Summary:
If the z-index was updated after the initial mount, changes would not be reflected because we did not recalculate the z-index mapped child views and redraw the view. This adds code to do that and call it whenever we update z-index.
**Test plan**
Tested by reproducing the bug with 2 overlapping views that change z-index every second. Made sure it now works properly and z-index changes are reflected.
Closes https://github.com/facebook/react-native/pull/15203
Differential Revision: D5564832
Pulled By: achen1
fbshipit-source-id: 5b6c20147211ce0b7e8954d60f8614eafe128fb4
Summary:
Use `getChildDrawingOrder` instead of reordering views. The old implementation didn't work properly when `removeClippedSubviews` was enabled and this one should have better performance since we don't play with the view hierarchy at all.
This fixes weird bugs with sticky headers in `SectionList` and allows removing the hack that disabled `removeClippedSubviews` when using sticky section headers.
**Test plan**
Tested using the SectionList and ListViewPaging examples that use sticky headers which uses z-index.
Closes https://github.com/facebook/react-native/pull/13105
Reviewed By: sahrens
Differential Revision: D4765869
Pulled By: achen1
fbshipit-source-id: be3c824658a3ce965b6e7324ad95c77cbd8a86ae