Useful extras

These tips aren't specific to 🖖 React UseGesture but might come handy to anyone building mobile-friendly UI interfaces.

touch-action

Let's take the mailbox email list: panning vertically should scroll vertically through the emails, and dragging horizontally should unveil options such as delete and mark undread.

In these situations you don't want the body of your page to scroll along with the user manipulating the item horizontally. Your first instinct might be to prevent the event default action by calling event.preventDefault() in your handler. But there is a simpler, more effective solution, which has to do with a simple CSS property.

touch-action is a CSS property that sets how an element's region can be manipulated by a touchscreen user.

This demo only makes sense on mobile or when your browser inspector is set for touch devices.

← Drag me →
← Drag me →
← Drag me →
← Drag me →

Setting touch-action: pan-y on your draggable element class or style indicates the browser should only react to vertical scrolling when interacting with the item.

If you don't want the browser scrolling either vertically or horizontally, set touch-action: none.

function TouchActionExample() {
const [springs, set] = useSprings(4, () => ({ x: 0 }))
const bind = useDrag(({ down, movement: [x], args: [index] }) => set(i => i === index && { x: down ? x : 0 }), {
axis: 'x',
})
return springs.map(({ x }, i) => <animated.div {...bind(i)} style={{ x, touchAction: 'pan-y' }} />)
}

In your drag options, you should then set {axis:'x'}. This will result in the browser natively canceling vertical scrolling when it detects movement intent on the horizontal axis, while your handler will trigger your horizontal logic. When movement intent is detected as vertical by the browser, it will allow your body to scroll, but the {axis:'x'} option on the drag handler will prevent your item to move horizontally.

Note that you can fail this behaviour by slooowly scrolling sideways and then firmly up or down. But it should work in most situations.

Body Scroll Lock

When you have a menu overlay on top of your page you generally don't want the body to scroll along with the menu content. Body scroll lock is a javascript library that disable body scroll.

Make sure you can't solve your problem scroll problem with touch-action before using this library though.

Lethargy

Lethargy is a library which objective is to help distinguish between scroll events initiated by the user, and those by inertial scrolling. It's especially useful when you want to create full page sliders. Here is an example on how to use it with useWheel.

This demo only makes sense on wheel-based devices. The sensitivity to wheeling depends on your device and can be adjusted with Lethargy options.

0
1
2
3
4
5
Show code
const slides = [0, 1, 2, 3, 4, 5]
// creates a new Lethargy check
// could be stored as a ref, or a global anywhere in your app
const lethargy = new Lethargy()
function LethargyWheel() {
const [index, setIndex] = useState(0)
const ref = useRef()
useWheel(
({ event, last, memo: wait = false }) => {
if (last) return // event can be undefined as the last event is debounced
event.preventDefault() // this is needed to prevent the native browser scroll
const wheelDirection = lethargy.check(event)
// wheelDirection === 0 when Lethargy thinks it's an inertia-triggered event
if (wheelDirection) {
// wait is going to switch from false to true when an intentional wheel
// event has been detected
if (!wait) setIndex(i => clamp(i - wheelDirection, 0, slides.length - 1))
return true // will set to wait to true in the next event frame
}
return false // will set to wait to false in the next event frame
},
// we need to use a ref to be able to get non passive events and be able
// to trigger event.preventDefault()
{ domTarget: ref, eventOptions: { passive: false } }
)
return (
<div ref={ref} style={{ transform: `translateY(${-index * 330}px)` }}>
{slides.map(i => (
<div key={i}>{i}</div>
))}
</div>
)
}

Example on CodeSandbox: https://codesandbox.io/s/lethargy-2coe8