I want to use a keyDown event on a div in React. I do:
componentWillMount() {
document.addEventListener("keydown", this.onKeyPressed.bind(this));
}
componentWillUnmount() {
document.removeEventListener("keydown", this.onKeyPressed.bind(this));
}
onKeyPressed(e) {
console.log(e.keyCode);
}
render() {
let player = this.props.boards.dungeons[this.props.boards.currentBoard].player;
return (
<div
className="player"
style={{ position: "absolute" }}
onKeyDown={this.onKeyPressed} // not working
>
<div className="light-circle">
<div className="image-wrapper">
<img src={IMG_URL+player.img} />
</div>
</div>
</div>
)
}
It works fine, but I would like to do it more in React style. I tried
onKeyDown={this.onKeyPressed}
on the component. But it doesn't react. It works on input elements as I recall.
How can I do it?
6 Answers
You should use tabIndex attribute to be able to listen onKeyDown event on a div in React. Setting tabIndex="0" should fire your handler.
You need to write it this way
<div
className="player"
style={{ position: "absolute" }}
onKeyDown={this.onKeyPressed}
tabIndex="0"
>
If onKeyPressed is not bound to this, then try to rewrite it using arrow function or bind it in the component constructor.
You're thinking too much in pure Javascript. Get rid of your listeners on those React lifecycle methods and use event.key instead of event.keyCode (because this is not a JS event object, it is a React SyntheticEvent). Your entire component could be as simple as this (assuming you haven't bound your methods in a constructor).
onKeyPressed(e) {
console.log(e.key);
}
render() {
let player = this.props.boards.dungeons[this.props.boards.currentBoard].player;
return (
<div
className="player"
style={{ position: "absolute" }}
onKeyDown={this.onKeyPressed}
>
<div className="light-circle">
<div className="image-wrapper">
<img src={IMG_URL+player.img} />
</div>
</div>
</div>
)
}
Using the div trick with tab_index="0" or tabIndex="-1" works, but any time the user is focusing a view that's not an element, you get an ugly focus-outline on the entire website. This can be fixed by setting the CSS for the div to use outline: none in the focus.
Here's the implementation with styled components:
import styled from "styled-components"
const KeyReceiver = styled.div`
&:focus {
outline: none;
}
`
and in the App class:
render() {
return (
<KeyReceiver onKeyDown={this.handleKeyPress} tabIndex={-1}>
Display stuff...
</KeyReceiver>
)
The answer with
<div
className="player"
onKeyDown={this.onKeyPressed}
tabIndex={0}
>
works for me, please note that the tabIndex requires a number, not a string, so tabIndex="0" doesn't work.
Also, remember that this trick will only work when focus is set on your div. If you want to manage keypress as soon as the div pops up, you can use this trick (especially useful for Drawers/Modals)
