ActivityLifecycle.md

Results of some experiments to determine which Activity lifecycle methods get called in certain situations.

Scenario: Launch app from home, then return home

Launch:

• activity.onCreate()
• activity.onStart()
• activity.onResume()
• activity.onWindowFocusChanged(true)

Note: Launching already-running app is similar, except a call to activity.onRestart() will occur instead of onCreate().

Press Home:

• activity.onUserInteraction()
• activity.onUserLeaveHint()
• activity.onPause()
• activity.onWindowFocusChanged(false)
• activity.onSaveInstanceState()
• activity.onStop(); isChangingConfigurations() returns false

Scenario: App pushes new activity onto stack

(activity1 is the activity that was on the top of the stack. activity2 is the new activity being pushed on top.)

• activity1.onPause()
• activity2.onCreate()
• activity2.onStart()
• activity2.onResume()
• activity1.onWindowFocusChanged(false)
• activity2.onWindowFocusChanged(true)
• activity1.onSaveInstanceState()
• activity1.onStop(); isChangingConfigurations() returns false

If activity1 calls finish(), then activity1.onDestroy() will occur after onStop()

Scenario: User presses Back button to dismiss activity and reveal previous activity

(activity2 is the top-of-stack activity being dismissed. activity1 is the activity that is beneath activity2.)

• activity2.onUserInteraction()
• activity2.onPause()
• activity1.onRestart()
• activity1.onStart()
• activity1.onResume()
• activity1.onWindowFocusChanged(true)
• activity2.onWindowFocusChanged(false)
• activity2.onStop()
• activity2.onDestroy()

Scenario: Orientation change in activity that does not implement onConfigurationChanged()

• activity.onConfigurationChanged()

Scenario: Orientation change in activity that does implement onConfigurationChanged()

• activity.onPause()
• activity.onSaveInstanceState()
• activity.onStop(); isChangingConfigurations() returns true
• activity.onDestroy()
• activity.onCreate()
• activity.onStart()
• activity.onRestoreInstanceState()
• activity.onResume()
• activity.onWindowFocusChanged(true)