This was taken from flutter/examples

• There are 3 pages in a ViewPager
  • Page 0 is an android view (p0)
  • Page 1 is the flutter view (p1)
    • FlutterView has 3 pages and a translucent listener (l0) in a Stack.
      • f0, f1, f2
  • Page 2 is an android view (p2)

Target: Scroll smoothly like it's all a big ViewPager or a PageView p0 -> p1 -> p2 i.e. p0 -> f0 -> f1 -> f2 -> p2

Curently the scroll is implemented like this:

• App is initialized and the vs(viewpager scrolling) is enabled.
• l0 listens for any horizontal pointer movements.
• After scrolling from p0 to p1 the l0 will respond like this:
  • if finger is moving left (scrolling right)
    • vs is enabled if in f0.
    • vs is disabled if in f2.
  • if finger is moving right (scrolling left)
    • vs is disabled if in f0.
    • vs is enabled if in f2.
• When scrolled from f1 to f0, vs is enabled.
• When scrolled from f1 to f2, vs is enabled.
• Whenever vs is disabled the pointer will be read by pageview which will scroll the flutter pages.
• Whenever vs is enabled the pointer will be read by viewpager which will scroll the android views.
• Currently doesn't require any scroll events of the ViewPager.

Theoretically this should work but it isn't.

• The scrolling of ViewPager stops halfway sometimes.
• The scrolling of PageView doesn't occur sometimes and ViewPager is scrolled instead.

The new implementation that I'm thinking of:

• Must ensure that halfway scroll blocks doesn't happen.
• When the viewpager scrolls from p0 to p1 or p2 to p1 disable the scrolling of ViewPager (android side)
• If in flutterview
  • if finger is moving left (scrolling right)
    • vs is enabled if in f2.
  • if finger is moving right (scrolling left)
    • vs is enabled if in f0.