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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
import androidx.compose.runtime.Immutable
import androidx.compose.ui.util.packInts
import androidx.compose.ui.util.unpackInt1
import androidx.compose.ui.util.unpackInt2
fun CharSequence.substring(range: TextRange): String = this.substring(range.min, range.max)
/**
* An immutable text range class, represents a text range from [start] (inclusive) to [end]
* (exclusive). [end] can be smaller than [start] and in those cases [min] and [max] can be
* used in order to fetch the values.
*
* @param start the inclusive start offset of the range. Must be non-negative, otherwise an
* exception will be thrown.
* @param end the exclusive end offset of the range. Must be non-negative, otherwise an
* exception will be thrown.
*/
fun TextRange(/*@IntRange(from = 0)*/ start: Int, /*@IntRange(from = 0)*/ end: Int) =
TextRange(packWithCheck(start, end))
/**
* An immutable text range class, represents a text range from [start] (inclusive) to [end]
* (exclusive). [end] can be smaller than [start] and in those cases [min] and [max] can be
* used in order to fetch the values.
*/
@Suppress("INLINE_CLASS_DEPRECATED", "EXPERIMENTAL_FEATURE_WARNING")
@Immutable
inline class TextRange internal constructor(private val packedValue: Long) {
val start: Int get() = unpackInt1(packedValue)
val end: Int get() = unpackInt2(packedValue)
/** The minimum offset of the range. */
val min: Int get() = if (start > end) end else start
/** The maximum offset of the range. */
val max: Int get() = if (start > end) start else end
/**
* Returns true if the range is collapsed
*/
val collapsed: Boolean get() = start == end
/**
* Returns true if the start offset is larger than the end offset.
*/
val reversed: Boolean get() = start > end
/**
* Returns the length of the range.
*/
val length: Int get() = max - min
/**
* Returns true if the given range has intersection with this range
*/
fun intersects(other: TextRange): Boolean = min < other.max && other.min < max
/**
* Returns true if this range covers including equals with the given range.
*/
operator fun contains(other: TextRange): Boolean = min <= other.min && other.max <= max
/**
* Returns true if the given offset is a part of this range.
*/
operator fun contains(offset: Int): Boolean = offset in min until max
override fun toString(): String {
return "TextRange($start, $end)"
}
companion object {
val Zero = TextRange(0)
}
}
/**
* Creates a [TextRange] where start is equal to end, and the value of those are [index].
*/
fun TextRange(index: Int): TextRange = TextRange(start = index, end = index)
/**
* Ensures that [TextRange.start] and [TextRange.end] values lies in the specified range
* [minimumValue] and [maximumValue]. For each [TextRange.start] and [TextRange.end] values:
* - if value is smaller than [minimumValue], value is replaced by [minimumValue]
* - if value is greater than [maximumValue], value is replaced by [maximumValue]
*
* @param minimumValue the minimum value that [TextRange.start] or [TextRange.end] can be.
* @param maximumValue the exclusive maximum value that [TextRange.start] or [TextRange.end] can be.
*/
internal fun TextRange.constrain(minimumValue: Int, maximumValue: Int): TextRange {
val newStart = start.coerceIn(minimumValue, maximumValue)
val newEnd = end.coerceIn(minimumValue, maximumValue)
if (newStart != start || newEnd != end) {
return TextRange(newStart, newEnd)
}
return this
}
private fun packWithCheck(start: Int, end: Int): Long {
require(start >= 0) {
"start cannot be negative. [start: $start]"
}
require(end >= 0) {
"end cannot negative. [end: $end]"
}
return packInts(start, end)
}