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Template:Iitm/slideshow
From 2010.igem.org
<HEAD> <TITLE>JavaScript Slideshow Template</TITLE> <SCRIPT type="text/javascript">
/*==================================================*
$Id: slideshow.js,v 1.16 2003/10/14 12:39:00 pat Exp $ Copyright 2000-2003 Patrick Fitzgerald http://slideshow.barelyfitz.com/
This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA *==================================================*/
// There are two objects defined in this file: // "slide" - contains all the information for a single slide // "slideshow" - consists of multiple slide objects and runs the slideshow
//================================================== // slide object //================================================== function slide(src,link,text,target,attr) {
// This is the constructor function for the slide object. // It is called automatically when you create a new slide object. // For example: // s = new slide();
// Image URL this.src = src;
// Link URL this.link = link;
// Text to display this.text = text;
// Name of the target window ("_blank")
this.target = target;
// Custom duration for the slide, in milliseconds. // This is an optional parameter. // this.timeout = 3000
// Attributes for the target window: // width=n,height=n,resizable=yes or no,scrollbars=yes or no, // toolbar=yes or no,location=yes or no,directories=yes or no, // status=yes or no,menubar=yes or no,copyhistory=yes or no // Example: "width=200,height=300" this.attr = attr;
// Create an image object for the slide
if (document.images) {
this.image = new Image();
}
// Flag to tell when load() has already been called this.loaded = false;
//--------------------------------------------------
this.load = function() {
// This method loads the image for the slide
if (!document.images) { return; }
if (!this.loaded) {
this.image.src = this.src;
this.loaded = true;
}
}
//--------------------------------------------------
this.hotlink = function() {
// This method jumps to the slide's link.
// If a window was specified for the slide, then it opens a new window.
var mywindow;
// If this slide does not have a link, do nothing if (!this.link) return;
// Open the link in a separate window?
if (this.target) {
// If window attributes are specified,
// use them to open the new window
if (this.attr) {
mywindow = window.open(this.link, this.target, this.attr);
} else {
// If window attributes are not specified, do not use them
// (this will copy the attributes from the originating window)
mywindow = window.open(this.link, this.target);
}
// Pop the window to the front
if (mywindow && mywindow.focus) mywindow.focus();
} else {
// Open the link in the current window
location.href = this.link;
}
}
}
//================================================== // slideshow object //================================================== function slideshow( slideshowname ) {
// This is the constructor function for the slideshow object.
// It is called automatically when you create a new object.
// For example:
// ss = new slideshow("ss");
// Name of this object // (required if you want your slideshow to auto-play) // For example, "SLIDES1" this.name = slideshowname;
// When we reach the last slide, should we loop around to start the // slideshow again? this.repeat = true;
// Number of images to pre-fetch. // -1 = preload all images. // 0 = load each image is it is used. // n = pre-fetch n images ahead of the current image. // I recommend preloading all images unless you have large // images, or a large amount of images. this.prefetch = -1;
// IMAGE element on your HTML page. // For example, document.images.SLIDES1IMG this.image;
// ID of a DIV element on your HTML page that will contain the text. // For example, "slides2text" // Note: after you set this variable, you should call // the update() method to update the slideshow display. this.textid;
// TEXTAREA element on your HTML page. // For example, document.SLIDES1FORM.SLIDES1TEXT // This is a depracated method for displaying the text, // but you might want to supply it for older browsers. this.textarea;
// Milliseconds to pause between slides. // Individual slides can override this. this.timeout = 3000;
// Hook functions to be called before and after updating the slide
// this.pre_update_hook = function() { }
// this.post_update_hook = function() { }
// These are private variables this.slides = new Array(); this.current = 0; this.timeoutid = 0;
//--------------------------------------------------
// Public methods
//--------------------------------------------------
this.add_slide = function(slide) {
// Add a slide to the slideshow.
// For example:
// SLIDES1.add_slide(new slide("s1.jpg", "link.html"))
var i = this.slides.length;
// Prefetch the slide image if necessary
if (this.prefetch == -1) {
slide.load();
}
this.slides[i] = slide; }
//--------------------------------------------------
this.play = function(timeout) {
// This method implements the automatically running slideshow.
// If you specify the "timeout" argument, then a new default
// timeout will be set for the slideshow.
// Make sure we're not already playing
this.pause();
// If the timeout argument was specified (optional)
// then make it the new default
if (timeout) {
this.timeout = timeout;
}
// If the current slide has a custom timeout, use it;
// otherwise use the default timeout
if (typeof this.slides[ this.current ].timeout != 'undefined') {
timeout = this.slides[ this.current ].timeout;
} else {
timeout = this.timeout;
}
// After the timeout, call this.loop() this.timeoutid = setTimeout( this.name + ".loop()", timeout); }
//--------------------------------------------------
this.pause = function() {
// This method stops the slideshow if it is automatically running.
