<?php
/**
 * Metabox class.
 *
 * @since 1.0.0
 *
 * @package Envira_Gallery
 * @author  Thomas Griffin
 */
class Envira_Gallery_Metaboxes {

    /**
     * Holds the class object.
     *
     * @since 1.0.0
     *
     * @var object
     */
    public static $instance;

    /**
     * Path to the file.
     *
     * @since 1.0.0
     *
     * @var string
     */
    public $file = __FILE__;

    /**
     * Holds the base class object.
     *
     * @since 1.0.0
     *
     * @var object
     */
    public $base;

    /**
     * Primary class constructor.
     *
     * @since 1.0.0
     */
    public function __construct() {

        // Load the base class object.
        $this->base = Envira_Gallery_Lite::get_instance();

        // Output a notice if missing cropping extensions because Envira needs them.
        if ( ! $this->has_gd_extension() && ! $this->has_imagick_extension() ) {
            add_action( 'admin_notices', array( $this, 'notice_missing_extensions' ) );
        }

        // Scripts and styles
        add_action( 'admin_enqueue_scripts', array( $this, 'styles' ) );
        add_action( 'admin_enqueue_scripts', array( $this, 'scripts' ) );

        // Conflict resolvers and plugin busters
        add_action( 'admin_enqueue_scripts', array( $this, 'fix_plugin_js_conflicts' ), 100 );
        add_action( 'wp_print_scripts', array( $this, 'fix_plugin_js_conflicts' ), 100 );

        // Metaboxes
        add_action( 'add_meta_boxes', array( $this, 'add_meta_boxes' ), 1 );

        // Add the envira-gallery class to the form, so our styles can be applied
        add_action( 'post_edit_form_tag', array( $this, 'add_form_class' ) );

        // Modals
        add_filter( 'media_view_strings', array( $this, 'media_view_strings' ) );

        // Load all tabs.
        add_action( 'envira_gallery_tab_images', array( $this, 'images_tab' ) );
        add_action( 'envira_gallery_tab_config', array( $this, 'config_tab' ) );
        add_action( 'envira_gallery_tab_lightbox', array( $this, 'lightbox_tab' ) );
        add_action( 'envira_gallery_tab_misc', array( $this, 'misc_tab' ) );

		add_filter( 'envira_gallery_tab_nav', array( $this, 'lite_tabs' ) );
        add_action( 'envira_gallery_tab_mobile', array( $this, 'lite_mobile_tab' ) );
        add_action( 'envira_gallery_tab_videos', array( $this, 'lite_videos_tab' ) );
        add_action( 'envira_gallery_tab_social', array( $this, 'lite_social_tab' ) );
        add_action( 'envira_gallery_tab_tags', array( $this, 'lite_tags_tab' ) );
        add_action( 'envira_gallery_tab_pagination', array( $this, 'lite_pagination_tab' ) );

        // Save Gallery
        add_action( 'save_post', array( $this, 'save_meta_boxes' ), 10, 2 );

    }

    /**
     * Outputs a notice when the GD and Imagick PHP extensions aren't installed.
     *
     * @since 1.0.0
     */
    public function notice_missing_extensions() {

        ?>
        <div class="error">
            <p><strong><?php _e( 'The GD or Imagick libraries are not installed on your server. Envira Gallery requires at least one (preferably Imagick) in order to crop images and may not work properly without it. Please contact your webhost and ask them to compile GD or Imagick for your PHP install.', 'envira-gallery' ); ?></strong></p>
        </div>
        <?php

    }

    /**
    * Changes strings in the modal image selector if we're editing an Envira Gallery
    *
    * @since 1.4.0
    *
    * @param    array   $strings    Media View Strings
    * @return   array               Media View Strings
    */
    public function media_view_strings( $strings ) {

        // Check if we can get a current screen
        // If not, we're not on an Envira screen so we can bail
        if ( ! function_exists( 'get_current_screen' ) ) {
            return $strings;
        }

        // Get the current screen
        $screen = get_current_screen();

        // Check we're editing an Envira CPT
        if ( ! $screen ) {
            return $strings;
        }
        if ( $screen->post_type != 'envira' ) {
            return $strings;
        }

        // If here, we're editing an Envira CPT
        // Modify some of the media view's strings
        $strings['insertIntoPost'] = __( 'Insert into Gallery', 'envira-gallery' );
        $strings['inserting'] = __( 'Inserting...', 'envira-gallery' );

        // Allow addons to filter strings
        $strings = apply_filters( 'envira_gallery_media_view_strings', $strings, $screen );

        // Return
        return $strings;

    }

    /**
     * Appends the "Select Files From Other Sources" button to the Media Uploader, which is called using WordPress'
     * media_upload_form() function.
     *
     * Also appends a hidden upload progress bar, which is displayed by js/media-upload.js when the user uploads images
     * from their computer.
     *
     * CSS positions this button to improve the layout.
     *
     * @since 1.5.0
     */
    public function append_media_upload_form() {

        ?>
        <!-- Add from Media Library -->
        <a href="#" class="envira-media-library button" title="<?php _e( 'Click Here to Insert from Other Image Sources', 'envira-gallery' ); ?>" style="vertical-align: baseline;">
            <?php _e( 'Select Files from Other Sources', 'envira-gallery' ); ?>
        </a>

        <!-- Progress Bar -->
        <div class="envira-progress-bar">
            <div class="envira-progress-bar-inner"></div>
            <div class="envira-progress-bar-status">
                <span class="uploading">
                    <?php _e( 'Uploading Image', 'envira-gallery' ); ?>
                    <span class="current">1</span>
                    <?php _e( 'of', 'envira-gallery' ); ?>
                    <span class="total">3</span>
                </span>

                <span class="done"><?php _e( 'All images uploaded.', 'envira-gallery' ); ?></span>
            </div>
        </div>

        <div class="envira-progress-adding-images">
            <div class="envira-progress-status">
                <span class="spinner"></span><span class="adding_images"><?php _e( 'Adding items to gallery.', 'envira-gallery' ); ?></span>
            </div>
        </div>
        <?php

    }

    /**
     * Loads styles for our metaboxes.
     *
     * @since 1.0.0
     *
     * @return null Return early if not on the proper screen.
     */
    public function styles() {

        // Get current screen.
        $screen = get_current_screen();

        // Bail if we're not on the Envira Post Type screen.
        if ( 'envira' !== $screen->post_type ) {
            return;
        }

        // Bail if we're not on an editing screen.
        if ( 'post' !== $screen->base ) {
            return;
        }

        // Load necessary metabox styles.
        wp_register_style( $this->base->plugin_slug . '-metabox-style', plugins_url( 'assets/css/metabox.css', $this->base->file ), array(), $this->base->version );
        wp_enqueue_style( $this->base->plugin_slug . '-metabox-style' );

        // Fire a hook to load in custom metabox styles.
        do_action( 'envira_gallery_metabox_styles' );

    }

    /**
     * Loads scripts for our metaboxes.
     *
     * @since 1.0.0
     *
     * @global int $id      The current post ID.
     * @global object $post The current post object.
     * @return null         Return early if not on the proper screen.
     */
    public function scripts( $hook ) {

        global $id, $post;

        // Get current screen.
        $screen = get_current_screen();

        // Bail if we're not on the Envira Post Type screen.
        if ( 'envira' !== $screen->post_type ) {
            return;
        }

        // Bail if we're not on an editing screen.
        if ( 'post' !== $screen->base ) {
            return;
        }

        // Set the post_id for localization.
        $post_id = isset( $post->ID ) ? $post->ID : (int) $id;

        // Sortables
        wp_enqueue_script( 'jquery-ui-sortable' );

        // Image Uploader
        wp_enqueue_media( array(
            'post' => $post_id,
        ) );
        add_filter( 'plupload_init', array( $this, 'plupload_init' ) );

        // Tabs
        wp_register_script( $this->base->plugin_slug . '-tabs-script', plugins_url( 'assets/js/min/tabs-min.js', $this->base->file ), array( 'jquery' ), $this->base->version, true );
        wp_enqueue_script( $this->base->plugin_slug . '-tabs-script' );

        // Clipboard
        wp_register_script( $this->base->plugin_slug . '-clipboard-script', plugins_url( 'assets/js/min/clipboard-min.js', $this->base->file ), array( 'jquery' ), $this->base->version, true );
        wp_enqueue_script( $this->base->plugin_slug . '-clipboard-script' );

        // Conditional Fields
        wp_register_script( $this->base->plugin_slug . '-conditional-fields-script', plugins_url( 'assets/js/min/conditional-fields-min.js', $this->base->file ), array( 'jquery' ), $this->base->version, true );
        wp_enqueue_script( $this->base->plugin_slug . '-conditional-fields-script' );

        // Gallery / Album Selection
        wp_enqueue_script( $this->base->plugin_slug . '-gallery-select-script', plugins_url( 'assets/js/gallery-select.js', $this->base->file ), array( 'jquery' ), $this->base->version, true );
        wp_localize_script( $this->base->plugin_slug . '-gallery-select-script', 'envira_gallery_select', array(
            'get_galleries_nonce'   => wp_create_nonce( 'envira-gallery-editor-get-galleries' ),
            'modal_title'           => __( 'Insert', 'envira-gallery' ),
            'insert_button_label'   => __( 'Insert', 'envira-gallery' ),
        ) );

