Center Image

Improved controls for images directly opened with your browser - hotkeys & resizing & visuals

Від 26.05.2022. Дивіться остання версія.

You will need to install an extension such as Tampermonkey, Greasemonkey or Violentmonkey to install this script.

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

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

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

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

You will need to install a user script manager extension to install this script.

(У мене вже є менеджер скриптів, дайте мені встановити його!)

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

(I already have a user style manager, let me install it!)

// ==UserScript==
// @name          Center Image
// @namespace     CenterImage
// @author        Owyn
// @version       2.00
// @description   Improved controls for images directly opened with your browser - hotkeys & resizing & visuals
// @supportURL    https://github.com/Owyn/Center_Image/issues
// @homepage      https://github.com/Owyn/Center_Image
// @run-at        document-end
// @noframes
// @grant         GM.getValue
// @grant         GM.setValue
// @grant         GM_registerMenuCommand
// @match         http://*/*
// @match         https://*/*
// @match         file:///*/*
// ==/UserScript==

"use strict";

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

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

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

var theStyle;
function makeimage()
{
	if(typeof cfg_js !== "string") {setTimeout(function() { makeimage(); }, 11); return false;} // lets wait for async
	if(cfg_bgclr)
	{
		document.body.bgColor = cfg_bgclr;
		if(document.head){document.head.innerHTML = "";} // remove FireFox background
	}
	document.body.innerHTML = "<style id=img_style>img { position: absolute; top: 0; right: 0; bottom: 0; left: 0; background-color: "+cfg_bgclr+" !important}</style>"; // center image & change loading image color from white in Chrome
	theStyle = document.body.querySelector("#img_style");
	i.style = ""; // chrome has lots of crap there
	document.body.style = "";
	theStyle.sheet.rules[0].style.margin = "auto"; // center image
	document.body.style.margin = "0px";
	document.body.appendChild(i);
	i.addEventListener("mousedown", onmousedown, true);
	i.addEventListener("click", rescale, true);
	i.addEventListener("auxclick", rescale, true);
	window.addEventListener("keydown", onkeydown, true);
	window.addEventListener("scroll", onscroll, false);
	window.addEventListener("resize", onresize, true);
	onVisibilityChange();
}

function onVisibilityChange()
{
	if (document.visibilityState === 'visible')
	{
		if(i)
		{
			autoresize();
			document.removeEventListener('visibilitychange', onVisibilityChange);
		}
	}
}
document.addEventListener("visibilitychange", onVisibilityChange);

var scrolledY, scrolledX;
function onscroll()
{
	scrolledY = window.pageYOffset;
	scrolledX = window.pageXOffset;
}

var FireFox = ((navigator.userAgent.indexOf('Firefox') != -1) ? true : false);
function onresize() // doesn't let image change back to "fit to window" in chrome & in both helps keep scroll progress
{
	if(rescaled != 1)
	{
		let wasFilled = (rescaled === 2 ? true : false);
		rescaled = 1;
		let chromeplsstopX, chromeplsstopY;
		if(!FireFox){ chromeplsstopX = window.pageXOffset; chromeplsstopY = window.pageYOffset;}
		rescale(null, wasFilled);
		if(!FireFox){ window.scrollTo(chromeplsstopX,chromeplsstopY);}
	}
}

function changeCursor()
{
	//i.style.margin = "auto";
	if(rescaled === 0) // original
	{
		if((orgImgWidth == window.innerWidth && orgImgHeight <= window.innerHeight) || (orgImgWidth <= window.innerWidth && orgImgHeight == window.innerHeight)) // perfect fit on one side, can't resize
		{
			i.style.cursor = "";
		}
		else if (orgImgWidth > window.innerWidth || orgImgHeight > window.innerHeight)
		{
			i.style.cursor = "zoom-out";
		}
		else
		{
			i.style.cursor = "zoom-in";
		}
	}
	else if(rescaled === 2) // fill
	{
		if(orgImgWidth == window.innerWidth && orgImgHeight == window.innerHeight) // perfect fit, can't resize
		{
			i.style.cursor = "";
		}
		else if (orgImgWidth > i.width)
		{
			i.style.cursor = "zoom-in";
		}
		else
		{
			i.style.cursor = "zoom-out";
		}
	}
	else // if(rescaled === 1) // fit
	{
		if((orgImgWidth == window.innerWidth && orgImgHeight <= window.innerHeight) || (orgImgWidth <= window.innerWidth && orgImgHeight == window.innerHeight)) // perfect fit on one side, can't resize
		{
			i.style.cursor = "";
		}
		else if (orgImgWidth > i.width)
		{
			i.style.cursor = "zoom-in";
		}
		else
		{
			i.style.cursor = "zoom-out";
		}
	}

