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

The current answer is very good and helped guide me towards my own solution. There are a few reasons why I decided to post my own solution even though this question already has a valid answer:

• I´m working in Kotlin, not Java. People who find themselves with the same issue will have to translate the current solution.
• I wanted to write an answer that was more legible so that people can more easily adapt it to their own problems.
• As suggested by dengue8830, I encapsulated the solution to this problem in a class, so anyone can use without even worrying about the implementation.

To use it, just do something like:

• DateInputMask(mEditText).listen()

And the solution is shown below:

class DateInputMask(val input : EditText) {

    fun listen() {
        input.addTextChangedListener(mDateEntryWatcher)
    }

    private val mDateEntryWatcher = object : TextWatcher {

        var edited = false
        val dividerCharacter = "/"

        override fun onTextChanged(s: CharSequence, start: Int, before: Int, count: Int) {
            if (edited) {
                edited = false
                return
            }

            var working = getEditText()

            working = manageDateDivider(working, 2, start, before)
            working = manageDateDivider(working, 5, start, before)

            edited = true
            input.setText(working)
            input.setSelection(input.text.length)
        }

        private fun manageDateDivider(working: String, position : Int, start: Int, before: Int) : String{
            if (working.length == position) {
                return if (before <= position && start < position)
                    working + dividerCharacter
                else
                    working.dropLast(1)
            }
            return working
        }

        private fun getEditText() : String {
            return if (input.text.length >= 10)
                input.text.toString().substring(0,10)
            else
                input.text.toString()
        }

        override fun afterTextChanged(s: Editable) {}
        override fun beforeTextChanged(s: CharSequence, start: Int, count: Int, after: Int) {}
    }
}