diff -r 137a5da55ed9 -r bedda51b88eb ui/src/main/java/com/geekorum/aboutoss/ui/OpenSourceLicenseScreen.kt
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ui/src/main/java/com/geekorum/aboutoss/ui/OpenSourceLicenseScreen.kt	Thu Apr 13 17:11:33 2023 -0400
@@ -0,0 +1,177 @@
+/*
+ * AboutOss is a utility library to retrieve and display
+ * opensource licenses in Android applications.
+ *
+ * Copyright (C) 2023 by Frederic-Charles Barthelery.
+ *
+ * This file is part of AboutOss.
+ *
+ * AboutOss is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * AboutOss is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with AboutOss.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package com.geekorum.aboutoss.ui
+
+import androidx.compose.animation.core.animateDpAsState
+import androidx.compose.foundation.gestures.detectTapGestures
+import androidx.compose.foundation.layout.*
+import androidx.compose.foundation.rememberScrollState
+import androidx.compose.foundation.verticalScroll
+import androidx.compose.material.Icon
+import androidx.compose.material.IconButton
+import androidx.compose.material.MaterialTheme
+import androidx.compose.material.Scaffold
+import androidx.compose.material.Text
+import androidx.compose.material.TopAppBar
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.ArrowBack
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.collectAsState
+import androidx.compose.runtime.derivedStateOf
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.input.pointer.pointerInput
+import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.text.AnnotatedString
+import androidx.compose.ui.text.ExperimentalTextApi
+import androidx.compose.ui.text.SpanStyle
+import androidx.compose.ui.text.TextLayoutResult
+import androidx.compose.ui.text.UrlAnnotation
+import androidx.compose.ui.text.buildAnnotatedString
+import androidx.compose.ui.text.style.TextDecoration
+import androidx.compose.ui.text.style.TextOverflow
+import androidx.compose.ui.text.withAnnotation
+import androidx.compose.ui.text.withStyle
+import androidx.compose.ui.unit.dp
+import androidx.core.net.toUri
+
+@Composable
+fun OpenSourceLicenseScreen(
+    viewModel: OpenSourceLicensesViewModel,
+    dependency: String,
+    onBackClick: () -> Unit,
+) {
+    val context = LocalContext.current
+    val license by viewModel.getLicenseDependency(dependency).collectAsState("")
+    OpenSourceLicenseScreen(
+        dependency = dependency,
+        license = license,
+        onBackClick = onBackClick,
+        onUrlClick = {
+            viewModel.openLinkInBrowser(context, it)
+        },
+        onUrlsFound = {
+            val uris = it.map { uri -> uri.toUri() }
+            viewModel.mayLaunchUrl(*uris.toTypedArray())
+        }
+    )
+}
+
+@OptIn(ExperimentalLayoutApi::class, ExperimentalTextApi::class)
+@Composable
+fun OpenSourceLicenseScreen(
+    dependency: String,
+    license: String,
+    onBackClick: () -> Unit,
+    onUrlClick: (String) -> Unit,
+    onUrlsFound: (List<String>) -> Unit,
+) {
+    val linkifiedLicense = linkifyText(text = license)
+    LaunchedEffect(linkifiedLicense) {
+        val uris =
+            linkifiedLicense.getUrlAnnotations(0, linkifiedLicense.length).map { it.item.url }
+        onUrlsFound(uris)
+    }
+
+    val scrollState = rememberScrollState()
+    val hasScrolled by remember {
+        derivedStateOf { scrollState.value > 0 }
+    }
+    val topBarElevation by animateDpAsState(
+        if (hasScrolled) 4.dp else 0.dp
+    )
+    Scaffold(topBar = {
+        TopAppBar(title = { Text(dependency, overflow = TextOverflow.Ellipsis, maxLines = 1) },
+            navigationIcon = {
+                IconButton(onClick = onBackClick) {
+                    Icon(
+                        Icons.Default.ArrowBack,
+                        contentDescription = null
+                    )
+                }
+            },
+            elevation = topBarElevation
+        )
+    }) { paddingValues ->
+        val layoutResult = remember { mutableStateOf<TextLayoutResult?>(null) }
+        val pressIndicator = Modifier.pointerInput(layoutResult, linkifiedLicense) {
+            detectTapGestures { pos ->
+                layoutResult.value?.let { layoutResult ->
+                    val posWithScroll = pos.copy(y = pos.y + scrollState.value)
+                    val offset = layoutResult.getOffsetForPosition(posWithScroll)
+                    linkifiedLicense.getUrlAnnotations(start = offset, end = offset)
+                        .firstOrNull()?.let { annotation ->
+                            onUrlClick(annotation.item.url)
+                        }
+                }
+            }
+        }
+
+        Text(linkifiedLicense,
+            modifier = Modifier
+                .padding(horizontal = 16.dp)
+                .fillMaxSize()
+                .then(pressIndicator)
+                .verticalScroll(scrollState)
+                .padding(paddingValues)
+                .consumeWindowInsets(paddingValues),
+            onTextLayout = {
+                layoutResult.value = it
+            }
+        )
+    }
+}
+
+/**
+ * https://regexr.com/37i6s
+ */
+private val UrlRegexp = """https?://(www\.)?[-a-zA-Z0-9@:%._+~#=]{2,256}\.[a-z]{2,4}\b([-a-zA-Z0-9@:%_+.~#?&/=]*)""".toRegex()
+
+@OptIn(ExperimentalTextApi::class)
+@Composable
+private fun linkifyText(text: String): AnnotatedString {
+    val style = SpanStyle(
+        color = MaterialTheme.colors.secondary,
+        textDecoration = TextDecoration.Underline
+    )
+    return remember(text, style) {
+        buildAnnotatedString {
+            var currentIdx = 0
+            for (match in UrlRegexp.findAll(text)) {
+                if (currentIdx < match.range.first) {
+                    append(text.substring(currentIdx, match.range.first))
+                }
+                val url = text.substring(match.range)
+                withAnnotation(UrlAnnotation(url)) {
+                    withStyle(style) {
+                        append(url)
+                    }
+                }
+                currentIdx = match.range.last + 1
+            }
+            append(text.substring(currentIdx))
+        }
+    }
+}