Genesis Tabs with first tab showing all categories.

plugin.php

<?php
/*
	Plugin Name: Genesis Tabs
	Plugin URI: http://www.studiopress.com/plugins/genesis-tabs
	Description: Genesis Simple Tabs extends the Featured Post widget to create a simple tabbed area.
	Author: StudioPress
	Author URI: http://www.studiopress.com

	Version: 0.9.0

	License: GNU General Public License v2.0 (or later)
	License URI: http://www.opensource.org/licenses/gpl-license.php
*/

register_activation_hook( __FILE__, 'genesis_tabs_activation_check' );
/**
 * This function runs on plugin activation. It checks to make sure the required
 * minimum Genesis version is installed. If not, it deactivates itself.
 *
 * @since 0.9.0
 */
function genesis_tabs_activation_check() {

		$latest = '1.7.1';

		$theme_info = get_theme_data( TEMPLATEPATH . '/style.css' );

		if ( 'genesis' != basename( TEMPLATEPATH ) ) {
	        deactivate_plugins( plugin_basename( __FILE__ ) ); /** Deactivate ourself */
			wp_die( sprintf( __( 'Sorry, you can\'t activate unless you have installed <a href="%s">Genesis</a>', 'apl' ), 'http://www.studiopress.com/themes/genesis' ) );
		}

		if ( version_compare( $theme_info['Version'], $latest, '<' ) ) {
			deactivate_plugins( plugin_basename( __FILE__ ) ); /** Deactivate ourself */
			wp_die( sprintf( __( 'Sorry, you cannot activate without <a href="%s">Genesis %s</a> or greater', 'apl' ), 'http://www.studiopress.com/support/showthread.php?t=19576', $latest ) );
		}

}

/** Initialize Genesis Tabs */
add_action( 'after_setup_theme', array( 'Genesis_Tabs', 'init' ) );

/**
 * Simple class to handle all the non-widget aspects of the plugin
 *
 * @package Genesis Tabs
 * @since 0.9.0
 **/
class Genesis_Tabs {

	/** Faux Constructor */
	function init() {

		add_action( 'widgets_init', array( __CLASS__, 'register_widget' ) );

		add_action( 'wp_print_styles', array( __CLASS__, 'register_styles' ) );
		add_action( 'wp_enqueue_scripts', array( __CLASS__, 'register_scripts' ) );

		add_action( 'wp_footer', array( __CLASS__, 'footer_js' ), 20 );

	}

	function register_widget() {
		register_widget( 'Genesis_Tabs_Widget' );
	}

	function register_scripts() {
		wp_enqueue_script( 'jquery-ui-tabs' );
	}

	function register_styles() {
		wp_enqueue_style('genesis-tabs-stylesheet', plugins_url( 'style.css', __FILE__ ), false, '');
	}

	function footer_js() {
		echo '<script type="text/javascript">jQuery(document).ready(function($) { $(".ui-tabs").tabs(); });</script>' . "\n";
	}

}

/**
 * Widget Class. Handles the widget form and output.
 *
 * @package Genesis_Tabs
 * @since 0.9.0
 */
class Genesis_Tabs_Widget extends WP_Widget {

	/** Constructor */
	function __construct() {
		$widget_ops = array( 'classname' => 'ui-tabs', 'description' => __('Displays featured posts in Tabs', 'genesis') );
		$control_ops = array( 'width' => 505, 'height' => 350, 'id_base' => 'tabs' );
		$this->WP_Widget( 'tabs', __( 'Genesis - Tabs', 'genesis' ), $widget_ops, $control_ops );
	}

	/** Widget Output */
	function widget( $args, $instance ) {
		extract( $args );

		// defaults
		$instance = wp_parse_args( (array) $instance, array(
			'title'				=> '',
			'posts_cat_1'		=> '',
			'posts_cat_2'		=> '',
			'posts_cat_3'		=> '',
			'posts_cat_4'		=> '',
			'posts_cat_5'		=> '',
			'posts_cat_6'		=> '',
			'posts_cat_7'		=> '',
			'posts_cat_8'		=> '',
			'posts_cat_9'		=> '',
			'posts_cat_10'		=> '',
			'show_image'		=> 0,
			'image_alignment'	=> '',
			'image_size'		=> '',
			'show_title'		=> 0,
			'show_byline'		=> 0,
			'post_info'			=> '[post_date] ' . __('By', 'genesis') . ' [post_author_posts_link] [post_comments]',
			'show_content'		=> 'excerpt',
			'content_limit'		=> '',
			'more_text'			=> __( '[Read More...]', 'genesis' )
		) );

		echo $before_widget;

