My Android API journey

To simply declare a fragment that you can call later in your code:

class SecondFragSampleName : Fragment(R.layout.second_fragment)

or if you want to specify extra methods that will run when the fragment becomes active.

class SecondFragSampleName : Fragment(R.layout.second_fragment) {
  // Declare methods here, ie, OnCreate, etc.
}

Notes:

• Do not declare this inside the main activity fragment. Suggested placement is after the main activity fragment.
• Ensure that a second_fragment layout exists, and that it contains the androidx.fragment.app.FragmentContainerView element.

Then when you want to switch to this "second fragment", add the following code as an action/method on the currently active fragment:

supportFragmentManager
    .beginTransaction()
    .setTransition(TRANSIT_FRAGMENT_OPEN)
    .setReorderingAllowed(true)
    .addToBackStack("DefaultView")
    .add(R.id.map, SecondFragSampleName())
    .commit()