if (this.timeoutid != 0) {
clearTimeout(this.timeoutid);
this.timeoutid = 0;
} }
//--------------------------------------------------
this.update = function() {
// This method updates the slideshow image on the page
// Make sure the slideshow has been initialized correctly
if (! this.valid_image()) { return; }
// Call the pre-update hook function if one was specified
if (typeof this.pre_update_hook == 'function') {
this.pre_update_hook();
}
// Convenience variable for the current slide var slide = this.slides[ this.current ];
// Determine if the browser supports filters
var dofilter = false;
if (this.image &&
typeof this.image.filters != 'undefined' &&
typeof this.image.filters[0] != 'undefined') {
dofilter = true;
}
// Load the slide image if necessary
slide.load();
// Apply the filters for the image transition
if (dofilter) {
// If the user has specified a custom filter for this slide,
// then set it now
if (slide.filter &&
this.image.style &&
this.image.style.filter) {
this.image.style.filter = slide.filter;
}
this.image.filters[0].Apply();
}
// Update the image. this.image.src = slide.image.src;
// Play the image transition filters
if (dofilter) {
this.image.filters[0].Play();
}
// Update the text this.display_text();
// Call the post-update hook function if one was specified
if (typeof this.post_update_hook == 'function') {
this.post_update_hook();
}
// Do we need to pre-fetch images?
if (this.prefetch > 0) {
var next, prev, count;
// Pre-fetch the next slide image(s)
next = this.current;
prev = this.current;
count = 0;
do {
// Get the next and previous slide number
// Loop past the ends of the slideshow if necessary
if (++next >= this.slides.length) next = 0;
if (--prev < 0) prev = this.slides.length - 1;
// Preload the slide image
this.slides[next].load();
this.slides[prev].load();
// Keep going until we have fetched
// the designated number of slides
} while (++count < this.prefetch); } }
//--------------------------------------------------
this.goto_slide = function(n) {
// This method jumpts to the slide number you specify.
// If you use slide number -1, then it jumps to the last slide.
// You can use this to make links that go to a specific slide,
// or to go to the beginning or end of the slideshow.
// Examples:
// onClick="myslides.goto_slide(0)"
// onClick="myslides.goto_slide(-1)"
// onClick="myslides.goto_slide(5)"
if (n == -1) {
n = this.slides.length - 1;
}
if (n < this.slides.length && n >= 0) {
this.current = n;
}
this.update();
}
//--------------------------------------------------
this.goto_random_slide = function(include_current) {
// Picks a random slide (other than the current slide) and
// displays it.
// If the include_current parameter is true,
// then
// See also: shuffle()
var i;
// Make sure there is more than one slide
if (this.slides.length > 1) {
// Generate a random slide number,
// but make sure it is not the current slide
do {
i = Math.floor(Math.random()*this.slides.length);
} while (i == this.current);
// Display the slide
this.goto_slide(i);
}
}
//--------------------------------------------------
this.next = function() {
// This method advances to the next slide.
// Increment the image number
if (this.current < this.slides.length - 1) {
this.current++;
} else if (this.repeat) {
this.current = 0;
}
this.update(); }
//--------------------------------------------------
this.previous = function() {
// This method goes to the previous slide.
// Decrement the image number
if (this.current > 0) {
this.current--;
} else if (this.repeat) {
this.current = this.slides.length - 1;
}
this.update();
}
//--------------------------------------------------
this.shuffle = function() {
// This method randomly shuffles the order of the slides.
var i, i2, slides_copy, slides_randomized;
// Create a copy of the array containing the slides
// in sequential order
slides_copy = new Array();
for (i = 0; i < this.slides.length; i++) {
slides_copy[i] = this.slides[i];
}
// Create a new array to contain the slides in random order slides_randomized = new Array();
// To populate the new array of slides in random order, // loop through the existing slides, picking a random // slide, removing it from the ordered list and adding it to // the random list.
do {
// Pick a random slide from those that remain
i = Math.floor(Math.random()*slides_copy.length);
// Add the slide to the end of the randomized array
slides_randomized[ slides_randomized.length ] =
slides_copy[i];
// Remove the slide from the sequential array,
// so it cannot be chosen again
for (i2 = i + 1; i2 < slides_copy.length; i2++) {
slides_copy[i2 - 1] = slides_copy[i2];
}
slides_copy.length--;
// Keep going until we have removed all the slides
} while (slides_copy.length);
// Now set the slides to the randomized array this.slides = slides_randomized; }
//--------------------------------------------------
this.get_text = function() {
// This method returns the text of the current slide
return(this.slides[ this.current ].text);
}
//--------------------------------------------------
this.get_all_text = function(before_slide, after_slide) {
// Return the text for all of the slides.
// For the text of each slide, add "before_slide" in front of the
// text, and "after_slide" after the text.
