## Activity + Fragment Life Cycles

- [Basic](#basic)
- [Screen rotation, regular](#screen-rotation-regular)

Note: `/A` = activity calls , `/F` = fragment calls

### Basic
```
# Launch from home screen
D/A: Activity.constructor()
D/A: onCreate() : savedInstanceState = [null]
D/A: onCreateView()    ## multiple calls for different non-fragment parts
D/A: onContentChanged()
D/F:     Fragment.constructor()
D/F:     onAttach()
D/A: onAttachFragment() : fragment = [the fragment created]
D/F:     onCreate() : savedInstanceState = [null]
D/F:     onCreateView() : savedInstanceState = [null]
V/F:      |- isVisible = false
D/A: onCreateView()    ## multiple, to setup the view for the fragment
D/F:     onViewCreated() : savedInstanceState = [null]
V/F:      |- isVisible = false
D/F:     onActivityCreated() : savedInstanceState = [null]
D/F:     onViewStateRestored() : savedInstanceState = [null]
D/F:     onStart()
D/A: onStart()
D/A: onPostCreate() : savedInstanceState = [null]
D/A: onStateNotSaved()
D/A: onResume()
D/F:     onResume()
V/F:      |- isVisible = false  ## the view remains not visible even at onResume()
D/A: onResumeFragments()
D/A: onPostResume()
# The App is brought up and visible

# Press home screen button to hide the app
D/F:     onPause()
D/A: onPause()
D/F:     onStop()
D/A: onStop()
D/F:     onSaveInstanceState() : outState = [Bundle[{}]]
D/A: onSaveInstanceState() : outState = [some states from the framework]

# Brought back from recent app list
D/A: onRestart()
D/F:     onStart()
V/F:      |- isVisible = true
D/A: onStart()
D/A: onStateNotSaved()
D/A: onResume()
D/F:     onResume()
V/F:      |- isVisible = true
D/A: onResumeFragments()
D/A: onPostResume()

# Press home screen, then swipes the app away from recent app list
D/F:     onStop()
D/A: onStop()
D/F:     onSaveInstanceState() : outState = [Bundle[{}]]
D/A: onSaveInstanceState() : outState = [some states from the framework]
D/F:     onDestroyView()
D/F:     onDestroy()
D/F:     onDetach()
D/A: onDestroy()

```

### Screen Rotation (regular)
The default case the fragment is not retained, i.e., `Fragment.setRetainInstance(false)`.

It's basically the same as if the activity/fragment is created from scratch, except
- a non-null instanced state to all applicable methods
- The fragment is created and attached a bit earlier, before `Activity.onCreate()` is called.

```
# the app is visible, with last life cycle method
# being Activity.onPostResume()

# screen rotated
D/F:     onPause()
D/A: onPause()
D/F:     onStop()
D/A: onStop()
D/F:     onSaveInstanceState() : outState = [Bundle[{}]]
D/A: onSaveInstanceState() : outState = [some states from the framework]
D/F:     onDestroyView()
D/F:     onDestroy()
D/F:     onDetach()
D/A: onDestroy()
D/A: Activity.constructor()
D/F:     Fragment.constructor()
D/F:     onAttach()
D/A: onAttachFragment() : fragment = [fragment just created]
D/F:     onCreate() : savedInstanceState = [some states from the framework]
D/A: onCreate() : savedInstanceState = [some states from the framework]
D/A: onCreateView()    ## multiple calls for different non-fragment parts
D/A: onContentChanged()
D/F:     onCreateView() : savedInstanceState = [some states from the framework]
D/A: onCreateView()    ## multiple, to setup the view for the fragment
D/F:     onViewCreated() : savedInstanceState = [some states from the framework]
D/F:     onActivityCreated() : savedInstanceState = [some states from the framework]
D/F:     onViewStateRestored() : savedInstanceState = [some states from the framework]
D/F:     onStart()
D/A: onStart()
D/A: onRestoreInstanceState() : savedInstanceState = [some states from the framework]
D/A: onPostCreate() : savedInstanceState = [some states from the framework]
D/A: onStateNotSaved()
D/A: onResume()
D/F:     onResume()
D/A: onResumeFragments()
D/A: onPostResume()
```