Center Image

Centers images (directly opened with browser)(firefox-like) with hotkeys (to resize or scroll)

当前为 2016-10-05 提交的版本,查看 最新版本

您需要先安装一个扩展,例如 篡改猴Greasemonkey暴力猴,之后才能安装此脚本。

You will need to install an extension such as Tampermonkey to install this script.

您需要先安装一个扩展,例如 篡改猴暴力猴,之后才能安装此脚本。

您需要先安装一个扩展,例如 篡改猴Userscripts ,之后才能安装此脚本。

您需要先安装一款用户脚本管理器扩展,例如 Tampermonkey,才能安装此脚本。

您需要先安装用户脚本管理器扩展后才能安装此脚本。

(我已经安装了用户脚本管理器,让我安装!)

您需要先安装一款用户样式管理器扩展,比如 Stylus,才能安装此样式。

您需要先安装一款用户样式管理器扩展,比如 Stylus,才能安装此样式。

您需要先安装一款用户样式管理器扩展,比如 Stylus,才能安装此样式。

您需要先安装一款用户样式管理器扩展后才能安装此样式。

您需要先安装一款用户样式管理器扩展后才能安装此样式。

您需要先安装一款用户样式管理器扩展后才能安装此样式。

(我已经安装了用户样式管理器,让我安装!)

// ==UserScript==
// @name          Center Image
// @namespace     CenterImage
// @author        Owyn
// @version       1.82
// @description   Centers images (directly opened with browser)(firefox-like) with hotkeys (to resize or scroll)
// @homepage      https://greasyfork.org/scripts/110-center-image
// @run-at        document-start
// @noframes
// @grant         GM_getValue
// @grant         GM_setValue
// @grant         GM_registerMenuCommand
// @match         http://*/*
// @match         https://*/*
// @match         file://*/*
// ==/UserScript==

if (typeof GM_registerMenuCommand !== "undefined")
{
	GM_registerMenuCommand("Center Image Configuration", cfg, "n");
}

var images = document.images;
if (!images || images.length !== 1 || images[0].src !== location.href) 
{
	return false;
}

var rescaled = false;
var iot = 0, iol = 0;
var i = images[0];

var FireFox = ((navigator.userAgent.indexOf('Firefox') != -1) ? true : false);

function makeimage()
{
	if(cfg_bgclr)
	{
		document.body.bgColor = cfg_bgclr;
		if(document.head){document.head.innerHTML = "";} // remove FireFox background
	}
	document.body.innerHTML = "<style>img { position: absolute; top: 0; right: 0; bottom: 0; left: 0; }</style>"; // center image
	i.style.margin = "auto"; // center image
	document.body.style.margin = "0px";
	document.body.appendChild(i);
	i.addEventListener("mousedown", onmousedown, true);
	i.addEventListener("click", rescale, true);
	window.addEventListener("keydown", onkeydown, true);
	window.addEventListener("resize", onresize, true);
	autoresize();
}

function onresize()
{
	if(rescaled)
	{
		rescaled = false;
		rescale();
	}
}

function changecursor()
{
	i.style.margin = "auto";
	if(!rescaled && (((i.naturalHeight / window.devicePixelRatio).toFixed() == window.innerHeight && (i.naturalWidth / window.devicePixelRatio).toFixed() <= window.innerWidth) || ((i.naturalHeight / window.devicePixelRatio).toFixed() <= window.innerHeight && (i.naturalWidth / window.devicePixelRatio).toFixed() == window.innerWidth))) // one img dimension is equal to screen and other is the same or less than the screen
	{
		i.style.cursor = "";
	}
	else if((i.naturalHeight / window.devicePixelRatio).toFixed() > window.innerHeight || (i.naturalWidth / window.devicePixelRatio).toFixed() > window.innerWidth)
	{
		if(rescaled)
		{
			i.style.cursor = "-moz-zoom-in";
			i.style.cursor = "-webkit-zoom-in";
		}
		else
		{
			i.style.cursor = "-moz-zoom-out";
			i.style.cursor = "-webkit-zoom-out";
			if((i.naturalHeight / window.devicePixelRatio).toFixed() > window.innerHeight) // chrome bug fuuuuu
			{
				i.style.margin = "0px auto";
			}
		}
	}
	else
	{
		if(rescaled)
		{
			i.style.cursor = "-moz-zoom-out";
			i.style.cursor = "-webkit-zoom-out";
		}
		else
		{
			i.style.cursor = "-moz-zoom-in";
			i.style.cursor = "-webkit-zoom-in";
		}
	}
}

function onmousedown(event)
{
	if(i.offsetLeft > 0){iol = i.offsetLeft;}
	if(i.offsetTop > 0){iot = i.offsetTop;}
}