			// Pull the chosen categories into an array
			$cats = array( $instance['posts_cat_1'], $instance['posts_cat_2'], $instance['posts_cat_3'], $instance['posts_cat_4'], $instance['posts_cat_5'], $instance['posts_cat_6'], $instance['posts_cat_7'], $instance['posts_cat_8'] );

			// Display the tab links
			echo '<ul class="ui-tabs-nav">';
				foreach ( (array) $cats as $cat ) {
					if ( $cat ) echo '<li><a href="#cat-' . $cat . '">' . get_cat_name($cat) . '</a></li>';
				}
			echo '</ul>';

			// Loop through all chosen categories
			foreach ( (array) $cats as $cat ) :

				if ( ! $cat ) continue; // skip iteration if $cat is empty

				// Custom loop
				$tabbed_posts = new WP_Query( array( 'cat' => $cat, 'showposts' => 1, 'orderby' => 'date', 'order' => 'DESC' ) );
				if ( $tabbed_posts->have_posts() ) : while ( $tabbed_posts->have_posts() ) : $tabbed_posts->the_post();

					echo '<div id="cat-' . $cat . '" '; post_class( 'ui-tabs-hide' ); echo '>';

						if ( ! empty( $instance['show_image'] ) ) :
							printf( '<a href="%s" title="%s" class="%s">%s</a>', get_permalink(), the_title_attribute( 'echo=0' ), esc_attr( $instance['image_alignment'] ), genesis_get_image( array( 'format' => 'html', 'size' => $instance['image_size'] ) ) );
						endif;

						if( ! empty( $instance['show_title'] ) ) :
							printf( '<h2><a href="%s" title="%s">%s</a></h2>', get_permalink(), the_title_attribute( 'echo=0' ), get_the_title() );
						endif;

						if ( ! empty( $instance['show_byline'] ) && ! empty( $instance['post_info'] ) ) :
							printf( '<p class="byline post-info">%s</p>', do_shortcode( esc_html( $instance['post_info'] ) ) );
						endif;

						if( ! empty( $instance['show_content'] ) ) :

							if ( 'excerpt' == $instance['show_content'] ) :
								the_excerpt();
							elseif ( 'content-limit' == $instance['show_content'] ) :
								the_content_limit( (int) $instance['content_limit'], esc_html( $instance['more_text'] ) );
							else :
								the_content( esc_html( $instance['more_text'] ) );
							endif;

						endif;

					echo '</div><!--end post_class()-->'."\n\n";

				endwhile; endif;

			endforeach;

		echo $after_widget;
		wp_reset_query();
	}

	/** Update hook */
	function update( $new_instance, $old_instance ) {
		return $new_instance;
	}

	/** Form output */
	function form( $instance ) {

		// ensure value exists
		$instance = wp_parse_args( (array) $instance, array(
			'title'				=> '',
			'posts_cat_1'		=> '',
			'posts_cat_2'		=> '',
			'posts_cat_3'		=> '',
			'posts_cat_4'		=> '',
			'posts_cat_5'		=> '',
			'posts_cat_6'		=> '',
			'posts_cat_7'		=> '',
			'posts_cat_8'		=> '',
			'posts_cat_9'		=> '',
			'posts_cat_10'		=> '',
			'show_image'		=> 0,
			'image_alignment'	=> '',
			'image_size'		=> '',
			'show_title'		=> 0,
			'show_byline'		=> 0,
			'post_info'			=> '[post_date] ' . __('By', 'genesis') . ' [post_author_posts_link] [post_comments]',
			'show_content'		=> 'excerpt',
			'content_limit'		=> '',
			'more_text'			=> __( '[Read More...]', 'genesis' )
		) );
?>

	<p><label for="<?php echo $this->get_field_id( 'title' ); ?>"><?php _e( 'Title', 'genesis' ); ?>:</label>
	<input type="text" id="<?php echo $this->get_field_id( 'title' ); ?>" name="<?php echo $this->get_field_name( 'title' ); ?>" value="<?php echo esc_attr( $instance['title'] ); ?>" style="width:95%;" /></p>

	<div class="genesis-widget-column">

		<div class="genesis-widget-column-box genesis-widget-column-box-top">

		<p><span class="description">Choose up to 8 categories to pull posts from. Each category you choose will represent a single tab.</span></p>

