react-selectable-box/lib/hooks/useScroll.js

A React component used hooks that allows you to select elements in the drag area using the mouse

var __defProp = Object.defineProperty;
var __getOwnPropDesc = Object.getOwnPropertyDescriptor;
var __getOwnPropNames = Object.getOwnPropertyNames;
var __hasOwnProp = Object.prototype.hasOwnProperty;
var __export = (target, all) => {
  for (var name in all)
    __defProp(target, name, { get: all[name], enumerable: true });
};
var __copyProps = (to, from, except, desc) => {
  if (from && typeof from === "object" || typeof from === "function") {
    for (let key of __getOwnPropNames(from))
      if (!__hasOwnProp.call(to, key) && key !== except)
        __defProp(to, key, { get: () => from[key], enumerable: !(desc = __getOwnPropDesc(from, key)) || desc.enumerable });
  }
  return to;
};
var __toCommonJS = (mod) => __copyProps(__defProp({}, "__esModule", { value: true }), mod);

// src/hooks/useScroll.ts
var useScroll_exports = {};
__export(useScroll_exports, {
  default: () => useScroll
});
module.exports = __toCommonJS(useScroll_exports);
var import_react = require("react");
var import_utils = require("../utils");
var DEFAULT_SCROLL_SPEED = 4;
var EDGE_OFFSET = 1;
function useScroll(scrollSpeed = DEFAULT_SCROLL_SPEED) {
  const topRaf = (0, import_react.useRef)(null);
  const bottomRaf = (0, import_react.useRef)(null);
  const leftRaf = (0, import_react.useRef)(null);
  const rightRaf = (0, import_react.useRef)(null);
  const cancelRaf = (raf) => {
    if (raf.current) {
      cancelAnimationFrame(raf.current);
      raf.current = null;
    }
  };
  const cancelScroll = () => {
    cancelRaf(topRaf);
    cancelRaf(bottomRaf);
    cancelRaf(leftRaf);
    cancelRaf(rightRaf);
  };
  (0, import_react.useEffect)(() => {
    return cancelScroll;
  }, []);
  const smoothScroll = (e, _container) => {
    const container = _container === document.body ? document.documentElement : _container;
    const { clientX, clientY } = (0, import_utils.getClientXY)(e);
    if (clientY - EDGE_OFFSET <= 0 || clientY <= container.getBoundingClientRect().top) {
      if (!topRaf.current) {
        const callback = () => {
          if (container.scrollTop > 0) {
            topRaf.current = requestAnimationFrame(() => {
              container.scrollTop -= scrollSpeed;
              callback();
            });
          }
        };
        callback();
      }
    } else {
      cancelRaf(topRaf);
    }
    if (clientY + EDGE_OFFSET >= window.innerHeight || clientY >= container.getBoundingClientRect().bottom) {
      if (!bottomRaf.current) {
        const callback = () => {
          if (container.scrollTop < container.scrollHeight - container.clientHeight) {
            bottomRaf.current = requestAnimationFrame(() => {
              container.scrollTop += scrollSpeed;
              callback();
            });
          }
        };
        callback();
      }
    } else {
      cancelRaf(bottomRaf);
    }
    if (clientX - EDGE_OFFSET <= 0 || clientX <= container.getBoundingClientRect().left) {
      if (!leftRaf.current) {
        const callback = () => {
          if (container.scrollLeft > 0) {
            leftRaf.current = requestAnimationFrame(() => {
              container.scrollLeft -= scrollSpeed;
              callback();
            });
          }
        };
        callback();
      }
    } else {
      cancelRaf(leftRaf);
    }
    if (clientX + EDGE_OFFSET >= window.innerWidth || clientX >= container.getBoundingClientRect().right) {
      if (!rightRaf.current) {
        const callback = () => {
          if (container.scrollLeft < container.scrollWidth - container.clientWidth) {
            rightRaf.current = requestAnimationFrame(() => {
              container.scrollLeft += scrollSpeed;
              callback();
            });
          }
        };
        callback();
      }
    } else {
      cancelRaf(rightRaf);
    }
  };
  return {
    cancelScroll,
    smoothScroll
  };
}