	if(i.height > window.innerHeight) // image pushing out-of-screen browser bug fix
	{
		theStyle.sheet.rules[0].style.margin = "0px auto";
	}
	else
	{
		theStyle.sheet.rules[0].style.margin = "auto";
	}
	i.style.margin = ""; // chrome pls stop
}

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

	if(event.which === 2) // middle mouse Chrome fix
	{
		event.preventDefault();
		event.stopPropagation();
		return;
	}
}

function rescale(event, fill)
{
	let ex,ey;
	if(event) // mouse click
	{
		if (typeof event.y === "undefined") // Firefox
		{
			ex = event.clientX;
			ey = event.clientY;
		}
		else
		{
			ex = event.x;
			ey = event.y;
		}
		ex -= iol;
		ey -= iot;
		if(event.which === 2) // middle mouse
		{
			fill = true;
		}
		else if(event.which === 3) // right mouse
		{
			return;
		}
		event.preventDefault();
		event.stopPropagation();
	}

	document.body.style.overflowX = '';
	document.body.style.overflowY = '';

	let scrollMax_Y = window.scrollMaxY || ((document.body.scrollHeight || document.documentElement.scrollHeight)- document.documentElement.clientHeight);
	let scrollMax_X = window.scrollMaxX || ((document.body.scrollWidth || document.documentElement.scrollWidth)- document.documentElement.clientWidth);

	let scrollProgressY = scrolledY / scrollMax_Y;
	let scrollProgressX = scrolledX / scrollMax_X;

	let unFilling = false;

	let sidesCMP;
	if(fill)
	{
		if(rescaled === 2) // to original
		{
			rescaled = 0;
			theStyle.sheet.rules[0].style.width = orgImgWidth + "px";
			theStyle.sheet.rules[0].style.height = orgImgHeight + "px";
		}
		else // fill
		{
			sidesCMP = (orgImgWidth / orgImgHeight) < (window.innerWidth / window.innerHeight);
			rescaled = 2;
		}
	}
	else
	{
		if(rescaled != 0) // to original
		{
			if(rescaled === 2) {unFilling = true;}
			rescaled = 0;
			theStyle.sheet.rules[0].style.width = orgImgWidth + "px";
			theStyle.sheet.rules[0].style.height = orgImgHeight + "px";
		}
		else // fit
		{
			sidesCMP = (orgImgWidth / orgImgHeight) > (window.innerWidth / window.innerHeight);
			rescaled = 1;
		}
	}

	if(rescaled != 0)
	{
		if(sidesCMP)
		{
			theStyle.sheet.rules[0].style.width = "100%";
			theStyle.sheet.rules[0].style.height = "auto";
			document.body.style.overflowX = 'hidden'; // we don't need unscrollable scrollbars if they appear
		}
		else
		{
			theStyle.sheet.rules[0].style.height = "100%";
			theStyle.sheet.rules[0].style.width = "auto";
			document.body.style.overflowY = 'hidden'; // we don't need unscrollable scrollbars if they appear
		}
	}

	changeCursor();

	if(event && (!unFilling && (!fill || (fill && (scrollMax_Y <= 0 && scrollMax_X <= 0))))) // left mouse click (fill-click with no scrollbars and not left click after middle click - else preserve scroll percentage)
	{
		let scale = Math.min((window.innerWidth / i.width), (window.innerHeight / i.height));
		window.scrollTo((ex / scale) - (window.innerWidth / 2), (ey / scale) - (window.innerHeight / 2));
	}
	else // keep percentage scroll progress for KB hotkeys
	{
		
		scrollMax_Y = window.scrollMaxY || ((document.body.scrollHeight || document.documentElement.scrollHeight)- document.documentElement.clientHeight);
		scrollMax_X = window.scrollMaxX || ((document.body.scrollWidth || document.documentElement.scrollWidth)- document.documentElement.clientWidth);