		<p><?php wp_dropdown_categories( array( 'name' => $this->get_field_name( 'posts_cat_1' ), 'selected' => $instance['posts_cat_1'], 'orderby' => 'Name' , 'hierarchical' => 1, 'show_option_all' => __( "- None Selected -", 'genesis' ), 'hide_empty' => '0' ) ); ?></p>

		<p><?php wp_dropdown_categories( array( 'name' => $this->get_field_name( 'posts_cat_2' ), 'selected' => $instance['posts_cat_2'], 'orderby' => 'Name' , 'hierarchical' => 1, 'show_option_all' => __( "- None Selected -", 'genesis' ), 'hide_empty' => '0' ) ); ?></p>

		<p><?php wp_dropdown_categories( array( 'name' => $this->get_field_name( 'posts_cat_3' ), 'selected' => $instance['posts_cat_3'], 'orderby' => 'Name' , 'hierarchical' => 1, 'show_option_all' => __( "- None Selected -", 'genesis' ), 'hide_empty' => '0' ) ); ?></p>

		<p><?php wp_dropdown_categories( array( 'name' => $this->get_field_name( 'posts_cat_4' ), 'selected' => $instance['posts_cat_4'], 'orderby' => 'Name' , 'hierarchical' => 1, 'show_option_all' => __( "- None Selected -", 'genesis' ), 'hide_empty' => '0' ) ); ?></p>

		<p><?php wp_dropdown_categories( array( 'name' => $this->get_field_name( 'posts_cat_5' ), 'selected' => $instance['posts_cat_5'], 'orderby' => 'Name' , 'hierarchical' => 1, 'show_option_all' => __( "- None Selected -", 'genesis' ), 'hide_empty' => '0' ) ); ?></p>

		<p><?php wp_dropdown_categories( array( 'name' => $this->get_field_name( 'posts_cat_6' ), 'selected' => $instance['posts_cat_6'], 'orderby' => 'Name' , 'hierarchical' => 1, 'show_option_all' => __( "- None Selected -", 'genesis' ), 'hide_empty' => '0' ) ); ?></p>

		<p><?php wp_dropdown_categories( array( 'name' => $this->get_field_name( 'posts_cat_7' ), 'selected' => $instance['posts_cat_7'], 'orderby' => 'Name' , 'hierarchical' => 1, 'show_option_all' => __( "- None Selected -", 'genesis' ), 'hide_empty' => '0' ) ); ?></p>

		<p><?php wp_dropdown_categories( array( 'name' => $this->get_field_name( 'posts_cat_8' ), 'selected' => $instance['posts_cat_8'], 'orderby' => 'Name' , 'hierarchical' => 1, 'show_option_all' => __( "- None Selected -", 'genesis' ), 'hide_empty' => '0' ) ); ?></p>

		<p><?php wp_dropdown_categories( array( 'name' => $this->get_field_name( 'posts_cat_9' ), 'selected' => $instance['posts_cat_9'], 'orderby' => 'Name' , 'hierarchical' => 1, 'show_option_all' => __( "- None Selected -", 'genesis' ), 'hide_empty' => '0' ) ); ?></p>

		<p><?php wp_dropdown_categories( array( 'name' => $this->get_field_name( 'posts_cat_10' ), 'selected' => $instance['posts_cat_10'], 'orderby' => 'Name' , 'hierarchical' => 1, 'show_option_all' => __( "- None Selected -", 'genesis' ), 'hide_empty' => '0' ) ); ?></p>

		</div>

	</div>

	<div class="genesis-widget-column genesis-widget-column-right">

		<div class="genesis-widget-column-box genesis-widget-column-box-top">

		<p><input id="<?php echo $this->get_field_id( 'show_image' ); ?>" type="checkbox" name="<?php echo $this->get_field_name( 'show_image' ); ?>" value="1" <?php checked( 1, $instance['show_image'] ); ?>/> <label for="<?php echo $this->get_field_id( 'show_image' ); ?>"><?php _e( 'Show Featured Image', 'genesis' ); ?></label></p>

