Gym Log

An Android app for tracking workouts with a clean MVVM architecture, Room persistence, and a modern Android 14 (SDK 34) target. For sample I/O traces and additional information, visit the project page:
https://www.rsiddiq.com/software-design.html

Highlights

• Android SDK 34 (minSdk=34, targetSdk=34, compileSdk=34)
• Language: Java
• Architecture: MVVM (Activities → ViewModel → Repository → Room)
• Persistence: Room Database with entities for User and GymLog
• Reactive UI: LiveData-backed queries and a RecyclerView adapter
• Type safety: LocalDateTime persisted via a custom TypeConverter
• Build: Gradle Kotlin DSL

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Features

• Create accounts and log in (basic username/password model with optional admin flag).
• Add and view workout entries (exercise, weight, reps, timestamp).
• Per-user filtering of logs with queries ordered by most recent first.
• Lifecycle-aware data observation via LiveData.
• RecyclerView-based list rendering with a compact ViewHolder/Adapter layer.

Note: The database is configured with fallbackToDestructiveMigration (no auto-migrations defined yet). This simplifies local development but will drop data on schema changes during upgrades.

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Project Structure

app/
  src/main/java/com/gymlog/
    LoginActivity.java
    MainActivity.java
    viewHolders/
      GymLogAdapter.java
      GymLogViewHolder.java
      GymLogViewModel.java
    database/
      GymLogDatabase.java        # Room database, builder with fallbackToDestructiveMigration
      GymLogRepository.java      # App data access facade, wraps DAOs
      GymLogDAO.java             # Queries for GymLog
      UserDAO.java               # Queries for User
      entities/
        GymLog.java              # @Entity(id, exercise, weight, reps, date, userId)
        User.java                # @Entity(id, username, password, isAdmin)
      typeConverters/
        LocalDateTypeConverter.java   # Map LocalDateTime <-> Long/String
  src/main/res/                  # Layouts, strings, colors, themes
  src/androidTest/...            # Instrumented test scaffold
  src/test/...                   # Unit test scaffold
build.gradle.kts                 # Top-level build config
app/build.gradle.kts            # Android app module (Room, AppCompat, Material, etc.)
settings.gradle.kts             # Repos, plugin management
gradle/libs.versions.toml       # Centralized dependency versions

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Data Model

User

Field	Type	Notes
id	int (PK)	Auto-generated
username	String	Unique handle
password	String	Plain-string storage (demo only)
isAdmin	boolean	Optional privilege

GymLog

Field	Type	Notes
id	int (PK)	Auto-generated
exercise	String	Exercise name
weight	double	Working weight
reps	int	Repetitions
date	LocalDateTime	Stored via LocalDateTypeConverter
userId	int (FK)	Owner (User.id)

Key DAO methods

• GymLogDAO.getRecordsByUserId(...) / getRecordsByUserIdLiveData(...) – latest-first ordering.
• UserDAO.getUserByUserName(username) and getUserByUserId(id) for auth/lookup.

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Build & Run

Prerequisites

• Android Studio Giraffe or later
• Android SDK Platform 34
• JDK 17+

Steps

1. Clone or unzip the project.
2. Open the root folder in Android Studio.
3. Let Gradle sync dependencies.
4. Use the app run configuration to build & deploy to an emulator or device (Android 14 recommended).

Gradle (Kotlin DSL) dependencies include:

• AppCompat, Material, Activity, ConstraintLayout
• Room (runtime + compiler via annotationProcessor)
• JUnit / AndroidX Test / Espresso

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UI Flow (High Level)

• LoginActivity: Captures credentials and resolves the active User via UserDAO/Repository.
• MainActivity: Displays logs for the active user with a RecyclerView (GymLogAdapter/GymLogViewHolder), plus input fields for adding an entry. GymLogViewModel exposes LiveData lists to keep the UI in sync.

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Quality & Security Notes

• Passwords are stored as plain strings for simplicity. Consider adding hashing (e.g., BCrypt) and input validation for production scenarios.
• The database uses fallbackToDestructiveMigration. For persistence across app upgrades, define Room migrations and remove the fallback.
• Ensure null/empty input handling for weight/reps; current code logs and continues on parse errors.