StringHelpers.kt
/*
* Copyright 2021 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.foundation.text
import androidx.compose.ui.text.TextRange
// StringBuilder.appendCodePoint is already defined on JVM so it's called appendCodePointX
internal expect fun StringBuilder.appendCodePointX(codePoint: Int): StringBuilder
internal expect fun String.findPrecedingBreak(index: Int): Int
internal expect fun String.findFollowingBreak(index: Int): Int
internal fun String.findParagraphStart(startIndex: Int): Int {
for (index in startIndex - 1 downTo 1) {
if (this[index - 1] == '\n') {
return index
}
}
return 0
}
internal fun String.findParagraphEnd(startIndex: Int): Int {
for (index in startIndex + 1 until this.length) {
if (this[index] == '\n') {
return index
}
}
return this.length
}
/**
* Returns the text range of the paragraph at the given character offset.
*
* Paragraphs are separated by Line Feed character (\n).
*/
internal fun String.getParagraphBoundary(index: Int): TextRange {
return TextRange(findParagraphStart(index), findParagraphEnd(index))
}