Add support for text decoration line styles via PlatformTextStyle

compose/ui/ui-text/src/skikoMain/kotlin/androidx/compose/ui/text/TextDecorationLineStyle.kt

@@ -0,0 +1,68 @@
+/*
+ * Copyright 2024 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 kotlin.jvm.JvmInline
+
+/**
+ * Defines the style of the text decoration line (e.g. underline).
+ *
+ * The decoration itself is determined via [androidx.compose.ui.text.style.TextDecoration].
+ */
+@ExperimentalTextApi
+@JvmInline
+value class TextDecorationLineStyle internal constructor(val value: Int) {
+
+    override fun toString(): String {
+        return when (this) {
+            Solid -> "Solid"
+            Double -> "Double"
+            Dotted -> "Dotted"
+            Dashed -> "Dashed"
+            Wavy -> "Wavy"
+            else -> "Invalid"
+        }
+    }
+
+    companion object {
+        /**
+         * Solid line.
+         */
+        val Solid = TextDecorationLineStyle(1)
+
+        /**
+         * Double line.
+         */
+        val Double = TextDecorationLineStyle(2)
+
+        /**
+         * Dotted line.
+         */
+        val Dotted = TextDecorationLineStyle(3)
+
+        /**
+         * Dashed line.
+         */
+        val Dashed = TextDecorationLineStyle(4)
+
+        /**
+         * Wavy line.
+         */
+        val Wavy = TextDecorationLineStyle(5)
+    }
+
+}

compose/ui/ui-text/src/skikoMain/kotlin/androidx/compose/ui/text/DesktopTextStyle.skiko.kt → compose/ui/ui-text/src/skikoMain/kotlin/androidx/compose/ui/text/TextStyle.skiko.kt

@@ -14,8 +14,12 @@
  * limitations under the License.
  */
 
+@file:JvmName("DesktopTextStyleKt")
+
 package androidx.compose.ui.text
 
+import kotlin.jvm.JvmName
+
 /**
  * Provides configuration options for behavior compatibility for TextStyle.
  */
@@ -31,6 +35,17 @@ actual class PlatformTextStyle {
         this.paragraphStyle = paragraphStyle
     }
 
+    /**
+     * Allows specifying the style of the decoration line for the text.
+     */
+    @ExperimentalTextApi
+    constructor(
+        textDecorationLineStyle: TextDecorationLineStyle?
+    ) : this (
+        spanStyle = PlatformSpanStyle(textDecorationLineStyle),
+        paragraphStyle = null
+    )
+
     override fun equals(other: Any?): Boolean {
         if (this === other) return true
         if (other !is PlatformTextStyle) return false
@@ -78,8 +93,16 @@ actual class PlatformParagraphStyle {
 
 /**
  * Provides configuration options for behavior compatibility for SpanStyle.
+ *
+ * @param textDecorationLineStyle The style of the text decoration line.
  */
-actual class PlatformSpanStyle {
+actual class PlatformSpanStyle(
+    val textDecorationLineStyle: TextDecorationLineStyle?
+) {
+
+    constructor() : this(TextDecorationLineStyle.Solid)
+
+
     actual companion object {
         actual val Default: PlatformSpanStyle = PlatformSpanStyle()
     }
@@ -91,12 +114,12 @@ actual class PlatformSpanStyle {
     override fun equals(other: Any?): Boolean {
         if (this === other) return true
         if (other !is PlatformSpanStyle) return false
+        if (textDecorationLineStyle != other.textDecorationLineStyle) return false
         return true
     }
 
-    @Suppress("RedundantOverride")
     override fun hashCode(): Int {
-        return super.hashCode()
+        return textDecorationLineStyle.hashCode()
     }
 }
 
@@ -139,5 +162,13 @@ actual fun lerp(
     stop: PlatformSpanStyle,
     fraction: Float
 ): PlatformSpanStyle {
-    return start
+    if (start.textDecorationLineStyle == stop.textDecorationLineStyle) return start
+
+    return PlatformSpanStyle(
+        textDecorationLineStyle = lerpDiscrete(
+            start.textDecorationLineStyle,
+            stop.textDecorationLineStyle,
+            fraction
+        )
+    )
 }

compose/ui/ui-text/src/skikoMain/kotlin/androidx/compose/ui/text/platform/SkiaParagraph.skiko.kt