        // Metaboxes
        wp_register_script( $this->base->plugin_slug . '-metabox-script', plugins_url( 'assets/js/min/metabox-min.js', $this->base->file ), array( 'jquery', 'plupload-handlers', 'quicktags', 'jquery-ui-sortable' ), $this->base->version, true );
        wp_enqueue_script( $this->base->plugin_slug . '-metabox-script' );
        wp_localize_script(
            $this->base->plugin_slug . '-metabox-script',
            'envira_gallery_metabox',
            array(
                'ajax'                  => admin_url( 'admin-ajax.php' ),
                'change_nonce'          => wp_create_nonce( 'envira-gallery-change-type' ),
                'id'                    => $post_id,
                'import'                => __( 'You must select a file to import before continuing.', 'envira-gallery' ),
                'insert_nonce'          => wp_create_nonce( 'envira-gallery-insert-images' ),
                'inserting'             => __( 'Inserting...', 'envira-gallery' ),
                'library_search'        => wp_create_nonce( 'envira-gallery-library-search' ),
                'load_gallery'          => wp_create_nonce( 'envira-gallery-load-gallery' ),
                'load_image'            => wp_create_nonce( 'envira-gallery-load-image' ),
                'move_media_nonce'      => wp_create_nonce( 'envira-gallery-move-media' ),
                'move_media_modal_title'=> __( 'Move Media to Gallery', 'envira-gallery' ),
                'move_media_insert_button_label' => __( 'Move Media to Selected Gallery', 'envira-gallery' ),
                'preview_nonce'         => wp_create_nonce( 'envira-gallery-change-preview' ),
                'refresh_nonce'         => wp_create_nonce( 'envira-gallery-refresh' ),
                'remove'                => __( 'Are you sure you want to remove this image from the gallery?', 'envira-gallery' ),
                'remove_multiple'       => __( 'Are you sure you want to remove these images from the gallery?', 'envira-gallery' ),
                'remove_nonce'          => wp_create_nonce( 'envira-gallery-remove-image' ),
                'save_nonce'            => wp_create_nonce( 'envira-gallery-save-meta' ),
                'set_user_setting_nonce'=> wp_create_nonce( 'envira-gallery-set-user-setting' ),
                'saving'                => __( 'Saving...', 'envira-gallery' ),
                'saved'                 => __( 'Saved!', 'envira-gallery' ),
                'sort'                  => wp_create_nonce( 'envira-gallery-sort' ),
                'uploader_files_computer' => __( 'Select Files from Your Computer', 'envira-gallery' ),
            )
        );

        // Link Search
        wp_enqueue_script( 'wp-link' );

        // Add custom CSS for hiding specific things.
        add_action( 'admin_head', array( $this, 'meta_box_css' ) );

        // Fire a hook to load custom metabox scripts.
        do_action( 'envira_gallery_metabox_scripts' );

    }

    /**
     * Remove plugins scripts that break Envira's admin.
     *
     * @access public
     * @return void
     */
    public function fix_plugin_js_conflicts(){

        global $id, $post;

        // Get current screen.
        
        if ( ! function_exists( 'get_current_screen' ) ) {
            return;
        }

        $screen = get_current_screen();

        // Bail if we're not on the Envira Post Type screen.
        if ( 'envira' !== $screen->post_type ) {
            return;
        }

        wp_dequeue_style ( 'thrive-theme-options'  );
        wp_dequeue_script( 'thrive-theme-options' );
        wp_dequeue_script( 'ngg-igw' );
        wp_dequeue_script( 'yoast_ga_admin' ); /* Yoast Clicky Plugin */

    }

    /**
    * Amends the default Plupload parameters for initialising the Media Uploader, to ensure
    * the uploaded image is attached to our Envira CPT
    *
    * @since 1.0.0
    *
    * @param array $params Params
    * @return array Params
    */
    public function plupload_init( $params ) {

        global $post_ID;

        // Define the Envira Gallery Post ID, so Plupload attaches the uploaded images
        // to this Envira Gallery
        $params['multipart_params']['post_id'] = $post_ID;

        // Build an array of supported file types for Plupload
        $supported_file_types = Envira_Gallery_Common::get_instance()->get_supported_filetypes();

        // Assign supported file types and return
        $params['filters']['mime_types'] = $supported_file_types;

        // Return and apply a custom filter to our init data.
        $params = apply_filters( 'envira_gallery_plupload_init', $params, $post_ID );
        return $params;

    }

    /**
     * Hides unnecessary meta box items on Envira post type screens.
     *
     * @since 1.0.0
     */
    public function meta_box_css() {

        ?>
        <style type="text/css">.misc-pub-section:not(.misc-pub-post-status) { display: none; }</style>
        <?php

        // Fire action for CSS on Envira post type screens.
        do_action( 'envira_gallery_admin_css' );

    }

    /**
     * Creates metaboxes for handling and managing galleries.
     *
     * @since 1.0.0
     */
    public function add_meta_boxes() {

        global $post;

        // Check we're on an Envira Gallery
        if ( 'envira' != $post->post_type ) {
            return;
        }

        // Let's remove all of those dumb metaboxes from our post type screen to control the experience.
        $this->remove_all_the_metaboxes();

        // Add our metaboxes to Envira CPT.

        // Types Metabox
        // Allows the user to upload images or choose an External Gallery Type
        // We don't display this if the Gallery is a Dynamic or Default Gallery, as these settings don't apply
        $type = $this->get_config( 'type', $this->get_config_default( 'type' ) );
        if ( ! in_array( $type, array( 'defaults', 'dynamic' ) ) ) {
            add_meta_box( 'envira-gallery', __( 'Envira Gallery', 'envira-gallery' ), array( $this, 'meta_box_gallery_callback' ), 'envira', 'normal', 'high' );
        }

        // Settings Metabox
        add_meta_box( 'envira-gallery-settings', __( 'Envira Gallery Settings', 'envira-gallery' ), array( $this, 'meta_box_callback' ), 'envira', 'normal', 'high' );

        // Preview Metabox
        // Displays the images to be displayed when using an External Gallery Type
        // In the future, this could include a 'live' preview of the gallery theme options etc.
        add_meta_box( 'envira-gallery-preview', __( 'Envira Gallery Preview', 'envira-gallery' ), array( $this, 'meta_box_preview_callback' ), 'envira', 'normal', 'high' );

        // Display the Gallery Code metabox if we're editing an existing Gallery
        if ( $post->post_status != 'auto-draft' ) {
            add_meta_box( 'envira-gallery-code', __( 'Envira Gallery Code', 'envira-gallery' ), array( $this, 'meta_box_gallery_code_callback' ), 'envira', 'side', 'default' );
        }

        // Output 'Select Files from Other Sources' button on the media uploader form
        add_action( 'post-plupload-upload-ui', array( $this, 'append_media_upload_form' ), 1 );
        add_action( 'post-html-upload-ui', array( $this, 'append_media_upload_form' ), 1 );

    }

    /**
     * Removes all the metaboxes except the ones I want on MY POST TYPE. RAGE.
     *
     * @since 1.0.0
     *
     * @global array $wp_meta_boxes Array of registered metaboxes.
     * @return smile $for_my_buyers Happy customers with no spammy metaboxes!
     */
    public function remove_all_the_metaboxes() {

        global $wp_meta_boxes;

        // This is the post type you want to target. Adjust it to match yours.
        $post_type  = 'envira';

        // These are the metabox IDs you want to pass over. They don't have to match exactly. preg_match will be run on them.
        $pass_over_defaults = array( 'submitdiv', 'envira' );
        $pass_over  = apply_filters( 'envira_gallery_metabox_ids', $pass_over_defaults );

        // All the metabox contexts you want to check.
        $contexts_defaults = array( 'normal', 'advanced', 'side' );
        $contexts   = apply_filters( 'envira_gallery_metabox_contexts', $contexts_defaults );

        // All the priorities you want to check.
        $priorities_defaults = array( 'high', 'core', 'default', 'low' );
        $priorities = apply_filters( 'envira_gallery_metabox_priorities', $priorities_defaults );

        // Loop through and target each context.
        foreach ( $contexts as $context ) {
            // Now loop through each priority and start the purging process.
            foreach ( $priorities as $priority ) {
                if ( isset( $wp_meta_boxes[$post_type][$context][$priority] ) ) {
                    foreach ( (array) $wp_meta_boxes[$post_type][$context][$priority] as $id => $metabox_data ) {
                        // If the metabox ID to pass over matches the ID given, remove it from the array and continue.
                        if ( in_array( $id, $pass_over ) ) {
                            unset( $pass_over[$id] );
                            continue;
                        }

                        // Otherwise, loop through the pass_over IDs and if we have a match, continue.
                        foreach ( $pass_over as $to_pass ) {
                            if ( preg_match( '#^' . $id . '#i', $to_pass ) ) {
                                continue;
                            }
                        }

                        // If we reach this point, remove the metabox completely.
                        unset( $wp_meta_boxes[$post_type][$context][$priority][$id] );
                    }
                }
            }
        }

    }

    /**
     * Adds an envira-gallery class to the form when adding or editing an Album,
     * so our plugin's CSS and JS can target a specific element and its children.
     *
     * @since 1.5.0
     *
     * @param   WP_Post     $post   WordPress Post
     */
    public function add_form_class( $post ) {

        // Check the Post is a Gallery
        if ( 'envira' != get_post_type( $post ) ) {
            return;
        }

        echo ' class="envira-gallery"';

    }

    /**
     * Callback for displaying the Gallery Type section.
     *
     * @since 1.5.0
     *
     * @param object $post The current post object.
     */
    public function meta_box_gallery_callback( $post ) {

        // Load view
        $this->base->load_admin_partial( 'metabox-gallery-type', array(
            'post'      => $post,
            'types'     => $this->get_envira_types( $post ),
            'instance'  => $this,
        ) );

    }

    /**
     * Callback for displaying the Gallery Settings section.
     *
     * @since 1.0.0
     *
     * @param object $post The current post object.
     */
    public function meta_box_callback( $post ) {

        // Keep security first.
        wp_nonce_field( 'envira-gallery', 'envira-gallery' );

        // Load view
        $this->base->load_admin_partial( 'metabox-gallery-settings', array(
            'post'  => $post,
            'tabs'  => $this->get_envira_tab_nav(),
        ) );

