generate third-party licenses at build and show them from settings

Add AboutLibraries, whose Android Gradle plugin collects the licence and
attribution of every dependency into a generated resource at build time,
and surface it under a new About section in Settings.

app/build.gradle.kts

@@ -6,6 +6,7 @@ plugins {
     alias(libs.plugins.roborazzi)
     alias(libs.plugins.ksp)
     alias(libs.plugins.ktlint)
+    alias(libs.plugins.aboutLibraries)
 }
 
 ktlint {
@@ -131,6 +132,8 @@ dependencies {
     implementation(libs.coil.compose)
     implementation(libs.coil.network.okhttp)
     implementation(libs.koin.androidx.compose)
+    implementation(libs.aboutlibraries.core)
+    implementation(libs.aboutlibraries.compose.m3)
     ksp(libs.androidx.room3.compiler)
 
     coreLibraryDesugaring(libs.desugar.jdk.libs)

app/src/main/kotlin/com/subtracks/ui/AppRoot.kt

@@ -77,6 +77,7 @@ import com.subtracks.ui.playback.MiniPlayer
 import com.subtracks.ui.playback.NowPlayingRoute
 import com.subtracks.ui.playback.QueueRoute
 import com.subtracks.ui.settings.AddSourceRoute
+import com.subtracks.ui.settings.LicensesRoute
 import com.subtracks.ui.settings.SettingsRoute
 import com.subtracks.ui.theme.ArtworkTheme
 import com.subtracks.ui.theme.rememberArtworkColors
@@ -110,6 +111,7 @@ private object Routes {
     const val LIBRARY = "library"
     const val SETTINGS = "settings"
     const val DOWNLOADS = "downloads"
+    const val LICENSES = "licenses"
     const val ADD_SERVER = "add-server"
     const val EDIT_SERVER = "edit-server/{sourceId}"
     const val ALBUM_DETAIL = "album/{albumId}?coverArt={coverArt}"
@@ -358,6 +360,7 @@ private fun MainNavigation() {
                         SettingsRoute(
                             onAddServer = { navController.navigate(Routes.ADD_SERVER) },
                             onOpenDownloads = { navController.navigate(Routes.DOWNLOADS) },
+                            onOpenLicenses = { navController.navigate(Routes.LICENSES) },
                             onEditServer = { id -> navController.navigate(Routes.editServer(id)) },
                             onBack = { navController.popBackStack() },
                         )
@@ -365,6 +368,9 @@ private fun MainNavigation() {
                     composable(Routes.DOWNLOADS) {
                         DownloadsRoute(onBack = { navController.popBackStack() })
                     }
+                    composable(Routes.LICENSES) {
+                        LicensesRoute(onBack = { navController.popBackStack() })
+                    }
                     composable(
                         route = Routes.ALBUM_DETAIL,
                         arguments =

app/src/main/kotlin/com/subtracks/ui/settings/LicensesScreen.kt

@@ -0,0 +1,55 @@
+package com.subtracks.ui.settings
+
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.padding
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.automirrored.rounded.ArrowBack
+import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.Icon
+import androidx.compose.material3.IconButton
+import androidx.compose.material3.Scaffold
+import androidx.compose.material3.Text
+import androidx.compose.material3.TopAppBar
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.ui.Modifier
+import com.mikepenz.aboutlibraries.Libs
+import com.mikepenz.aboutlibraries.ui.compose.android.produceLibraries
+import com.mikepenz.aboutlibraries.ui.compose.m3.LibrariesContainer
+import com.subtracks.R
+
+@Composable
+fun LicensesRoute(
+    onBack: () -> Unit,
+    modifier: Modifier = Modifier,
+) {
+    val libs by produceLibraries(R.raw.aboutlibraries)
+    LicensesScreen(libs = libs, onBack = onBack, modifier = modifier)
+}
+
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+fun LicensesScreen(
+    libs: Libs?,
+    onBack: () -> Unit,
+    modifier: Modifier = Modifier,
+) {
+    Scaffold(
+        modifier = modifier,
+        topBar = {
+            TopAppBar(
+                title = { Text("Licenses") },
+                navigationIcon = {
+                    IconButton(onClick = onBack) {
+                        Icon(Icons.AutoMirrored.Rounded.ArrowBack, contentDescription = "Back")
+                    }
+                },
+            )
+        },
+    ) { padding ->
+        LibrariesContainer(
+            libraries = libs,
+            modifier = Modifier.fillMaxSize().padding(padding),
+        )
+    }
+}

app/src/main/kotlin/com/subtracks/ui/settings/SettingsScreen.kt

@@ -62,6 +62,7 @@ private enum class SettingsDialog { WifiQuality, MobileQuality, DownloadQuality,
 fun SettingsRoute(
     onAddServer: () -> Unit,
     onOpenDownloads: () -> Unit,
+    onOpenLicenses: () -> Unit,
     onEditServer: (Long) -> Unit,
     onBack: () -> Unit,
     viewModel: SettingsViewModel = koinViewModel(),
@@ -96,6 +97,7 @@ fun SettingsRoute(
         onOfflineChange = viewModel::setOfflineMode,
         onAddServer = onAddServer,
         onOpenDownloads = onOpenDownloads,
+        onOpenLicenses = onOpenLicenses,
         onBack = onBack,
     )
 }
@@ -123,6 +125,7 @@ fun SettingsScreen(
     onOfflineChange: (Boolean) -> Unit = {},
     onAddServer: () -> Unit,
     onOpenDownloads: () -> Unit,
+    onOpenLicenses: () -> Unit,
     onBack: () -> Unit,
     modifier: Modifier = Modifier,
 ) {
@@ -277,6 +280,14 @@ fun SettingsScreen(
                     colors = ListItemDefaults.colors(containerColor = Color.Transparent),
                 )
             }
+            item { SectionHeader("About") }
+            item {
+                ListItem(
+                    headlineContent = { Text("Licenses") },
+                    modifier = Modifier.clickable(onClick = onOpenLicenses),
+                    colors = ListItemDefaults.colors(containerColor = Color.Transparent),
+                )
+            }
             item { Spacer(Modifier.height(fill)) }
         }
     }

