danbooruの画像をクリックしたら適当な名前を付けてだうんよーよするやつ

danbooru_dl.user.js

// ==UserScript==
// @name         danbooru dl support
// @namespace    http://tampermonkey.net/
// @version      0.1
// @description  try to take over the world!
// @author       karubabu
// @match        https://*/post/show/*
// @grant        none
// ==/UserScript==

function exist_png(){
    return document.getElementsByClassName("original-file-unchanged").length === 1;
}

function get_url(is_png=false){
    if(is_png === true){
        return document.getElementsByClassName("original-file-unchanged")[0].href;
    }
    return document.getElementsByClassName("original-file-changed")[0].href;
}
(function() {
    'use strict';

    console.log("url: " + get_url(exist_png()));
    var pic_url = get_url(exist_png());
    var fileName = decodeURI(pic_url.match(".*/([^\?#;/:]+).*$")[1]);
    console.log("filename: " + fileName);
    (function(){
        var a = document.createElement('a');
        a.download = fileName;
        a.href = pic_url;
        //a.click();
    })();

    var sub = document.getElementById("image");
    sub.addEventListener("click", function(e){
        var a = document.createElement('a');
        a.download = fileName;
        a.href = pic_url;
        var evt = document.createEvent('MouseEvent');
        evt.initEvent("click",true,false);
        a.dispatchEvent(evt);
    });
})();