Add a dedicated screen showing all categories

app/src/main/kotlin/org/fdroid/ui/Main.kt

@@ -16,6 +16,8 @@ import androidx.navigation3.runtime.NavEntry
 import androidx.navigation3.runtime.NavKey
 import androidx.navigation3.runtime.entryProvider
 import org.fdroid.ui.apps.myAppsEntry
+import org.fdroid.ui.categories.Categories
+import org.fdroid.ui.categories.CategoriesViewModel
 import org.fdroid.ui.details.NoAppSelected
 import org.fdroid.ui.details.appDetailsEntry
 import org.fdroid.ui.discover.discoverEntry
@@ -78,6 +80,14 @@ fun Main(onListeningForIntent: () -> Unit = {}) {
         onSearchCleared = viewModel::onSearchCleared,
       )
     }
+    entry(NavigationKey.Categories) {
+      val viewModel = hiltViewModel<CategoriesViewModel>()
+      Categories(
+        categories = viewModel.categories.collectAsStateWithLifecycle(null).value,
+        onNav = { navKey -> navigator.navigate(navKey) },
+        onBackClicked = { navigator.goBack() },
+      )
+    }
     entry(NavigationKey.Settings) {
       val viewModel = hiltViewModel<SettingsViewModel>()
       Settings(

app/src/main/kotlin/org/fdroid/ui/categories/Categories.kt

@@ -0,0 +1,94 @@
+package org.fdroid.ui.categories
+
+import androidx.compose.foundation.layout.Arrangement.spacedBy
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.foundation.lazy.LazyListState
+import androidx.compose.foundation.lazy.items
+import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.Scaffold
+import androidx.compose.material3.Text
+import androidx.compose.material3.TopAppBar
+import androidx.compose.material3.TopAppBarDefaults.enterAlwaysScrollBehavior
+import androidx.compose.material3.rememberTopAppBarState
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.saveable.rememberSaveable
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.input.nestedscroll.nestedScroll
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.text.style.TextOverflow
+import androidx.compose.ui.tooling.preview.PreviewLightDark
+import androidx.compose.ui.unit.dp
+import androidx.navigation3.runtime.NavKey
+import org.fdroid.R
+import org.fdroid.ui.FDroidContent
+import org.fdroid.ui.utils.BackButton
+import org.fdroid.ui.utils.BigLoadingIndicator
+
+@Composable
+@OptIn(ExperimentalMaterial3Api::class)
+fun Categories(
+  categories: List<CategoryItem>?,
+  onNav: (NavKey) -> Unit,
+  onBackClicked: () -> Unit,
+  modifier: Modifier = Modifier,
+) {
+  val scrollBehavior = enterAlwaysScrollBehavior(rememberTopAppBarState())
+  Scaffold(
+    topBar = {
+      TopAppBar(
+        title = {
+          Text(
+            text = stringResource(R.string.main_menu__categories),
+            maxLines = 1,
+            overflow = TextOverflow.MiddleEllipsis,
+          )
+        },
+        navigationIcon = { BackButton(onClick = onBackClicked) },
+        scrollBehavior = scrollBehavior,
+      )
+    },
+    modifier = modifier.nestedScroll(scrollBehavior.nestedScrollConnection),
+  ) { paddingValues ->
+    val listState = rememberSaveable(saver = LazyListState.Saver) { LazyListState() }
+    if (categories == null) {
+      BigLoadingIndicator(modifier.padding(paddingValues))
+    } else {
+      LazyColumn(
+        state = listState,
+        contentPadding = paddingValues,
+        verticalArrangement = spacedBy(8.dp),
+      ) {
+        items(items = categories, key = { it.id }, contentType = { "C" }) { categoryItem ->
+          CategoryRow(categoryItem, onNav)
+        }
+      }
+    }
+  }
+}
+
+@Composable
+@PreviewLightDark
+private fun PreviewLoading() {
+  FDroidContent {
+    Categories(null, {}, {})
+  }
+}
+
+@Composable
+@PreviewLightDark
+private fun Preview() {
+  FDroidContent {
+    val categories =
+      listOf(
+        CategoryItem("App Store & Updater", "App Store & Updater"),
+        CategoryItem("Browser", "Browser"),
+        CategoryItem("Calendar & Agenda", "Calendar & Agenda"),
+        CategoryItem("Cloud Storage & File Sync", "Cloud Storage & File Sync"),
+        CategoryItem("Connectivity", "Connectivity"),
+        CategoryItem("Development", "Development"),
+        CategoryItem("doesn't exist", "Foo bar"),
+      )
+    Categories(categories, {}, {})
+  }
+}

app/src/main/kotlin/org/fdroid/ui/categories/CategoriesViewModel.kt

@@ -0,0 +1,28 @@
+package org.fdroid.ui.categories
+
+import android.app.Application
+import androidx.core.os.LocaleListCompat
+import androidx.lifecycle.AndroidViewModel
+import androidx.lifecycle.asFlow
+import dagger.hilt.android.lifecycle.HiltViewModel
+import java.text.Collator
+import java.util.Locale
+import javax.inject.Inject
+import kotlinx.coroutines.flow.map
+import org.fdroid.database.FDroidDatabase
+
+@HiltViewModel
+class CategoriesViewModel @Inject constructor(app: Application, db: FDroidDatabase) :
+  AndroidViewModel(app) {
+  private val collator = Collator.getInstance(Locale.getDefault())
+  private val localeList = LocaleListCompat.getDefault()
+
+  val categories =
+    db.getRepositoryDao().getLiveCategories().asFlow().map { categories ->
+      categories
+        .map { category ->
+          CategoryItem(id = category.id, name = category.getName(localeList) ?: "Unknown Category")
+        }
+        .sortedWith { c1, c2 -> collator.compare(c1.name, c2.name) }
+    }
+}

app/src/main/kotlin/org/fdroid/ui/categories/CategoryList.kt

@@ -21,6 +21,7 @@ import androidx.compose.ui.unit.sp
 import androidx.navigation3.runtime.NavKey
 import org.fdroid.R
 import org.fdroid.ui.FDroidContent
+import org.fdroid.ui.navigation.NavigationKey
 
 @Composable
 @OptIn(ExperimentalMaterial3ExpressiveApi::class)
@@ -29,7 +30,7 @@ fun CategoryList(
   onNav: (NavKey) -> Unit,
   modifier: Modifier = Modifier,
 ) {
-  val onAllCategories = { /* TODO */ }
+  val onAllCategories = { onNav(NavigationKey.Categories) }
   AnimatedVisibility(!categoryList.isNullOrEmpty()) {
     Column(modifier = modifier) {
       Row(

app/src/main/kotlin/org/fdroid/ui/navigation/NavigationKey.kt

@@ -39,6 +39,8 @@ sealed interface NavigationKey : NavKey {
 
   @Serializable data class AppList(val type: AppListType) : NavigationKey
 
+  @Serializable data object Categories : NavigationKey
+
   @Serializable data object Repos : NavigationKey
 
   @Serializable data class RepoDetails(val repoId: Long) : NavigationKey