13.6 Experimenting with the Activity

With the diagnostics working, it is now time to exercise the application with a view to gaining an understanding of the activity lifecycle state changes. To begin with, consider the initial sequence of log events in the Logcat panel:

onCreate

onStart

onResume

Clearly, the initial state changes are exactly as outlined in “Understanding Android Application and Activity Lifecycles”. Note, however, that a call was not made to onRestoreInstanceState() since the Android runtime detected that there was no state to restore in this situation.

Tap on the Home icon in the bottom status bar on the device display and note the sequence of method calls reported in the log as follows:

onPause

onStop

onSaveInstanceState

In this case, the runtime has noticed that the activity is no longer in the foreground, is not visible to the user and has stopped the activity, but not without providing an opportunity for the activity to...