minishouyin/node_modules/rc-virtual-list/lib/hooks/useScrollDrag.js
2025-11-12 11:35:57 +08:00

84 lines
3.0 KiB
JavaScript

"use strict";
var _interopRequireWildcard = require("@babel/runtime/helpers/interopRequireWildcard").default;
var _interopRequireDefault = require("@babel/runtime/helpers/interopRequireDefault").default;
Object.defineProperty(exports, "__esModule", {
value: true
});
exports.default = useScrollDrag;
exports.getPageXY = getPageXY;
var _raf = _interopRequireDefault(require("rc-util/lib/raf"));
var React = _interopRequireWildcard(require("react"));
function smoothScrollOffset(offset) {
return Math.floor(Math.pow(offset, 0.5));
}
function getPageXY(e, horizontal) {
var obj = 'touches' in e ? e.touches[0] : e;
return obj[horizontal ? 'pageX' : 'pageY'] - window[horizontal ? 'scrollX' : 'scrollY'];
}
function useScrollDrag(inVirtual, componentRef, onScrollOffset) {
React.useEffect(function () {
var ele = componentRef.current;
if (inVirtual && ele) {
var mouseDownLock = false;
var rafId;
var _offset;
var stopScroll = function stopScroll() {
_raf.default.cancel(rafId);
};
var continueScroll = function continueScroll() {
stopScroll();
rafId = (0, _raf.default)(function () {
onScrollOffset(_offset);
continueScroll();
});
};
var clearDragState = function clearDragState() {
mouseDownLock = false;
stopScroll();
};
var onMouseDown = function onMouseDown(e) {
// Skip if element set draggable
if (e.target.draggable || e.button !== 0) {
return;
}
// Skip if nest List has handled this event
var event = e;
if (!event._virtualHandled) {
event._virtualHandled = true;
mouseDownLock = true;
}
};
var onMouseMove = function onMouseMove(e) {
if (mouseDownLock) {
var mouseY = getPageXY(e, false);
var _ele$getBoundingClien = ele.getBoundingClientRect(),
top = _ele$getBoundingClien.top,
bottom = _ele$getBoundingClien.bottom;
if (mouseY <= top) {
var diff = top - mouseY;
_offset = -smoothScrollOffset(diff);
continueScroll();
} else if (mouseY >= bottom) {
var _diff = mouseY - bottom;
_offset = smoothScrollOffset(_diff);
continueScroll();
} else {
stopScroll();
}
}
};
ele.addEventListener('mousedown', onMouseDown);
ele.ownerDocument.addEventListener('mouseup', clearDragState);
ele.ownerDocument.addEventListener('mousemove', onMouseMove);
ele.ownerDocument.addEventListener('dragend', clearDragState);
return function () {
ele.removeEventListener('mousedown', onMouseDown);
ele.ownerDocument.removeEventListener('mouseup', clearDragState);
ele.ownerDocument.removeEventListener('mousemove', onMouseMove);
ele.ownerDocument.removeEventListener('dragend', clearDragState);
stopScroll();
};
}
}, [inVirtual]);
}