41.1 Introducing Android Transitions and Scenes

Transitions allow the changes made to the layout and appearance of the views in a user interface to be animated during application runtime. While there are a number of different ways to implement Transitions from within application code, perhaps the most powerful mechanism involves the use of Scenes. A scene represents either the entire layout of a user interface screen, or a subset of the layout (represented by a ViewGroup).

To implement transitions using this approach, scenes are defined that reflect the two different user interface states (these can be thought of as the “before” and “after” scenes). One scene, for example, might consist of EditText, Button and TextView views positioned near the top of the screen. The second scene might remove the Button view and move the remaining EditText and TextView objects to the bottom of the screen to make room for the introduction of a MapView instance. Using the...