I want to insert a space every 2 digits when inputting a string in edittext

For example, if you have the string 'abcdefghijk'

I want the edittext to come out like this 'ab cd ef gh ij k'

What should I do? thank you

CodePudding user response：

The best way of doing this is to do something similar that this answer is doing.

For your code it would mean something like this:

class SpacedTextWatcher(private val editText: EditText) : TextWatcher {

    override fun afterTextChanged(s: Editable?) {
        editText.removeTextChangedListener(this)
        val initialLength = editText.text.length

        val v = s.toString().chunked(2).joinToString(" ")

        val cp = editText.selectionStart
        editText.setText(v)
        val endLength = editText.length()
        val selection = (cp   (endLength - initialLength))
        if (selection > 0 && selection <= editText.text.length) {
            editText.setSelection(selection)
        } else {
            editText.setSelection(editText.text.length - 1)
        }


        editText.addTextChangedListener(this)
    }

    override fun onTextChanged(s: CharSequence?, start: Int, before: Int, count: Int) {}

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

This answer is not handling special use-cases where there is a space in the string or anything else, but I think you can figure out the rest yourself. Just make sure you register this textWatcher on the editText you want to format.

CodePudding user response：

Here is the exact solution what you want:

 fun editTextSetContentMemorizeSelection(editText: EditText, charSequence: CharSequence) {
        var selectionStart = editText.selectionStart
        var selectionEnd = editText.selectionEnd
        editText.setText(charSequence.toString())
        if (selectionStart > charSequence.toString().length) {
            selectionStart = charSequence.toString().length
        }
        if (selectionStart < 0) {
            selectionStart = 0
        }
        if (selectionEnd > charSequence.toString().length) {
            selectionEnd = charSequence.toString().length
        }
        if (selectionEnd < 0) {
            selectionEnd = 0
        }
        editText.setSelection(selectionStart, selectionEnd)
    }
    
    fun formatStrWithSpaces(can: CharSequence): String? {
        val sb = StringBuffer()
        for (i in 0 until can.length) {
            if (i != 0 && i % 2 == 0) {
                sb.append(' ')
            }
            sb.append(can[i])
        }
        return sb.toString()
    }

In your onCreate or where ever you want to use textwatcher:

editText.addTextChangedListener(object : TextWatcher {
    override fun beforeTextChanged(s: CharSequence, start: Int, count: Int, after: Int) {}
    override fun onTextChanged(s: CharSequence, start: Int, before: Int, count: Int) {
        val origin = s.toString().replace(" ".toRegex(), "")
        val formatStr = formatStrWithSpaces(origin)
        if (s.toString() != formatStr) {
            editTextSetContentMemorizeSelection( editText, formatStr!!)
            if (before == 0 && count == 1 && formatStr!![ editText.getSelectionEnd() - 1] == ' ') {
                editText.setSelection(editText.getSelectionEnd()   1)
            }
        }
    }

    override fun afterTextChanged(s: Editable) {}
})

Here is the Source of this answer. You can also check.