[ListView] Fix RCTScrollView stickyHeader touch passing.

[MattFoley]

Point must be converted to the stickyHeader's coordinate space and then passed to the stickyHeaders hitTest:withEvent: method in order to be correctly routed to any subviews of the stickyHeader.

This resolves this issue.

[MattFoley]

@nicklockwood @brentvatne I believe this modifies code that was last touched by you guys, please take a look. Thanks!

Relevant Issues: #875 & #1415

[ide]

Could change __block UIView *stickyHeader to __block UIView *hitView and set it inside the enumeration loop, avoiding an extra hitTest: call at the end of this method.

[MattFoley]

Oh yeah, I missed that bit. That's the problem. Let me update this.

[ide]

Out of scope of this diff but I'm wondering if it's more correct to override pointInside:withEvent:, which hitTest:withEvent: will call.

[MattFoley]

Told @ide that I figured this line of code would be frowned upon, so I broke it out a bit more.

*stop = hitView = [stickyHeader hitTest:convertedPoint
                              withEvent:event];

[nicklockwood]

@MattFoley that line would have randomly failed if the pointer address of hitView was ever exactly divisible by 128, which probably wasn't what you intended :-)

(assigning a pointer to a BOOL variable just truncates the value to fit inside a char, it doesn't check if it's != 0 like normal boolean operations such as if, ?, ! do)

[MattFoley]

I had no idea, that's a cool tidbit. Thanks @nicklockwood.

[ide]

This looks good to me. @nicklockwood can you import this if it looks good to you too?