JavaScript + Ajax 実践サンプル集 - サムネイルビューアー

サムネイルビューアー

説明補足説明コード関連書籍コメント投稿

このサンプルは、Webページに縮小したイメージ（サムネイル）を表示してサムネイルをクリックすると拡大したイメージを表示します。拡大したイメージの[x]をクリックすると消えます。

このサンプルに必要なイメージは、ここからダウンロードしてください。

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
<title>Lightbox image viewer</title>
<style type="text/css">
#lightbox{
	background-color:#eee;
	padding: 10px;
	border-bottom: 2px solid #666;
	border-right: 2px solid #666;
	}
#lightboxDetails{
	font-size: 0.8em;
	padding-top: 0.4em;
	}	
#lightboxCaption{ float: left; }
#keyboardMsg{ float: right; }
#closeButton{ top: 5px; right: 5px; }

#lightbox img{ border: none; clear: both;} 
#overlay img{ border: none; }

#overlay{ background-image: url(images/lightbox/overlay.png); }

* html #overlay{
	background-color: #333;
	back\ground-color: transparent;
	background-image: url(images/lightbox/blank.gif);
	filter: progid:DXImageTransform.Microsoft.AlphaImageLoader(src="images/lightbox/overlay.png", sizingMethod="scale");
	}
	
</style>
<script type="text/javascript">
/*
	Lightbox JS: Fullsize Image Overlays 
	by Lokesh Dhakar - http://www.huddletogether.com

For more information on this script, visit:
	http://huddletogether.com/projects/lightbox/

Licensed under the Creative Commons Attribution 2.5 License - http://creativecommons.org/licenses/by/2.5/
	(basically, do anything you want, just leave my name and link)
	
	Table of Contents
	-----------------
	Configuration
	
	Functions
	- getPageScroll()
	- getPageSize()
	- pause()
	- getKey()
	- listenKey()
	- showLightbox()
	- hideLightbox()
	- initLightbox()
	- addLoadEvent()
	
	Function Calls
	- addLoadEvent(initLightbox)

//
// Configuration
//

// If you would like to use a custom loading image or close button reference them in the next two lines.
var loadingImage = 'images/lightbox/loading.gif';		
var closeButton = 'images/lightbox/close.gif';

//
// getPageScroll()
// Returns array with x,y page scroll values.
// Core code from - quirksmode.org
//
function getPageScroll(){

var yScroll;

if (self.pageYOffset) {
		yScroll = self.pageYOffset;
	} else if (document.documentElement && document.documentElement.scrollTop){	 // Explorer 6 Strict
		yScroll = document.documentElement.scrollTop;
	} else if (document.body) {// all other Explorers
		yScroll = document.body.scrollTop;
	}

arrayPageScroll = new Array('',yScroll) 
	return arrayPageScroll;
}

//
// getPageSize()
// Returns array with page width, height and window width, height
// Core code from - quirksmode.org
// Edit for Firefox by pHaez
//
function getPageSize(){
	
	var xScroll, yScroll;
	
	if (window.innerHeight && window.scrollMaxY) {	
		xScroll = document.body.scrollWidth;
		yScroll = window.innerHeight + window.scrollMaxY;
	} else if (document.body.scrollHeight > document.body.offsetHeight){ // all but Explorer Mac
		xScroll = document.body.scrollWidth;
		yScroll = document.body.scrollHeight;
	} else { // Explorer Mac...would also work in Explorer 6 Strict, Mozilla and Safari
		xScroll = document.body.offsetWidth;
		yScroll = document.body.offsetHeight;
	}
	
	var windowWidth, windowHeight;
	if (self.innerHeight) {	// all except Explorer
		windowWidth = self.innerWidth;
		windowHeight = self.innerHeight;
	} else if (document.documentElement && document.documentElement.clientHeight) { // Explorer 6 Strict Mode
		windowWidth = document.documentElement.clientWidth;
		windowHeight = document.documentElement.clientHeight;
	} else if (document.body) { // other Explorers
		windowWidth = document.body.clientWidth;
		windowHeight = document.body.clientHeight;
	}	
	
	// for small pages with total height less then height of the viewport
	if(yScroll < windowHeight){
		pageHeight = windowHeight;
	} else { 
		pageHeight = yScroll;
	}

// for small pages with total width less then width of the viewport
	if(xScroll < windowWidth){	
		pageWidth = windowWidth;
	} else {
		pageWidth = xScroll;
	}

arrayPageSize = new Array(pageWidth,pageHeight,windowWidth,windowHeight) 
	return arrayPageSize;
}

