Frequently Asked Questions

Index

• What is the difference the React-with-gesture library?
• Why use react-spring instead of React.useState?
• What are the differences between using use[Gesture] hooks and adding listeners manually?
• Why onMove when onDrag already exists?
• Why onWheel and onScroll?
• Accessing source event triggers a warning in the console!
• Why do I need to return memo?
• Why is drag being triggered when I just click on an element?
• Why am I getting warnings from preventDefault() after I pass {passive:false}

What is the difference the React-with-gesture library?

react-with-gesture is the old name for react-use-gesture and is not maintained anymore¹. We decided to drop support for render props and focus on hooks as we believe they’re much more convenient. react-with-gesture was solely focused on drag, where react-use-gesture supports scroll, wheel, pinch and more.

Why use react-spring instead of React.useState?

Simply because setting state in the gesture handler would re-render the component on each gesture frame, which isn't always good for performance. React-spring lets us animate components without triggering renders. You could still use useState if you'd like though!

What are the differences between using use[Gesture] hooks and adding listeners manually?

Not a lot! Essentially these useXXXX hooks simplify the implementation of the drag and pinch gestures, calculate kinematics values you wouldn't get out of the box from the listeners, and debounce move, scroll and wheel events to let you know when they end.

Why onMove when onDrag already exists?

onDrag only fires while you touch or press the element. You just need to hover your mouse above the element to trigger onMove.

Why onWheel and onScroll?

Scrolling and wheeling are structurally different events although they produce similar results (i.e. scrolling a page). First of all, wheel is a mouse-only event. Then, for onScroll to be fired, the element you're scrolling needs to actually scroll, therefore have content overflowing, while you just need to wheel over an element to trigger onWheel. If you use react-three-fiber, onWheel might prove useful to simulate scroll on canvas elements.

Accessing source event triggers a warning in the console!

You're probably trying to access an event in onScroll, onMove or onWheel handlers. The last event is debounced, and therefore not accessible asynchronously because of how React pools events. A possible solution would be to make sure the event is not part of the last state update:

useScroll(
  ({ event, last }) => {
    !last && event.preventDefault() // <-- event will not be accessed in the last event
  },
  { domTarget: myRef }
)

Why do I need to return memo?

As you've seen in some examples, whenever memo is used, it is always returned in the handler function. Essentially memo is a gesture state attribute that is undefined when the gesture starts, but then takes the return value of the handler function.

It may sound silly but returning memo makes sure that we continue holding a reference to the initial value of memo.

Why is drag being triggered when I just click on an element?

This is typically a-feature-not-a-bug situation 🙃 Drag is triggered as soon as you mouse down on your component, which means it will be triggered when you just briefly click on it. However, there is an option to not trigger the drag handler before a certain delay, using the config option delay.

// using the default delay
const bind = useDrag(() => console.log(`Won't show if you hold your mouse less than 180ms`), { delay: true })

Why am I getting warnings from preventDefault() after I pass {passive:false}

The basic use of <Component {...bind()) /> passes the task of attaching listeners to React. React does not yet support binding passive listeners via props. To have useGesture attach the listeners, you must also use the domTarget option. This is only required if you plan to preventDefault or cancel the event.