    }

    /**
     * Callback for displaying the Preview metabox.
     *
     * @since 1.5.0
     *
     * @param object $post The current post object.
     */
    public function meta_box_preview_callback( $post ) {

        // Get the gallery data
        $data = get_post_meta( $post->ID, '_eg_gallery_data', true );

        // Output the display based on the type of slider being created.
        echo '<div id="envira-gallery-preview-main" class="envira-clear">';

        $this->preview_display( $this->get_config( 'type', $this->get_config_default( 'type' ) ), $data );

        echo '</div>
              <div class="spinner"></div>';

    }

    /**
     * Callback for displaying the Gallery Code metabox.
     *
     * @since 1.5.0
     *
     * @param object $post The current post object.
     */
    public function meta_box_gallery_code_callback( $post ) {

        // Load view
        $this->base->load_admin_partial( 'metabox-gallery-code', array(
            'post'          => $post,
            'gallery_data'  => get_post_meta( $post->ID, '_eg_gallery_data', true ),
        ) );

    }

    /**
     * Returns the types of galleries available.
     *
     * @since 1.0.0
     *
     * @param object $post The current post object.
     * @return array       Array of gallery types to choose.
     */
    public function get_envira_types( $post ) {

        $types = array(
            'default' => __( 'Default', 'envira-gallery' )
        );

        return apply_filters( 'envira_gallery_types', $types, $post );

    }

    /**
     * Returns the tabs to be displayed in the settings metabox.
     *
     * @since 1.0.0
     *
     * @return array Array of tab information.
     */
    public function get_envira_tab_nav() {

        $tabs = array(
            'images'     => __( 'Images', 'envira-gallery' ),
            'config'     => __( 'Config', 'envira-gallery' ),
            'lightbox'   => __( 'Lightbox', 'envira-gallery' ),
            'mobile'     => __( 'Mobile', 'envira-gallery' ),
        );
        $tabs = apply_filters( 'envira_gallery_tab_nav', $tabs );

        // "Misc" tab is required.
        $tabs['misc'] = __( 'Misc', 'envira-gallery' );

        return $tabs;

    }

    /**
     * Callback for displaying the settings UI for the Gallery tab.
     *
     * @since 1.0.0
     *
     * @param object $post The current post object.
     */
    public function images_tab( $post ) {

        // Output the display based on the type of slider being created.
        echo '<div id="envira-gallery-main" class="envira-clear">';

        // Allow Addons to display a WordPress-style notification message
        echo apply_filters( 'envira_gallery_images_tab_notice', '', $post );

        // Output the tab panel for the Gallery Type
        $this->images_display( $this->get_config( 'type', $this->get_config_default( 'type' ) ), $post );

        echo '</div>
              <div class="spinner"></div>';

    }

    /**
     * Determines the Images tab display based on the type of gallery selected.
     *
     * @since 1.0.0
     *
     * @param string $type The type of display to output.
     * @param object $post The current post object.
     */
    public function images_display( $type = 'default', $post ) {

        // Output a unique hidden field for settings save testing for each type of slider.
        echo '<input type="hidden" name="_envira_gallery[type_' . $type . ']" value="1" />';

        // Output the display based on the type of slider available.
        switch ( $type ) {
            case 'default' :
                $this->do_default_display( $post );
                break;
            default:
                do_action( 'envira_gallery_display_' . $type, $post );
                break;
        }

    }

    /**
     * Determines the Preview metabox display based on the type of gallery selected.
     *
     * @since 1.5.0
     *
     * @param string $type The type of display to output.
     * @param object $data Gallery Data
     */
    public function preview_display( $type = 'default', $data ) {

        // Output the display based on the type of slider available.
        switch ( $type ) {
            case 'default' :
                // Don't preview anything
                break;
            default:
                do_action( 'envira_gallery_preview_' . $type, $data );
                break;
        }

    }

    /**
     * Callback for displaying the default gallery UI.
     *
     * @since 1.0.0
     *
     * @param object $post The current post object.
     */
    public function do_default_display( $post ) {

        // Prepare output data.
        $gallery_data = get_post_meta( $post->ID, '_eg_gallery_data', true );

        // Determine whether to use the list or grid layout, depending on the user's setting
        $layout = get_user_setting( 'envira_gallery_image_view', 'grid' );
        ?>

        <!-- Title and Help -->
        <p class="envira-intro">
            <?php _e( 'Currently in your Gallery', 'envira-gallery' ); ?>
            <small>
                <?php _e( 'Need some help?', 'envira-gallery' ); ?>
                <a href="http://enviragallery.com/docs/creating-first-envira-gallery/" class="envira-doc" target="_blank">
                    <?php _e( 'Read the Documentation', 'envira-gallery' ); ?>
                </a>
                <?php _e( 'or', 'envira-gallery' ); ?>
                <a href="https://www.youtube.com/embed/F9_wOefuBaw?autoplay=1&amp;rel=0" class="envira-video" target="_blank">
                    <?php _e( 'Watch a Video', 'envira-gallery' ); ?>
                </a>
            </small>
        </p>

		<?php do_action( 'envira_gallery_do_default_display', $post ); ?>

        <ul id="envira-gallery-output" class="envira-gallery-images-output <?php echo $layout; ?>">
            <?php
            if ( ! empty( $gallery_data['gallery'] ) ) {
                foreach ( $gallery_data['gallery'] as $id => $data ) {
                    echo $this->get_gallery_item( $id, $data, $post->ID );
                }
            }
            ?>
        </ul>

        <?php
        // Output an upgrade notice
        Envira_Gallery_Notice_Admin::get_instance()->display_inline_notice(
            'envira_gallery_images_tab',
            __( 'Want to make your gallery workflow even better?', 'envira-gallery' ),
            __( 'By upgrading to Envira Pro, you can get access to numerous other features, including: a fully featured gallery widget, complete gallery API, powerful gallery documentation, full mobile and Retina support, dedicated customer support and so much more!', 'envira-gallery' ),
            'warning',
            __( 'Click here to Upgrade', 'envira-gallery' ),
            Envira_Gallery_Common_Admin::get_instance()->get_upgrade_link(),
            false
        );

    }

    /**
     * Callback for displaying the settings UI for the Configuration tab.
     *
     * @since 1.0.0
     *
     * @param object $post The current post object.
     */
    public function config_tab( $post ) {

        ?>
        <div id="envira-config">
            <!-- Title and Help -->
            <p class="envira-intro">
                <?php _e( 'Gallery Settings', 'envira-gallery' ); ?>
                <small>
                    <?php _e( 'The settings below adjust the basic configuration options for the gallery.', 'envira-gallery' ); ?><br />
                    <?php _e( 'Need some help?', 'envira-gallery' ); ?>
                    <a href="http://enviragallery.com/docs/creating-first-envira-gallery/" class="envira-doc" target="_blank">
                        <?php _e( 'Read the Documentation', 'envira-gallery' ); ?>
                    </a>
                    or
                    <a href="https://www.youtube.com/embed/F9_wOefuBaw?autoplay=1&amp;rel=0" class="envira-video" target="_blank">
                        <?php _e( 'Watch a Video', 'envira-gallery' ); ?>
                    </a>
                </small>
            </p>
            <table class="form-table" style="margin-bottom: 0;">
                <tbody>
                    <tr id="envira-config-columns-box">
                        <th scope="row">
                            <label for="envira-config-columns"><?php _e( 'Number of Gallery Columns', 'envira-gallery' ); ?></label>
                        </th>
                        <td>
                            <select id="envira-config-columns" name="_envira_gallery[columns]">
                                <?php foreach ( (array) $this->get_columns() as $i => $data ) : ?>
                                    <option value="<?php echo $data['value']; ?>"<?php selected( $data['value'], $this->get_config( 'columns', $this->get_config_default( 'columns' ) ) ); ?>><?php echo $data['name']; ?></option>
                                <?php endforeach; ?>
                            </select>
                            <p class="description"><?php _e( 'Determines the number of columns in the gallery. Automatic will attempt to fill each row as much as possible before moving on to the next row.', 'envira-gallery' ); ?></p>
                        </td>
                    </tr>

                    <?php

                    if ( !isset( $post ) || $post->post_status == 'auto-draft' ) {
                        // make the lazy loading checkbox "checked", otherwise if this is a previous post don't force it

                    ?>
                    <tr id="envira-config-lazy-loading-box">
                        <th scope="row">
                            <label for="envira-config-lazy-loading"><?php _e( 'Enable Lazy Loading?', 'envira-gallery' ); ?></label>
                        </th>
                        <td>
                            <input id="envira-config-lazy-loading" type="checkbox" name="_envira_gallery[lazy_loading]" value="<?php echo $this->get_config( 'lazy_loading', $this->get_config_default( 'lazy_loading' ) ); ?>" <?php checked( $this->get_config( 'lazy_loading', $this->get_config_default( 'lazy_loading' ) ), 1 ); ?> />
                            <span class="description"><?php _e( 'Enables or disables lazy loading, which helps with performance by loading thumbnails only when they are visible. See our documentation for more information.', 'envira-gallery' ); ?></span>
                        </td>
                    </tr>

                    <?php } else { ?>

                    <tr id="envira-config-lazy-loading-box">
                        <th scope="row">
                            <label for="envira-config-lazy-loading"><?php _e( 'Enable Lazy Loading?', 'envira-gallery' ); ?></label>
                        </th>
                        <td>
                            <input id="envira-config-lazy-loading" type="checkbox" name="_envira_gallery[lazy_loading]" value="<?php echo $this->get_config( 'lazy_loading', $this->get_config_default( 'lazy_loading' ) ); ?>" <?php checked( $this->get_config( 'lazy_loading' ), 1 ); ?> />
                            <span class="description"><?php _e( 'Enables or disables lazy loading, which helps with performance by loading thumbnails only when they are visible. See our documentation for more information.', 'envira-gallery' ); ?></span>
                        </td>
                    </tr>

