Snap Links の真似事

SnapLinks.js

javascript:({
	init: function() {
		this.box = document.createElement("div");
		this.box.id = "snap-links-box";
		this.bs = this.box.style;
		this.bs.backgroundColor = "rgba(0,128,255,.1)";
		this.bs.border = "1px solid rgb(255,255,0)";
		this.bs.WebkitBoxSizing = 
		this.bs.OBoxSizing = 
		this.bs.MozBoxSizing = 
		this.bs.boxSizing = 'border-box';
		this.bs.position = "absolute";
		this.bs.zIndex = "2147483647";
		this.cursor = document.body.style.cursor;
		document.body.style.setProperty("cursor", "crosshair", "important");
		addEventListener("mousedown", this, true);
	},
	uninit: function() {
		var self = this;
		removeEventListener("mousemove", this, true);
		removeEventListener("mouseup", this, true);
		setTimeout(function(){
			removeEventListener("click", self, true);
		}, 10);

		this.box.parentNode.removeChild(this.box);
		this.box = null;
		if (this.cursor) {
			document.body.style.cursor = this.cursor;
		} else {
			document.body.style.removeProperty("cursor");
		}
	},
	handleEvent : function(event){
		if (event.button) return false;
		event.preventDefault();
		event.stopPropagation();
		switch(event.type){
			case "mousedown":
				this.downX = event.pageX;
				this.downY = event.pageY;
				this.bs.left = this.downX + "px";
				this.bs.top  = this.downY + "px";
				document.body.appendChild(this.box);
				removeEventListener("mousedown", this, true);
				addEventListener("mousemove", this, true);
				addEventListener("mouseup", this, true);
				addEventListener("click", this, true);
				break;
			case "mousemove":
				var moveX = event.pageX;
				var moveY = event.pageY;
				if (this.downX > moveX) this.bs.left = moveX + "px";
				if (this.downY > moveY) this.bs.top  = moveY + "px";
				this.bs.width  = Math.abs(moveX - this.downX) + "px";
				this.bs.height = Math.abs(moveY - this.downY) + "px";
				break;
			case "mouseup":
				this.boxRect = this.box.getBoundingClientRect();
				this.uninit();
				if (this.boxRect.width > 0 && this.boxRect.height > 0)
					this.command(event);
				break;
		}
	},
	command: function(aEvent) {
		var links = [];
		var checks = [];
		var linkhash = {};
		var x = document.evaluate(
			'//a[not(.//img)] | //a//img | //input[@type="checkbox"]',
			document.body,
			null,
			XPathResult.ORDERED_NODE_SNAPSHOT_TYPE,
			null
		);
		for (var i = 0, len = x.snapshotLength; i < len; i++) {
			var elem = x.snapshotItem(i);
			if (elem.offsetWidth <= 1 || elem.offsetHeight === 0)
				continue;
			if (!this.isOverlap(elem))
				continue;
			if (getComputedStyle(elem, null).visibility === "hidden")
				continue;

			if (elem instanceof HTMLImageElement) {
				elem = document.evaluate(
					'ancestor-or-self::a', elem, null, XPathResult.FIRST_ORDERED_NODE_TYPE, null)
					.singleNodeValue;
			}
			if (elem instanceof HTMLAnchorElement) {
				if (!linkhash[elem.href] && 
				    /^(?:http|data|file)/.test(elem.href) && 
				    elem.hasAttribute("href") && 
				    elem.getAttribute("href")[0] != "#") {
					linkhash[elem.href] = true;
					links.push(elem);
				}
			}
			else if (!elem.disabled){
				checks.push(elem);
			}
		};
		if (links.length === 0 && checks.length === 0)
			return;
		if ((links.length === 0 || aEvent.shiftkey) && checks.length > 0) {
			this.toggleChecks(checks);
		} else if (links.length > 0 && aEvent.ctrlKey) {
			alert(links.join("\n"));
		} else if (links.length > 0 && checks.length === 0) {
			this.openLinks(links);
		} else if (confirm("OK: リンクを開く\nキャンセル: チェックボックス ON/OFF")) {
			this.openLinks(links);
		} else {
			this.toggleChecks(checks);
		}
	},
	openLinks: function(links) {
		if (window.chrome) {
			for (var i = 0, len = links.length; i < len; i++) {
				var evt = document.createEvent("MouseEvents");
				evt.initMouseEvent(
					"click", true, true, window, 
					0, 0, 0, 0, 0, 
					true, false, i===0, false, 
					0, null);
				var a = document.createElement("a");
				a.href = links[i].href;
				a.dispatchEvent(evt);
			};
		} else if (window.opera) {
			var i = 0;
			function o(url) {
				var elem = links[i++];
				if (!elem) return;
				window.open(elem.href);
				setTimeout(o, i * 10);
			}
			setTimeout(o, i * 10);
		} else {
			for (var i = 0, len = links.length; i < len; i++) {
				window.open(links[i].href);
			};
		}
	},
	toggleChecks: function(checks) {
		for (var i = 0, len = checks.length; i < len; i++) {
			checks[i].checked = !checks[i].checked;
		};
	},
	isOverlap: function(aElem) {
		var rects = aElem.getClientRects();
		for (var i = 0, rect; rect = rects[i]; i++) {
			if (this.boxRect.left < rect.right &&
			    this.boxRect.right > rect.left &&
			    this.boxRect.top < rect.bottom &&
			    this.boxRect.bottom > rect.top)
			return true;
		};
		return false;
	},

}).init();