//
// pause(numberMillis)
// Pauses code execution for specified time. Uses busy code, not good.
// Code from http://www.faqts.com/knowledge_base/view.phtml/aid/1602
//
function pause(numberMillis) {
	var now = new Date();
	var exitTime = now.getTime() + numberMillis;
	while (true) {
		now = new Date();
		if (now.getTime() > exitTime)
			return;
	}
}

//
// getKey(key)
// Gets keycode. If 'x' is pressed then it hides the lightbox.
//

//
// listenKey()
//
function listenKey () {	document.onkeypress = getKey; }

//
// showLightbox()
// Preloads images. Pleaces new image in lightbox then centers and displays.
//
function showLightbox(objLink)
{
	// prep objects
	var objOverlay = document.getElementById('overlay');
	var objLightbox = document.getElementById('lightbox');
	var objCaption = document.getElementById('lightboxCaption');
	var objImage = document.getElementById('lightboxImage');
	var objLoadingImage = document.getElementById('loadingImage');
	var objLightboxDetails = document.getElementById('lightboxDetails');

var arrayPageSize = getPageSize();
	var arrayPageScroll = getPageScroll();

// center loadingImage if it exists
	if (objLoadingImage) {
		objLoadingImage.style.top = (arrayPageScroll[1] + ((arrayPageSize[3] - 35 - objLoadingImage.height) / 2) + 'px');
		objLoadingImage.style.left = (((arrayPageSize[0] - 20 - objLoadingImage.width) / 2) + 'px');
		objLoadingImage.style.display = 'block';
	}

// set height of Overlay to take up whole page and show
	objOverlay.style.height = (arrayPageSize[1] + 'px');
	objOverlay.style.display = 'block';

// preload image
	imgPreload = new Image();

imgPreload.onload=function(){
		objImage.src = objLink.href;

// center lightbox and make sure that the top and left values are not negative
		// and the image placed outside the viewport
		var lightboxTop = arrayPageScroll[1] + ((arrayPageSize[3] - 35 - imgPreload.height) / 2);
		var lightboxLeft = ((arrayPageSize[0] - 20 - imgPreload.width) / 2);
		
		objLightbox.style.top = (lightboxTop < 0) ? "0px" : lightboxTop + "px";
		objLightbox.style.left = (lightboxLeft < 0) ? "0px" : lightboxLeft + "px";

objLightboxDetails.style.width = imgPreload.width + 'px';
		
		if(objLink.getAttribute('title')){
			objCaption.style.display = 'block';
			//objCaption.style.width = imgPreload.width + 'px';
			objCaption.innerHTML = objLink.getAttribute('title');
		} else {
			objCaption.style.display = 'none';
		}
		
		// A small pause between the image loading and displaying is required with IE,
		// this prevents the previous image displaying for a short burst causing flicker.
		if (navigator.appVersion.indexOf("MSIE")!=-1){
			pause(250);
		}

if (objLoadingImage) {	objLoadingImage.style.display = 'none'; }
		objLightbox.style.display = 'block';

// After image is loaded, update the overlay height as the new image might have
		// increased the overall page height.
		arrayPageSize = getPageSize();
		objOverlay.style.height = (arrayPageSize[1] + 'px');
		
		// Check for 'x' keypress
		listenKey();

return false;
	}

imgPreload.src = objLink.href;
	
}

//
// hideLightbox()
//
function hideLightbox()
{
	// get objects
	objOverlay = document.getElementById('overlay');
	objLightbox = document.getElementById('lightbox');

// hide lightbox and overlay
	objOverlay.style.display = 'none';
	objLightbox.style.display = 'none';
	
	// disable keypress listener
	document.onkeypress = '';
}

//
// initLightbox()
// Function runs on window load, going through link tags looking for rel="lightbox".
// These links receive onclick events that enable the lightbox display for their targets.
// The function also inserts html markup at the top of the page which will be used as a
// container for the overlay pattern and the inline image.
//
function initLightbox()
{
	
	if (!document.getElementsByTagName){ return; }
	var anchors = document.getElementsByTagName("a");

// loop through all anchor tags
	for (var i=0; i<anchors.length; i++){
		var anchor = anchors[i];

if (anchor.getAttribute("href") && (anchor.getAttribute("rel") == "lightbox")){
			anchor.onclick = function () {showLightbox(this); return false;}
		}
	}

// the rest of this code inserts html at the top of the page that looks like this:
	//
	// <div id="overlay">
	//		<a href="#" onclick="hideLightbox(); return false;"><img id="loadingImage" /></a>
	//	</div>
	// <div id="lightbox">
	//		<a href="#" onclick="hideLightbox(); return false;" title="Click anywhere to close image">
	//			<img id="closeButton" />		
	//			<img id="lightboxImage" />
	//		</a>
	//		<div id="lightboxDetails">
	//			<div id="lightboxCaption"></div>
	//			<div id="keyboardMsg"></div>
	//		</div>
	// </div>
	
	var objBody = document.getElementsByTagName("body").item(0);
	
