Root element of a motion scene file. The <MotionScene> contains one or more
<Transition>
elements, each of which defines the start and end state of a
motion sequence and the transition between the two.
Syntax
<MotionScene xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:android="http://schemas.android.com/apk/res/android">
...
</MotionScene>
Must contain
<Transition>- Specifies the motion sequence to perform. If the
<MotionScene>contains multiple<Transition>elements, the MotionLayout chooses the most appropriatebased on the user's interaction. For example, a <MotionScene>might have four<Transition>children, each with an<onSwipe>for a user swipe in a different direction. When the user swipes on the screen, the MotionLayout uses the appropriate<Transition>for a swipe in that direction.
Can contain
<ConstraintSet>- Specifies a beginning or ending state for one or more of the
<Transition>nodes. The<MotionLayout>is permitted to have zero<ConstraintSet>children, since the<Transition>can point to XML layouts instead of pointing to constraint sets.
Attributes
defaultDuration- Default duration for all transitions, in milliseconds. The default duration is
used for any motion sequences that do not specify their own duration. For
example, if you set
defaultDuration="300", all motion sequences default to 300 milliseconds in length if they do not explicitly specify their own duration.

