<?php
/*
 * Plugin Name: Grid Columns
 * Plugin URI: http://themehybrid.com/plugins/grid-columns
 * Description: A [column] shortcode plugin.
 * Version: 0.1.1
 * Author: Justin Tadlock
 * Author URI: http://justintadlock.com
 *
 * Grid Columns was created because of the sheer number of WordPress themes adding poorly-coded
 * column shortcodes, which lock users into use that theme and system forever.  The plugin is
 * meant to be an all-around solution for any WordPress user, regardless of theme, to be able
 * to have columnized content using a simple [column] shortcode.
 *
 * 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.
 *
 * 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 *
 * @package   GridColumns
 * @version   0.1.1
 * @author    Justin Tadlock <justin@justintadlock.com>
 * @copyright Copyright (c) 2012, Justin Tadlock
 * @link      http://themehybrid.com/plugins/grid-columns
 * @license   http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
 */

class Grid_Columns {

    /**
     * The current grid.
     *
     * @since  0.1.0
     * @access public
     * @var    int
     */
    public $grid = 4;

    /**
     * The current total number of columns in the grid.
     *
     * @since  0.1.0
     * @access public
     * @var    int
     */
    public $span = 0;

    /**
     * Whether we're viewing the first column.
     *
     * @since  0.1.0
     * @access public
     * @var    bool
     */
    public $is_first_column = true;

    /**
     * Whether we're viewing the last column.
     *
     * @since  0.1.0
     * @access public
     * @var    bool
     */
    public $is_last_column = false;

    /**
     * Allowed grids can be 2, 3, 4, 5, or 12 columns.
     *
     * @since  0.1.0
     * @access public
     * @var    array
     */
    public $allowed_grids = array( 2, 3, 4, 5, 12 );

    /**
     * Sets up our actions/filters.
     *
     * @since 0.1.0
     * @access public
     * @return void
     */
    public function __construct() {

        /* Register shortcodes on 'init'. */
        add_action( 'init', array( &$this, 'register_shortcode' ) );

        /* Enqueue stylesheets on 'wp_enqueue_scripts'. */
        add_action( 'wp_enqueue_scripts', array( &$this, 'enqueue_styles' ), 1 );

        /* Apply filters to the column content. */
        add_filter( 'gc_column_content', 'wpautop' );
        add_filter( 'gc_column_content', 'shortcode_unautop' );
        add_filter( 'gc_column_content', 'do_shortcode' );
    }

    /**
     * Registers the [column] shortcode.
     *
     * @since  0.1.0
     * @access public
     * @return void
     */
    public function register_shortcode() {
        add_shortcode( 'column', array( &$this, 'do_shortcode' ) );
    }

    /**
     * Enqueues the columns.css stylesheet to make the columns pretty.
     *
     * @since  0.1.0
     * @access public
     * @return void
     */
    public function enqueue_styles() {

        /* Use the .min stylesheet if SCRIPT_DEBUG is turned off. */
        $suffix = ( defined( 'SCRIPT_DEBUG' ) && SCRIPT_DEBUG ) ? '' : '.min';

        /* Enqueue the stylesheet. */
        wp_enqueue_style(
            'grid-columns',
            trailingslashit( plugin_dir_url( __FILE__ ) ) . "css/columns$suffix.css",
            null,
            '20121007'
        );
    }

    /**
     * Returns the content of the column shortcode.
     *
     * @since  0.1.0
     * @access public
     * @param  array  $attr The user-inputted arguments.
     * @param  string $content The content to wrap in a shortcode.
     * @return string
     */
    public function do_shortcode( $attr, $content = null ) {

        /* If there's no content, just return back what we got. */
        if ( is_null( $content ) )
            return $content;

        /* Set up the default variables. */
        $output = '';
        $row_classes = array();
        $column_classes = array();

        /* Set up the default arguments. */
        $defaults = apply_filters(
            'gc_column_defaults',
            array(
                'grid'  => $this->grid,
                'span'  => 1,
                'push'  => 0,
                'class' => ''
            )
        );

        /* Parse the arguments. */
        $attr = shortcode_atts( $defaults, $attr );

        /* Allow devs to filter the arguments. */
        $attr = apply_filters( 'gc_column_args', $attr );

        /* Allow devs to overwrite the allowed grids. */
        $this->allowed_grids = apply_filters( 'gc_allowed_grids', $this->allowed_grids );

        /* Make sure the grid is in the allowed grids array. */
        if ( $this->is_first_column && in_array( $attr['grid'], $this->allowed_grids ) )
            $this->grid = absint( $attr['grid'] );

        /* Span cannot be greater than the grid. */
        $attr['span'] = ( $this->grid >= $attr['span'] ) ? absint( $attr['span'] ) : 1;

        /* The push argument should always be less than the grid. */
        $attr['push'] = ( $this->grid > $attr['push'] ) ? absint( $attr['push'] ) : 0;

        /* Add to the total $span. */
        $this->span = $this->span + $attr['span'] + $attr['push'];

        /* Column classes. */
        $column_classes[] = 'column';
        $column_classes[] = "column-span-{$attr['span']}";
        $column_classes[] = "column-push-{$attr['push']}";

        /* Add user-input custom class(es). */
        if ( !empty( $attr['class'] ) ) {
            if ( !is_array( $attr['class'] ) )
                $attr['class'] = preg_split( '#\s+#', $attr['class'] );
            $column_classes = array_merge( $column_classes, $attr['class'] );
        }

        /* Add the 'column-first' class if this is the first column. */
        if ( $this->is_first_column )
            $column_classes[] = 'column-first';

        /* If the $span property is greater than (shouldn't be) or equal to the $grid property. */
        if ( $this->span >= $this->grid ) {

            /* Add the 'column-last' class. */
            $column_classes[] = 'column-last';

            /* Set the $is_last_column property to true. */
            $this->is_last_column = true;
        }

        /* Object properties. */
        $object_vars = get_object_vars( $this );

        /* Allow devs to create custom classes. */
        $column_classes = apply_filters( 'gc_column_class', $column_classes, $attr, $object_vars );

        /* Sanitize and join all classes. */
        $column_class = join( ' ', array_map( 'sanitize_html_class', array_unique( $column_classes ) ) );

        /* Output */

        /* If this is the first column. */
        if ( $this->is_first_column ) {

            /* Row classes. */
            $row_classes = array( 'column-grid', "column-grid-{$this->grid}" );
            $row_classes = apply_filters( 'gc_row_class', $row_classes, $attr, $object_vars );
            $row_class = join( ' ', array_map( 'sanitize_html_class', array_unique( $row_classes ) ) );

            /* Open a wrapper <div> to contain the columns. */
            $output .= '<div class="' . $row_class . '">';

            /* Set the $is_first_column property back to false. */
            $this->is_first_column = false;
        }

        /* Add the current column to the output. */
        $output .= '<div class="' . $column_class . '">' . apply_filters( 'gc_column_content', $content ) . '</div>';

        /* If this is the last column. */
        if ( $this->is_last_column ) {

            /* Close the wrapper. */
            $output .= '</div>';

            /* Reset the properties that have been changed. */
            $this->reset();
        }

        /* Return the output of the column. */
        return apply_filters( 'gc_column', $output );
    }

    /**
     * Resets the properties to their original states.
     *
     * @since  0.1.0
     * @access public
     * @return void
     */
    public function reset() {

        foreach ( get_class_vars( __CLASS__ ) as $name => $default )
            $this->$name = $default;
    }
}

new Grid_Columns();

?>