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@tikotzky
Forked from gragland/use-key-press-example.jsx
Created February 13, 2019 23:17
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import { useState, useEffect } from 'react';
// Usage
function App() {
// Call our hook for each key that we'd like to monitor
const happyPress = useKeyPress('h');
const sadPress = useKeyPress('s');
const robotPress = useKeyPress('r');
const foxPress = useKeyPress('f');
return (
<div>
<div>h, s, r, f</div>
<div>
{happyPress && '😊'}
{sadPress && '😢'}
{robotPress && '🤖'}
{foxPress && '🦊'}
</div>
</div>
);
}
// Hook
function useKeyPress(targetKey) {
// State for keeping track of whether key is pressed
const [keyPressed, setKeyPressed] = useState(false);
// If pressed key is our target key then set to true
function downHandler({ key }) {
if (key === targetKey) {
setKeyPressed(true);
}
}
// If released key is our target key then set to false
const upHandler = ({ key }) => {
if (key === targetKey) {
setKeyPressed(false);
}
};
// Add event listeners
useEffect(() => {
window.addEventListener('keydown', downHandler);
window.addEventListener('keyup', upHandler);
// Remove event listeners on cleanup
return () => {
window.removeEventListener('keydown', downHandler);
window.removeEventListener('keyup', upHandler);
};
}, [targetKey]); // rerun the effect if the targetKey changes
return keyPressed;
}
@zhangenming
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zhangenming commented Jun 30, 2022

Avoid recreating the handle function every time when rerender

// Hook
function useKeyPress(targetKey) {
  // State for keeping track of whether key is pressed
  const [keyPressed, setKeyPressed] = useState(false);

  // Add event listeners
  useEffect(() => {
    // If pressed key is our target key then set to true
    function downHandler({ key }) {
      if (key === targetKey) {
        setKeyPressed(true);
      }
    }
    // If released key is our target key then set to false
    const upHandler = ({ key }) => {
      if (key === targetKey) {
        setKeyPressed(false);
      }
    };

    window.addEventListener('keydown', downHandler);
    window.addEventListener('keyup', upHandler);
    // Remove event listeners on cleanup
    return () => {
      window.removeEventListener('keydown', downHandler);
      window.removeEventListener('keyup', upHandler);
    };
  }, [targetKey]); // rerun the effect if the targetKey changes

  return keyPressed;
}

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