Improve OSS licenses screen

app-android/src/main/java/io/github/droidkaigi/confsched2023/KaigiApp.kt

@@ -41,6 +41,10 @@ import io.github.droidkaigi.confsched2023.designsystem.theme.KaigiTheme
 import io.github.droidkaigi.confsched2023.floormap.floorMapScreenRoute
 import io.github.droidkaigi.confsched2023.floormap.navigateFloorMapScreen
 import io.github.droidkaigi.confsched2023.floormap.nestedFloorMapScreen
+import io.github.droidkaigi.confsched2023.license.navigateOssLicenseDetailScreen
+import io.github.droidkaigi.confsched2023.license.navigateOssLicenseScreen
+import io.github.droidkaigi.confsched2023.license.nestedOssLicenseDetailScreen
+import io.github.droidkaigi.confsched2023.license.nestedOssLicenseScreen
 import io.github.droidkaigi.confsched2023.main.MainNestedGraphStateHolder
 import io.github.droidkaigi.confsched2023.main.MainScreenTab
 import io.github.droidkaigi.confsched2023.main.MainScreenTab.About
@@ -125,6 +129,19 @@ private fun KaigiNavHost(
             onBackClick = navController::popBackStack,
             onStaffClick = externalNavController::navigate,
         )
+        nestedOssLicenseScreen(
+            onLicenseClick = { license ->
+                navController.navigateOssLicenseDetailScreen(license)
+            },
+            onUpClick = {
+                navController.navigateUp()
+            },
+        )
+        nestedOssLicenseDetailScreen(
+            onUpClick = {
+                navController.navigateUp()
+            },
+        )
         // For KMP, we are not using navigation abstraction for contributors screen
         composable(contributorsScreenRoute) {
             val lifecycleOwner = LocalLifecycleOwner.current
@@ -171,7 +188,7 @@ private fun NavGraphBuilder.mainScreen(
                         Sponsors -> navController.navigateSponsorsScreen()
                         CodeOfConduct -> { externalNavController.navigate(url = "$portalBaseUrl/about/code-of-conduct") }
                         Contributors -> navController.navigate(contributorsScreenRoute)
-                        License -> externalNavController.navigateToLicenseScreen()
+                        License -> navController.navigateOssLicenseScreen()
                         Medium -> externalNavController.navigate(url = "https://medium.com/droidkaigi")
                         PrivacyPolicy -> {
                             externalNavController.navigate(url = "$portalBaseUrl/about/privacy")

app-android/src/main/java/io/github/droidkaigi/confsched2023/license/License.kt

@@ -0,0 +1,21 @@
+package io.github.droidkaigi.confsched2023.license
+
+import kotlinx.collections.immutable.PersistentList
+import kotlinx.collections.immutable.persistentListOf
+
+data class License(
+    val name: String,
+    val offset: Int,
+    val length: Int,
+    val detail: String = "",
+)
+
+data class OssLicenseGroup(
+    val title: String,
+    val licenses: List<License>,
+    val expand: Boolean = false,
+)
+
+data class OssLicense(
+    val groupList: PersistentList<OssLicenseGroup> = persistentListOf(),
+)

app-android/src/main/java/io/github/droidkaigi/confsched2023/license/OssLicenseDetailScreen.kt

