MBTI Test App

What I learned

• ViewPager2
• Fragment lifecycle
  • fragment.arguments
• Repeated View (UI) initialization
• ZoomOutPageTransformer animation

Key Function

• Conduct MBTI tests through multiple fragment pages on ViewPager.
• View results based on selected categorized data in the result page.

Fragment initializing

1. onCreate()
   • Retrieve the data from Fragment arguments
2. onCreateView()
   • Inflate the fragment layout, get view references, set up data on the views, and return the view
3. onViewCreated()
   • Define the functionality of an interactive UI component like the nextButton

How it works

1. Navigate from MainActivity to TestActivity using Intent.
2. TestActivity contains a ViewPager2 object and a moveToNextQuestion() method to control it.
3. Apply the adapter in TestActivity, passing the instance of TestActivity to ViewPagerAdapter during this process.
4. In ViewPagerAdapter, reference TestActivity's member variables, methods, and layout objects using the received context.
   • Note that ViewPagerAdapter receives the Activity's instance as FragmentActivity, so a type-cast to TestActivity is required to access the Activity instance's members. Otherwise, only FragmentActivity's members can be accessed.
5. ViewPagerAdapter, using TestActivity's context, implements the slide function between fragments created by itself.
6. ViewPagerAdapter has members from QuestionFragment to create and return fragments.
7. In QuestionFragment, configure the UI, use (activity as TestActivity) to store test results data in TestActivity, and call TestActivity.moveToNextQuestion() to move to the next page.
   • There is logic in TestActivity.moveToNextQuestion() to navigate to the result Activity when reaching the last page.
8. Check the result page, and if the retryButton is clicked, move to MainActivity with the option Intent.FLAG_ACTIVITY_CLEAR_TASK or Intent.FLAG_ACTIVITY_NEW_TASK.

Something I’m not sure about

• When wanting control over a View component, which approach is preferable? By lazy or lateinit?
• Is it the best approach to manage all Fragment data within an Activity?

What could be better

• Managing UI data using a data class instead of individual processing would enhance maintainability.

GitHub link