Fragments and Navigation Components

This set of flashcards covers the fundamental concepts of Fragments, their lifecycle states, FragmentManager operations, and the Navigation Components as presented in Lecture 7.

Fragment

A block of UI, with its own lifecycle, that can be reused within different activities to create modular user-interface components.

onInflate

Method called only to define a fragment directly in the layout using the tag; it saves configuration parameters and attributes defined in the XML layout file.

onAttach

Method called as soon as the fragment is attached to the father activity, used to store the reference about the activity.

onCreate

An important step where the fragment is in the creation process; it can be used to start threads to retrieve data from sources like a remote server.

onCreateView

The method called when the fragment creates its view hierarchy and the layout is inflated inside the fragment.

onActivityCreated

Method that notifies when the father activity is created and ready for use, meaning the activity is active and can be used.

onStart

Phase where the fragment is visible but is not yet interacting with the user.

onResume

Method called when the fragment is ready to interact with the user and is up and running.

onPause()

Lifecycle method for fragments that is similar to Activity.onPause().

onDestroyView()

Final fragment cleaning up method called if the OS decides to destroy the fragment view.

onDestroy()

Called when all active connections should be released because the fragment is close to shutting down.

onDetach

Method used to detach the fragment from the activity.

onStop()

Lifecycle method called when the fragment is no longer visible.

FragmentManager

A component in the Activity used to handle fragments, allowing them to be added, removed, replaced, or found at runtime.

Transaction

The operation required to activate any kind of manipulation (add, remove, replace) on a fragment through the FragmentManager.

Navigation

The interactions that allow users to navigate across, into, and back out from different pieces of content within an app.

Navigation graph

An XML resource file containing all navigation-related information, including destinations and the possible paths a user can take.

Destinations

The individual content areas within an app defined in the navigation graph.

NavHost

An empty container that displays destinations from the navigation graph.

NavHostFragment

The default NavHost implementation that displays fragment destinations.

NavController

An object that manages app navigation within a NavHost and orchestrates the swapping of destination content.