@@ -0,0 +1,90 @@
+package io.github.droidkaigi.confsched2023.license
+
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.rememberScrollState
+import androidx.compose.foundation.verticalScroll
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.ArrowBack
+import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.Icon
+import androidx.compose.material3.IconButton
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Scaffold
+import androidx.compose.material3.Text
+import androidx.compose.material3.TopAppBar
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.collectAsState
+import androidx.compose.runtime.getValue
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.unit.dp
+import androidx.hilt.navigation.compose.hiltViewModel
+import androidx.navigation.NavController
+import androidx.navigation.NavGraphBuilder
+import androidx.navigation.compose.composable
+
+const val ossLicenseDetailScreenRouteNameArgument = "name"
+const val ossLicenseDetailScreenRoute = "osslicense"
+fun NavGraphBuilder.nestedOssLicenseDetailScreen(onUpClick: () -> Unit) {
+    composable("$ossLicenseDetailScreenRoute/{$ossLicenseDetailScreenRouteNameArgument}") {
+        OssLicenseDetailScreen(
+            onUpClick = onUpClick,
+        )
+    }
+}
+
+fun NavController.navigateOssLicenseDetailScreen(
+    license: License,
+) {
+    val licenseName = license.name.replace(' ', '-')
+    navigate("$ossLicenseDetailScreenRoute/$licenseName")
+}
+
+data class OssLicenseDetailScreenUiState(
+    val ossLicense: License? = null,
+)
+
+@OptIn(ExperimentalMaterial3Api::class)
+@Composable
+fun OssLicenseDetailScreen(
+    modifier: Modifier = Modifier,
+    viewModel: OssLicenseDetailViewModel = hiltViewModel<OssLicenseDetailViewModel>(),
+    onUpClick: () -> Unit,
+) {
+    val uiState by viewModel.uiState.collectAsState()
+
+    Scaffold(
+        modifier = modifier,
+        topBar = {
+            TopAppBar(
+                title = {
+                    Text(text = "OSS ライセンス")
+                },
+                navigationIcon = {
+                    IconButton(onClick = { onUpClick() }) {
+                        Icon(
+                            imageVector = Icons.Default.ArrowBack,
+                            contentDescription = "back button",
+                        )
+                    }
+                },
+            )
+        },
+    ) { paddingValues ->
+        Box(modifier = Modifier.padding(paddingValues)) {
+            Column(
+                modifier = Modifier
+                    .verticalScroll(rememberScrollState())
+                    .padding(horizontal = 8.dp),
+            ) {
+                uiState.ossLicense?.run {
+                    Text(
+                        text = this.detail,
+                        style = MaterialTheme.typography.bodyMedium,
+                    )
+                }
+            }
+        }
+    }
+}

app-android/src/main/java/io/github/droidkaigi/confsched2023/license/OssLicenseDetailViewModel.kt

@@ -0,0 +1,59 @@
+package io.github.droidkaigi.confsched2023.license
+
+import androidx.lifecycle.SavedStateHandle
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import dagger.hilt.android.lifecycle.HiltViewModel
+import io.github.droidkaigi.confsched2023.ui.buildUiState
+import kotlinx.collections.immutable.PersistentList
+import kotlinx.collections.immutable.persistentListOf
+import kotlinx.coroutines.flow.SharingStarted
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.stateIn
+import javax.inject.Inject
+
+@HiltViewModel
+class OssLicenseDetailViewModel @Inject constructor(
+    private val ossLicenseRepository: OssLicenseRepository,
+    savedStateHandle: SavedStateHandle,
+) : ViewModel() {
+
+    private val licenseName = savedStateHandle.getStateFlow<String>(
+        ossLicenseDetailScreenRouteNameArgument,
+        "",
+    )
+
+    private val licenseStateFlow: StateFlow<PersistentList<License>> =
+        ossLicenseRepository.licenseMetaData()
+            .stateIn(
+                scope = viewModelScope,
+                started = SharingStarted.WhileSubscribed(5_000),
+                initialValue = persistentListOf(),
+            )
+
+    private val licenseDetailStateFlow: StateFlow<List<String>> =
+        ossLicenseRepository.licenseDetailData()
+            .stateIn(
+                scope = viewModelScope,
+                started = SharingStarted.WhileSubscribed(5_000),
+                initialValue = emptyList(),
+            )
+
+    internal val uiState: StateFlow<OssLicenseDetailScreenUiState> =
+        buildUiState(licenseStateFlow, licenseDetailStateFlow) { metadata, detail ->
+            val license = metadata.firstOrNull { it.name.replace(' ', '-') == licenseName.value }
+                ?.let { license ->
+                    val detail = kotlin.runCatching {
+                        val start = license.offset
+                        val end = license.offset + license.length
+                        detail.subList(
+                            fromIndex = start,
+                            toIndex = end,
+                        ).joinToString("\n")
+                    }.getOrElse { "" }
+                    license.copy(detail = detail)
+                }
+
+            OssLicenseDetailScreenUiState(license)
+        }
+}

