| /* |
| * Copyright 2020 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.ui.text.AnnotatedString.Range |
| |
| import java.util.SortedSet |
| |
| /** |
| * The core function of [AnnotatedString] transformation. |
| * |
| * @param transform the transformation method |
| * @return newly allocated transformed AnnotatedString |
| */ |
| internal actual fun AnnotatedString.transform( |
| transform: (String, Int, Int) -> String |
| ): AnnotatedString { |
| val transitions = sortedSetOf(0, text.length) |
| collectRangeTransitions(spanStyles, transitions) |
| collectRangeTransitions(paragraphStyles, transitions) |
| |
| var resultStr = "" |
| val offsetMap = mutableMapOf(0 to 0) |
| transitions.windowed(size = 2) { (start, end) -> |
| resultStr += transform(text, start, end) |
| offsetMap.put(end, resultStr.length) |
| } |
| |
| val newSpanStyles = spanStyles.map { |
| // The offset map must have mapping entry from all style start, end position. |
| Range(it.item, offsetMap[it.start]!!, offsetMap[it.end]!!) |
| } |
| val newParaStyles = paragraphStyles.map { |
| Range(it.item, offsetMap[it.start]!!, offsetMap[it.end]!!) |
| } |
| val newAnnotations = annotations.map { |
| Range(it.item, offsetMap[it.start]!!, offsetMap[it.end]!!) |
| } |
| |
| return AnnotatedString( |
| text = resultStr, |
| spanStyles = newSpanStyles, |
| paragraphStyles = newParaStyles, |
| annotations = newAnnotations |
| ) |
| } |
| |
| /** |
| * Adds all [AnnotatedString.Range] transition points |
| * |
| * @param ranges The list of AnnotatedString.Range |
| * @param target The output list |
| */ |
| private fun <T> collectRangeTransitions( |
| ranges: List<Range<T>>, |
| target: SortedSet<Int> |
| ) { |
| ranges.fold(target) { acc, range -> |
| acc.apply { |
| add(range.start) |
| add(range.end) |
| } |
| } |
| } |