AndroidTextStyle.android.kt
/*
* Copyright 2022 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
internal const val DefaultIncludeFontPadding = true
/**
* Provides Android specific [TextStyle] configuration options for styling and compatibility.
*/
actual class PlatformTextStyle {
/**
* Android specific text span styling and compatibility configuration.
*/
actual val spanStyle: PlatformSpanStyle?
/**
* Android specific paragraph styling and compatibility configuration.
*/
actual val paragraphStyle: PlatformParagraphStyle?
constructor(
spanStyle: PlatformSpanStyle?,
paragraphStyle: PlatformParagraphStyle?
) {
this.spanStyle = spanStyle
this.paragraphStyle = paragraphStyle
}
/**
* Enables turning on and off for Android [includeFontPadding](https://developer.android.com/reference/android/text/StaticLayout.Builder#setIncludePad(boolean)).
*
* includeFontPadding was added to Android in order to prevent clipping issues on tall scripts.
* However that issue has been fixed since Android 28. Jetpack Compose backports the fix for
* Android versions prior to Android 28. Therefore the original reason why includeFontPadding
* was needed in invalid on Compose.
*
* This configuration was added for migration of the apps in case some code or design was
* relying includeFontPadding=true behavior and will be removed.
*
* @param includeFontPadding Set whether to include extra space beyond font ascent and descent.
*/
@Suppress("DEPRECATION")
@Deprecated(
"includeFontPadding was added to Android in order to prevent clipping issues on tall " +
"scripts. However that issue has been fixed since Android 28. Compose backports the " +
"fix for Android versions prior to Android 28. Therefore the original reason why " +
"includeFontPadding was needed is invalid on Compose." +
"This configuration was added for migration of the apps in case some code or design " +
"was relying includeFontPadding=true behavior; and will be removed."
)
constructor(
includeFontPadding: Boolean = DefaultIncludeFontPadding
) : this(
paragraphStyle = PlatformParagraphStyle(includeFontPadding = includeFontPadding),
spanStyle = null
)
override fun hashCode(): Int {
var result = spanStyle?.hashCode() ?: 0
result = 31 * result + (paragraphStyle?.hashCode() ?: 0)
return result
}
override fun equals(other: Any?): Boolean {
if (this === other) return true
if (other !is PlatformTextStyle) return false
if (paragraphStyle != other.paragraphStyle) return false
if (spanStyle != other.spanStyle) return false
return true
}
override fun toString(): String {
return "PlatformTextStyle(" +
"spanStyle=$spanStyle, " +
"paragraphSyle=$paragraphStyle" +
")"
}
}
internal actual fun createPlatformTextStyle(
spanStyle: PlatformSpanStyle?,
paragraphStyle: PlatformParagraphStyle?
): PlatformTextStyle {
return PlatformTextStyle(spanStyle, paragraphStyle)
}
/**
* Provides Android specific [ParagraphStyle] configuration options for styling and compatibility.
*/
@Suppress("DEPRECATION")
actual class PlatformParagraphStyle {
actual companion object {
actual val Default: PlatformParagraphStyle =
PlatformParagraphStyle()
}
@Deprecated("Sets includeFontPadding parameter for transitioning. Will be removed.")
val includeFontPadding: Boolean
@Deprecated("Provides configuration options for behavior compatibility.")
constructor(includeFontPadding: Boolean = DefaultIncludeFontPadding) {
this.includeFontPadding = includeFontPadding
}
constructor() : this(includeFontPadding = DefaultIncludeFontPadding)
override fun equals(other: Any?): Boolean {
if (this === other) return true
if (other !is PlatformParagraphStyle) return false
if (includeFontPadding != other.includeFontPadding) return false
return true
}
override fun hashCode(): Int {
return includeFontPadding.hashCode()
}
override fun toString(): String {
return "PlatformParagraphStyle(" +
"includeFontPadding=$includeFontPadding" +
")"
}
actual fun merge(other: PlatformParagraphStyle?): PlatformParagraphStyle {
if (other == null) return this
// this should be AndroidParagraphConfig(param1=..., param2=...) when a new param is added.
// right now it is not needed to create a copy
return other
}
}
/**
* Provides Android specific [SpanStyle] configuration options for styling and compatibility.
*/
actual class PlatformSpanStyle {
actual companion object {
actual val Default: PlatformSpanStyle = PlatformSpanStyle()
}
actual fun merge(other: PlatformSpanStyle?): PlatformSpanStyle {
return this
}
override fun equals(other: Any?): Boolean {
if (this === other) return true
if (other !is PlatformSpanStyle) return false
return true
}
@Suppress("RedundantOverride")
override fun hashCode(): Int {
return super.hashCode()
}
override fun toString(): String {
return "PlatformSpanStyle()"
}
}
/**
* Interpolate between two PlatformParagraphStyle's.
*
* This will not work well if the styles don't set the same fields.
*
* The [fraction] argument represents position on the timeline, with 0.0 meaning
* that the interpolation has not started, returning [start] (or something
* equivalent to [start]), 1.0 meaning that the interpolation has finished,
* returning [stop] (or something equivalent to [stop]), and values in between
* meaning that the interpolation is at the relevant point on the timeline
* between [start] and [stop]. The interpolation can be extrapolated beyond 0.0 and
* 1.0, so negative values and values greater than 1.0 are valid.
*/
@Suppress("DEPRECATION")
actual fun lerp(
start: PlatformParagraphStyle,
stop: PlatformParagraphStyle,
fraction: Float
): PlatformParagraphStyle {
if (start.includeFontPadding == stop.includeFontPadding) return start
return PlatformParagraphStyle(
includeFontPadding = lerpDiscrete(
start.includeFontPadding,
stop.includeFontPadding,
fraction
)
)
}
/**
* Interpolate between two PlatformSpanStyle's.
*
* This will not work well if the styles don't set the same fields.
*
* The [fraction] argument represents position on the timeline, with 0.0 meaning
* that the interpolation has not started, returning [start] (or something
* equivalent to [start]), 1.0 meaning that the interpolation has finished,
* returning [stop] (or something equivalent to [stop]), and values in between
* meaning that the interpolation is at the relevant point on the timeline
* between [start] and [stop]. The interpolation can be extrapolated beyond 0.0 and
* 1.0, so negative values and values greater than 1.0 are valid.
*/
actual fun lerp(
start: PlatformSpanStyle,
stop: PlatformSpanStyle,
fraction: Float
): PlatformSpanStyle {
return start
}