Handling Gestures

React UI Animate provides a powerful set of gesture hooks that enable you to easily bind mouse and touch events to any node. This allows for the creation of complex interactions, such as dragging and scrolling, with just a few lines of code.

DRAG ME

Defining a gesture

To get started with gestures, you first need to import the appropriate gesture hook and define it inside a component. For instance, to use the useDrag hook, you can set it up as follows:

import { useDrag } from 'react-ui-animate';

function Component() {
  const bind = useDrag(() => {});
}

The useDrag hook takes a function as an argument, which receives all the drag/event data. This hook is assigned to a bind variable that contains all the necessary event handlers. You can then attach these handlers to a component.

Binding a gesture to a Node

Thanks to the consistent pattern of gesture hooks, binding a gesture to a node is straightforward. The gesture hooks return a function that, when called, provides an object with event handlers. Here’s an example of making a <div /> draggable:

import { useDrag } from 'react-ui-animate';

export default function () {
  const bind = useDrag((state) => doSomething(state));

  return (
    <div
      {...bind()}
      style={{
        width: 60,
        height: 60,
        backgroundColor: '#3399ff',
      }}
    />
  );
}

In this example, the <div /> element receives an object with event handlers when you spread ...bind(). This includes handlers like onPointerDown and onMouseDown. The useDrag hook's callback function receives a state object containing all the gesture's attributes. This state object is passed to your handler every time the gesture updates.

To implement actual dragging, use the gesture hook in conjunction with an Animated Value:

import { useDrag, useAnimatedValue, animate } from 'react-ui-animate';

export default function () {
  const left = useAnimatedValue(0);

  const bind = useDrag(({ down, movementX }) => {
    left.value = down ? movementX : 0;
  });

  return (
    <animate.div
      {...bind()}
      style={{
        width: 100,
        height: 100,
        backgroundColor: '#f5533d',
        borderRadius: 4,
        position: 'relative',
        left: left.value,
      }}
    />
  );
}

In this example, left is an animated value. The state object includes down, which represents whether the mouse button is pressed, and movementX, which tracks the movement along the x-axis starting from 0.

Available gesture hooks

React UI Animate offers the following gesture hooks, all of which share a similar API pattern:

• useScroll for scroll gestures.
• useMouseMove for mouse move gestures.
• useDrag for drag gestures.
• useWheel for mouse wheel gestures.
• useGesture for multiple gesturess.

These hooks provide a flexible and efficient way to handle various user interactions, making it easy to implement responsive and interactive UI elements.