3D transition animation between Activities

I have got a question in this post on the Sfonge site whether it is possible to create a 3D transition effect between two Activities. There is a sample program that does it among the API Demos but this program plays the transition effect between two views of the same Activity. The adaptation to do the same between two activities is not very complicated but has some tricks, that's why I decided to publish this example program.

Click here to access the example program.

First and foremost, I unashamedly stole the custom 3D animation from the API Demos application, that's what you find in Rotate3dAnimation.java. It is invoked in the landing Activity (Activity3dTransitionActivity) when the user initates transition to the second Activity (Screen2Activity) using the menu. The trick here is to attach an animation listener to the 3D animation object, start the animation in the outgoing Activity and only invoke startActivity() when the animation finishes. Note the overridePendingTransition( 0,0 ) invocation; this ensures that the system itself will not play any activity transition animation.

The incoming Screen2Activity seems simple but there is hidden gem here too. Observe that the top layout of the activity (in screen2.xml) is not a stock LinearLayout but a descendant (aexp.activity3dtransition.AnimatedLinearLayout). Overriding onMeasure() in this subclass makes sure that the incoming animation is started only after the elements of the layout (a single TextView here) have been laid out.