	// create overlay div and hardcode some functional styles (aesthetic styles are in CSS file)
	var objOverlay = document.createElement("div");
	objOverlay.setAttribute('id','overlay');
	objOverlay.onclick = function () {hideLightbox(); return false;}
	objOverlay.style.display = 'none';
	objOverlay.style.position = 'absolute';
	objOverlay.style.top = '0';
	objOverlay.style.left = '0';
	objOverlay.style.zIndex = '90';
 	objOverlay.style.width = '100%';
	objBody.insertBefore(objOverlay, objBody.firstChild);
	
	var arrayPageSize = getPageSize();
	var arrayPageScroll = getPageScroll();

// preload and create loader image
	var imgPreloader = new Image();
	
	// if loader image found, create link to hide lightbox and create loadingimage
	imgPreloader.onload=function(){

var objLoadingImageLink = document.createElement("a");
		objLoadingImageLink.setAttribute('href','#');
		objLoadingImageLink.onclick = function () {hideLightbox(); return false;}
		objOverlay.appendChild(objLoadingImageLink);
		
		var objLoadingImage = document.createElement("img");
		objLoadingImage.src = loadingImage;
		objLoadingImage.setAttribute('id','loadingImage');
		objLoadingImage.style.position = 'absolute';
		objLoadingImage.style.zIndex = '150';
		objLoadingImageLink.appendChild(objLoadingImage);

imgPreloader.onload=function(){};	//	clear onLoad, as IE will flip out w/animated gifs

return false;
	}

imgPreloader.src = loadingImage;

// create lightbox div, same note about styles as above
	var objLightbox = document.createElement("div");
	objLightbox.setAttribute('id','lightbox');
	objLightbox.style.display = 'none';
	objLightbox.style.position = 'absolute';
	objLightbox.style.zIndex = '100';	
	objBody.insertBefore(objLightbox, objOverlay.nextSibling);
	
	// create link
	var objLink = document.createElement("a");
	objLink.setAttribute('href','#');
	objLink.setAttribute('title','Click to close');
	objLink.onclick = function () {hideLightbox(); return false;}
	objLightbox.appendChild(objLink);

// preload and create close button image
	var imgPreloadCloseButton = new Image();

// if close button image found, 
	imgPreloadCloseButton.onload=function(){

var objCloseButton = document.createElement("img");
		objCloseButton.src = closeButton;
		objCloseButton.setAttribute('id','closeButton');
		objCloseButton.style.position = 'absolute';
		objCloseButton.style.zIndex = '200';
		objLink.appendChild(objCloseButton);

return false;
	}

imgPreloadCloseButton.src = closeButton;

// create image
	var objImage = document.createElement("img");
	objImage.setAttribute('id','lightboxImage');
	objLink.appendChild(objImage);
	
	// create details div, a container for the caption and keyboard message
	var objLightboxDetails = document.createElement("div");
	objLightboxDetails.setAttribute('id','lightboxDetails');
	objLightbox.appendChild(objLightboxDetails);

// create caption
	var objCaption = document.createElement("div");
	objCaption.setAttribute('id','lightboxCaption');
	objCaption.style.display = 'none';
	objLightboxDetails.appendChild(objCaption);

// create keyboard message
	var objKeyboardMsg = document.createElement("div");
	objKeyboardMsg.setAttribute('id','keyboardMsg');
	objKeyboardMsg.innerHTML = 'press <kbd>x</kbd> to close';
	objLightboxDetails.appendChild(objKeyboardMsg);

}

//
// addLoadEvent()
// Adds event to window.onload without overwriting currently assigned onload functions.
// Function found at Simon Willison's weblog - http://simon.incutio.com/
//
function addLoadEvent(func)
{	
	var oldonload = window.onload;
	if (typeof window.onload != 'function'){
    	window.onload = func;
	} else {
		window.onload = function(){
		oldonload();
		func();
		}
	}

}

addLoadEvent(initLightbox);	// run initLightbox onLoad
</script>
</head>
<body>

<a href="images/lightbox/photo1.jpg" rel="lightbox" ><img src="images/lightbox/photo1thumb.bmp" border=0 /></a>
<a href="images/lightbox/photo2.jpg" rel="lightbox" title="Photo2"><img src="images/lightbox/photo2thumb.bmp" border=0 /></a>
<br /><br />
<a href="images/lightbox/photo3.jpg" rel="lightbox" title="Photo3">Photo3</a>

</body>
</html>