@@ -41,7 +41,6 @@ import androidx.compose.ui.text.intl.LocaleList
 import androidx.compose.ui.text.style.*
 import androidx.compose.ui.unit.*
 import org.jetbrains.skia.FontFeature
-import org.jetbrains.skia.FontMetrics
 import org.jetbrains.skia.Paint
 import org.jetbrains.skia.paragraph.*
 import org.jetbrains.skia.paragraph.ParagraphStyle
@@ -102,7 +101,6 @@ internal actual fun ActualParagraph(
     constraints
 )
 
-@Suppress("UNUSED_PARAMETER")
 internal actual fun ActualParagraph(
     paragraphIntrinsics: ParagraphIntrinsics,
     maxLines: Int,
@@ -134,6 +132,7 @@ internal data class ComputedStyle(
     var localeList: LocaleList?,
     var background: Color = Color.Unspecified,
     var textDecoration: TextDecoration?,
+    var textDecorationLineStyle: TextDecorationLineStyle?,
     var shadow: Shadow?,
     var drawStyle: DrawStyle?,
     var blendMode: BlendMode,
@@ -163,6 +162,7 @@ internal data class ComputedStyle(
         localeList = spanStyle.localeList,
         background = spanStyle.background,
         textDecoration = spanStyle.textDecoration,
+        textDecorationLineStyle = spanStyle.platformStyle?.textDecorationLineStyle,
         shadow = spanStyle.shadow,
         drawStyle = spanStyle.drawStyle,
         blendMode = blendMode,
@@ -194,7 +194,8 @@ internal data class ComputedStyle(
             res.fontStyle = it.toSkFontStyle()
         }
         textDecoration?.let {
-            res.decorationStyle = it.toSkDecorationStyle(textForegroundStyle.color)
+            res.decorationStyle =
+                it.toSkDecorationStyle(textForegroundStyle.color, textDecorationLineStyle)
         }
         if (background != Color.Unspecified) {
             res.background = Paint().also {
@@ -216,7 +217,6 @@ internal data class ComputedStyle(
 
         res.fontSize = fontSize
         fontFamily?.let {
-            @Suppress("UNCHECKED_CAST")
             val resolved = fontFamilyResolver.resolve(
                 it,
                 fontWeight ?: FontWeight.Normal,
@@ -258,6 +258,11 @@ internal data class ComputedStyle(
         other.textDecoration?.let { textDecoration = it }
         other.shadow?.let { shadow = it }
         other.drawStyle?.let { drawStyle = it }
+        other.platformStyle?.let { platformStyle ->
+            platformStyle.textDecorationLineStyle?.let {
+                textDecorationLineStyle = it
+            }
+        }
     }
 }
 
@@ -625,12 +630,16 @@ fun FontStyle.toSkFontStyle(): SkFontStyle {
 }
 
 // TODO: Remove from public
-fun TextDecoration.toSkDecorationStyle(color: Color): SkDecorationStyle {
+fun TextDecoration.toSkDecorationStyle(
+    color: Color,
+    textDecorationLineStyle: TextDecorationLineStyle?
+): SkDecorationStyle {
     val underline = contains(TextDecoration.Underline)
     val overline = false
     val lineThrough = contains(TextDecoration.LineThrough)
     val gaps = false
-    val lineStyle = SkDecorationLineStyle.SOLID
+    val lineStyle =
+        textDecorationLineStyle?.toSkDecorationLineStyle() ?: SkDecorationLineStyle.SOLID
     val thicknessMultiplier = 1f
     return SkDecorationStyle(
         underline,
@@ -643,6 +652,17 @@ fun TextDecoration.toSkDecorationStyle(color: Color): SkDecorationStyle {
     )
 }
 
+private fun TextDecorationLineStyle.toSkDecorationLineStyle(): SkDecorationLineStyle {
+    return when (this) {
+        TextDecorationLineStyle.Solid -> SkDecorationLineStyle.SOLID
+        TextDecorationLineStyle.Double -> SkDecorationLineStyle.DOUBLE
+        TextDecorationLineStyle.Dotted -> SkDecorationLineStyle.DOTTED
+        TextDecorationLineStyle.Dashed -> SkDecorationLineStyle.DASHED
+        TextDecorationLineStyle.Wavy -> SkDecorationLineStyle.WAVY
+        else -> SkDecorationLineStyle.SOLID
+    }
+}
+
 // TODO: Remove from public
 fun PlaceholderVerticalAlign.toSkPlaceholderAlignment(): PlaceholderAlignment {
     return when (this) {