53 lines
1.2 KiB
JavaScript
53 lines
1.2 KiB
JavaScript
export const findElementPosition = el => {
|
|
let box;
|
|
|
|
if (el.getBoundingClientRect && el.parentNode) {
|
|
box = el.getBoundingClientRect();
|
|
}
|
|
|
|
if (!box) {
|
|
return {
|
|
left: 0,
|
|
top: 0,
|
|
};
|
|
}
|
|
|
|
const docEl = document.documentElement;
|
|
const body = document.body;
|
|
|
|
const clientLeft = docEl.clientLeft || body.clientLeft || 0;
|
|
const scrollLeft = window.pageXOffset || body.scrollLeft;
|
|
const left = (box.left + scrollLeft) - clientLeft;
|
|
|
|
const clientTop = docEl.clientTop || body.clientTop || 0;
|
|
const scrollTop = window.pageYOffset || body.scrollTop;
|
|
const top = (box.top + scrollTop) - clientTop;
|
|
|
|
return {
|
|
left: Math.round(left),
|
|
top: Math.round(top),
|
|
};
|
|
};
|
|
|
|
export const getPointerPosition = (el, event) => {
|
|
const position = {};
|
|
const box = findElementPosition(el);
|
|
const boxW = el.offsetWidth;
|
|
const boxH = el.offsetHeight;
|
|
const boxY = box.top;
|
|
const boxX = box.left;
|
|
|
|
let pageY = event.pageY;
|
|
let pageX = event.pageX;
|
|
|
|
if (event.changedTouches) {
|
|
pageX = event.changedTouches[0].pageX;
|
|
pageY = event.changedTouches[0].pageY;
|
|
}
|
|
|
|
position.y = Math.max(0, Math.min(1, (pageY - boxY) / boxH));
|
|
position.x = Math.max(0, Math.min(1, (pageX - boxX) / boxW));
|
|
|
|
return position;
|
|
};
|