LDRize like JK scroll.

_readme.txt

思いつきで作った LDRize みたいに "J","K" でスクロールできるスクリプト。
とりあえず Firefox 専用。

JK_Walker.user.js

// ==UserScript==
// @name           JK Walker
// @description    LDRize like JK scroll.
// @namespace      http://d.hatena.ne.jp/Griever/
// @license        MIT License
// @compatibility  Firefox 12
// @version        0.0.1
// @include        http://**
// @include        https://*
// @exclude        http://reader.livedoor.com/*
// @exclude        http://fastladder.com/*
// @exclude        http://www.google.co.jp/reader/*
// @exclude        https://www.google.co.jp/reader/*
// @exclude        http://translate.google.*
// @exclude        http://maps.google.*
// @exclude        http://twitter.com/*
// @exclude        https://twitter.com/*
// @exclude        http://b.hatena.ne.jp/*
// ==/UserScript==

var SITEINFO = [
	{	url: '^https?://www\\.google\\.[^/]+/.'
		,target: 'h3, #pnnext, a[href^="/imgres?"], .autopagerize_link'
	}
	,{	url: '^https?://realtime\\.search\\.yahoo\\.[^/]+/.'
		,target: 'div.cnt, a#btn_TSp_1',
	}
	,{	url: '^https?://blog\\.search\\.yahoo\\.[^/]+/.'
		,target: 'h2, span.m:last-child',
	}
	,{	url: '^https?://[\\w.]+\\.yahoo\\.[^/]+/.'
		,target: 'h3, span.m:last-child, a[target="imagewin"], div.item'
	}
	,{	url: '^https?://mobile\\.twitter\\.com'
		,target: '[id^="tweet_"]'
	}
	,{	url: '^https?://github\\.com/'
		,target: 'td.content > a'
	}
	,{	url: '^https?://www\\.youtube\\.com/'
		,target: 'h2, .browse-item, .result-item, .yt-uix-pager-next'
	}
	,{	url: '^http://seiga\\.nicovideo\\.jp/'
		,target: '.illust_list_img, .illust_area ~ * a[rel="next"] '
	}
	,{	url: '^http://live\\.nicovideo\\.jp/'
		,target: '.detail, a[rel="next"]'
	}
	,{	url: '^http://\\w+\\.nicovideo\\.jp/'
		,target: 'div[class^="thumb_col_"], a[href^="/mylist/"], .illust_list_img'
	}
];
var MICROFORMAT = {
	target: 'h2, h3, h4, h5, h6, section, dt, .autopagerize_link',
	through: ''
};

function JKWalkerClass(win, info) {
	this.win = win;
	this.doc = win.document;
	this._target = info.target || MICROFORMAT.target;
	this._through = info.through || MICROFORMAT.through;

	this.addStyle();
	this.treeWalker = this.doc.createTreeWalker(this.doc, 1, this.filter.bind(this), false); // NodeFilter.SHOW_ELEMENT
	this.doc.addEventListener('keypress', this, false);
}
JKWalkerClass.prototype = {
	_input : 'textarea, input[type="text"], input:not([type]), input[type="password"], input[type="search"]',
	filter: function(node) {
		if (node.mozMatchesSelector(this._target) && 
				(!this._through || !node.mozMatchesSelector(this._through)) && 
				node.offsetHeight)
			return 1;// NodeFilter.FILTER_ACCEPT
		return 3;// NodeFilter.FILTER_SKIP;
	},
	handleEvent: function(event) {
		switch(event.type) {
			case 'keypress':
				if (event.ctrlKey || event.shiftKey || event.altKey) return;
				if (event.target.mozMatchesSelector(this._input)) return;
				if (event.charCode === 106) {//j
					this.find(false);
				} else if (event.charCode === 107) {//k
					this.find(true);
				} else if (event.charCode === 111) {//o
					var anchor = this.doc.activeElement;
					if (this.lastFocusedNode != anchor) return;
					if (!anchor.href || /^javascript|^mailto/i.test(anchor.href)) return;
					GM_openInTab(anchor.href);
				} else {
					return;
				}
				event.preventDefault();
				event.stopPropagation();
				break;
		}
	},
	find: function(isPrev) {
		// 最後にクリックした位置を探す
		var sel = this.win.getSelection();
		if (sel.focusNode) {
			this.treeWalker.currentNode = isPrev ? sel.anchorNode : sel.focusNode;
		}

		var node;
		if (isPrev) {
			node = this.treeWalker.previousNode();
			if (!node) {
				this.treeWalker.currentNode = this.doc.body.lastChild;
				node = this.treeWalker.previousNode();
			}
		} else {
			node = this.treeWalker.nextNode();
			if (!node) {
				this.treeWalker.currentNode = this.doc.body;
				node = this.treeWalker.nextNode();
			}
		}
		if (!node) return;
		this.treeWalker.currentNode = node;

		this.scrollTo(node);
		this.focusAndHighlight(node);
		sel.collapse(node, 0);
	},
	scrollTo: function(node, isPrev) {
		var rect = node.getBoundingClientRect();
		var t = parseInt(rect.top - (Math.max(this.win.innerHeight - rect.height, 0)) / 2, 10);
		var l = parseInt(rect.left - (Math.max(this.win.innerWidth - rect.width, 0)) / 2, 10);
		this.win.scrollBy(l, t);
	},
	focusAndHighlight: function(node) {
		var anchor = this.doc.evaluate('descendant-or-self::a[@href]|ancestor-or-self::a[@href]',
			node, null, XPathResult.FIRST_ORDERED_NODE_TYPE, null).singleNodeValue;
		if (anchor && !/^mailto/.test(anchor.href)) {
			anchor.focus();
			this.lastFocusedNode = anchor;
		}
		node.setAttribute("jkwalker_focus", "true");
		this.win.setTimeout(function() {
			node.removeAttribute('jkwalker_focus');
		}, 400);
	},
	addStyle: function() {
		this.style = this.doc.createElement('style');
		this.style.type = 'text/css';
		this.style.appendChild(this.doc.createTextNode(<![CDATA[
			[jkwalker_focus] {
				outline: 3px solid magenta !important;
				outline-offset: -2px !important;
			}
			[jkwalker_focus] :focus {
				outline: 2px dotted red !important;
				outline-offset: -1px !important;
			}
		]]>.toString()));
		(this.doc.head || this.doc.documentElement).appendChild(this.style);
	},
};

function launch() {
	var url = document.URL;
	var isLaunched = SITEINFO.some(function(info){
		try {
			if (new RegExp(info.url).test(url)) {
				window.jk = new JKWalkerClass(window, info);
				return true;
			}
		} catch (e) {
			GM_log('error at ' + info.url + '\n' + e);
		}
	});
	if (!isLaunched)
		window.jk = new JKWalkerClass(window, MICROFORMAT);
}
launch();