Detect Hover

JavaScript wrapper for hover and any-hover media queries.

[Live detection test][liveDetectionTest]

Exports a reference to a singleton object (a micro state machine with an update function) with its state set to the results of the hover and any-hover media queries, as well as an update() function which re-runs the tests and updates the object's state.

Note that detect-hover is one of the micro state machines used by [detect-it][detectItRepo] to determine if a device is mouseOnly, touchOnly, or hybrid.

For more information on the hover and any-hover media queries, please see the [W3C Media Queries Level 4 specification][w3cSpecLatest]. For information on browser compatibility, please see [Can I Use matchMedia][canIUseMatchMedia].

$3

``javascript
const detectHover = {
// mutually exclusive (only one will be true)
hover: boolean,
none: boolean,

// not mutually exclusive
anyHover: boolean,
anyNone: boolean,

// re-run all the detection tests and update state
update() {...},
}
`

$3


`terminal
$ npm install detect-hover
`

$3

`javascript
import detectHover from 'detect-hover';
`
`javascript
// using the state
detectHover.hover === true; // primary pointing system can hover
detectHover.none === true; // primary pointing system can’t hover, or there is no pointing system

/*
* identical to the hover media feature, but they correspond to the
* union of capabilities of all the pointing devices available to the user -
* more than one of their values can be true, if different pointing devices have
* different characteristics
*/
detectHover.anyHover === true;
detectHover.anyNone === true;


// updating the state - most apps won't need to use this at all
detectHover.update();
`

`javascript
/*
* note that in the case of a legacy computer and browser, one that
* doesn't support detect-hover's detection tests, the default state will be:
*/
const detectHover = {
hover: undefined,
none: undefined,
anyHover: undefined,
anyNone: undefined,
}
`

Note that the update() function is run once at the time of import to set the object's initial state, and generally doesn't need to be run again. If it doesn't have access to the window or the browser doesn't support the matchMedia() function (all modern browser do), then the state will be undefined (detect-hover will not throw an error). If detect-hover doesn't have access to the window at the time of import, you will have to call the update() function manually at a later time to update its state.

Note that the hover on-demand value was removed from the [July 6th 2016 W3C Media Queries Level 4][w3cSpec7-6-2016] draft specification, but was included in the [previous draft (January 26th 2016)][w3cSpec1-26-2016] of the spec. Any device that registers as having hover on-demand capabilities will show up as hover none in detectHover's state. As a side note, hover on-demand is pretty much useless for practical purposes, and Android touch only devices register that they can hover on-demand, which is achieved via a long press - I view this as a feature that is a bug.

$3


- [detect-it][detectItRepo]
- detect-hover
- [detect-pointer][detectPointerRepo]
- [detect-touch-events][detectTouchEventsRepo]
- [detect-passive-events`][detectPassiveEventsRepo]

[liveDetectionTest]: https://detect-it.rafgraph.dev/#detect-hover
[w3cSpecLatest]: https://www.w3.org/TR/mediaqueries-4/#hover
[w3cSpec7-6-2016]: https://www.w3.org/TR/2016/WD-mediaqueries-4-20160706/#hover
[w3cSpec1-26-2016]: https://www.w3.org/TR/2016/WD-mediaqueries-4-20160126/#hover
[canIUseMatchMedia]: https://caniuse.com/#feat=matchmedia
[detectItRepo]: https://github.com/rafgraph/detect-it
[detectPointerRepo]: https://github.com/rafgraph/detect-pointer
[detectTouchEventsRepo]: https://github.com/rafgraph/detect-touch-events
[detectPassiveEventsRepo]: https://github.com/rafgraph/detect-passive-events