Tieba Preload

贴吧预加载，自动加载下一页内容，同时附带消灭贴吧自带 Lazy Load 功能
当前为 2014-04-05 提交的版本，查看最新版本。
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// ==UserScript==
// @name        Tieba Preload
// @version     1.1.4.2
// @description 贴吧预加载，自动加载下一页内容，同时附带消灭贴吧自带 Lazy Load 功能
// @match       http://tieba.baidu.com/*
// @include     http://tieba.baidu.com/*
// @author      864907600cc
// @icon        http://1.gravatar.com/avatar/147834caf9ccb0a66b2505c753747867
// @grant       none
// @run-at      document-end
// @namespace https://greasyfork.org/users/141
// ==/UserScript==

// 贴子判断方式由 kookxiang 提供
// 本脚本基于 GPLv3 协议开源 http://www.gnu.org/licenses/gpl.html‎
// (c) 86497600cc. Some Rights Reserved.

// 以下语句中部分判断代码来自 Chrome 扩展程序 KK 贴吧工具箱 (by kookxiang | https://chrome.google.com/webstore/detail/bcmemjlkdbeephmnklgimfnjlmfhfdgi)

if(typeof PageData!='undefined'&&PageData&&(PageData.product=='pb'||PageData.product=='frs')){ // 判断是否载入
	var setting=window.localStorage.getItem('tb_preload_setting')?(window.localStorage.getItem('tb_preload_setting').indexOf('{')>=0?JSON.parse(window.localStorage.getItem('tb_preload_setting')):{thread_preload:1,thread_list_lazyload:1}):{thread_preload:1,thread_list_lazyload:1};
	var stylesheet='.tb_preload_notification{position:fixed;right:10px;padding:5px;bottom:-50px;box-shadow:0 0 1px 5px rgba(0,0,0,0.5);background:rgba(0,0,0,0.5);font-size:12px;color:#fff;opacity:0;-webkit-transition:0.25s all linear;-o-transition:0.25s all linear;transition:0.25s all linear;user-select:none;-webkit-user-select:none;-moz-user-select:none;-ms-user-select:none;cursor:pointer;z-index:999999}.tb_preload_notification[show]{bottom:10px;opacity:1}.tb_preload_page{width:100%;font-size:14px;text-align:center}.tb_preload_page a{text-decoration:none;color:#333;margin:20px 0;display:block}.tb_preload_setting{color:#2d64b3;cursor:pointer}.list_loading,.right_section [data-type="tb-datalazyload"]{display:none}.vpic_wrap img{max-height:90px}';
	var ss=document.createElement('style');
	ss.textContent=stylesheet;
	document.head.appendChild(ss);
	var loading=false,
		loader=null;

	// 以下语句中代码来自 Kill Tieba Lazy Load (by 864907600cc, Licence: WTFPL)

	function kill_tieba_lazyload(){
		var codearea=document.getElementById('pblistCodeArea')||document.getElementById('frslistCodeArea')||null;
		if(codearea!=null){
			//document.getElementById('list_loading').outerHTML=document.getElementById('pblistCodeArea').value;
			//document.getElementById('pblistCodeArea').parentElement.removeChild(document.getElementById('pblistCodeArea'));
			var lazyload_t_nodes=codearea.childNodes;
			for(var i=0;i<lazyload_t_nodes.length;i++){
				if(lazyload_t_nodes[i].nodeType==8){
					codearea.outerHTML=lazyload_t_nodes[i].data;
					//lazyload_nodes[i].parentElement.removeChild(lazyload_nodes[i])
					break;
				}
			}
			_.Module.use("pb/widget/ForumListV3", {});
		}
		if(document.querySelectorAll('img[data-tb-lazyload]')){
			var lazyload_i_nodes=document.querySelectorAll('img[data-tb-lazyload]');
			for(var i=0;i<lazyload_i_nodes.length;i++){
				lazyload_i_nodes[i].setAttribute('src',lazyload_i_nodes[i].getAttribute('data-tb-lazyload'));
				lazyload_i_nodes[i].removeAttribute('data-tb-lazyload');
			}
		}
		if(document.querySelectorAll('img[onloadfun="listimg"][original]')){
			var lazyload_i_nodes=document.querySelectorAll('img[onloadfun="listimg"][original]');
			for(var i=0;i<lazyload_i_nodes.length;i++){
				lazyload_i_nodes[i].setAttribute('src',lazyload_i_nodes[i].getAttribute('original'));
			}
		}
	}

	// 以下语句中代码基于 Tieba Preload 修改 (by 864907600cc, Licence: GPLv3 | http://ccloli.com/201212/tieba-preload-source/)

	function whether_fetching(){
		//console.log('whether_fetching');
		var getscroll=document.documentElement.scrollTop||document.body.scrollTop,
			scroll_psi=document.body.scrollHeight-getscroll;
		if(scroll_psi<=5000&&loading==false){
			if(cur_page<total_page){
				loading=true;
				fetch_next_page();
			}
			//else window.onscroll=null;
			else clearInterval(loader);
		}
	}

