What's the best way to limit text length of EditText in Android

Question

What\'s the best way to limit the text length of an EditText in Android?

Is there a way to do this via xml?

Answer 1

Kotlin:

edit_text.filters += InputFilter.LengthFilter(10)

ZTE Blade A520 has strange effect. When you type more than 10 symbols (for instance, 15), EditText shows first 10, but other 5 are not visible and not accessible. But when you delete symbols with Backspace, it first deletes right 5 symbols and then removes remaining 10. To overcome this behaviour use a solution:

android:inputType="textNoSuggestions|textVisiblePassword"
android:maxLength="10"

or this:

android:inputType="textNoSuggestions"

or this, if you want to have suggestions:

private class EditTextWatcher(private val view: EditText) : TextWatcher {
    private var position = 0
    private var oldText = ""

    override fun afterTextChanged(s: Editable?) = Unit

    override fun beforeTextChanged(s: CharSequence?, start: Int, count: Int, after: Int) {
        oldText = s?.toString() ?: ""
        position = view.selectionStart
    }

    override fun onTextChanged(s: CharSequence?, start: Int, before: Int, count: Int) {
        val newText = s?.toString() ?: ""
        if (newText.length > 10) {
            with(view) {
                setText(oldText)
                position = if (start > 0 && count > 2) {
                    // Text paste in nonempty field.
                    start
                } else {
                    if (position in 1..10 + 1) {
                        // Symbol paste in the beginning or middle of the field.
                        position - 1
                    } else {
                        if (start > 0) {
                            // Adding symbol to the end of the field.
                            start - 1
                        } else {
                            // Text paste in the empty field.
                            0
                        }
                    }
                }
                setSelection(position)
            }
        }
    }
}

// Usage:
editTextWatcher = EditTextWatcher(view.edit_text)
view.edit_text.addTextChangedListener(editTextWatcher)