Hide top nav on reading docs on mobile #856
Merged
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The top navigation disappears when you scroll down and reappears when you scroll up. Like browsers, and many content services like Medium,
This is a necessary feature for mobile readers with a small viewport.
Also made some code changes here to add memoization, because the scroll event is highly frequant.
React.useState
preserves the reference of the set dispatcher, but doesn't for the surrounding tuple. Adding a few memo, most children, except for components that are cheap to render, are not re-rendered.Also no deep re-render, the appearance state is propagated via old good CSS cascading rather than React state.