/*
* Copyright 2019 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package androidx.compose.ui.text.input
import androidx.compose.runtime.Immutable
import androidx.compose.runtime.Stable
import androidx.compose.ui.text.AnnotatedString
/**
* The transformed text with offset offset mapping
*/
class TransformedText(
/**
* The transformed text
*/
val text: AnnotatedString,
/**
* The map used for bidirectional offset mapping from original to transformed text.
*/
val offsetMapping: OffsetMapping
) {
override fun equals(other: Any?): Boolean {
if (this === other) return true
if (other !is TransformedText) return false
if (text != other.text) return false
if (offsetMapping != other.offsetMapping) return false
return true
}
override fun hashCode(): Int {
var result = text.hashCode()
result = 31 * result + offsetMapping.hashCode()
return result
}
override fun toString(): String {
return "TransformedText(text=$text, offsetMapping=$offsetMapping)"
}
}
/**
* Interface used for changing visual output of the input field.
*
* This interface can be used for changing visual output of the text in the input field.
* For example, you can mask characters in password field with asterisk with
* [PasswordVisualTransformation].
*/
@Immutable
fun interface VisualTransformation {
/**
* 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: **************
*
* @sample androidx.compose.ui.text.samples.passwordFilter
*
* Example: Credit Card Visual Output (inserting hyphens each 4 digits)
* original text : 1234567890123456
* transformed text: 1234-5678-9012-3456
*
* @sample androidx.compose.ui.text.samples.creditCardFilter
*
* @param text The original text
* @return the pair of filtered text and offset translator.
*/
fun filter(text: AnnotatedString): TransformedText
companion object {
/**
* A special visual transformation object indicating that no transformation is applied.
*/
@Stable
val None: VisualTransformation = VisualTransformation { text ->
TransformedText(text, OffsetMapping.Identity)
}
}
}
/**
* The Visual Filter can be used for password Input Field.
*
* Note that this visual filter only works for ASCII characters.
*
* @param mask The mask character used instead of original text.
*/
class PasswordVisualTransformation(val mask: Char = '\u2022') : VisualTransformation {
override fun filter(text: AnnotatedString): TransformedText {
return TransformedText(
AnnotatedString(mask.toString().repeat(text.text.length)),
OffsetMapping.Identity
)
}
override fun equals(other: Any?): Boolean {
if (this === other) return true
if (other !is PasswordVisualTransformation) return false
if (mask != other.mask) return false
return true
}
override fun hashCode(): Int {
return mask.hashCode()
}
}