum(Calendar.DATE):day;
        clean = String.format("%02d%02d%02d",day, mon, year);
    }

    clean = String.format("%s/%s/%s", clean.substring(0, 2),
            clean.substring(2, 4),
            clean.substring(4, 8));

    sel = sel < 0 ? 0 : sel;
    current = clean;
    input.setText(current);
    input.setSelection(sel < current.length() ? sel : current.length());
}

@Override
public void afterTextChanged(Editable s) {

}
}

then you can reuse it

new DateInputMask(myEditTextInstance);