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Comment by ashleyn | Hacker News Reader

Wait, iphones now support detection of finger hover? I remember hearing about iOS introducing software support for this, presumably for when the hardware can catch up. But never heard of it actually being implemented.

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Of course not. Only tapping. But the camera hardware gets booted up as soon as you tap the icon, without waiting to see if the tap is a swipe, and without waiting for you to lift your finger (which is when other apps would open).

> Of course not

Actually of course yes, every capacitive touchscreen has basic hover capabilities in some form, it’s just a fairly narrow range (a few mm at most) and not exposed as a public API.

Samsung phones excel in this.

There's an API in iOS/iPadOS named UIHoverGestureRecognizer, but it only detects hover from cursors and from the Apple Pencil. The Apple Pencil hover is neat and actual "hover" detection in the way you're thinking; it can be detected up to 12mm away from the screen. But right now there's no actual detection for finger hover, even though Apple patented a technique for it almost 10 years ago.

I think capacitive touchscreens always did? It was never reliable enough or something. The panels generate scanned strength maps for the whole displays. Values for locations that aren't being touched aren't zeroes.

Yes, but it’s a couple mm at most and not exposed as a public API.

I think this is more of an Apple specific hack to get latency down; boot the cameras up as early as possible.

Can third party apps use this to speed up their use of camera hardware too?

I doubt it - Apple has a bad habit of putting in specific behaviors for certain home screen icons in Springboard (consider the clock and calendar icons) which are tied to the app identity but executed by Springboard.

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