// ==UserScript==
// @name        DropStop
// @author      Jefferson "jscher2000" Scher
// @namespace   JeffersonScher
// @version     1
// @description Cancel drop event so page doesn't navigate away
// @copyright   Copyright 2015 Jefferson Scher
// @license     BSD
// @include     *
// @grant       none
// ==/UserScript==
function IgnoreDrop(evt){
// allow drop for inputs and textareas
if (evt.target.nodeName == "INPUT" || evt.target.nodeName == "TEXTAREA") return;
// allow drop for contenteditable elements
if (evt.target.getAttribute("contenteditable") == "true") return;
// prevent default action and kill the event
evt.preventDefault();
evt.stopPropagation();
return false;
}
document.body.addEventListener("drop", IgnoreDrop, true);
// Per https://opensourcehacker.com/2011/11/11/cancelling-html5-drag-and-drop-events-in-web-browsers/
document.body.addEventListener("dragover", IgnoreDrop, true);
document.body.addEventListener("dragenter", IgnoreDrop, true);