Swipe effect in react js
Might be for someone my solution will be also useful:
export const useSwipe = ({left, right, up, down}: {left?: () => void; right?: () => void; up?: () => void; down?: () => void;}) => {
const touchCoordsRef = useRef({touchStart: {x: 0, y: 0, time: Date.now()}});
const fnsRef = useRef({up, down, left, right});
fnsRef.current = {
up,
left,
down,
right,
};
useEffect(() => {
const handleTouchStart = (e: TouchEvent) => {
touchCoordsRef.current.touchStart.x = e.targetTouches[0].clientX;
touchCoordsRef.current.touchStart.y = e.targetTouches[0].clientY;
touchCoordsRef.current.touchStart.time = Date.now();
};
const handleTouchEnd = (e: TouchEvent) => {
const threshold = 150;
const swipeSpeed = 1; // sec;
const touchEndX = e.changedTouches[0].clientX;
const touchEndY = e.changedTouches[0].clientY;
const touchStartX = touchCoordsRef.current.touchStart.x;
const touchStartY = touchCoordsRef.current.touchStart.y;
const elapsedTime = (Date.now() - touchCoordsRef.current.touchStart.time) / 1000;
if(elapsedTime > swipeSpeed) {
return;
}
const xDistance = touchStartX - touchEndX;
const yDistance = touchStartY - touchEndY;
if(Math.abs(xDistance) < threshold && Math.abs(yDistance) < threshold) {
return;
}
if(Math.abs(xDistance) >= Math.abs(yDistance)) {
xDistance > 0 ? fnsRef.current.right?.() : fnsRef.current.left?.();
} else {
yDistance > 0 ? fnsRef.current.down?.() : fnsRef.current.up?.();
}
};
window.addEventListener('touchstart', handleTouchStart);
window.addEventListener('touchend', handleTouchEnd);
return () => {
window.removeEventListener('touchstart', handleTouchStart);
window.removeEventListener('touchend', handleTouchEnd);
};
});
};
I used solution above as a foundation for build what I was needed. Maybe somebody need something like this. Idea was to move my custom slider left and right on swipe effect. If you want it to be more sensitive - adjust value 150 to 75.
const [touchStart, setTouchStart] = React.useState(0);
const [touchEnd, setTouchEnd] = React.useState(0);
function handleTouchStart(e) {
setTouchStart(e.targetTouches[0].clientX);
}
function handleTouchMove(e) {
setTouchEnd(e.targetTouches[0].clientX);
}
function handleTouchEnd() {
if (touchStart - touchEnd > 150) {
// do your stuff here for left swipe
moveSliderRight();
}
if (touchStart - touchEnd < -150) {
// do your stuff here for right swipe
moveSliderLeft();
}
}
You can add onTouch
event handlers to your React components:
onTouchStart={touchStartEvent => this.handleTouchStart(touchStartEvent)}
onTouchMove={touchMoveEvent => this.handleTouchMove(touchMoveEvent)}
onTouchEnd={() => this.handleTouchEnd()}
You may also want to add event handlers for mouse events for cross-platform compatibility:
onMouseDown={mouseDownEvent => this.handleMouseDown(mouseDownEvent)}
onMouseMove={mouseMoveEvent => this.handleMouseMove(mouseMoveEvent)}
onMouseUp={() => this.handleMouseUp()}
onMouseLeave={() => this.handleMouseLeave()}
You have the right idea for updating the left
property of state in an event handler, but if you want the swiping functionality to feel natural you'll need to track the position of the pointer (be it a mouse or a touch) by updating left
using the event's clientX
property.
To do this, you'll need to store the position of the first touch and set left
equal to the change in the touch's location. For added realism, you can also keep track of the touch's velocity and continue animating the component after the touch is finished.
Here's a quick-n-dirty Codepen I made for swiping to remove items from a list:
https://codepen.io/swingthing/pen/ZBGBJb/