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/*
* 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.style
import androidx.compose.runtime.Immutable
import androidx.compose.runtime.Stable
import androidx.compose.ui.text.lerpTextUnitInheritable
import androidx.compose.ui.unit.TextUnit
import androidx.compose.ui.unit.sp
/**
* Specify the indentation of a paragraph.
*
* @param firstLine the amount of indentation applied to the first line.
* @param restLine the amount of indentation applied to every line except the first line.
*/
@Immutable
class TextIndent(
val firstLine: TextUnit = 0.sp,
val restLine: TextUnit = 0.sp
) {
companion object {
/**
* Constant fot no text indent.
*/
@Stable
val None = TextIndent()
}
fun copy(
firstLine: TextUnit = this.firstLine,
restLine: TextUnit = this.restLine
): TextIndent {
return TextIndent(firstLine, restLine)
}
override operator fun equals(other: Any?): Boolean {
if (this === other) return true
if (other !is TextIndent) return false
if (firstLine != other.firstLine) return false
if (restLine != other.restLine) return false
return true
}
override fun hashCode(): Int {
var result = firstLine.hashCode()
result = 31 * result + restLine.hashCode()
return result
}
override fun toString(): String {
return "TextIndent(firstLine=$firstLine, restLine=$restLine)"
}
}
/**
* Linearly interpolate between two [TextIndent]s.
*
* 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.
*/
fun lerp(start: TextIndent, stop: TextIndent, fraction: Float): TextIndent {
return TextIndent(
lerpTextUnitInheritable(start.firstLine, stop.firstLine, fraction),
lerpTextUnitInheritable(start.restLine, stop.restLine, fraction)
)
}