| /* |
| * 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.ui.text |
| |
| import androidx.ui.text.font.Font |
| import androidx.ui.text.style.TextDirection |
| import androidx.ui.unit.Density |
| |
| /** |
| * Calculates and provides the intrinsic width and height of text that contains [ParagraphStyle]. |
| * |
| * @param annotatedString the text to be laid out |
| * @param style the [TextStyle] to be applied to the whole text |
| * @param placeholders a list of [Placeholder]s that specify ranges of text which will be |
| * skipped during layout and replaced with [Placeholder]. It's required that the range of each |
| * [Placeholder] doesn't cross paragraph boundary, otherwise [IllegalArgumentException] is thrown. |
| * @param density density of the device |
| * @param resourceLoader [Font.ResourceLoader] to be used to load the font given in [SpanStyle]s |
| |
| * @see MultiParagraph |
| * @see Placeholder |
| * |
| * @throws IllegalArgumentException if [ParagraphStyle.textDirection] is not set, or any |
| * of the [placeholders] crosses paragraph boundary. |
| */ |
| class MultiParagraphIntrinsics( |
| val annotatedString: AnnotatedString, |
| style: TextStyle, |
| val placeholders: List<AnnotatedString.Range<Placeholder>>, |
| density: Density, |
| resourceLoader: Font.ResourceLoader |
| ) : ParagraphIntrinsics { |
| |
| override val minIntrinsicWidth: Float by lazy { |
| infoList.maxByOrNull { |
| it.intrinsics.minIntrinsicWidth |
| }?.intrinsics?.minIntrinsicWidth ?: 0f |
| } |
| |
| override val maxIntrinsicWidth: Float by lazy { |
| infoList.maxByOrNull { |
| it.intrinsics.maxIntrinsicWidth |
| }?.intrinsics?.maxIntrinsicWidth ?: 0f |
| } |
| |
| /** |
| * [ParagraphIntrinsics] for each paragraph included in the [annotatedString]. For empty string |
| * there will be a single empty paragraph intrinsics info. |
| */ |
| internal val infoList: List<ParagraphIntrinsicInfo> |
| |
| init { |
| val paragraphStyle = style.toParagraphStyle() |
| infoList = annotatedString |
| .mapEachParagraphStyle(paragraphStyle) { annotatedString, paragraphStyleItem -> |
| val currentParagraphStyle = resolveTextDirection( |
| paragraphStyleItem.item, |
| paragraphStyle |
| ) |
| |
| ParagraphIntrinsicInfo( |
| intrinsics = ParagraphIntrinsics( |
| text = annotatedString.text, |
| style = style.merge(currentParagraphStyle), |
| spanStyles = annotatedString.spanStyles, |
| placeholders = placeholders.getLocalPlaceholders( |
| paragraphStyleItem.start, |
| paragraphStyleItem.end |
| ), |
| density = density, |
| resourceLoader = resourceLoader |
| ), |
| startIndex = paragraphStyleItem.start, |
| endIndex = paragraphStyleItem.end |
| ) |
| } |
| } |
| |
| /** |
| * if the [style] does `not` have [TextDirection] set, it will return a new |
| * [ParagraphStyle] where [TextDirection] is set using the [defaultStyle]. Otherwise |
| * returns the same [style] object. |
| * |
| * @param style ParagraphStyle to be checked for [TextDirection] |
| * @param defaultStyle [ParagraphStyle] passed to [MultiParagraphIntrinsics] as the main style |
| */ |
| private fun resolveTextDirection( |
| style: ParagraphStyle, |
| defaultStyle: ParagraphStyle |
| ): ParagraphStyle { |
| return style.textDirection?.let { style } ?: style.copy( |
| textDirection = defaultStyle.textDirection |
| ) |
| } |
| } |
| |
| private fun List<AnnotatedString.Range<Placeholder>>.getLocalPlaceholders(start: Int, end: Int) = |
| filter { intersect(start, end, it.start, it.end) }.map { |
| require(start <= it.start && it.end <= end) { |
| "placeholder can not overlap with paragraph." |
| } |
| AnnotatedString.Range(it.item, it.start - start, it.end - start) |
| } |
| |
| internal data class ParagraphIntrinsicInfo( |
| val intrinsics: ParagraphIntrinsics, |
| val startIndex: Int, |
| val endIndex: Int |
| ) |