lightbox.js

js 图片浏览

// -----------------------------------------------------------------------------------
//
//	Lightbox v2.04
//	by Lokesh Dhakar - http://www.lokeshdhakar.com
//	Last Modification: 2/9/08
//
//	For more information, visit:
//	http://lokeshdhakar.com/projects/lightbox2/
//
//	Licensed under the Creative Commons Attribution 2.5 License - http://creativecommons.org/licenses/by/2.5/
//  	- Free for use in both personal and commercial projects
//		- Attribution requires leaving author name, author link, and the license info intact.
//	
//  Thanks: Scott Upton(uptonic.com), Peter-Paul Koch(quirksmode.com), and Thomas Fuchs(mir.aculo.us) for ideas, libs, and snippets.
//  		Artemy Tregubenko (arty.name) for cleanup and help in updating to latest ver of proto-aculous.
//
// -----------------------------------------------------------------------------------
/*

    Table of Contents
    -----------------
    Configuration

    Lightbox Class Declaration
    - initialize()
    - updateImageList()
    - start()
    - changeImage()
    - resizeImageContainer()
    - showImage()
    - updateDetails()
    - updateNav()
    - enableKeyboardNav()
    - disableKeyboardNav()
    - keyboardAction()
    - preloadNeighborImages()
    - end()
    
    Function Calls
    - document.observe()
   
*/
// -----------------------------------------------------------------------------------

//
//  Configurationl
//
LightboxOptions = Object.extend({
    fileLoadingImage:        'images/loading.gif',     
    fileBottomNavCloseImage: 'images/closelabel.gif',

    overlayOpacity: 0.8,   // controls transparency of shadow overlay

    animate: true,         // toggles resizing animations
    resizeSpeed: 7,        // controls the speed of the image resizing animations (1=slowest and 10=fastest)

    borderSize: 10,         //if you adjust the padding in the CSS, you will need to update this variable

	// When grouping images this is used to write: Image # of #.
	// Change it for non-english localization
	labelImage: "Image",
	labelOf: "of"
}, window.LightboxOptions || {});

// -----------------------------------------------------------------------------------

var Lightbox = Class.create();

Lightbox.prototype = {
    imageArray: [],
    activeImage: undefined,
    
    // initialize()
    // Constructor runs on completion of the DOM loading. Calls updateImageList and then
    // the function inserts html at the bottom of the page which is used to display the shadow 
    // overlay and the image container.
    //
    initialize: function() {    
        
        this.updateImageList();
        
        this.keyboardAction = this.keyboardAction.bindAsEventListener(this);

        if (LightboxOptions.resizeSpeed > 10) LightboxOptions.resizeSpeed = 10;
        if (LightboxOptions.resizeSpeed < 1)  LightboxOptions.resizeSpeed = 1;

	    this.resizeDuration = LightboxOptions.animate ? ((11 - LightboxOptions.resizeSpeed) * 0.15) : 0;
	    this.overlayDuration = LightboxOptions.animate ? 0.2 : 0;  // shadow fade in/out duration

        // When Lightbox starts it will resize itself from 250 by 250 to the current image dimension.
        // If animations are turned off, it will be hidden as to prevent a flicker of a
        // white 250 by 250 box.
        var size = (LightboxOptions.animate ? 250 : 1) + 'px';
        

        // Code inserts html at the bottom of the page that looks similar to this:
        //
        //  <div id="overlay"></div>
        //  <div id="lightbox">
        //      <div id="outerImageContainer">
        //          <div id="imageContainer">
        //              <img id="lightboxImage">
        //              <div style="" id="hoverNav">
        //                  <a href="#" id="prevLink"></a>
        //                  <a href="#" id="nextLink"></a>
        //              </div>
        //              <div id="loading">
        //                  <a href="#" id="loadingLink">
        //                      <img src="images/loading.gif">
        //                  </a>
        //              </div>
        //          </div>
        //      </div>
        //      <div id="imageDataContainer">
        //          <div id="imageData">
        //              <div id="imageDetails">
        //                  <span id="caption"></span>
        //                  <span id="numberDisplay"></span>
        //              </div>
        //              <div id="bottomNav">
        //                  <a href="#" id="bottomNavClose">
        //                      <img src="images/close.gif">
        //                  </a>
        //              </div>
        //          </div>
        //      </div>
        //  </div>


        var objBody = $$('body')[0];

		objBody.appendChild(Builder.node('div',{id:'overlay'}));
	
