# Hover Card
Allows sighted users to preview content available behind a link.
## Import
```
Copyts
import { HoverCard } from "@kobalte/core/hover-card";
// or
import { Root, Trigger, ... } from "@kobalte/core/hover-card";
// or (deprecated)
import { HoverCard } from "@kobalte/core";
```
```
Copyts
import { HoverCard } from "@kobalte/core/hover-card";
// or
import { Root, Trigger, ... } from "@kobalte/core/hover-card";
// or (deprecated)
import { HoverCard } from "@kobalte/core";
```
## Features
- Opens on hover only.
- Supports custom open and close delays.
- Optionally render a pointing arrow.
- Ignored by screen readers.
- Can be controlled or uncontrolled.
## Anatomy
The hovercard consists of:
- **HoverCard:** The root container for a hovercard.
- **HoverCard.Trigger:** The link that opens the hovercard.
- **HoverCard.Portal:** Portals its children into the `body` when the hovercard is open.
- **HoverCard.Content:** Contains the content to be rendered when the hovercard is open.
- **HoverCard.Arrow:** An optional arrow element to render alongside the hovercard.
```
Copytsx
```
```
Copytsx
```
## Example
[@MLFabien](https://twitter.com/mlfabien)
index.tsxstyle.css
```
Copytsx
import { HoverCard } from "@kobalte/core/hover-card";
import "./style.css";
function App() {
return (
@MLFabien
Fabien MARIE-LOUISE
Developer and UI Design enthusiast. Building UI related stuffs for @solid_js
);
}
```
```
Copytsx
import { HoverCard } from "@kobalte/core/hover-card";
import "./style.css";
function App() {
return (
@MLFabien
Fabien MARIE-LOUISE
Developer and UI Design enthusiast. Building UI related stuffs for @solid_js
);
}
```
## Usage
### Default open
An initial, uncontrolled open value can be provided using the `defaultOpen` prop.
```
Copytsx
...
```
```
Copytsx
...
```
### Controlled open
The `open` prop can be used to make the open state controlled. The `onOpenChange` event is fired when the user pointer enter or leave the trigger, and receives the new value.
```
Copytsx
import { createSignal } from "solid-js";
function ControlledExample() {
const [open, setOpen] = createSignal(false);
return (
...
);
}
```
```
Copytsx
import { createSignal } from "solid-js";
function ControlledExample() {
const [open, setOpen] = createSignal(false);
return (
...
);
}
```
### Origin-aware animations
We expose a CSS custom property `--kb-hovercard-content-transform-origin` which can be used to animate the content from its computed origin.
```
Copycss
/* style.css */
.hovercard__content {
transform-origin: var(--kb-hovercard-content-transform-origin);
animation: contentHide 250ms ease-in forwards;
}
.hovercard__content[data-expanded] {
animation: contentShow 250ms ease-out;
}
@keyframes contentShow {
from {
opacity: 0;
transform: scale(0.96);
}
to {
opacity: 1;
transform: scale(1);
}
}
@keyframes contentHide {
from {
opacity: 1;
transform: scale(1);
}
to {
opacity: 0;
transform: scale(0.96);
}
}
```
```
Copycss
/* style.css */
.hovercard__content {
transform-origin: var(--kb-hovercard-content-transform-origin);
animation: contentHide 250ms ease-in forwards;
}
.hovercard__content[data-expanded] {
animation: contentShow 250ms ease-out;
}
@keyframes contentShow {
from {
opacity: 0;
transform: scale(0.96);
}
to {
opacity: 1;
transform: scale(1);
}
}
@keyframes contentHide {
from {
opacity: 1;
transform: scale(1);
}
to {
opacity: 0;
transform: scale(0.96);
}
}
```
## API Reference
### HoverCard
`HoverCard` is equivalent to the `Root` import from `@kobalte/core/hover-card` (and deprecated `HoverCard.Root`).
| Prop | Description |
| --- | --- |
| open | `boolean` The controlled open state of the hovercard. |
| defaultOpen | `boolean` The default open state when initially rendered. Useful when you do not need to control the open state. |
| onOpenChange | `(open: boolean) => void` Event handler called when the open state of the hovercard changes. |
| openDelay | `number` The duration from when the mouse enters the trigger until the hovercard opens. |
| closeDelay | `number` The duration from when the mouse leaves the trigger or content until the hovercard closes. |
| ignoreSafeArea | `boolean` Whether to close the hovercard even if the user cursor is inside the safe area between the trigger and hovercard. |
| id | `string` A unique identifier for the component. The id is used to generate id attributes for nested components. If no id prop is provided, a generated id will be used. |
| forceMount | `boolean` Used to force mounting the hovercard (portal and content) when more control is needed. Useful when controlling animation with SolidJS animation libraries. |
`HoverCard` also accepts the following props to customize the placement of the `HoverCard.Content`.
| Prop | Description |
| --- | --- |
| getAnchorRect | `(anchor?: HTMLElement) => AnchorRect | undefined` Function that returns the anchor element's DOMRect. |
| placement | `Placement` The placement of the hovercard. |
| gutter | `number` The distance between the hovercard and the trigger element. By default, it's 0 plus half of the arrow offset, if it exists. |
| shift | `number` The skidding of the hovercard along the trigger element. |
| flip | `boolean | string` Controls the behavior of the hovercard when it overflows the viewport: \- If a `boolean`, specifies whether the hovercard should flip to the opposite side when it overflows. \- If a `string`, indicates the preferred fallback placements when it overflows. The placements must be spaced-delimited, e.g. "top left". |
| slide | `boolean` Whether the hovercard should slide when it overflows. |
| overlap | `boolean` Whether the hovercard can overlap the trigger element when it overflows. |
| sameWidth | `boolean` Whether the hovercard should have the same width as the trigger element. This will be exposed to CSS as `--kb-popper-anchor-width`. |
| fitViewport | `boolean` Whether the hovercard should fit the viewport. If this is set to true, the hovercard content will have `maxWidth` and `maxHeight` set to the viewport size. This will be exposed to CSS as `--kb-popper-available-width` and `--kb-popper-available-height`. |
| hideWhenDetached | `boolean` Whether to hide the hovercard when the trigger element becomes occluded. |
| detachedPadding | `number` The minimum padding in order to consider the trigger element occluded. |
| arrowPadding | `number` The minimum padding between the arrow and the hovercard corner. |
| overflowPadding | `number` The minimum padding between the hovercard and the viewport edge. This will be exposed to CSS as `--kb-popper-overflow-padding`. |
### HoverCard.Content
The popper positioner will copy the same `z-index` as the `HoverCard.Content`.
### HoverCard.Trigger
`HoverCard.Trigger` consists of [Link](https://kobalte.dev/docs/core/components/link).
| Data attribute | Description |
| --- | --- |
| data-expanded | Present when the hovercard is open. |
| data-closed | Present when the hovercard is close. |
`HoverCard.Content` share the same data-attributes.
## Rendered elements
| Component | Default rendered element |
| --- | --- |
| `HoverCard` | none |
| `HoverCard.Trigger` | `a` |
| `HoverCard.Portal` | `Portal` |
| `HoverCard.Content` | `div` |
| `HoverCard.Arrow` | `div` |
## Accessibility
### Keyboard Interactions
The hover card is intended for mouse users only so will not respond to keyboard navigation.
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