	function fetch_next_page(){
		//console.log('fetch_next_page');
		var url=page_url+'?see_lz='+see_lz+'&pn='+next_page;
		xhr.onreadystatechange=function(){
			if(xhr.readyState==4&&xhr.status==200){
				var str=xhr.responseText;
				if(PageData.page=='v1')var data=str.split('"p_postlist"')[1].split('<div class="p_thread')[0].match(/>([\s\S]+)/)[1]; // 旧版贴吧
				else var data=str.split('"p_postlist"')[1].split('"right_section')[0].match(/>([\s\S]+)<\/div>[\s\S]*<\/div>[\s\S]*<div/)[1]; // 先 split 再 match 减少资源消耗（>20s → <1s）
				var node=document.getElementsByClassName('p_postlist')[0],
					t_node=document.createElement('div'),
					p_node=document.createElement('div');
				p_node.className='tb_preload_page';
				p_node.innerHTML='<a href="'+url+'">第 '+next_page+' 页，共 '+total_page+' 页</a>';
				node.appendChild(p_node);
				node.appendChild(t_node);
				t_node.outerHTML=data;
				kill_tieba_lazyload();
				++cur_page;
				++next_page;
				loading=false;
				if(cur_page==total_page)clearInterval(loader);
				notification.removeAttribute('show');
			}
		}
		xhr.open('GET',url);
		xhr.send();
		notification.setAttribute('show','true');
		notification.textContent='正在加载第 '+next_page+' 页......';
	}

	function set_function(v){
		if(v==1){
			if(setting.thread_preload==1){
				setting.thread_preload=0;
				setting_node.textContent='开启自动加载';
				setting_node_2.textContent='开启自动加载';
				if(loader!=null){
					clearInterval(loader);
					loader=null;
				}
				notification.textContent='已关闭自动加载......';
				notification.setAttribute('show','true');
				setTimeout(function(){notification.removeAttribute('show')},5000);
			}
			else{
				setting.thread_preload=1;
				setting_node.textContent='关闭自动加载';
				setting_node_2.textContent='关闭自动加载';
				if(loader==null)preload_listener();
				notification.textContent='已开启自动加载......';
				notification.setAttribute('show','true');
				setTimeout(function(){notification.removeAttribute('show')},5000);
			}
		}
		else if(v==2){
			if(setting.thread_list_lazyload==1){
				setting.thread_list_lazyload=0;
				setting_node.textContent='开启自动去除首页 lazyload';
				if(loader!=null){
					clearInterval(loader);
					loader=null;
				}
				notification.textContent='已禁用自动去除首页 lazyload......';
				notification.setAttribute('show','true');
				setTimeout(function(){notification.removeAttribute('show')},5000);
				document.getElementById('frs_list_pager').onclick=null;
			}
			else{
				setting.thread_list_lazyload=1;
				setting_node.textContent='禁用自动去除首页 lazyload';
				if(loader==null)kill_tieba_lazyload_listener();
				notification.textContent='已开启自动去除首页 lazyload......';
				notification.setAttribute('show','true');
				setTimeout(function(){notification.removeAttribute('show')},5000);
			}
		}
		window.localStorage.setItem('tb_preload_setting',JSON.stringify(setting));
	}

	function preload_listener(){
		if(setting.thread_preload==1&&cur_page!=total_page){
			//console.log('aaa');
			//window.onscroll=function(){ // 改用定时器以节省资源
			loader=setInterval(function(){whether_fetching()},1000);
			//}
		}
	}

	function kill_tieba_lazyload_listener(){
		if(setting.thread_list_lazyload==1){
			document.getElementById('frs_list_pager').onclick=function(){
				if(loader==null)loader=setInterval(function(){
					if(document.getElementById('frslistCodeArea')){
						kill_tieba_lazyload();
						clearInterval(loader);
						loader=null;
						kill_tieba_lazyload_listener();
					}
				},1000);
			}
		}
	}

	kill_tieba_lazyload();
	var notification=document.createElement('div');
	notification.className='tb_preload_notification';
	document.body.appendChild(notification);
	notification.onclick=function(){set_function(1)};

	if(PageData.product=='frs'){
		if(document.getElementsByClassName('th_footer_l')[0]){
			var setting_node=document.createElement('a'),
				page_node=document.getElementsByClassName('th_footer_l')[0];
			setting_node.textContent=setting.thread_list_lazyload==1?'禁用自动去除首页 lazyload':'开启自动去除首页 lazyload'; // 好长 _(:з」∠)_
			setting_node.className='tb_preload_setting';
			setting_node.onclick=function(){set_function(2)};
			page_node.appendChild(setting_node);
		}
		notification.style.pointerEvents='none';
		kill_tieba_lazyload_listener();
	}
	else if(PageData.product=='pb'&&PageData.pager){
		/*cur_page=0,
		total_page=0,
		page_url='',
		see_lz=0,*/
		var xhr=new XMLHttpRequest(),
			cur_page=PageData.pager.cur_page,
			total_page=PageData.pager.total_page,
			page_url=PageData.thread_url?'//tieba.baidu.com'+PageData.thread_url:location.href.match(/\/\/tieba\.baidu\.com\/p\/\d+/)[0],
			see_lz=PageData.special.lz_only,
			next_page=cur_page+1;

		var setting_node=document.createElement('li'),
			page_node=document.getElementsByClassName('l_posts_num');
		setting_node.textContent=setting.thread_preload==1?'关闭自动加载':'开启自动加载';
		setting_node.className='tb_preload_setting';
		var setting_node_2=setting_node.cloneNode(true);
		setting_node.onclick=function(){set_function(1)};
		setting_node_2.onclick=function(){set_function(1)};
		if(page_node[0])page_node[0].insertBefore(setting_node,page_node[0].getElementsByClassName('l_pager')[0].nextSibling);
		if(page_node[1])page_node[1].insertBefore(setting_node_2,page_node[1].getElementsByClassName('l_pager')[0].nextSibling);
		preload_listener();
	}
}