Apply HTML to Wikipedia text

ui/build.gradle.kts

@@ -66,6 +66,8 @@ dependencies {
 
     implementation(libs.composecolorpicker)
 
+    implementation(libs.jsoup)
+
     // Legacy dependencies
     implementation(libs.androidx.transition)
 

ui/src/main/java/de/mm20/launcher2/ui/launcher/search/wikipedia/WikipediaItem.kt

@@ -33,6 +33,7 @@ import de.mm20.launcher2.ui.component.ToolbarAction
 import de.mm20.launcher2.ui.ktx.toDp
 import de.mm20.launcher2.ui.launcher.search.website.WebsiteItem
 import de.mm20.launcher2.ui.locals.LocalFavoritesEnabled
+import de.mm20.launcher2.ui.utils.htmlToAnnotatedString
 
 @Composable
 fun WikipediaItem(
@@ -72,7 +73,7 @@ fun WikipediaItem(
             )
             Text(
                 modifier = Modifier.padding(vertical = 8.dp),
-                text = wikipedia.text,
+                text = htmlToAnnotatedString(wikipedia.text),
                 style = MaterialTheme.typography.bodySmall
             )
         }

ui/src/main/java/de/mm20/launcher2/ui/utils/htmlToAnnotatedString.kt

@@ -0,0 +1,105 @@
+package de.mm20.launcher2.ui.utils
+
+import androidx.compose.ui.text.*
+import androidx.compose.ui.text.font.FontFamily
+import androidx.compose.ui.text.font.FontStyle
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.text.style.BaselineShift
+import androidx.compose.ui.text.style.TextDecoration
+import androidx.compose.ui.text.style.TextIndent
+import androidx.compose.ui.unit.em
+import org.jsoup.Jsoup
+import org.jsoup.nodes.Element
+import org.jsoup.nodes.TextNode
+
+fun htmlToAnnotatedString(html: String): AnnotatedString {
+    val document = Jsoup.parse(html.replace("\n", ""))
+    return buildAnnotatedString {
+        addNodes(this, document)
+    }
+}
+
+private val blockElements = arrayOf("p", "h1", "h2", "h3", "h4", "h5", "h6", "li", "pre")
+
+private val inlineElements = arrayOf("i", "b", "strong", "em", "sup", "sub", "u", "s", "code", "br")
+
+/**
+ * @param inParagraph: ParagraphStyles may not be nested, this parameter indicates if we are already inside a paragraph
+ */
+private fun addNodes(builder: AnnotatedString.Builder, element: Element, inParagraph: Boolean = false) {
+    val tagName = element.tag().normalName()
+    when {
+        blockElements.contains(tagName) -> {
+            val spanStyle = SpanStyle(
+                fontSize = when (tagName) {
+                    "h1" -> 2.em
+                    "h2" -> 1.75.em
+                    "h3" -> 1.5.em
+                    "h4" -> 1.25.em
+                    "h5" -> 1.125.em
+                    "h6" -> 1.em
+                    else -> 1.em
+                },
+                fontWeight = if (tagName.matches(Regex("h[1-6]"))) FontWeight.Bold else FontWeight.Normal,
+                fontFamily = if (tagName == "pre") FontFamily.Monospace else null
+            )
+
+            if (!inParagraph) {
+                builder.withStyle(ParagraphStyle(
+                    textIndent = if (tagName == "li") TextIndent(0.em, 1.em) else TextIndent.None
+                )) {
+                    withStyle(
+                        spanStyle
+                    ) {
+                        if (tagName == "li") builder.append(" • ")
+                        children(builder, element, true)
+                    }
+                }
+            } else {
+                builder.append("\n")
+                builder.withStyle(
+                    spanStyle
+                ) {
+                    if (tagName == "li") builder.append(" • ")
+                    children(builder, element, true)
+                }
+            }
+        }
+        inlineElements.contains(tagName) -> {
+            builder.withStyle(
+                SpanStyle(
+                    fontStyle = if (tagName == "i" || tagName == "em") FontStyle.Italic else FontStyle.Normal,
+                    fontWeight = if (tagName == "b" || tagName == "strong") FontWeight.Bold else FontWeight.Normal,
+                    textDecoration = when (tagName) {
+                        "u" -> TextDecoration.Underline
+                        "s" -> TextDecoration.LineThrough
+                        else -> TextDecoration.None
+                    },
+                    baselineShift = when (tagName) {
+                        "sup" -> BaselineShift.Superscript
+                        "sub" -> BaselineShift.Subscript
+                        else -> BaselineShift.None
+                    },
+                    fontFamily = if (tagName == "code") FontFamily.Monospace else null
+                )
+            ) {
+                if(tagName == "br") builder.append("\n")
+                children(builder, element, inParagraph)
+            }
+        }
+        else -> {
+            children(builder, element, inParagraph)
+        }
+    }
+}
+
+private fun children(builder: AnnotatedString.Builder, element: Element, inParagraph: Boolean) {
+    for (node in element.childNodes()) {
+        if (node is TextNode) {
+            builder.append(node.text())
+        }
+        if (node is Element) {
+            addNodes(builder, node, inParagraph)
+        }
+    }
+}

wikipedia/src/main/java/de/mm20/launcher2/wikipedia/WikipediaApi.kt

@@ -34,7 +34,7 @@ data class WikipediaGetPageImageResultQueryPageThumnail(
 )
 
 interface WikipediaApi {
-    @GET("w/api.php?action=query&generator=search&redirects=true&gsrlimit=1&explaintext=true&exchars=500&prop=extracts&exintro=true&format=json")
+    @GET("w/api.php?action=query&generator=search&redirects=true&gsrlimit=1&exchars=500&prop=extracts&exintro=true&format=json")
     suspend fun search(@Query("gsrsearch") query: String): WikipediaSearchResult
 
     @GET("w/api.php?action=query&prop=pageimages&format=json")