A simple dragging helper library
This script should not be not be installed directly. It is a library for other scripts to include with the meta directive // @require https://update.greasyfork.org/scripts/428694/945686/CKDragHelper.js
// ==UserScript==
// @name CKDragHelper
// @namespace dragger.ckylin.site
// @version 0.1
// @author CKylinMC
// @grant unsafeWindow
// @license GPLv3 License
// ==/UserScript==
if(!("wait" in window)){
window.wait = (t) => {
return new Promise(r => setTimeout(r, t));
}
}
const dragger = {
defaultHandler: (val) => console.log("DRAG:", val),
waitForDragger: async (waitStatus = true) => {
while (dragger.dragging !== waitStatus) await wait(10);
return dragger;
},
regHandler: async (func) => {
if (!(func instanceof Function)) throw "Param must be a func!";
await dragger.waitForDragger(false);
dragger.handler = func;
return dragger;
},
handler: () => {
},
dragging: false,
initialDragData: {
x: 0,
y: 0
},
lastDragData: {
x: 0,
y: 0
},
startDrag: (e) => {
if (dragger.dragging) return;
dragger.dragging = true;
console.log(dragger.initialDragData);
dragger.initialDragData.x = e.screenX;
dragger.initialDragData.y = e.screenY;
dragger.lastDragData.x = e.screenX;
dragger.lastDragData.y = e.screenY;
document.body.addEventListener("mouseup", dragger.stopDrag);
document.body.addEventListener("mousemove", dragger.handleDrag);
console.info("DRAG:", "Start Drag");
return dragger;
},
handleDrag: (e) => {
const currPos = {
x: e.screenX,
y: e.screenY
};
const initPos = dragger.initialDragData;
const delta = {
x: initPos.x - currPos.x,
y: initPos.y - currPos.y
}
const lastdelta = {
x: dragger.lastDragData.x - currPos.x,
y: dragger.lastDragData.y - currPos.y
}
dragger.lastDragData = currPos;
dragger.handler(delta, lastdelta);
},
stopDrag: () => {
document.body.removeEventListener("mouseup", dragger.stopDrag);
document.body.removeEventListener("mousemove", dragger.handleDrag);
dragger.handler = dragger.defaultHandler;
console.info("DRAG:", "Stop Drag");
dragger.dragging = false;
return dragger;
},
}