                    <?php } ?>

                    <tr id="envira-config-lazy-loading-delay">
                        <th scope="row">
                            <label for="envira-config-lazy-loading-delay"><?php _e( 'Lazy Loading Delay', 'envira-gallery' ); ?></label>
                        </th>
                            <td>
                                <input id="envira-config-lazy-loading-delay" type="number" name="_envira_gallery[lazy_loading_delay]" value="<?php echo $this->get_config( 'lazy_loading_delay', $this->get_config_default( 'lazy_loading_delay' ) ); ?>" /> <span class="envira-unit"><?php _e( 'milliseconds', 'envira-gallery' ); ?></span>
                                <p class="description"><?php _e( 'Set a delay when new images are loaded', 'envira-gallery' ); ?></p>
                            </td>
                    </tr>
                </tbody>
            </table>
            <?php // New Automatic Layout / Justified Layout Options ?>
            <div id="envira-config-justified-settings-box">
                <table class="form-table" style="margin-bottom: 0;">
                    <tbody>
                        <tr id="envira-config-justified-row-height">
                            <th scope="row">
                                <label for="envira-config-justified-row-height"><?php _e( 'Automatic Layout: Row Height', 'envira-gallery' ); ?></label>
                            </th>
                            <td>
                                <input id="envira-config-justified-row-height" type="number" name="_envira_gallery[justified_row_height]" value="<?php echo $this->get_config( 'justified_row_height', $this->get_config_default( 'justified_row_height' ) ); ?>" /> <span class="envira-unit"><?php _e( 'px', 'envira-gallery' ); ?></span>
                                <p class="description"><?php _e( 'Determines how high (in pixels) each row will be. 150px is default. ', 'envira-gallery' ); ?></p>
                            </td>
                        </tr>
                        <tr id="envira-config-gallery-justified-theme-box">
                            <th scope="row">
                                <label for="envira-config-gallery-justified-theme"><?php _e( 'Automatic Layout: Gallery Theme', 'envira-gallery' ); ?></label>
                            </th>
                            <td>
                                <select id="envira-config-gallery-justified-theme" name="_envira_gallery[justified_gallery_theme]">
                                    <?php foreach ( (array) $this->get_justified_gallery_themes() as $i => $data ) : ?>
                                        <option value="<?php echo $data['value']; ?>"<?php selected( $data['value'], $this->get_config( 'justified_gallery_theme', $this->get_config_default( 'justified_gallery_theme' ) ) ); ?>><?php echo $data['name']; ?></option>
                                    <?php endforeach; ?>
                                </select>
                                <p class="description"><?php _e( 'Sets the theme for the gallery display.', 'envira-gallery' ); ?></p>
                            </td>
                        </tr>
                    </tbody>
                </table>
            </div>

            <div id="envira-config-standard-settings-box">
                <table class="form-table">
                    <tbody>

                        <tr id="envira-config-gallery-theme-box">
                            <th scope="row">
                                <label for="envira-config-gallery-theme"><?php _e( 'Gallery Theme', 'envira-gallery' ); ?></label>
                            </th>
                            <td>
                                <select id="envira-config-gallery-theme" name="_envira_gallery[gallery_theme]">
                                    <?php foreach ( (array) $this->get_gallery_themes() as $i => $data ) : ?>
                                        <option value="<?php echo $data['value']; ?>"<?php selected( $data['value'], $this->get_config( 'gallery_theme', $this->get_config_default( 'gallery_theme' ) ) ); ?>><?php echo $data['name']; ?></option>
                                    <?php endforeach; ?>
                                </select>
                                <p class="description"><?php _e( 'Sets the theme for the gallery display.', 'envira-gallery' ); ?></p>
                            </td>
                        </tr>
                        <tr id="envira-config-gutter-box">
                            <th scope="row">
                                <label for="envira-config-gutter"><?php _e( 'Column Gutter Width', 'envira-gallery' ); ?></label>
                            </th>
                            <td>
                                <input id="envira-config-gutter" type="number" name="_envira_gallery[gutter]" value="<?php echo $this->get_config( 'gutter', $this->get_config_default( 'gutter' ) ); ?>" /> <span class="envira-unit"><?php _e( 'px', 'envira-gallery' ); ?></span>
                                <p class="description"><?php _e( 'Sets the space between the columns (defaults to 10).', 'envira-gallery' ); ?></p>
                            </td>
                        </tr>
                        <tr id="envira-config-margin-box">
                            <th scope="row">
                                <label for="envira-config-margin"><?php _e( 'Margin Below Each Image', 'envira-gallery' ); ?></label>
                            </th>
                            <td>
                                <input id="envira-config-margin" type="number" name="_envira_gallery[margin]" value="<?php echo $this->get_config( 'margin', $this->get_config_default( 'margin' ) ); ?>" /> <span class="envira-unit"><?php _e( 'px', 'envira-gallery' ); ?></span>
                                <p class="description"><?php _e( 'Sets the space below each item in the gallery.', 'envira-gallery' ); ?></p>
                            </td>
                        </tr>

                        <?php do_action( 'envira_gallery_config_box', $post ); ?>
                    </tbody>
                </table>
            </div>
          
            
            <div id="envira-image-settings-box">
                <table class="form-table">
                    <tbody>
	                    <!-- Dimensions -->
                        <tr id="envira-config-image-size-box">
                            <th scope="row">
                                <label for="envira-config-image-size"><?php _e( 'Image Size', 'envira-gallery' ); ?></label>
                            </th>
                            <td>
                                <select id="envira-config-image-size" name="_envira_gallery[image_size]">
                                    <?php
                                    foreach ( (array) $this->get_image_sizes() as $i => $data ) {
                                        ?>
                                        <option value="<?php echo $data['value']; ?>"<?php selected( $data['value'], $this->get_config( 'image_size', $this->get_config_default( 'image_size' ) ) ); ?>><?php echo $data['name']; ?></option>
                                        <?php
                                    }
                                    ?>
                                </select>
                                <p class="description"><?php _e( 'Define the maximum image size for the Gallery view. Default will use the below Image Dimensions; Random will allow you to choose one or more WordPress image sizes, which will be used for the gallery output.', 'envira-gallery' ); ?></p>
                            </td>
                        </tr>
                        <tr id="envira-config-crop-size-box">
                            <th scope="row">
                                <label for="envira-config-crop-width"><?php _e( 'Image Dimensions', 'envira-gallery' ); ?></label>
                            </th>
                            <td>
                                <input id="envira-config-crop-width" type="number" name="_envira_gallery[crop_width]" value="<?php echo $this->get_config( 'crop_width', $this->get_config_default( 'crop_width' ) ); ?>" /> &#215; <input id="envira-config-crop-height" type="number" name="_envira_gallery[crop_height]" value="<?php echo $this->get_config( 'crop_height', $this->get_config_default( 'crop_height' ) ); ?>" /> <span class="envira-unit"><?php _e( 'px', 'envira-gallery' ); ?></span>
                                <p class="description"><?php _e( 'You should adjust these dimensions based on the number of columns in your gallery. This does not affect the full size lightbox images.', 'envira-gallery' ); ?></p>
                            </td>
                        </tr>
                        <tr id="envira-config-crop-box">
                            <th scope="row">
                                <label for="envira-config-crop"><?php _e( 'Crop Images?', 'envira-gallery' ); ?></label>
                            </th>
                            <td>
                                <input id="envira-config-crop" type="checkbox" name="_envira_gallery[crop]" value="<?php echo $this->get_config( 'crop', $this->get_config_default( 'crop' ) ); ?>" <?php checked( $this->get_config( 'crop', $this->get_config_default( 'crop' ) ), 1 ); ?> />
                                <span class="description"><?php _e( 'If enabled, forces images to exactly match the sizes defined above for Image Dimensions and Mobile Dimensions.', 'envira-gallery' ); ?></span>
                                <span class="description"><?php _e( 'If disabled, images will be resized to maintain their aspect ratio.', 'envira-gallery' ); ?></span>

                            </td>
                        </tr>	
                    </tbody>            
	            </table>
	            
        </div>
        </div>	
        <?php Envira_Gallery_Notice_Admin::get_instance()->display_inline_notice(
                'envira_gallery_config_tab',
                __( 'Want to do even more with your gallery display?', 'envira-gallery' ),
                __( 'By upgrading to Envira Pro, you can get access to numerous other gallery display features, including: custom image tagging and filtering, mobile specific image assets for blazing fast load times, dedicated and unique gallery URLs, custom gallery themes, gallery thumbnail support and so much more!', 'envira-gallery' ),
                'warning',
                __( 'Click here to Upgrade', 'envira-gallery' ),
                Envira_Gallery_Common_Admin::get_instance()->get_upgrade_link(),
                false
            );

    }

    /**
     * Callback for displaying the settings UI for the Lightbox tab.
     *
     * @since 1.0.0
     *
     * @param object $post The current post object.
     */
    public function lightbox_tab( $post ) {

        ?>
        <div id="envira-lightbox">
            <p class="envira-intro">
                <?php _e( 'Lightbox Settings', 'envira-gallery' ); ?>
                <small>
                    <?php _e( 'The settings below adjust the lightbox output.', 'envira-gallery' ); ?>
                    <br />
                    <?php _e( 'Need some help?', 'envira-gallery' ); ?>
                    <a href="http://enviragallery.com/docs/creating-first-envira-gallery/" class="envira-doc" target="_blank">
                        <?php _e( 'Read the Documentation', 'envira-gallery' ); ?>
                    </a>
                    or
                    <a href="https://www.youtube.com/embed/4jHG3LOmV-c?autoplay=1&amp;rel=0" class="envira-video" target="_blank">
                        <?php _e( 'Watch a Video', 'envira-gallery' ); ?>
                    </a>
                </small>
            </p>

