# Hover inspection card
Display a measured point in a bounded hover card.

## APIs demonstrated

- [HoverData](/reference/components/hover-data/) from `@pibbl/core/viz`
- [HoverDataProps](/reference/components/hover-data/) from `@pibbl/core/viz`
- [HoverCard](/reference/components/hover-card/) from `@pibbl/core/viz`
- [HoverCardProps](/reference/components/hover-card/) from `@pibbl/core/viz`
- [HoverCardStyle](/reference/components/hover-card/) from `@pibbl/core/viz`
- [HoverBounds](/reference/components/hover-card/) from `@pibbl/core/viz`
- [HoverPlacement](/reference/components/hover-card/) from `@pibbl/core/viz`

## Complete example

[Plain source](/minimal/viz/hover-card.tsx). Run as a browser module after the document body exists. TSX uses `jsx: "react-jsx"` and `jsxImportSource: "@pibbl/core"`.

```tsx
import { pibbl, Circle, Rectangle, Text } from "@pibbl/core";
import { closestPoint, defineSeries, HoverCard, HoverData, type HoverBounds, type HoverCardProps, type HoverCardStyle, type HoverDataProps, type HoverPlacement, LinearScale } from "@pibbl/core/viz";

const data = [{ x: 2, y: 3, label: "Peak" }];
const query = closestPoint({
  series: { series: defineSeries({ data, x: "x", y: "y" }) },
  position: { x: 160, y: 88 },
  xScale: "x",
  yScale: "y",
});
const bounds: HoverBounds = { x: 0, y: 0, width: 320, height: 220 };
const placement: HoverPlacement = "above";
const cardStyle: HoverCardStyle = {
  width: 96,
  height: 32,
  fill: "#ffffff",
  stroke: "#0f766e",
};
const hover: HoverDataProps<NonNullable<ReturnType<typeof query>>> = {
  query,
  children: (hit) => {
    if (!hit) return null;
    const card: HoverCardProps = {
      anchor: hit.anchor,
      bounds,
      placement,
      style: cardStyle,
      children: (
        <Text
          style={{ left: 8, top: 20, font: "12px sans-serif", fill: "#111827" }}
        >
          {hit.datum.label}
        </Text>
      ),
    };
    return (
      <>
        <Circle
          style={{
            cx: hit.anchor.x,
            cy: hit.anchor.y,
            radius: 5,
            fill: "#f97316",
          }}
        />
        <HoverCard {...card} />
      </>
    );
  },
};
const canvas = document.createElement("canvas");
canvas.width = 320;
canvas.height = 220;
document.body.append(canvas);
const app = pibbl(
  canvas,
  <>
    <Rectangle style={{ width: 320, height: 220, fill: "#f8fafc" }} />
    <LinearScale
      id="x"

      domain={[0, 4]}
      range="width"
      style={{ width: 320, height: 220 }}
    >
      <LinearScale id="y"  domain={[0, 6]} range="height" reverse>
        <HoverData {...hover} />
      </LinearScale>
    </LinearScale>
  </>,
);
window.addEventListener("pagehide", () => app.dispose(), { once: true });

```

## Usage notes

- Creates its own canvas and disposes the Pibbl mount on pagehide.

## Documentation version

Documentation built with @pibbl/core 0.0.2, revision 272a94a. ALPHA — NOT FOR PRODUCTION USE.