app/src/test/kotlin/com/subtracks/ui/AppScreenshotTest.kt

@@ -361,6 +361,7 @@ class AppScreenshotTest {
                     onScrobblingChange = {},
                     onAddServer = {},
                     onOpenDownloads = {},
+                    onOpenLicenses = {},
                     onBack = {},
                 )
             }

app/src/test/kotlin/com/subtracks/ui/settings/LicensesScreenTest.kt

@@ -0,0 +1,132 @@
+package com.subtracks.ui.settings
+
+import androidx.activity.ComponentActivity
+import androidx.compose.ui.test.hasScrollToNodeAction
+import androidx.compose.ui.test.hasText
+import androidx.compose.ui.test.junit4.v2.createAndroidComposeRule
+import androidx.compose.ui.test.onAllNodesWithText
+import androidx.compose.ui.test.onNodeWithText
+import androidx.compose.ui.test.onRoot
+import androidx.compose.ui.test.performClick
+import androidx.compose.ui.test.performScrollToNode
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import com.github.takahirom.roborazzi.RobolectricDeviceQualifiers
+import com.github.takahirom.roborazzi.captureRoboImage
+import com.mikepenz.aboutlibraries.Libs
+import com.subtracks.data.prefs.StreamQuality
+import com.subtracks.ui.theme.SubtracksTheme
+import org.junit.Assert.assertTrue
+import org.junit.Rule
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.robolectric.annotation.Config
+import org.robolectric.annotation.GraphicsMode
+
+/** Render smoke test: asserts the awaited node exists and writes a PNG for local review; it does not verify pixels. */
+@RunWith(AndroidJUnit4::class)
+@GraphicsMode(GraphicsMode.Mode.NATIVE)
+@Config(qualifiers = RobolectricDeviceQualifiers.PixelXL)
+class LicensesScreenTest {
+    @get:Rule
+    val composeRule = createAndroidComposeRule<ComponentActivity>()
+
+    @Test
+    fun licenses() {
+        val libs = Libs.Builder().withJson(fixture).build()
+        composeRule.setContent {
+            SubtracksTheme {
+                LicensesScreen(libs = libs, onBack = {})
+            }
+        }
+        awaitText("OkHttp")
+        composeRule.onRoot().captureRoboImage("src/test/screenshots/licenses.png")
+    }
+
+    @Test
+    fun settingsOpensLicenses() {
+        var opened = false
+        composeRule.setContent {
+            SubtracksTheme {
+                SettingsScreen(
+                    sources = emptyList(),
+                    activeSourceId = null,
+                    wifiQuality = StreamQuality(),
+                    mobileQuality = StreamQuality(),
+                    syncConcurrency = 1,
+                    downloadQuality = StreamQuality(),
+                    downloadOverMetered = false,
+                    scrobbling = false,
+                    onSelectSource = {},
+                    onEditServer = {},
+                    onWifiQualityChange = {},
+                    onMobileQualityChange = {},
+                    onSyncConcurrencyChange = {},
+                    onDownloadQualityChange = {},
+                    onDownloadOverMeteredChange = {},
+                    onScrobblingChange = {},
+                    onAddServer = {},
+                    onOpenDownloads = {},
+                    onOpenLicenses = { opened = true },
+                    onBack = {},
+                )
+            }
+        }
+        awaitText("Add server")
+        composeRule.onNode(hasScrollToNodeAction()).performScrollToNode(hasText("Licenses"))
+        composeRule.onNodeWithText("Licenses").performClick()
+        composeRule.waitForIdle()
+        assertTrue(opened)
+    }
+
+    private fun awaitText(text: String) {
+        composeRule.waitUntil(timeoutMillis = 5_000) {
+            composeRule.onAllNodesWithText(text).fetchSemanticsNodes().isNotEmpty()
+        }
+    }
+
+    private val fixture =
+        """
+        {
+            "libraries": [
+                {
+                    "uniqueId": "com.squareup.okhttp3:okhttp",
+                    "artifactVersion": "5.5.0",
+                    "name": "OkHttp",
+                    "description": "Square's HTTP client",
+                    "website": "https://square.github.io/okhttp/",
+                    "licenses": ["Apache-2.0"]
+                },
+                {
+                    "uniqueId": "io.coil-kt.coil3:coil-compose",
+                    "artifactVersion": "3.6.3",
+                    "name": "Coil",
+                    "description": "Image loading for Android",
+                    "website": "https://coil-kt.github.io/coil/",
+                    "licenses": ["Apache-2.0"]
+                },
+                {
+                    "uniqueId": "com.google.guava:guava",
+                    "artifactVersion": "33.0.0",
+                    "name": "Guava",
+                    "description": "Google core libraries",
+                    "website": "https://github.com/google/guava",
+                    "licenses": ["MIT"]
+                }
+            ],
+            "licenses": {
+                "Apache-2.0": {
+                    "name": "Apache License 2.0",
+                    "url": "https://spdx.org/licenses/Apache-2.0.html",
+                    "spdxId": "Apache-2.0",
+                    "hash": "Apache-2.0"
+                },
+                "MIT": {
+                    "name": "MIT License",
+                    "url": "https://spdx.org/licenses/MIT.html",
+                    "spdxId": "MIT",
+                    "hash": "MIT"
+                }
+            }
+        }
+        """.trimIndent()
+}