// For example:
// document.write("- ");
// document.write(s.get_all_text("
- ","\n"));
// document.write("<\/ul>");
all_text = "";
// Loop through all the slides in the slideshow
for (i=0; i < this.slides.length; i++) {
slide = this.slides[i];
if (slide.text) {
all_text += before_slide + slide.text + after_slide;
}
}
return(all_text);
}
//--------------------------------------------------
this.display_text = function(text) {
// Display the text for the current slide
// If the "text" arg was not supplied (usually it isn't),
// get the text from the slideshow
if (!text) {
text = this.slides[ this.current ].text;
}
// If a textarea has been specified,
// then change the text displayed in it
if (this.textarea && typeof this.textarea.value != 'undefined') {
this.textarea.value = text;
}
// If a text id has been specified,
// then change the contents of the HTML element
if (this.textid) {
r = this.getElementById(this.textid);
if (!r) { return false; }
if (typeof r.innerHTML == 'undefined') { return false; }
// Update the text
r.innerHTML = text;
}
}
//--------------------------------------------------
this.hotlink = function() {
// This method calls the hotlink() method for the current slide.
this.slides[ this.current ].hotlink();
}
//--------------------------------------------------
this.save_position = function(cookiename) {
// Saves the position of the slideshow in a cookie,
// so when you return to this page, the position in the slideshow
// won't be lost.
if (!cookiename) {
cookiename = this.name + '_slideshow';
}
document.cookie = cookiename + '=' + this.current;
}
//--------------------------------------------------
this.restore_position = function(cookiename) {
// If you previously called slideshow_save_position(),
// returns the slideshow to the previous state.
//Get cookie code by Shelley Powers
if (!cookiename) {
cookiename = this.name + '_slideshow';
}
var search = cookiename + "=";
if (document.cookie.length > 0) {
offset = document.cookie.indexOf(search);
// if cookie exists
if (offset != -1) {
offset += search.length;
// set index of beginning of value
end = document.cookie.indexOf(";", offset);
// set index of end of cookie value
if (end == -1) end = document.cookie.length;
this.current = parseInt(unescape(document.cookie.substring(offset, end)));
}
}
}
//--------------------------------------------------
this.noscript = function() {
// This method is not for use as part of your slideshow,
// but you can call it to get a plain HTML version of the slideshow
// images and text.
// You should copy the HTML and put it within a NOSCRIPT element, to
// give non-javascript browsers access to your slideshow information.
// This also ensures that your slideshow text and images are indexed
// by search engines.
$html = "\n";
// Loop through all the slides in the slideshow
for (i=0; i < this.slides.length; i++) {
slide = this.slides[i];
$html += '
'; if (slide.link) { $html += '<a href="' + slide.link + '">'; } $html += '<img src="' + slide.src + '" ALT="slideshow image">'; if (slide.link) { $html += "<\/a>"; } if (slide.text) { $html += "
\n" + slide.text; } $html += "<\/P>" + "\n\n"; } // Make the HTML browser-safe $html = $html.replace(/\&/g, "&" ); $html = $html.replace(/</g, "<" ); $html = $html.replace(/>/g, ">" ); return('' + $html + '
');}
//================================================== // Private methods //==================================================
//-------------------------------------------------- this.loop = function() { // This method is for internal use only. // This method gets called automatically by a JavaScript timeout. // It advances to the next slide, then sets the next timeout. // If the next slide image has not completed loading yet, // then do not advance to the next slide yet.// Make sure the next slide image has finished loading if (this.current < this.slides.length - 1) { next_slide = this.slides[this.current + 1]; if (next_slide.image.complete == null || next_slide.image.complete) { this.next(); } } else { // we're at the last slide this.next(); } // Keep playing the slideshow this.play( ); }
//-------------------------------------------------- this.valid_image = function() { // Returns 1 if a valid image has been set for the slideshow if (!this.image) { return false; } else { return true; } }//-------------------------------------------------- this.getElementById = function(element_id) { // This method returns the element corresponding to the idif (document.getElementById) { return document.getElementById(element_id); } else if (document.all) { return document.all[element_id]; } else if (document.layers) { return document.layers[element_id]; } else { return undefined; } }//================================================== // Deprecated methods // I don't recommend the use of the following methods, // but they are included for backward compatibility. // You can delete them if you don't need them. //==================================================
//-------------------------------------------------- this.set_image = function(imageobject) { // This method is deprecated; you should use // the following code instead: // s.image = document.images.myimagename; // s.update();if (!document.images) return; this.image = imageobject; }//-------------------------------------------------- this.set_textarea = function(textareaobject) { // This method is deprecated; you should use // the following code instead: // s.textarea = document.form.textareaname; // s.update();this.textarea = textareaobject; this.display_text(); }
//-------------------------------------------------- this.set_textid = function(textidstr) { // This method is deprecated; you should use // the following code instead: // s.textid = "mytextid"; // s.update();this.textid = textidstr; this.display_text(); }
} </script>
<SCRIPT type="text/javascript"> </SCRIPT> </HEAD>
<BODY onLoad="SLIDES1.update();SLIDES2.update();">
<P> <IMG name="SLIDES1IMG" src="pics/pic1.jpg" alt="Slideshow image"> <IMG name="SLIDES2IMG" src="pics/pic2.jpg" alt="Slideshow image">
<SCRIPT type="text/javascript">
</SCRIPT>