        objBody.appendChild(Builder.node('div',{id:'lightbox'}, [
            Builder.node('div',{id:'outerImageContainer'}, 
                Builder.node('div',{id:'imageContainer'}, [
                    Builder.node('img',{id:'lightboxImage'}), 
                    Builder.node('div',{id:'hoverNav'}, [
                        Builder.node('a',{id:'prevLink', href: '#' }),
                        Builder.node('a',{id:'nextLink', href: '#' })
                    ]),
                    Builder.node('div',{id:'loading'}, 
                        Builder.node('a',{id:'loadingLink', href: '#' }, 
                            Builder.node('img', {src: LightboxOptions.fileLoadingImage})
                        )
                    )
                ])
            ),
            Builder.node('div', {id:'imageDataContainer'},
                Builder.node('div',{id:'imageData'}, [
                    Builder.node('div',{id:'imageDetails'}, [
                        Builder.node('span',{id:'caption'}),
                        Builder.node('span',{id:'numberDisplay'})
                    ]),
                    Builder.node('div',{id:'bottomNav'},
                        Builder.node('a',{id:'bottomNavClose', href: '#' },
                            Builder.node('img', { src: LightboxOptions.fileBottomNavCloseImage })
                        )
                    )
                ])
            )
        ]));


		$('overlay').hide().observe('click', (function() { this.end(); }).bind(this));
		$('lightbox').hide().observe('click', (function(event) { if (event.element().id == 'lightbox') this.end(); }).bind(this));
		$('outerImageContainer').setStyle({ width: size, height: size });
		$('prevLink').observe('click', (function(event) { event.stop(); this.changeImage(this.activeImage - 1); }).bindAsEventListener(this));
		$('nextLink').observe('click', (function(event) { event.stop(); this.changeImage(this.activeImage + 1); }).bindAsEventListener(this));
		$('loadingLink').observe('click', (function(event) { event.stop(); this.end(); }).bind(this));
		$('bottomNavClose').observe('click', (function(event) { event.stop(); this.end(); }).bind(this));

        var th = this;
        (function(){
            var ids = 
                'overlay lightbox outerImageContainer imageContainer lightboxImage hoverNav prevLink nextLink loading loadingLink ' + 
                'imageDataContainer imageData imageDetails caption numberDisplay bottomNav bottomNavClose';   
            $w(ids).each(function(id){ th[id] = $(id); });
        }).defer();
    },

    //
    // updateImageList()
    // Loops through anchor tags looking for 'lightbox' references and applies onclick
    // events to appropriate links. You can rerun after dynamically adding images w/ajax.
    //
    updateImageList: function() {   
        this.updateImageList = Prototype.emptyFunction;

        document.observe('click', (function(event){
            var target = event.findElement('a[rel^=lightbox]') || event.findElement('area[rel^=lightbox]');
            if (target) {
                event.stop();
                this.start(target);
            }
        }).bind(this));
    },
    
    //
    //  start()
    //  Display overlay and lightbox. If image is part of a set, add siblings to imageArray.
    //
    start: function(imageLink) {    

        $$('select', 'object', 'embed').each(function(node){ node.style.visibility = 'hidden' });

        // stretch overlay to fill page and fade in
        var arrayPageSize = this.getPageSize();
        $('overlay').setStyle({ width: arrayPageSize[0] + 'px', height: arrayPageSize[1] + 'px' });

        new Effect.Appear(this.overlay, { duration: this.overlayDuration, from: 0.0, to: LightboxOptions.overlayOpacity });

        this.imageArray = [];
        var imageNum = 0;       

        if ((imageLink.rel == 'lightbox')){
            // if image is NOT part of a set, add single image to imageArray
            this.imageArray.push([imageLink.href, imageLink.title]);         
        } else {
            // if image is part of a set..
            this.imageArray = 
                $$(imageLink.tagName + '[href][rel="' + imageLink.rel + '"]').
                collect(function(anchor){ return [anchor.href, anchor.title]; }).
                uniq();
            
            while (this.imageArray[imageNum][0] != imageLink.href) { imageNum++; }
        }

        // calculate top and left offset for the lightbox 
        var arrayPageScroll = document.viewport.getScrollOffsets();
        var lightboxTop = arrayPageScroll[1] + (document.viewport.getHeight() / 10);
        var lightboxLeft = arrayPageScroll[0];
        this.lightbox.setStyle({ top: lightboxTop + 'px', left: lightboxLeft + 'px' }).show();
        
        this.changeImage(imageNum);
    },

    //
    //  changeImage()
    //  Hide most elements and preload image in preparation for resizing image container.
    //
    changeImage: function(imageNum) {   
        
        this.activeImage = imageNum; // update global var

        // hide elements during transition
        if (LightboxOptions.animate) this.loading.show();
        this.lightboxImage.hide();
        this.hoverNav.hide();