		window.scrollTo(Math.round(scrollProgressX * scrollMax_X), Math.round(scrollProgressY * scrollMax_Y));

		scrolledY = window.pageYOffset;
		scrolledX = window.pageXOffset;
	}
}

var orgImgWidth;
var orgImgHeight;

var ARC = 0;
function autoresize()
{
	if(!i.naturalHeight) // it was always working before but not anymore
	{
		ARC++;
		if(ARC < 500)
		{
			unsafeWindow.setTimeout(autoresize, 10);
		}
		else
		{
			console.warn("Center Image: Gave up waiting for a working image, it is broken");
		}
		return;
	}
	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
	if(FireFox) // chrome already does ~this
	{
		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
	}
	
	orgImgWidth = Math.round(i.naturalWidth / window.devicePixelRatio);
	orgImgHeight = Math.round(i.naturalHeight / window.devicePixelRatio);

	let InitRescale = false; // directly opened image is already fit to window if it is bigger by the browser
	if(cfg_fitWH && orgImgHeight > window.innerHeight && orgImgWidth > window.innerWidth) // both scrollbars
	{
		InitRescale = false;
	}
	else if(cfg_fitB && (orgImgHeight > window.innerHeight || orgImgWidth > window.innerWidth)) // one scrollbar
	{
		InitRescale = false;
	}
	else if(cfg_fitS && orgImgHeight <= window.innerHeight && orgImgWidth <= window.innerWidth) // no scrollbars
	{
		InitRescale = true;
	}
	else
	{
		theStyle.sheet.rules[0].style.width = orgImgWidth + "px";
		theStyle.sheet.rules[0].style.height = orgImgHeight + "px";
	}
	if(InitRescale)
	{
		rescale(null, cfg_fill ? true : false);
	}
	else
	{
		changeCursor();
	}
	if(cfg_js){eval(cfg_js);}
}

// 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,
		DOM_VK_F5: 116,
		DOM_VK_TAB: 9,
		DOM_VK_ENTER: 13
	};
}

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_TAB:
	case KeyEvent.DOM_VK_ENTER:
		rescale(null, true);
		cancelEvent(b);
		break;
	case KeyEvent.DOM_VK_Q:
	case KeyEvent.DOM_VK_NUMPAD5:
		rescale(null, false);
		cancelEvent(b);
		break;
	case KeyEvent.DOM_VK_P:
		cfg();
		cancelEvent(b);
	}
}

var cfg_bgclr = "grey";
var cfg_fitWH = true;
var cfg_fitB = false;
var cfg_fitS = true;
var cfg_fill = false;
var cfg_js;

function cfg(){}

if (typeof GM !== "undefined" && typeof GM.getValue !== "undefined")
{
	async function loadCfg()
	{
			cfg_bgclr = await GM.getValue("bgColor", "grey");
			cfg_fitWH = await GM.getValue("fitWH", true);
			cfg_fitB = await GM.getValue("fitB", false);
			cfg_fitS = await GM.getValue("fitS", true);
			cfg_fill = await GM.getValue("fill", false);
			cfg_js = await GM.getValue("js", "");
		makeimage();
	}
	loadCfg();

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

	cfg = function ()
	{
		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("fill", $("ci_cfg_7_fill").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);
			i.removeEventListener("auxclick", rescale, true);
			i.removeEventListener("mousedown", onmousedown, 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.color = "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:" + " ( Fill to window instead <input id='ci_cfg_7_fill' type='checkbox'> )"
		+ "<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 = cfg_bgclr;
		$("ci_cfg_3_fitWH").checked = cfg_fitWH;
		$("ci_cfg_4_fitB").checked = cfg_fitB;
		$("ci_cfg_5_fitS").checked = cfg_fitS;
		$("ci_cfg_7_fill").checked = cfg_fill;
		$("ci_cfg_6_js").value = cfg_js;
		$("ci_cfg_save").addEventListener("click", saveCfg, true);
	}
}
else
{
	cfg_js = "";
	cfg = function ()
	{
		alert("Sorry, Chrome userscripts in native mode can't have configurations! You need to install TamperMonkey userscript manager extension. (it's very good)");
	}
	
}