function rescale(event)
{
	if(rescaled)
	{
		rescaled = false;
		var scale;
		if(event)
		{
			if (typeof event.y === "undefined") // Firefox
			{
				ex = event.clientX;
				ey = event.clientY;
			}
			else
			{
				ex = event.x;
				ey = event.y;
			}
			ex -= iol;
			ey -= iot;
			scale = Math.min((window.innerWidth / (i.naturalWidth / window.devicePixelRatio).toFixed()), (window.innerHeight / (i.naturalHeight / window.devicePixelRatio).toFixed()));
		}
		i.removeAttribute("width");
		i.removeAttribute("height");
		i.style.width = (i.naturalWidth / window.devicePixelRatio).toFixed() + "px";
		i.style.height = (i.naturalHeight / window.devicePixelRatio).toFixed() + "px";
		changecursor();
		if(event)
		{
			window.scrollTo(ex / scale - window.innerWidth / 2, ey / scale - window.innerHeight / 2);
		}
	}
	else
	{
		i.removeAttribute("width");
		i.removeAttribute("height");
		i.style.width = (i.naturalWidth / window.devicePixelRatio).toFixed() + "px";
		i.style.height = (i.naturalHeight / window.devicePixelRatio).toFixed() + "px";
		if((i.naturalWidth / window.devicePixelRatio).toFixed() != window.innerWidth)
		{
			i.style.width = window.innerWidth + "px";
			i.style.height = "";
			rescaled = true;
		}
		
		if((i.height > window.innerHeight) || (i.width > window.innerWidth))
		{
			i.style.width = (i.naturalWidth / window.devicePixelRatio).toFixed() + "px";
			i.style.height = (i.naturalHeight / window.devicePixelRatio).toFixed() + "px";
			if((i.naturalHeight / window.devicePixelRatio).toFixed() != window.innerHeight)
			{
				i.style.height = window.innerHeight + "px";
				i.style.width = "";
				rescaled = true;
			}
		}
		changecursor();
	}
}

var ARC = false;
function autoresize()
{
	if(i.naturalWidth && ARC) // stupidfox
	{
		if(!document.head) // old fix for old chrome - let it be
		{
			document.lastChild.insertBefore(document.createElement("head"), document.body);
		}
		var link = document.createElement('link');
		link.type = 'image/x-icon';
		link.rel = 'shortcut icon';
		link.href = i.src;
		document.head.appendChild(link); // favicon
		var title = i.src.substr(i.src.lastIndexOf("/")+1);
		if(title.indexOf("?") != -1)
		{
			title = title.substr(0, title.indexOf("?"));
		}
		document.title = title + " (" + i.naturalWidth + "x" + i.naturalHeight + ")"; // title
		
		rescaled = true;rescale(0); // to original size in pixels
		if(cfg_fitWH && i.height > window.innerHeight && i.width > window.innerWidth) // both scrollbars
		{
			rescale(0);
		}
		else if(cfg_fitB && (i.height > window.innerHeight || i.width > window.innerWidth)) // one scrollbar
		{
			rescale(0);
		}
		else if(cfg_fitS && i.height <= window.innerHeight && i.width <= window.innerWidth) // no scrollbars
		{
			rescale(0);
		}
		if(cfg_js){eval(cfg_js);}
	}
	else
	{
		ARC = true;
		setTimeout(function() { autoresize(); }, 10);
	}
}

// hotkeys
if (typeof KeyEvent === "undefined")
{
	var KeyEvent = {
		DOM_VK_SPACE: 32,
		DOM_VK_LEFT: 37,
		DOM_VK_UP: 38,
		DOM_VK_RIGHT: 39,
		DOM_VK_DOWN: 40,
		DOM_VK_A: 65,
		DOM_VK_D: 68,
		DOM_VK_P: 80,
		DOM_VK_Q: 81,
		DOM_VK_S: 83,
		DOM_VK_W: 87,
		DOM_VK_NUMPAD2: 98,
		DOM_VK_NUMPAD4: 100,
		DOM_VK_NUMPAD5: 101,
		DOM_VK_NUMPAD6: 102,
		DOM_VK_NUMPAD8: 104
	};
}

function cancelEvent(a)
{
	a = a ? a : window.event;
	if (a.stopPropagation)
	{
		a.stopPropagation();
	}
	if (a.preventDefault)
	{
		a.preventDefault();
	}
	a.cancelBubble = true;
	a.cancel = true;
	a.returnValue = false;
	return false;
}

function scroll_space(a, b)
{
	var by = Math.round((b ? window.innerHeight : window.innerWidth) * 0.50 * (a ? -1 : 1));
	if(!b)
	{
		window.scrollBy(0, by);
	}
	else
	{
		window.scrollBy(by, 0);
	}
}