            <table class="form-table no-margin">
                <tbody>
                    <tr id="envira-config-lightbox-enabled-box">
                        <th scope="row">
                            <label for="envira-config-lightbox-enabled"><?php _e( 'Enable Lightbox?', 'envira-gallery' ); ?></label>
                        </th>
                        <td>
                            <input id="envira-config-lightbox-enabled" type="checkbox" name="_envira_gallery[lightbox_enabled]" value="<?php echo $this->get_config( 'lightbox_enabled', $this->get_config_default( 'lightbox_enabled' ) ); ?>" <?php checked( $this->get_config( 'lightbox_enabled', $this->get_config_default( 'lightbox_enabled' ) ), 1 ); ?> />
                            <span class="description"><?php _e( 'Enables or disables the gallery lightbox.', 'envira-gallery' ); ?></span>
                        </td>
                    </tr>
                </tbody>
            </table>

            <div id="envira-lightbox-settings">
                <table class="form-table">
                    <tbody>
                        <tr id="envira-config-lightbox-theme-box">
                            <th scope="row">
                                <label for="envira-config-lightbox-theme"><?php _e( 'Gallery Lightbox Theme', 'envira-gallery' ); ?></label>
                            </th>
                            <td>
                                <select id="envira-config-lightbox-theme" name="_envira_gallery[lightbox_theme]">
                                    <?php foreach ( (array) $this->get_lightbox_themes() as $i => $data ) : ?>
                                        <option value="<?php echo $data['value']; ?>"<?php selected( $data['value'], $this->get_config( 'lightbox_theme', $this->get_config_default( 'lightbox_theme' ) ) ); ?>><?php echo $data['name']; ?></option>
                                    <?php endforeach; ?>
                                </select>
                                <p class="description"><?php _e( 'Sets the theme for the gallery lightbox display.', 'envira-gallery' ); ?></p>
                            </td>
                        </tr>
                        <tr id="envira-config-lightbox-image-size-box">
                            <th scope="row">
                                <label for="envira-config-lightbox-image-size"><?php _e( 'Image Size', 'envira-gallery' ); ?></label>
                            </th>
                            <td>
                                <select id="envira-config-lightbox-image-size" name="_envira_gallery[lightbox_image_size]">
                                    <?php foreach ( (array) $this->get_image_sizes() as $i => $data ) : ?>
                                        <option value="<?php echo $data['value']; ?>" <?php selected( $data['value'], $this->get_config( 'lightbox_image_size', $this->get_config_default( 'lightbox_image_size' ) ) ); ?>><?php echo $data['name']; ?></option>
                                    <?php endforeach; ?>
                                </select><br>
                                <p class="description"><?php _e( 'Define the maximum image size for the Lightbox view. Default will display the original, full size image.', 'envira-gallery' ); ?></p>
                            </td>
                        </tr>
                        <tr id="envira-config-lightbox-title-display-box">
                            <th scope="row">
                                <label for="envira-config-lightbox-title-display"><?php _e( 'Caption Position', 'envira-gallery' ); ?></label>
                            </th>
                            <td>
                                <select id="envira-config-lightbox-title-display" name="_envira_gallery[title_display]">
                                    <?php foreach ( (array) $this->get_title_displays() as $i => $data ) : ?>
                                        <option value="<?php echo $data['value']; ?>"<?php selected( $data['value'], $this->get_config( 'title_display', $this->get_config_default( 'title_display' ) ) ); ?>><?php echo $data['name']; ?></option>
                                    <?php endforeach; ?>
                                </select>
                                <p class="description"><?php _e( 'Sets the display of the lightbox image\'s caption.', 'envira-gallery' ); ?></p>
                            </td>
                        </tr>

                        <?php do_action( 'envira_gallery_lightbox_box', $post ); ?>
                    </tbody>
                </table>
            </div>
        </div>
        <?php

        // Output an upgrade notice
            Envira_Gallery_Notice_Admin::get_instance()->display_inline_notice(
                'envira_gallery_lightbox_tab',
                __( 'Want even more fine tuned control over your lightbox display?', 'envira-gallery' ),
                __( 'By upgrading to Envira Pro, you can get access to numerous other lightbox features, including: custom lightbox titles, enable/disable lightbox controls (arrow, keyboard and mousehweel navigation), custom lightbox transition effects, native fullscreen support, gallery deeplinking, image protection, lightbox supersize effects, lightbox slideshows and so much more!', 'envira-gallery' ),
                'warning',
                __( 'Click here to Upgrade', 'envira-gallery' ),
                Envira_Gallery_Common_Admin::get_instance()->get_upgrade_link(),
                false
            );

    }

    /**
     * Callback for displaying the settings UI for the Misc tab.
     *
     * @since 1.0.0
     *
     * @param object $post The current post object.
     */
    public function misc_tab( $post ) {

        ?>
        <div id="envira-misc">
            <p class="envira-intro">
                <?php _e( 'Miscellaneous Settings', 'envira-gallery' ); ?>
                <small>
                    <?php _e( 'The settings below adjust miscellaneous options for the Gallery.', 'envira-gallery' ); ?>
                    <br />
                    <?php _e( 'Need some help?', 'envira-gallery' ); ?>
                    <a href="http://enviragallery.com/docs/creating-first-envira-gallery/" class="envira-doc" target="_blank">
                        <?php _e( 'Read the Documentation', 'envira-gallery' ); ?>
                    </a>
                    or
                    <a href="https://www.youtube.com/embed/4jHG3LOmV-c?autoplay=1&amp;rel=0" class="envira-video" target="_blank">
                        <?php _e( 'Watch a Video', 'envira-gallery' ); ?>
                    </a>
                </small>
            </p>
            <table class="form-table">
                <tbody>
                    <tr id="envira-config-title-box">
                        <th scope="row">
                            <label for="envira-config-title"><?php _e( 'Gallery Title', 'envira-gallery' ); ?></label>
                        </th>
                        <td>
                            <input id="envira-config-title" type="text" name="_envira_gallery[title]" value="<?php echo $this->get_config( 'title', $this->get_config_default( 'title' ) ); ?>" />
                            <p class="description"><?php _e( 'Internal gallery title for identification in the admin.', 'envira-gallery' ); ?></p>
                        </td>
                    </tr>
                    <tr id="envira-config-slug-box">
                        <th scope="row">
                            <label for="envira-config-slug"><?php _e( 'Gallery Slug', 'envira-gallery' ); ?></label>
                        </th>
                        <td>
                            <input id="envira-config-slug" type="text" name="_envira_gallery[slug]" value="<?php echo $this->get_config( 'slug', $this->get_config_default( 'slug' ) ); ?>" />
                            <p class="description"><?php _e( '<strong>Unique</strong> internal gallery slug for identification and advanced gallery queries.', 'envira-gallery' ); ?></p>
                        </td>
                    </tr>
                    <tr id="envira-config-classes-box">
                        <th scope="row">
                            <label for="envira-config-classes"><?php _e( 'Custom Gallery Classes', 'envira-gallery' ); ?></label>
                        </th>
                        <td>
                            <textarea id="envira-config-classes" rows="5" cols="75" name="_envira_gallery[classes]" placeholder="<?php _e( 'Enter custom gallery CSS classes here, one per line.', 'envira-gallery' ); ?>"><?php echo implode( "\n", (array) $this->get_config( 'classes', $this->get_config_default( 'classes' ) ) ); ?></textarea>
                            <p class="description"><?php _e( 'Adds custom CSS classes to this gallery. Enter one class per line.', 'envira-gallery' ); ?></p>
                        </td>
                    </tr>
                    <tr id="envira-config-rtl-box">
                        <th scope="row">
                            <label for="envira-config-rtl"><?php _e( 'Enable RTL Support?', 'envira-gallery' ); ?></label>
                        </th>
                        <td>
                            <input id="envira-config-rtl" type="checkbox" name="_envira_gallery[rtl]" value="<?php echo $this->get_config( 'rtl', $this->get_config_default( 'rtl' ) ); ?>" <?php checked( $this->get_config( 'rtl', $this->get_config_default( 'rtl' ) ), 1 ); ?> />
                            <span class="description"><?php _e( 'Enables or disables RTL support in Envira for right-to-left languages.', 'envira-gallery' ); ?></span>
                        </td>
                    </tr>
                    <?php do_action( 'envira_gallery_misc_box', $post ); ?>

                </tbody>
            </table>
        </div>
        <?php
        // Output an upgrade notice
            Envira_Gallery_Notice_Admin::get_instance()->display_inline_notice(
                'envira_gallery_misc_tab',
                __( 'Want to take your galleries further?', 'envira-gallery' ),
                __( 'By upgrading to Envira Pro, you can get access to numerous other features, including: a fully-integrated import/export module for your galleries, custom CSS controls for each gallery and so much more!', 'envira-gallery' ),
                'warning',
                __( 'Click here to Upgrade', 'envira-gallery' ),
                Envira_Gallery_Common_Admin::get_instance()->get_upgrade_link(),
                false
            );

    }

    /**
     * Adds Envira Gallery Lite-specific tabs
     *
     * @since 1.5.0
     *
     * @param   array   $tabs   Tabs
     * @return  array           Tabs
     */
    public function lite_tabs( $tabs ) {

        $tabs['mobile']     = __( 'Mobile', 'envira-gallery' );
        $tabs['videos']     = __( 'Videos', 'envira-gallery' );
        $tabs['social']     = __( 'Social', 'envira-gallery' );
        $tabs['tags']       = __( 'Tags', 'envira-gallery' );
        $tabs['pagination'] = __( 'Pagination', 'envira-gallery' );
        return $tabs;

    }

    /**
     * Callback for displaying the settings UI for the Mobile tab.
     *
     * @since 1.5.0
     *
     * @param object $post The current post object.
     */
    public function lite_mobile_tab( $post ) {

