PasswordVisualTransformation

The Visual Filter can be used for password Input Field.

Note that this visual filter only works for ASCII characters.

Summary

Public constructors
Cmn

Public functions
open operator Boolean
equals(other: Any?)
Cmn
open TransformedText

Change the visual output of given text.
Cmn
open Int
Cmn

Public properties
Char

The mask character used instead of original text.
Cmn

Public constructors

PasswordVisualTransformation

Cmn
Added in 1.0.0
PasswordVisualTransformation(mask: Char = '\u2022')
Parameters
mask: Char = '\u2022'

The mask character used instead of original text.

Public functions

equals

Cmn 
open operator fun equals(other: Any?): Boolean

filter

Cmn
Added in 1.8.0-alpha07
open fun filter(text: AnnotatedString): TransformedText

Change the visual output of given text.

Note that the returned text length can be different length from the given text. The composable will call the offset translator for converting offsets for various reasons, cursor drawing position, text selection by gesture, etc.

Example: The ASCII only password (replacing with '*' chars) original text : thisispassword transformed text: **************

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
)

Example: Credit Card Visual Output (inserting hyphens each 4 digits) original text : 1234567890123456 transformed text: 1234-5678-9012-3456

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)
Parameters
text: AnnotatedString

The original text
Returns
TransformedText

the pair of filtered text and offset translator.

hashCode

Cmn 
open fun hashCode(): Int

Public properties

mask

Cmn
Added in 1.0.0
val mask: Char

The mask character used instead of original text.