Update: Creating a news carousel with jQuery, now with time based switching
This is just a simple and quick update on the Creating a news carousel with jQuery post.
After reading this comment, and going through the code, I decided to implement the time-based switching functionality and also clean up the code a little bit (check it out here).
The additions made (along with some code cleaning) were:
- Append a simple div that will shrink while the picture is shown and reinitialized when the picture is switched.
- Add a setInterval call that will do the picture switching (and the new div's animation).
Update 01/12: I added some fixes to the code
- Use the image's load event to calculate each individual width. When all images are loaded, then the carousel is initiated.
- The animate_timer function now stops all animations on the timer div before reinitializing the animation
- Work with cases were images are already in cache and load event is fired before we attach to it.
- Fixed the way the news animation was calculated.
- Added 2 more news to help test it better.
So here's the new javascript that will do this:
$(function() { var carousel = $('#news_carousel'); var news = carousel.find('ul.news'); var controls = null; // Will hold the ul with the controls var timer = null; // Will hold the timer div var wait = 5000; // Milliseconds to wait for auto-switching var widths = []; // Will hold the widths of each image var items_size = news.find('li').length; var initialized = false; if (!items_size) { return; } // Controls html to append var controls_str = '<ul class="controls">'; for ( var i = 1; i <= items_size; i++) { controls_str += '<li><a href="#">' + i + '</a></li>'; } controls_str += '</ul>'; // Cache the controls list controls = carousel.append(controls_str).find('ul.controls'); // Make the first button in controls active controls.find('li:first a').addClass('active'); // Hook to the controls' click events controls.find('li a').click(function(event) { move_news( $(this) ); return false; }); // Append the timer and cache it timer = carousel.append('<div class="timer"></div>').find('div.timer'); // Store each item's width and calculate the total width news.find('li img') .each(function(i, e) { widths[i] = $(e).width(); if ( all_images_loaded() ) { init_carousel(); } }) .load(function(e) { var i = news.find('li img').index(this); widths[i] = $(this).width(); if ( all_images_loaded() ) { init_carousel(); } }); function all_images_loaded() { if (items_size == widths.length) && (jQuery.inArray(0, widths) 1 ) { return false; } var current_active = controls.find('li a.active'); if (new_active == 'next') { var next = current_active.parent().next().find('a'); if ( !next.length ) { next = controls.find('li:first a'); } new_active = next; } var current_index = parseInt(current_active.text(), 10) - 1; var new_index = parseInt(new_active.text(), 10) - 1; var move_to = new_index - current_index; if (!move_to) { return false; } var direction = (move_to > 0)? '-=': '+='; var move = 0; var bottom = Math.min(current_index, new_index); var top = Math.max(current_index, new_index); while (bottom < top) { move += widths[bottom]; bottom++; } news.animate({marginLeft: direction + move }, 500); new_active.addClass('active'); current_active.removeClass('active'); } function animate_timer() { timer.stop().css({width: '100px'}).animate({width: '1px'}, wait); } // Initializer, called when all images are loaded function init_carousel() { if (initialized) { return false; } // Set the news ul total width var width = 0; for( var i = 0; i < widths.length; i++) { width += widths[i]; } news.width(width); // Make the news change every X seconds setInterval(function() { move_news('next'); animate_timer(); }, wait); animate_timer(); initialized = true; } });