Debugging Android

Fragments

Meghaditya Roy ChaudhurySoftware Engineer, Citrix

Fragment – What and Why? Definition: A Fragment represents a behavior or a portion of

user interface in an activity.

Flexible UI

Re-usable

Embedded in the parent activity

Application specific subclasses –◦ DialogFragment, ListFragment, PreferenceFragment

Key Classes:

- Fragment

- FragmentManager

- FragmentTransaction

Ref: http://developer.android.com/guide/components/fragments.html

Fragment Life cycle

Concerns for Developers

Creation of fragments

◦ Adding UI

◦ Adding to parent activity

Management of fragments

Performing fragment transactions

Communicating with activities and

other fragments

Handling the fragment life-cycle

(Fragment + Activity) Lifecycle

FragmentManager.enableDebugLogging

(true)

Fragment in action

Fragment Debugging -

Terminology

moveFrom RESUMED – fragment.onPause()

moveFrom STARTED – fragment.onStop()

moveFrom ACTIVITY_CREATED – ??? [getActivity() is

destroyed]

moveFrom CREATED – fragment.onDestroy()

moveTo CREATED – fragment.onCreate()

moveTo ACTIVITY_CREATED – fragment.onActivityCreated()

moveTo STARTED – fragment.onStart()

moveTo RESUMED – fragment.onResume()

BackStackEntry Listing

BackStack Operations – add, commit, remove

MainActivity - onCreate

Application Launch – Debug

Log

Application moved to

Background

Application on Rotation

Safer to play by the book

Fragment best practices guidelines –

◦ Creating a fragment –

https://developer.android.com/training/basics/fr

agments/creating.html

◦ Building a flexible UI -

https://developer.android.com/training/basics/fr

agments/fragment-ui.html

◦ Communicating with other fragments –

https://developer.android.com/training/basics/fr

agments/communicating.html

Work Better. Live Better.

CITRIX