[MaterialArcMotion] MaterialArcMotion not working properly

[Description]

The MaterialArcMotion not working properly in 1.2.0-beta01. (After transitions to be based on androidx and add transitions platform subpackage)

[AS-IS]

When we transform View A into View B using MaterialArcMotion as a PathMotion and MaterialContainerTransform, it is delaying, transition incompletely, move weirdly.

[TO-BE]

It should be work properly. In the Alpha05/Alpha06 are working well. However, as we can see below in the beta01 the transitions working not properly.

Alpha-06

Beta-01

Screenshot Index	Issue Description	Device Information	API
first	delayed when returning the transformation.	Pixel 2, Samsung Galaxy s10	23, 29
second	Transformed incompletely.	Pixel 2, Samsung Galaxy s7, Nexus 10, Samsung Galaxy s10	23, 27, 29, 29
third	Returning weirdly when using with RecyclerView.Adapter	Pixel 2, Samsung Galaxy s10	23, 29

[Source code repository]

Material-alpha06 branch Material-beta01 branch / migrated commit

[Android API version]

23, 29

[Gradle Build Tool Version]

3.6.3

[Material Library version]

1.2.0-beta01

[hunterstich]

Hey @skydoves,

Dan and I had a chance to look into a few of the issues you’re experiencing with 1.2.0-beta01.

There are two things happening

[1] When you perform a View->View container transform, as you’re doing when transforming a FAB into a toolbar or a FAB into a card, you have to set the container transform’s target view to the endView using addTarget(endView). This prevents the container transform from being run on both views that are changing and eliminates the visual glitches you’re seeing. Running your project, I was able to fix the problems by updating TransformationLayout with:

  private fun getTransform(mStartView: View, mEndView: View): MaterialContainerTransform {
    return MaterialContainerTransform().apply {
      startView = mStartView
      endView = mEndView
      addTarget(endView)
      ...

Not sure if this will work in all cases where you’re using the layout, but hopefully it points you in the right direction : ).

[2] The duplicate animation running when you return to the list of cards is being caused by commit/57a8ebdcdd4e6. We’re working on a fix for this and will keep you updated!

Let me know if the suggestions in [1] work for solving some of the issues you’re seeing.

Hunter

[dsn5ft]

@skydoves so I added back a slight additional background fade duration which seems to fix the extra return transition issue (https://github.com/material-components/material-components-android/commit/661c6a112712079e57a26a210b3bacc5967832b1). It’s available in 1.2.0-rc01 which was released yesterday in case you want to try it out here.

We’re tracking the potential container transform performance issues in https://github.com/material-components/material-components-android/issues/1415, and I’m wondering if that’s related to the fact that addTarget is now required, because without it there may be multiple container transforms running. Anyway I’m closing this issue because I believe all of the problems have been addressed, but feel free to reopen or file separate more specific issues.