Make language picker sheet half-height, fix appearance in non-pure-black dark mode

Packages/ComposeUI/Sources/ComposeUI/Controllers/ComposeController.swift

@@ -119,6 +119,7 @@ public final class ComposeController: ViewController {
             .environment(\.managedObjectContext, DraftsPersistentContainer.shared.viewContext)
             .environmentObject(draft)
             .environmentObject(mastodonController.instanceFeatures)
+            .environment(\.composeUIConfig, config)
     }
     
     public func canPaste(itemProviders: [NSItemProvider]) -> Bool {
@@ -450,3 +451,13 @@ private struct GlobalFrameOutsideListPrefKey: PreferenceKey {
         value = nextValue()
     }
 }
+
+private struct ComposeUIConfigEnvironmentKey: EnvironmentKey {
+    static let defaultValue = ComposeUIConfig()
+}
+extension EnvironmentValues {
+    var composeUIConfig: ComposeUIConfig {
+        get { self[ComposeUIConfigEnvironmentKey.self] }
+        set { self[ComposeUIConfigEnvironmentKey.self] = newValue }
+    }
+}

Packages/ComposeUI/Sources/ComposeUI/Views/LanguagePicker.swift

@@ -69,6 +69,7 @@ struct LanguagePicker: View {
             NavigationStack {
                 LanguagePickerList(languageCode: languageCode, hasChangedSelection: $hasChangedSelection, isPresented: $isShowingSheet)
             }
+            .presentationDetents([.large, .medium])
         }
     }
 }
@@ -78,6 +79,8 @@ private struct LanguagePickerList: View {
     @Binding var languageCode: Locale.LanguageCode
     @Binding var hasChangedSelection: Bool
     @Binding var isPresented: Bool
+    @Environment(\.composeUIConfig.groupedBackgroundColor) private var groupedBackgroundColor
+    @Environment(\.composeUIConfig.groupedCellBackgroundColor) private var groupedCellBackgroundColor
     @State private var recentLangs: [Lang] = []
     @State private var langs: [Lang] = []
     @State private var filteredLangs: [Lang]?
@@ -102,6 +105,7 @@ private struct LanguagePickerList: View {
                 ForEach(recentLangs) { lang in
                     button(for: lang)
                 }
+                .listRowBackground(groupedCellBackgroundColor)
             } header: {
                 Text("Recently Used")
             }
@@ -110,11 +114,16 @@ private struct LanguagePickerList: View {
                 ForEach(filteredLangs ?? langs) { lang in
                     button(for: lang)
                 }
+                .listRowBackground(groupedCellBackgroundColor)
             } header: {
                 Text("All Languages")
             }
         }
+        .listStyle(.insetGrouped)
+        .scrollContentBackground(.hidden)
+        .background(groupedBackgroundColor.edgesIgnoringSafeArea(.all))
         .searchable(text: $query)
+        .scrollDismissesKeyboard(.interactively)
         .navigationTitle("Post Language")
         .navigationBarTitleDisplayMode(.inline)
         .toolbar {