Summary: public
Added opacity property to RCTShadowText, and use it to adjust the alpha
color component of nested text nodes when collapsing the RCTShadowText tree
into an NSAttributedString. The opacity is propagated down the tree,
multiplying the aggregate with the current node's opacity at each step. Also,
foreground and background colors are propagated down the tree so that in case
a node has an opacity style but no colors, the ancestor's colors can be used
when adjusting the alpha components.
Reviewed By: nicklockwood
Differential Revision: D2600402
fb-gh-sync-id: 2adb7b598b0a73c984bb2edaab545c02ab911c6b
6b9e4ec4b2