app-android/src/main/java/io/github/droidkaigi/confsched2023/license/OssLicenseRepository.kt

@@ -0,0 +1,80 @@
+package io.github.droidkaigi.confsched2023.license
+
+import android.content.Context
+import io.github.droidkaigi.confsched2023.R
+import kotlinx.collections.immutable.PersistentList
+import kotlinx.collections.immutable.persistentListOf
+import kotlinx.collections.immutable.toPersistentList
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.MutableStateFlow
+import okio.BufferedSource
+import okio.buffer
+import okio.source
+import javax.inject.Inject
+
+public interface OssLicenseRepository {
+    public fun licenseMetaData(): Flow<PersistentList<License>>
+
+    public fun licenseDetailData(): Flow<List<String>>
+
+    public fun refresh(): Unit
+}
+
+internal class OssLicenseRepositoryImpl @Inject constructor(
+    private val context: Context,
+) : OssLicenseRepository {
+
+    private val licenseMetaStateFlow =
+        MutableStateFlow<PersistentList<License>>(persistentListOf())
+
+    private val licenseDetailStateFlow = MutableStateFlow<List<String>>(emptyList())
+
+    override fun licenseMetaData(): Flow<PersistentList<License>> {
+        refresh()
+        return licenseMetaStateFlow
+    }
+
+    override fun licenseDetailData(): Flow<List<String>> {
+        refresh()
+        return licenseDetailStateFlow
+    }
+
+    override fun refresh() {
+        licenseMetaStateFlow.value = readLicensesMetaFile()
+            .toRowList()
+            .parseToLibraryItem()
+            .toPersistentList()
+
+        licenseDetailStateFlow.value = readLicensesFile()
+            .toRowList()
+    }
+
+    private fun readLicensesMetaFile(): BufferedSource {
+        return context.resources.openRawResource(R.raw.third_party_license_metadata)
+            .source()
+            .buffer()
+    }
+
+    private fun readLicensesFile(): BufferedSource {
+        return context.resources.openRawResource(R.raw.third_party_licenses)
+            .source()
+            .buffer()
+    }
+
+    private fun List<String>.parseToLibraryItem(): List<License> {
+        return map {
+            val (position, name) = it.split(' ', limit = 2)
+            val (offset, length) = position.split(':').map { it.toInt() }
+            License(name, offset, length)
+        }
+    }
+
+    private fun BufferedSource.toRowList(): List<String> {
+        val list: MutableList<String> = mutableListOf()
+        while (true) {
+            val line = readUtf8Line() ?: break
+            list.add(line)
+        }
+        return list
+    }
+}

app-android/src/main/java/io/github/droidkaigi/confsched2023/license/OssLicenseRepositoryModule.kt

@@ -0,0 +1,21 @@
+package io.github.droidkaigi.confsched2023.license
+
+import android.content.Context
+import dagger.Module
+import dagger.Provides
+import dagger.hilt.InstallIn
+import dagger.hilt.android.qualifiers.ApplicationContext
+import dagger.hilt.components.SingletonComponent
+import javax.inject.Singleton
+
+@Module
+@InstallIn(SingletonComponent::class)
+class OssLicenseRepositoryModule {
+    @Provides
+    @Singleton
+    fun provideSponsorsRepository(
+        @ApplicationContext context: Context,
+    ): OssLicenseRepository {
+        return OssLicenseRepositoryImpl(context = context)
+    }
+}