Android's UI thread

As mentioned in the first chapter, Android applications have a thread that is dedicated to updating the UI and also to listening to user interactions and processing the events generated by the user – like the user clicking on a menu.

Let's review the basics of Android's UI thread to guarantee that we separate the work between the UI and background threads in the best way possible.

CalledFromWrongThreadException

Android will throw a CalledFromWrongThreadException whenever a thread that didn't create a view hierarchy tries to update its views. In practical terms, this exception will happen whenever a thread other than the UI thread updates a view. This is because the UI thread is...