ykatchou/ylauncher

Purpose and runtime

yLauncher is a native Android home-screen launcher: a minimalist, gesture-driven interface for launching installed apps, organizing favorites/folders/panels, showing notification summaries, and hosting widgets. It is Kotlin 2.1 on Android (min SDK 26, compile SDK 36), using Jetpack Compose/Material 3, MVVM with StateFlow, Hilt, Room, DataStore, and Navigation Compose.

Application bootstrap and composition

Android launches through the manifest and Compose activity; the application class initializes process-level dependencies. Hilt’s module defines the dependency boundary for repositories, persistence, and platform integrations.

• app/src/main/AndroidManifest.xml

• app/src/main/java/com/ykatchou/ylauncher/MainActivity.kt

• app/src/main/java/com/ykatchou/ylauncher/YLauncherApp.kt

• app/src/main/java/com/ykatchou/ylauncher/di/AppModule.kt

Home workspace and state orchestration

The home screen is the primary workspace: it renders a selected panel’s favorites, folders, clock, notification badges, widgets, gesture targets, and configurable HAL button. HomeViewModel coordinates initial loading and mutations across app inventory, persisted favorites/folders/panels, and preferences; UI editing surfaces feed those changes back through it.

• app/src/main/java/com/ykatchou/ylauncher/ui/home/HomeScreen.kt

• app/src/main/java/com/ykatchou/ylauncher/ui/home/HomeViewModel.kt

• app/src/main/java/com/ykatchou/ylauncher/ui/home/EditFavoritesSheet.kt

• app/src/main/java/com/ykatchou/ylauncher/ui/home/EditPanelsDialog.kt

Installed-app discovery and drawer flow

AppRepository is the boundary to Android’s installed-app/package data and produces app information consumed by both home and drawer. The drawer ViewModel maintains searchable app-list state; the screen supports live filtering, single-match auto-launch, alphabet navigation, and !-prefixed DuckDuckGo bang search behavior. Launching crosses into Android intents via the launcher utility.

• app/src/main/java/com/ykatchou/ylauncher/data/repository/AppRepository.kt

• app/src/main/java/com/ykatchou/ylauncher/ui/drawer/AppDrawerViewModel.kt

• app/src/main/java/com/ykatchou/ylauncher/ui/drawer/AppDrawerScreen.kt

• app/src/main/java/com/ykatchou/ylauncher/util/AppLauncher.kt

Persistence and preference boundary

Room persists launcher-owned layout entities—favorites, folders, and panels—behind DAOs and a central database. DataStore-backed preferences hold user configuration such as gestures, visual settings, hidden apps, and action selection. Models form the shared data vocabulary between repository/ViewModel/UI layers.

• app/src/main/java/com/ykatchou/ylauncher/data/db/YLauncherDatabase.kt

• app/src/main/java/com/ykatchou/ylauncher/data/db/FavoriteDao.kt

• app/src/main/java/com/ykatchou/ylauncher/data/db/FolderDao.kt

• app/src/main/java/com/ykatchou/ylauncher/data/repository/PrefsRepository.kt

Android system integrations

Platform APIs provide notification access, usage statistics, flashlight control, app-widget hosting, app launching, and screen-lock-related actions. NotificationService is the privileged notification ingestion boundary; its output maps to app notification models for home display. Widget host code embeds Android widgets in Compose-facing UI.

• app/src/main/java/com/ykatchou/ylauncher/service/NotificationService.kt

• app/src/main/java/com/ykatchou/ylauncher/data/model/AppNotification.kt

• app/src/main/java/com/ykatchou/ylauncher/widget/LauncherWidgetHost.kt

• app/src/main/java/com/ykatchou/ylauncher/ui/components/AppWidgetContainer.kt

Configurable actions, settings, and monetization

The HAL button and home gestures resolve configured actions through a dedicated action model/executor, isolating UI events from platform side effects. Settings is the user-facing configuration surface. Billing supports optional purchase flows through Google Play Billing; review and Play Store helpers integrate with Play services/store intents.

• app/src/main/java/com/ykatchou/ylauncher/ui/hal/HalAction.kt

• app/src/main/java/com/ykatchou/ylauncher/ui/hal/HalActionExecutor.kt

• app/src/main/java/com/ykatchou/ylauncher/ui/settings/SettingsScreen.kt

• app/src/main/java/com/ykatchou/ylauncher/billing/BillingManager.kt>