useElementByPoint

useElementByPoint is a hook that returns the element at a given point. It is useful for implementing drag and drop, or for any other use case where you need to know what element is at a given point.

Usage

Live Editor

function Demo() {
  const { clientX: x, clientY: y } = useMouse();
  const { element, pause, resume } = useElementByPoint({ x, y });
  const bounding = useElementBounding(element);

  useEventListener("scroll", bounding.update, null, { capture: true });
  const boxStyles = (() => {
    if (element) {
      return {
        display: "block",
        width: `${bounding.width}px`,
        height: `${bounding.height}px`,
        left: `${bounding.left}px`,
        top: `${bounding.top}px`,
        backgroundColor: "#3eaf7c44",
        transition: "all 0.05s linear",
        position: "fixed",
        pointerEvents: "none",
        zIndex: 9999,
        border: "1px solid var(--vp-c-brand)",
      };
    }
    return {
      display: "none",
    };
  })();
  const pointStyles = (() => ({
    transform: `translate(calc(${x}px - 50%), calc(${y}px - 50%))`,
    position: "fixed",
    top: 0,
    left: 0,
    pointerEvents: "none",
    width: "8px",
    height: "8px",
    borderRadius: "50%",
    backgroundColor: "#4ade80",
    boxShadow: "0 0 2px rgba(0,0,0,0.3)",
    zIndex: 999,
  }))();

  return (
    <>
      <div style={boxStyles} />
      <div style={pointStyles} />
      <div style={{ display: "flex", alignItems: "center" }}>
        <span style={{ marginRight: "16px" }}>X: {x}</span>
      </div>
      <div style={{ display: "flex", alignItems: "center" }}>
        <span style={{ marginRight: "16px" }}>Y: {y}</span>
      </div>
      <div>
        <button onClick={pause}>Pause</button>
        <button onClick={resume}>Resume</button>
      </div>
    </>
  );
};

render(<Demo />);

Result

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API

UseElementByPoint

Returns

UseElementByPointReturn<M>

Arguments

Argument	Description	Type	DefaultValue
options	options	UseElementByPointOptions<M> (Required)	-

UseElementByPointOptions

Property	Description	Type	DefaultValue
x	The x coordinate of the point	number | (() => number) (Required)	-
y	The y coordinate of the point	number | (() => number) (Required)	-
document	The document to query	Document | null	-
multiple	Whether to query multiple elements	M	-
interval	The interval to query the element	number | 'requestAnimationFrame'	-
immediate	Whether to query the element immediately	boolean	-

UseElementByPointReturn

Property	Description	Type	DefaultValue
isSupported	Whether the feature is supported	boolean (Required)	-
element	The queried element	M extends true ? Element[] : Element | null (Required)	-
isActive	A ref indicate whether a pausable instance is active	boolean (Required)	-
pause	Temporary pause the effect from executing	Fn (Required)	-
resume	Resume the effects	Fn (Required)	-

Fn

export type Fn = (this: any, ...args: any[]) => any;