CS501-hw3

Q1 LifeTracker – A Lifecycle-Aware Activity Logger

./LifeTracker

Q2 Counter++ – Reactive UI with StateFlow & Coroutines

./CounterPlus

Q3 Temperature Dashboard – Simulated Sensor Data with StateFlow and Coroutines

./TemperatureDashBoard

How to Use the Apps

1. Clone this repository:

git clone https://github.com/Spectual/CS501-hw4.git

1. Open the root folder in Android Studio.
2. Each folder (Badge, Contacts, Login, Scaffold, SplitScreen) is an independent Android project.
3. To run a specific app:
   • Open the folder in Android Studio as a separate project, or
   • Use File > Open and choose the app folder you want.
   • Click ▶ Run to launch on emulator or device.

Explanation of the Apps

1. LifeTracker

• Task: Build an app that tracks and displays Android Activity lifecycle events in real time.

• Features:

  • Uses LifecycleEventObserver to capture lifecycle transitions (ON_CREATE, ON_START, ON_RESUME, etc.).

  • Stores all events in a ViewModel to persist logs across configuration changes.

  • Displays logs in a LazyColumn, with each entry showing:

    • The event name
    • A timestamp
    • A color code representing the event type

  • Shows a Snackbar notification whenever a new lifecycle event occurs.

  • Visually updates in real time as the Activity moves through lifecycle states.

2. Counter++

• Task: Create a reactive counter app that updates through both user interaction and background auto-increment.

• Features:

  • Uses a ViewModel to manage and persist the counter state during configuration changes.
  • Implements StateFlow for reactive, unidirectional data flow between ViewModel and UI.
  • Provides buttons for:
    • +1 — manually increment the counter
    • –1 — manually decrement the counter
    • Reset — reset the counter to zero
  • Includes an “Auto” mode toggle that starts or stops a coroutine-based background increment.
  • When Auto mode is ON, a coroutine automatically increases the counter every few seconds (default: 3 s).
  • Displays the current count and the status text (“Auto mode: ON/OFF”) in real time.
  • Offers a Settings dialog to configure the auto-increment interval without leaving the screen.

3. Temperature Dashboard

• Task: Build a real-time temperature dashboard that simulates sensor data and visualizes updates in a reactive Compose UI.

• Features:

  • Uses a ViewModel to manage simulated temperature readings and calculated summary statistics.
  • Implements StateFlow for reactive, unidirectional data flow between the ViewModel and UI.
  • Simulates new temperature readings every 2 seconds, generating random float values between 65°F and 85°F.
  • Maintains only the latest 20 readings, automatically removing older entries as new data arrives.
  • Displays:
    • A scrolling list of readings (timestamp + temperature value)
    • Summary values for Current, Average, Minimum, and Maximum temperature
  • Includes a simple line chart drawn with a Canvas to visualize recent temperature trends.
  • Provides Pause and Resume buttons to start or stop simulated data streaming.
  • All temperature updates occur in real time using coroutines and StateFlow, ensuring smooth, reactive UI updates.

AI Usage

For this assignment, I used OpenAI’s ChatGPT (GPT-5) as a study and support tool.

How I used AI

• Explain important Android development concepts.

• I provided sample classroom code and requested step-by-step explanations of why certain behaviors occur.

• I shared parts of my own Compose code and asked AI for suggestions to improve UI clarity and layout, such as adding padding, background colors, borders, and better text alignment.

• What I kept

  • I used the conceptual explanations and ui improvement suggestions to refine my own implementation.
  • I reused short snippets but rewrote them in my own structure to fit assignment requirements.

• What I discarded

  • I did not copy AI-generated solutions.