Check if browser tab has focus using React
To check if a browser tab has focus using React:
- Add event listeners for focus and blur events.
-
If the event is fired
focus, the tab has focus. -
If the event is fired
blur, the tab loses focus.
import {useEffect, useState} from 'react';
export default function App() {
const [tabHasFocus, setTabHasFocus] = useState(true);
useEffect(() => {
const handleFocus = () => {
console.log('Tab has focus');
setTabHasFocus(true);
};
const handleBlur = () => {
console.log('Tab lost focus');
setTabHasFocus(false);
};
window.addEventListener('focus', handleFocus);
window.addEventListener('blur', handleBlur);
return () => {
window.removeEventListener('focus', handleFocus);
window.removeEventListener('blur', handleBlur);
};
}, []);
return (
<div>
{tabHasFocus ? (
<h2>Tab has focus ✅</h2>
) : (
<h2>Tab does not have focus ⛔️</h2>
)}
</div>
);
}
We initialize a state variable to track whether the tab has focus.
We pass true to useStatethe hook to instruct the tab to receive focus when the component mounts.
In our useEffecthook, we added event listeners for the focus and blur events. We windowadded the events on the object.
When a tab receives focus, focusthe event is fired.
The event is fired when the tab loses focus blur.
We useEffectreturned a function from the hook. This function will be called when the component unmounts.
In our cleanup function, we use removeEventListener()the method to remove the event listener we registered earlier.
This helps us avoid memory leaks in our application.
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