maxLength

Returns [InputTransformation] that rejects input which causes the total length of the text field

maxLength

fun InputTransformation.maxLength(maxLength: Int): InputTransformation

Returns InputTransformation that rejects input which causes the total length of the text field to be more than maxLength characters.

This transformation also sets the maximum text length for accessibility services. When using an OutputTransformation that adds decorating characters, the announced maximum length may need to be adjusted to account for those characters. See the linked sample for an example of a custom maxLength filter that does this.

Code Examples

BasicTextFieldInputTransformationMaxLengthCustom

@Composable
fun BasicTextFieldInputTransformationMaxLengthCustom() {
    val state = remember { TextFieldState() }
    BasicTextField(
        state,
        inputTransformation =
            object : InputTransformation {
                override fun SemanticsPropertyReceiver.applySemantics() {
                    maxLength(14)
                }
                override fun TextFieldBuffer.transformInput() {
                    if (length > 10) revertAllChanges()
                }
            },
        outputTransformation =
            OutputTransformation {
                if (length > 0) insert(0, "(")
                if (length > 4) insert(4, ") ")
                if (length > 9) insert(9, "-")
            },
    )
}