VisualTransformation

val None: VisualTransformation

fun filter(text: AnnotatedString): TransformedText

import androidx.compose.ui.text.AnnotatedString
import androidx.compose.ui.text.input.OffsetMapping
import androidx.compose.ui.text.input.TransformedText

return TransformedText(
    AnnotatedString("*".repeat(text.text.length)),

    /**
     * [OffsetMapping.Identity] is a predefined [OffsetMapping] that can be used for the
     * transformation that does not change the character count.
     */
    OffsetMapping.Identity,
)

import androidx.compose.ui.text.AnnotatedString
import androidx.compose.ui.text.input.OffsetMapping
import androidx.compose.ui.text.input.TransformedText

// Making XXXX-XXXX-XXXX-XXXX string.
val trimmed = if (text.text.length >= 16) text.text.substring(0..15) else text.text
var out = ""
for (i in trimmed.indices) {
    out += trimmed[i]
    if (i % 4 == 3 && i != 15) out += "-"
}

/**
 * The offset translator should ignore the hyphen characters, so conversion from original offset
 * to transformed text works like
 * - The 4th char of the original text is 5th char in the transformed text.
 * - The 13th char of the original text is 15th char in the transformed text. Similarly, the
 *   reverse conversion works like
 * - The 5th char of the transformed text is 4th char in the original text.
 * - The 12th char of the transformed text is 10th char in the original text.
 */
val creditCardOffsetTranslator =
    object : OffsetMapping {
        override fun originalToTransformed(offset: Int): Int {
            if (offset <= 3) return offset
            if (offset <= 7) return offset + 1
            if (offset <= 11) return offset + 2
            if (offset <= 16) return offset + 3
            return 19
        }

        override fun transformedToOriginal(offset: Int): Int {
            if (offset <= 4) return offset
            if (offset <= 9) return offset - 1
            if (offset <= 14) return offset - 2
            if (offset <= 19) return offset - 3
            return 16
        }
    }

return TransformedText(AnnotatedString(out), creditCardOffsetTranslator)