		<p><label for="<?php echo $this->get_field_id( 'image_size' ); ?>"><?php _e( 'Image Size', 'genesis' ); ?>:</label>
		<?php $sizes = genesis_get_additional_image_sizes(); ?>
		<select id="<?php echo $this->get_field_id( 'image_size' ); ?>" name="<?php echo $this->get_field_name( 'image_size' ); ?>">
			<option value="thumbnail">thumbnail (<?php echo get_option( 'thumbnail_size_w' ); ?>x<?php echo get_option( 'thumbnail_size_h' ); ?>)</option>
			<?php
			foreach ( (array) $sizes as $name => $size ) :
			echo '<option value="' . esc_attr( $name ) . '" '.selected( $name, $instance['image_size'], FALSE ).'>' . esc_html( $name ) . ' (' . $size['width'] . 'x' . $size['height'] . ')</option>';
			endforeach;
			?>
		</select></p>

		<p><label for="<?php echo $this->get_field_id( 'image_alignment' ); ?>"><?php _e( 'Image Alignment', 'genesis' ); ?>:</label>
		<select id="<?php echo $this->get_field_id( 'image_alignment' ); ?>" name="<?php echo $this->get_field_name( 'image_alignment' ); ?>">
			<option value="">- <?php _e( 'None', 'genesis' ); ?> -</option>
			<option value="alignleft" <?php selected( 'alignleft', $instance['image_alignment'] ); ?>><?php _e( 'Left', 'genesis' ); ?></option>
			<option value="alignright" <?php selected( 'alignright', $instance['image_alignment'] ); ?>><?php _e( 'Right', 'genesis' ); ?></option>
		</select></p>

		</div>

		<div class="genesis-widget-column-box">

		<p><input id="<?php echo $this->get_field_id( 'show_title' ); ?>" type="checkbox" name="<?php echo $this->get_field_name( 'show_title' ); ?>" value="1" <?php checked( 1, $instance['show_title'] ); ?>/> <label for="<?php echo $this->get_field_id( 'show_title' ); ?>"><?php _e( 'Show Post Title', 'genesis' ); ?></label></p>

		<p><input id="<?php echo $this->get_field_id( 'show_byline' ); ?>" type="checkbox" name="<?php echo $this->get_field_name( 'show_byline' ); ?>" value="1" <?php checked( 1, $instance['show_byline'] ); ?>/> <label for="<?php echo $this->get_field_id( 'show_byline' ); ?>"><?php _e( 'Show Post Info', 'genesis' ); ?></label>

		<input type="text" id="<?php echo $this->get_field_id( 'post_info' ); ?>" name="<?php echo $this->get_field_name( 'post_info' ); ?>" value="<?php echo esc_attr( $instance['post_info'] ); ?>" class="widefat" />

		</p>

		<p><label for="<?php echo $this->get_field_id( 'show_content' ); ?>"><?php _e( 'Content Type', 'genesis' ); ?>:</label>
		<select id="<?php echo $this->get_field_id( 'show_content' ); ?>" name="<?php echo $this->get_field_name( 'show_content' ); ?>">
			<option value="content" <?php selected( 'content' , $instance['show_content'] ); ?>><?php _e( 'Show Content', 'genesis' ); ?></option>
			<option value="excerpt" <?php selected( 'excerpt' , $instance['show_content'] ); ?>><?php _e( 'Show Excerpt', 'genesis' ); ?></option>
			<option value="content-limit" <?php selected( 'content-limit' , $instance['show_content'] ); ?>><?php _e( 'Show Content Limit', 'genesis' ); ?></option>
			<option value="" <?php selected( '' , $instance['show_content'] ); ?>><?php _e( 'No Content', 'genesis' ); ?></option>
		</select>

		<br /><label for="<?php echo $this->get_field_id( 'content_limit' ); ?>"><?php _e( 'Limit content to', 'genesis' ); ?></label> <input type="text" id="<?php echo $this->get_field_id( 'image_alignment' ); ?>" name="<?php echo $this->get_field_name( 'content_limit' ); ?>" value="<?php echo esc_attr( intval( $instance['content_limit'] ) ); ?>" size="3" /> <?php _e( 'characters', 'genesis' ); ?></p>

		<p><label for="<?php echo $this->get_field_id( 'more_text' ); ?>"><?php _e( 'More Text (if applicable)', 'genesis' ); ?>:</label>
		<input type="text" id="<?php echo $this->get_field_id( 'more_text' ); ?>" name="<?php echo $this->get_field_name( 'more_text' ); ?>" value="<?php echo esc_attr( $instance['more_text'] ); ?>" /></p>

		</div>

	</div>

	<?php
	}
}