        // Output an upgrade notice
        Envira_Gallery_Notice_Admin::get_instance()->display_inline_notice(
            'envira_gallery_mobile_tab',
            __( 'Want to take your galleries further?', 'envira-gallery' ),
            __( 'By upgrading to Envira Pro, you can get access to mobile-specific settings, including mobile image sizes, number of columns, mobile-specific lightbox options and so much more!', 'envira-gallery' ),
            'warning',
            __( 'Click here to Upgrade', 'envira-gallery' ),
            Envira_Gallery_Common_Admin::get_instance()->get_upgrade_link(),
            false
        );

    }

    /**
     * Lite: Callback for displaying the settings UI for the Mobile tab.
     *
     * @since 1.5.0
     *
     * @param object $post The current post object.
     */
    public function lite_videos_tab( $post ) {

        // Output an upgrade notice
        Envira_Gallery_Notice_Admin::get_instance()->display_inline_notice(
            'envira_gallery_mobile_tab',
            __( 'Want to take your galleries further?', 'envira-gallery' ),
            __( 'By upgrading to Envira Pro, you can add Videos to your Envira Galleries from YouTube, Vimeo, Wistia, and your own self-hosted videos!', 'envira-gallery' ),
            'warning',
            __( 'Click here to Upgrade', 'envira-gallery' ),
            Envira_Gallery_Common_Admin::get_instance()->get_upgrade_link(),
            false
        );

    }

    /**
     * Lite: Callback for displaying the settings UI for the Mobile tab.
     *
     * @since 1.5.0
     *
     * @param object $post The current post object.
     */
    public function lite_social_tab( $post ) {

        // Output an upgrade notice
        Envira_Gallery_Notice_Admin::get_instance()->display_inline_notice(
            'envira_gallery_mobile_tab',
            __( 'Want to take your galleries further?', 'envira-gallery' ),
            __( 'By upgrading to Envira Pro, you can add social sharing buttons to your Gallery images and Lightbox images.  With support for Facebook, Twitter, Google+ and Pinterest why not check it out?', 'envira-gallery' ),
            'warning',
            __( 'Click here to Upgrade', 'envira-gallery' ),
            Envira_Gallery_Common_Admin::get_instance()->get_upgrade_link(),
            false
        );

    }

    /**
     * Lite: Callback for displaying the settings UI for the Mobile tab.
     *
     * @since 1.5.0
     *
     * @param object $post The current post object.
     */
    public function lite_tags_tab( $post ) {

        // Output an upgrade notice
        Envira_Gallery_Notice_Admin::get_instance()->display_inline_notice(
            'envira_gallery_mobile_tab',
            __( 'Want to take your galleries further?', 'envira-gallery' ),
            __( 'By upgrading to Envira Pro, you can add Tags to your Gallery images, allow users to filter your Gallery by tag and so much more!', 'envira-gallery' ),
            'warning',
            __( 'Click here to Upgrade', 'envira-gallery' ),
            Envira_Gallery_Common_Admin::get_instance()->get_upgrade_link(),
            false
        );

    }

    /**
     * Lite: Callback for displaying the settings UI for the Mobile tab.
     *
     * @since 1.5.0
     *
     * @param object $post The current post object.
     */
    public function lite_pagination_tab( $post ) {

        // Output an upgrade notice
        Envira_Gallery_Notice_Admin::get_instance()->display_inline_notice(
            'envira_gallery_mobile_tab',
            __( 'Want to take your galleries further?', 'envira-gallery' ),
            __( 'By upgrading to Envira Pro, you can split your Gallery across multiple pages with pagination, load paginated images via AJAX, lazy loading and more!', 'envira-gallery' ),
            'warning',
            __( 'Click here to Upgrade', 'envira-gallery' ),
            Envira_Gallery_Common_Admin::get_instance()->get_upgrade_link(),
            false
        );

    }

    /**
     * Callback for saving values from Envira metaboxes.
     *
     * @since 1.0.0
     *
     * @param int $post_id The current post ID.
     * @param object $post The current post object.
     */
    public function save_meta_boxes( $post_id, $post ) {

        // Bail out if we fail a security check.
        if ( ! isset( $_POST['envira-gallery'] ) || ! wp_verify_nonce( $_POST['envira-gallery'], 'envira-gallery' ) || ! isset( $_POST['_envira_gallery'] ) ) {
            return;
        }

        // Bail out if running an autosave, ajax, cron or revision.
        if ( defined( 'DOING_AUTOSAVE' ) && DOING_AUTOSAVE ) {
            return;
        }

        if ( defined( 'DOING_AJAX' ) && DOING_AJAX ) {
	        // Check if this is a Quick Edit request
	        if ( isset( $_POST['_inline_edit'] ) ) {

		        // Just update specific fields in the Quick Edit screen

		        // Get settings
		        $settings = get_post_meta( $post_id, '_eg_gallery_data', true );
		        if ( empty( $settings ) ) {
			        return;
		        }

				// Update Settings
	        	$settings['config']['columns']             = preg_replace( '#[^a-z0-9-_]#', '', $_POST['_envira_gallery']['columns'] );
                $settings['config']['gallery_theme']       = preg_replace( '#[^a-z0-9-_]#', '', $_POST['_envira_gallery']['gallery_theme'] );
                $settings['config']['justified_gallery_theme'] = preg_replace( '#[^a-z0-9-_]#', '', $_POST['_envira_gallery']['justified_gallery_theme'] );
                $settings['config']['gutter']              = absint( $_POST['_envira_gallery']['gutter'] );
                $settings['config']['margin']              = absint( $_POST['_envira_gallery']['margin'] );
                $settings['config']['crop_width']          = absint( $_POST['_envira_gallery']['crop_width'] );
                $settings['config']['crop_height']         = absint( $_POST['_envira_gallery']['crop_height'] );

		        // Provide a filter to override settings.
				$settings = apply_filters( 'envira_gallery_quick_edit_save_settings', $settings, $post_id, $post );

				// Update the post meta.
				update_post_meta( $post_id, '_eg_gallery_data', $settings );

				// Finally, flush all gallery caches to ensure everything is up to date.
                Envira_Gallery_Common::get_instance()->flush_gallery_caches( $post_id, $settings['config']['slug'] );

	        }

            return;
        }

        if ( defined( 'DOING_CRON' ) && DOING_CRON ) {
            return;
        }

        if ( wp_is_post_revision( $post_id ) ) {
            return;
        }

        // Bail out if the user doesn't have the correct permissions to update the slider.
        if ( ! current_user_can( 'edit_post', $post_id ) ) {
            return;
        }

        // If the post has just been published for the first time, set meta field for the gallery meta overlay helper.
        if ( isset( $post->post_date ) && isset( $post->post_modified ) && $post->post_date === $post->post_modified ) {
            update_post_meta( $post_id, '_eg_just_published', true );
        }

        // Sanitize all user inputs.
        $settings = get_post_meta( $post_id, '_eg_gallery_data', true );
        if ( empty( $settings ) ) {
            $settings = array();
        }

        // Force slider ID to match Post ID. This is deliberate; if a gallery is duplicated (either using a duplication)
        // plugin or WPML, the ID remains as the original gallery ID, which breaks things for translations etc.
        $settings['id'] = $post_id;

        // Config
        $settings['config']['type']                = isset( $_POST['_envira_gallery']['type'] ) ? $_POST['_envira_gallery']['type'] : $this->get_config_default( 'type' );
        $settings['config']['columns']             = preg_replace( '#[^a-z0-9-_]#', '', $_POST['_envira_gallery']['columns'] );
        $settings['config']['gallery_theme']       = preg_replace( '#[^a-z0-9-_]#', '', $_POST['_envira_gallery']['gallery_theme'] );
        $settings['config']['justified_gallery_theme'] = preg_replace( '#[^a-z0-9-_]#', '', $_POST['_envira_gallery']['justified_gallery_theme'] );
        $settings['config']['gutter']              = absint( $_POST['_envira_gallery']['gutter'] );
        $settings['config']['margin']              = absint( $_POST['_envira_gallery']['margin'] );
        $settings['config']['image_size']          = sanitize_text_field( esc_attr ( $_POST['_envira_gallery']['image_size'] ) );
        $settings['config']['crop_width']          = absint( $_POST['_envira_gallery']['crop_width'] ) > 0 ? absint( $_POST['_envira_gallery']['crop_width'] ) : $this->get_config_default( 'crop_width' );
        $settings['config']['crop_height']         = absint( $_POST['_envira_gallery']['crop_height'] ) > 0 ? absint( $_POST['_envira_gallery']['crop_height'] ) : $this->get_config_default( 'crop_height' );
        $settings['config']['crop']                = isset( $_POST['_envira_gallery']['crop'] ) ? 1 : 0;
        $settings['config']['lazy_loading']        = isset( $_POST['_envira_gallery']['lazy_loading'] ) ? 1 : 0;
        $settings['config']['lazy_loading_delay']  = absint( $_POST['_envira_gallery']['lazy_loading_delay'] );

        // Automatic/Justified
        $settings['config']['justified_row_height'] = isset( $_POST['_envira_gallery']['justified_row_height'] ) ? absint($_POST['_envira_gallery']['justified_row_height'] ) : 150;

        // Lightbox
        $settings['config']['lightbox_enabled']    = isset( $_POST['_envira_gallery']['lightbox_enabled'] ) ? 1 : 0;
        $settings['config']['lightbox_theme']      = preg_replace( '#[^a-z0-9-_]#', '', $_POST['_envira_gallery']['lightbox_theme'] );
        $settings['config']['lightbox_image_size'] = preg_replace( '#[^a-z0-9-_]#', '', $_POST['_envira_gallery']['lightbox_image_size'] );
        $settings['config']['title_display']       = preg_replace( '#[^a-z0-9-_]#', '', $_POST['_envira_gallery']['title_display'] );

        // Misc
        $settings['config']['classes']             = explode( "\n", $_POST['_envira_gallery']['classes'] );
        $settings['config']['rtl']                 = isset( $_POST['_envira_gallery']['rtl'] ) ? 1 : 0;
        $settings['config']['title']               = trim( strip_tags( $_POST['_envira_gallery']['title'] ) );
        $settings['config']['slug']                = sanitize_text_field( esc_attr( $_POST['_envira_gallery']['slug'] ) );

