commonMain.androidx.compose.foundation.text.StringHelpers.kt Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of foundation Show documentation
Show all versions of foundation Show documentation
Higher level abstractions of the Compose UI primitives. This library is design system agnostic, providing the high-level building blocks for both application and design-system developers
/*
* 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
/**
* Returns the index of the character break preceding [index].
*/
internal expect fun String.findPrecedingBreak(index: Int): Int
/**
* Returns the index of the character break following [index]. Returns -1 if there are no more
* breaks before the end of the string.
*/
internal expect fun String.findFollowingBreak(index: Int): Int
internal fun CharSequence.findParagraphStart(startIndex: Int): Int {
for (index in startIndex downTo 1) {
if (this[index - 1] == '\n') {
return index
}
}
return 0
}
internal fun CharSequence.findParagraphEnd(startIndex: Int): Int {
for (index in startIndex 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 CharSequence.getParagraphBoundary(index: Int): TextRange {
return TextRange(findParagraphStart(index), findParagraphEnd(index))
}