Precise control over Androids VectorDrawable animations

Question

UPDATE: Solution found! Scroll down for my accepted answer!

I want to animate multiple elements of one image and link the animation to ViewPagers po

Answer 1

Looks like it is possible to access paths and groups inside VectorDrawableCompat and animate/morph them however you want!

After a some research I ended up duplicating the following classes from the android.support.graphics.drawable package: AndroidResources, PathParser, TypedArrayUtils, VectorDrawableCommon and VectorDrawableCompat.

Next we need to make the following method and classes public inside of the VectorDrawableCompat class: getTargetByName, VGroup and VFullPath.

Next in the VectorDrawableCompat class remove the block that checks for Android version (Build.VERSION.SDK_INT >= 23). Don't know why, but if you don't do it, the animating won't work on android API 23 and up (need more research).

I may have missed a couple of private methods, but it's just a matter of making them public if you run into problems.

So, now we have access to the layers of our VectorDrawable! Here is a small example of scaling a vector group depending on the ViewPager's position:

And this is the code used to animate the group:

ImageView myImageView;
VectorDrawableCompat.VGroup myVectorGroup;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_welcome);

    myImageView = (ImageView) findViewById(R.id.image_1);

    VectorDrawableCompat vectorDrawable = VectorDrawableCompat.create(getResources(), R.drawable.my_vector_drawable, null);
    vectorDrawable.setAllowCaching(false); // Important to allow image updates
    myVectorGroup = (VectorDrawableCompat.VGroup) vectorDrawable.getTargetByName("my_group");

    myImageView.setImageDrawable(vectorDrawable);

    mViewPager = (ViewPager) findViewById(R.id.pager);
    mViewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
        @Override
        public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
            if(myVectorGroup != null && position < 1) {
                myVectorGroup.setScaleX(1f - positionOffset);
                myVectorGroup.setScaleY(1f - positionOffset);

                myImageView.invalidate();
            }
        }
    });
}

I need some more testing to determine compatibility, but it works for now!