        // If on an envira post type, map the title and slug of the post object to the custom fields if no value exists yet.
        if ( isset( $post->post_type ) && 'envira' == $post->post_type ) {
            if ( empty( $settings['config']['title'] ) ) {
                $settings['config']['title'] = trim( strip_tags( $post->post_title ) );
            }
            if ( empty( $settings['config']['slug'] ) ) {
                $settings['config']['slug']  = sanitize_text_field( $post->post_name );
            }
        }

        // Provide a filter to override settings.
        $settings = apply_filters( 'envira_gallery_save_settings', $settings, $post_id, $post );

        // Update the post meta.
        update_post_meta( $post_id, '_eg_gallery_data', $settings );

        // Change states of images in gallery from pending to active.
        $this->change_gallery_states( $post_id );

        // If the thumbnails option is checked, crop images accordingly.
        if ( isset( $settings['config']['thumbnails'] ) && $settings['config']['thumbnails'] ) {
            $args = array(
                'position' => 'c',
                'width'    => $this->get_config( 'thumbnails_width', $this->get_config_default( 'thumbnails_width' ) ),
                'height'   => $this->get_config( 'thumbnails_height', $this->get_config_default( 'thumbnails_height' ) ),
                'quality'  => 100,
                'retina'   => false
            );
            $args = apply_filters( 'envira_gallery_crop_image_args', $args );
            $this->crop_thumbnails( $args, $post_id );
        }

        // If the crop option is checked, crop images accordingly.
        if ( isset( $settings['config']['crop'] ) && $settings['config']['crop'] ) {
            $args = array(
                'position' => 'c',
                'width'    => $this->get_config( 'crop_width', $this->get_config_default( 'crop_width' ) ),
                'height'   => $this->get_config( 'crop_height', $this->get_config_default( 'crop_height' ) ),
                'quality'  => 100,
                'retina'   => false
            );
            $args = apply_filters( 'envira_gallery_crop_image_args', $args );
            $this->crop_images( $args, $post_id );
        }

        // If the mobile option is checked, crop images accordingly.
        if ( isset( $settings['config']['mobile'] ) && $settings['config']['mobile'] ) {
            $args = array(
                'position' => 'c',
                'width'    => $this->get_config( 'mobile_width', $this->get_config_default( 'mobile_width' ) ),
                'height'   => $this->get_config( 'mobile_height', $this->get_config_default( 'mobile_height' ) ),
                'quality'  => 100,
                'retina'   => false
            );
            $args = apply_filters( 'envira_gallery_crop_image_args', $args );
            $this->crop_images( $args, $post_id );
        }

        // Fire a hook for addons that need to utilize the cropping feature.
        do_action( 'envira_gallery_saved_settings', $settings, $post_id, $post );

        // Finally, flush all gallery caches to ensure everything is up to date.
        Envira_Gallery_Common::get_instance()->flush_gallery_caches( $post_id, $settings['config']['slug'] );

    }

    /**
     * Helper method for retrieving the gallery layout for an item in the admin.
     *
     * Also defines the item's model which is used in assets/js/media-edit.js
     *
     * @since 1.0.0
     *
     * @param int       $id         The ID of the item to retrieve.
     * @param array     $item       The item data (i.e. image / video).
     * @param int       $post_id    The current post ID.
     * @return string               The HTML output for the gallery item.
     */
    public function get_gallery_item( $id, $item, $post_id = 0 ) {

        // Get thumbnail
        $thumbnail = wp_get_attachment_image_src( $id, 'thumbnail' );

        // Add id to $item for Backbone model
        $item['id'] = $id;

        // Allow addons to populate the item's data - for example, tags which are stored against the attachment
        $item = apply_filters( 'envira_gallery_get_gallery_item', $item, $id, $post_id );
        $item['alt'] = str_replace( "&quot;", '\"', $item['alt'] );
        $item['_thumbnail'] = $thumbnail[0]; // Never saved against the gallery item, just used for the thumbnail output in the Edit Gallery screen.

        // JSON encode based on PHP version.
        $json = version_compare( PHP_VERSION, '5.3.0' ) >= 0 ? json_encode( $item, JSON_HEX_APOS ) : json_encode( $item );

        // Buffer the output
        ob_start();
        ?>
        <li id="<?php echo $id; ?>" class="envira-gallery-image envira-gallery-status-<?php echo $item['status']; ?>" data-envira-gallery-image="<?php echo $id; ?>" data-envira-gallery-image-model='<?php echo htmlspecialchars( $json, ENT_QUOTES, 'UTF-8' ); ?>'>
            <img src="<?php echo esc_url( $item['_thumbnail'] ); ?>" alt="<?php esc_attr_e( $item['alt'] ); ?>" />
            <div class="meta">
                <div class="title">
                    <span>
                        <?php
                        // Output Title.
                        echo ( isset( $item['title'] ) ? $item['title'] : '' );

                        // If the title exceeds 20 characters, the grid view will deliberately only show the first line of the title.
                        // Therefore we need to make it clear to the user that the full title is there by way of a hint.
                        ?>
                    </span>
                    <a class="hint <?php echo ( ( strlen( $item['title'] ) > 20 ) ? '' : ' hidden' ); ?>" title="<?php echo ( isset( $item['title'] ) ? $item['title'] : '' ); ?>">...</a>
                </div>
                <div class="additional">
                    <?php
                    // Addons can add content to this meta section, which is displayed when in the List View.
                    echo apply_filters( 'envira_gallery_metabox_output_gallery_item_meta', '', $item, $id, $post_id );
                    ?>
                </div>
            </div>

            <a href="#" class="check"><div class="media-modal-icon"></div></a>
            <a href="#" class="dashicons dashicons-trash envira-gallery-remove-image" title="<?php _e( 'Remove Image from Gallery?', 'envira-gallery' ); ?>"></a>
            <a href="#" class="dashicons dashicons-edit envira-gallery-modify-image" title="<?php _e( 'Modify Image', 'envira-gallery' ); ?>"></a>
        </li>
        <?php
        return ob_get_clean();

    }

    /**
     * Helper method to change a gallery state from pending to active. This is done
     * automatically on post save. For previewing galleries before publishing,
     * simply click the "Preview" button and Envira will load all the images present
     * in the gallery at that time.
     *
     * @since 1.0.0
     *
     * @param int $id The current post ID.
     */
    public function change_gallery_states( $post_id ) {

        $gallery_data = get_post_meta( $post_id, '_eg_gallery_data', true );
        if ( ! empty( $gallery_data['gallery'] ) ) {
            foreach ( (array) $gallery_data['gallery'] as $id => $item ) {
                $gallery_data['gallery'][ $id ]['status'] = 'active';
            }
        }

        update_post_meta( $post_id, '_eg_gallery_data', $gallery_data );

    }

    /**
     * Helper method to crop gallery thumbnails to the specified sizes.
     *
     * @since 1.0.0
     *
     * @param array $args  Array of args used when cropping the images.
     * @param int $post_id The current post ID.
     * @param bool $force_overwrite Forces an overwrite even if the thumbnail already exists (useful for applying watermarks)
     */
    public function crop_thumbnails( $args, $post_id, $force_overwrite = false ) {

        // Gather all available images to crop.
        $gallery_data = get_post_meta( $post_id, '_eg_gallery_data', true );
        $images       = ! empty( $gallery_data['gallery'] ) ? $gallery_data['gallery'] : false;
        $common       = Envira_Gallery_Common::get_instance();

        // Populate variable if we are using <= PHP 5.3
        $php_version = explode('.', phpversion() );

        if ( $php_version[0] <= 5 && $php_version[1] <= 3 ) {
            $is_using_old_php = true;
        } else {
            $is_using_old_php = false;
        }

        // Loop through the images and crop them.
        if ( $images ) {
            // Increase the time limit to account for large image sets and suspend cache invalidations.
            if ( ! $is_using_old_php ) {
                set_time_limit( Envira_Gallery_Common::get_instance()->get_max_execution_time() );
            } else if ( $is_using_old_php && ! ini_get( 'safe_mode' ) ) {
                set_time_limit( Envira_Gallery_Common::get_instance()->get_max_execution_time() );
            }
            wp_suspend_cache_invalidation( true );

            foreach ( $images as $id => $item ) {
                // Get the full image attachment. If it does not return the data we need, skip over it.
                $image = wp_get_attachment_image_src( $id, 'full' );

                if ( ! is_array( $image ) ) {
                    continue;
                }

                // Check the image is a valid URL
                // Some plugins decide to strip the blog's URL from the start of the URL, which can cause issues for Envira
                if ( strpos( $image[0], get_bloginfo( 'url' ) ) === false ) {
                    $image[0] = get_bloginfo( 'url' ) . '/' . $image[0];
                }

                // Generate the cropped image.
                $cropped_image = $common->resize_image( $image[0], $args['width'], $args['height'], true, $args['position'], $args['quality'], $args['retina'], null, $force_overwrite );

                // If there is an error, possibly output error message, otherwise woot!
                if ( is_wp_error( $cropped_image ) ) {
                    // If WP_DEBUG is enabled, and we're logged in, output an error to the user
                    if ( defined( 'WP_DEBUG' ) && WP_DEBUG && is_user_logged_in() ) {
                        echo '<pre>Envira: Error occured resizing image (these messages are only displayed to logged in WordPress users):<br />';
                        echo 'Error: ' . $cropped_image->get_error_message() . '<br />';
                        echo 'Image: ' . var_export( $image, true ) . '<br />';
                        echo 'Args: ' . var_export( $args, true ) . '</pre>';
                        die();
                    }
                } else {
                    $gallery_data['gallery'][ $id ]['thumb'] = $cropped_image;
                }
            }