function onkeydown (b)
{
	var a = (window.event) ? b.keyCode : b.which;
	
	if (a != KeyEvent.DOM_VK_SPACE && (b.altKey || b.ctrlKey || b.metaKey))
	{
		return;
	}
	
	var by = Math.round(window.innerHeight * 0.10);
	
	switch (a)
	{
	case KeyEvent.DOM_VK_RIGHT:
	case KeyEvent.DOM_VK_D:
	case KeyEvent.DOM_VK_NUMPAD6:
		window.scrollBy(by, 0);
		cancelEvent(b);
		break;
	case KeyEvent.DOM_VK_LEFT:
	case KeyEvent.DOM_VK_A:
	case KeyEvent.DOM_VK_NUMPAD4:
		window.scrollBy(by * -1, 0);
		cancelEvent(b);
		break;
	case KeyEvent.DOM_VK_W:
	case KeyEvent.DOM_VK_NUMPAD8:
		window.scrollBy(0, by * -1);
		cancelEvent(b);
		break;
	case KeyEvent.DOM_VK_S:
	case KeyEvent.DOM_VK_NUMPAD2:
		window.scrollBy(0, by);
		cancelEvent(b);
		break;
	case KeyEvent.DOM_VK_SPACE:
		scroll_space(b.shiftKey, b.ctrlKey);
		cancelEvent(b);
		break;
	case KeyEvent.DOM_VK_Q:
	case KeyEvent.DOM_VK_NUMPAD5:
		rescale(0);
		cancelEvent(b);
		break;
	case KeyEvent.DOM_VK_P:
		cfg();
		cancelEvent(b);
	}
}

var cfg_bgclr;
var cfg_fitWH = true;
var cfg_fitB = true;
var cfg_fitS;
var cfg_js;
if (typeof GM_getValue !== "undefined")
{
	cfg_bgclr = GM_getValue("bgColor");
	cfg_fitWH = GM_getValue("fitWH", true);
	cfg_fitB = GM_getValue("fitB", true);
	cfg_fitS = GM_getValue("fitS");
	cfg_js = GM_getValue("js");
}

function $(id) {return document.getElementById(id);} // for StupidFox

function cfg()
{
	if (typeof GM_setValue !== "undefined")
	{
		function saveCfg()
		{
			GM_setValue("bgColor", $("ci_cfg_2_bgclr").value);
			GM_setValue("fitWH", $("ci_cfg_3_fitWH").checked);
			GM_setValue("fitB", $("ci_cfg_4_fitB").checked);
			GM_setValue("fitS", $("ci_cfg_5_fitS").checked);
			GM_setValue("js", $("ci_cfg_6_js").value);
			alert("Configuration Saved");
			if($("ci_cfg_2_bgclr").value){document.body.bgColor = $("ci_cfg_2_bgclr").value;}else{document.body.removeAttribute("bgColor");}
		}
		if(i){i.removeEventListener("click", rescale, true);}
		window.removeEventListener("keydown", onkeydown, true);
		if(document.head){document.head.innerHTML = "";}
		document.body.innerHTML = "";
		var div = document.createElement("div");
		div.style.margin = "11% auto";
		div.style.width = "444px";
		div.style.border = "solid 1px black";
		div.style.background = "silver";
		div.innerHTML = "<b><center>Configuration</center></b>"
		+ "<br><input id='ci_cfg_2_bgclr' type='text' size='6'> Background color (empty = default)"
		+ "<br><br>Fit to window images:"
		+ "<br><br><input id='ci_cfg_3_fitWH' type='checkbox'> Larger than window both vertically and horizontally"
		+ "<br><br><input id='ci_cfg_4_fitB' type='checkbox'> Larger than window either vertically or horizontally"
		+ "<br><br><input id='ci_cfg_5_fitS' type='checkbox'> Smaller than window"
		+ "<br><br><center>Custom JS Action:<textarea id='ci_cfg_6_js' style='margin: 0px; width: 400px; height: 50px;'></textarea>"
		+ "<br><input id='ci_cfg_save' type='button' value='Save configuration'></center>";
		document.body.appendChild(div);
		$("ci_cfg_2_bgclr").value = GM_getValue("bgColor", "");
		$("ci_cfg_3_fitWH").checked = GM_getValue("fitWH", true);
		$("ci_cfg_4_fitB").checked = GM_getValue("fitB", true);
		$("ci_cfg_5_fitS").checked = GM_getValue("fitS");
		$("ci_cfg_6_js").value = GM_getValue("js", "");
		$("ci_cfg_save").addEventListener("click", saveCfg, true);
	}
	else
	{
		alert("Sorry, Chrome userscripts in native mode can't have configurations! Install TamperMonkey extension. (it's very good)");
	}
}
	
makeimage();