            // Turn off cache suspension and flush the cache to remove any cache inconsistencies.
            wp_suspend_cache_invalidation( false );
            wp_cache_flush();

            // Update the gallery data.
            update_post_meta( $post_id, '_eg_gallery_data', $gallery_data );
        }

    }

    /**
     * Helper method to crop gallery images to the specified sizes.
     *
     * @since 1.0.0
     *
     * @param array $args  Array of args used when cropping the images.
     * @param int $post_id The current post ID.
     * @param bool $force_overwrite Forces an overwrite even if the thumbnail already exists (useful for applying watermarks)
     */
    public function crop_images( $args, $post_id, $force_overwrite = false ) {

        // Gather all available images to crop.
        $gallery_data = get_post_meta( $post_id, '_eg_gallery_data', true );
        $images       = ! empty( $gallery_data['gallery'] ) ? $gallery_data['gallery'] : false;
        $common       = Envira_Gallery_Common::get_instance();

        // Populate variable if we are using <= PHP 5.3
        $php_version = explode('.', phpversion() );

        if ( $php_version[0] <= 5 && $php_version[1] <= 3 ) {
            $is_using_old_php = true;
        } else {
            $is_using_old_php = false;
        }

        // Loop through the images and crop them.
        if ( $images ) {
            // Increase the time limit to account for large image sets and suspend cache invalidations.
            if ( ! $is_using_old_php ) {
                set_time_limit( Envira_Gallery_Common::get_instance()->get_max_execution_time() );
            } else if ( $is_using_old_php && ! ini_get( 'safe_mode' ) ) {
                set_time_limit( Envira_Gallery_Common::get_instance()->get_max_execution_time() );
            }
            wp_suspend_cache_invalidation( true );

            foreach ( $images as $id => $item ) {
                // Get the full image attachment. If it does not return the data we need, skip over it.
                $image = wp_get_attachment_image_src( $id, 'full' );
                if ( ! is_array( $image ) ) {
                    continue;
                }

                // Check the image is a valid URL
                // Some plugins decide to strip the blog's URL
                if ( ! filter_var( $image[0], FILTER_VALIDATE_URL ) ) {
                    $image[0] = get_bloginfo( 'url' ) . '/' . $image[0];
                }

                // Generate the cropped image.
                $cropped_image = $common->resize_image( $image[0], $args['width'], $args['height'], true, $args['position'], $args['quality'], $args['retina'], null, $force_overwrite );

                // If there is an error, possibly output error message, otherwise woot!
                if ( is_wp_error( $cropped_image ) ) {
                    // If debugging is defined, print out the error.
                    if ( defined( 'ENVIRA_GALLERY_CROP_DEBUG' ) && ENVIRA_GALLERY_CROP_DEBUG ) {
                        echo '<pre>' . var_export( $cropped_image->get_error_message(), true ) . '</pre>';
                    }
                }
            }

            // Turn off cache suspension and flush the cache to remove any cache inconsistencies.
            wp_suspend_cache_invalidation( false );
            wp_cache_flush();
        }

    }

    /**
     * Helper method for retrieving config values.
     *
     * @since 1.0.0
     *
     * @global int $id        The current post ID.
     * @global object $post   The current post object.
     * @param string $key     The config key to retrieve.
     * @param string $default A default value to use.
     * @return string         Key value on success, empty string on failure.
     */
    public function get_config( $key, $default = false ) {

        global $id, $post;

        // Get the current post ID. If ajax, grab it from the $_POST variable.
        if ( defined( 'DOING_AJAX' ) && DOING_AJAX && array_key_exists( 'post_id', $_POST ) ) {
            $post_id = absint( $_POST['post_id'] );
        } else {
            $post_id = isset( $post->ID ) ? $post->ID : (int) $id;
        }

        // Get config
        $settings = get_post_meta( $post_id, '_eg_gallery_data', true );

        // Check config key exists
        if ( isset( $settings['config'][ $key ] ) ) {
            return $settings['config'][ $key ];
        } else {
            return $default ? $default : '';
        }

    }

    /**
     * Helper method for setting default config values.
     *
     * @since 1.0.0
     *
     * @param string $key The default config key to retrieve.
     * @return string Key value on success, false on failure.
     */
    public function get_config_default( $key ) {

        $instance = Envira_Gallery_Common::get_instance();
        return $instance->get_config_default( $key );

    }

    /**
     * Helper method for retrieving columns.
     *
     * @since 1.0.0
     *
     * @return array Array of column data.
     */
    public function get_columns() {

        $instance = Envira_Gallery_Common::get_instance();
        return $instance->get_columns();

    }

    /**
     * Helper method for retrieving gallery themes.
     *
     * @since 1.0.0
     *
     * @return array Array of gallery theme data.
     */
    public function get_gallery_themes() {

        $instance = Envira_Gallery_Common::get_instance();
        return $instance->get_gallery_themes();

    }

    /**
     * Helper method for retrieving justified gallery themes.
     *
     * @since 1.1.1
     *
     * @return array Array of gallery theme data.
     */
    public function get_justified_gallery_themes() {

        $instance = Envira_Gallery_Common::get_instance();
        return $instance->get_justified_gallery_themes();

    }

    /**
     * Helper method for retrieving description options.
     *
     * @since 1.0.0
     *
     * @return array Array of description options.
     */
    public function get_display_description_options() {

        $instance = Envira_Gallery_Common::get_instance();
        return $instance->get_display_description_options();

    }

    /**
     * Helper method for retrieving sorting options.
     *
     * @since 1.3.8
     *
     * @return array Array of sorting options.
     */
    public function get_sorting_options() {

        $instance = Envira_Gallery_Common::get_instance();
        return $instance->get_sorting_options();

    }

    /**
     * Helper method for retrieving sorting directions.
     *
     * @since 1.3.8
     *
     * @return array Array of sorting directions.
     */
    public function get_sorting_directions() {

        $instance = Envira_Gallery_Common::get_instance();
        return $instance->get_sorting_directions();

    }

    /**
     * Helper method for retrieving lightbox themes.
     *
     * @since 1.0.0
     *
     * @return array Array of lightbox theme data.
     */
    public function get_lightbox_themes() {

        $instance = Envira_Gallery_Common::get_instance();
        return $instance->get_lightbox_themes();

    }

    /**
     * Helper method for retrieving image sizes.
     *
     * @since 1.3.6
     *
     * @param   bool    $wordpress_only     WordPress Only image sizes (default: false)
     * @return array Array of image size data.
     */
    public function get_image_sizes( $wordpress_only = false ) {

        $instance = Envira_Gallery_Common::get_instance();
        return $instance->get_image_sizes( $wordpress_only );

    }

    /**
     * Helper method for retrieving title displays.
     *
     * @since 1.0.0
     *
     * @return array Array of title display data.
     */
    public function get_title_displays() {

        $instance = Envira_Gallery_Common::get_instance();
        return $instance->get_title_displays();

    }

    /**
     * Helper method for retrieving arrow positions.
     *
     * @since 1.3.3.7
     *
     * @return array Array of title display data.
     */
    public function get_arrows_positions() {

        $instance = Envira_Gallery_Common::get_instance();
        return $instance->get_arrows_positions();

    }

    /**
     * Helper method for retrieving toolbar positions.
     *
     * @since 1.0.0
     *
     * @return array Array of toolbar position data.
     */
    public function get_toolbar_positions() {

        $instance = Envira_Gallery_Common::get_instance();
        return $instance->get_toolbar_positions();

    }

    /**
     * Helper method for retrieving lightbox transition effects.
     *
     * @since 1.0.0
     *
     * @return array Array of transition effect data.
     */
    public function get_transition_effects() {

        $instance = Envira_Gallery_Common::get_instance();
        return $instance->get_transition_effects();

    }

    /**
     * Helper method for retrieving lightbox easing transition effects.
     *
     * @since 1.4.1.2
     *
     * @return array Array of transition effect data.
     */
    public function get_easing_transition_effects() {

        $instance = Envira_Gallery_Common::get_instance();
        return $instance->get_easing_transition_effects();

    }

    /**
     * Helper method for retrieving thumbnail positions.
     *
     * @since 1.0.0
     *
     * @return array Array of thumbnail position data.
     */
    public function get_thumbnail_positions() {

        $instance = Envira_Gallery_Common::get_instance();
        return $instance->get_thumbnail_positions();

    }

    /**
     * Returns the post types to skip for loading Envira metaboxes.
     *
     * @since 1.0.7
     *
     * @return array Array of skipped posttypes.
     */
    public function get_skipped_posttypes() {

        $skipped_posttypes = array( 'attachment', 'revision', 'nav_menu_item', 'soliloquy', 'soliloquyv2', 'envira_album' );
        return apply_filters( 'envira_gallery_skipped_posttypes', $skipped_posttypes );

    }

    /**
     * Flag to determine if the GD library has been compiled.
     *
     * @since 1.0.0
     *
     * @return bool True if has proper extension, false otherwise.
     */
    public function has_gd_extension() {

        return extension_loaded( 'gd' ) && function_exists( 'gd_info' );

    }

    /**
     * Flag to determine if the Imagick library has been compiled.
     *
     * @since 1.0.0
     *
     * @return bool True if has proper extension, false otherwise.
     */
    public function has_imagick_extension() {

        return extension_loaded( 'imagick' );

    }

    /**
     * Returns the singleton instance of the class.
     *
     * @since 1.0.0
     *
     * @return object The Envira_Gallery_Metaboxes object.
     */
    public static function get_instance() {

        if ( ! isset( self::$instance ) && ! ( self::$instance instanceof Envira_Gallery_Metaboxes ) ) {
            self::$instance = new Envira_Gallery_Metaboxes();
        }

        return self::$instance;

    }

}

// Load the metabox class.
$envira_gallery_metaboxes = Envira_Gallery_Metaboxes::get_instance();