dynamic_background.module in Dynamic Background 6

This module enables administrators to upload images used as background on the site. The selected background image link is exposed as either $background in the page.tpl file or as /background.css.

File

dynamic_background.module

<?php

/**
 * @file
 * This module enables administrators to upload images used as background on
 * the site. The selected background image link is exposed as either $background
 * in the page.tpl file or as /background.css.
 *
 */

// Get the upload form element
module_load_include('inc', 'dynamic_background', 'includes/upload.form');

/**
 * Implementation of hook_perm().
 */
function dynamic_background_perm() {
  return array(
    'configure dynamic backgrounds',
    'set dynamic backgrounds',
    'dynamic backgrounds css',
  );
}

/**
 * Implementation of hook_menu().
 */
function dynamic_background_menu() {
  $items = array();
  $items['admin/build/backgrounds'] = array(
    'title' => 'Dynamic background',
    'description' => t('Upload background images.'),
    'page callback' => 'drupal_get_form',
    'page arguments' => array(
      'dynamic_background_admin_images',
    ),
    'access arguments' => array(
      'set dynamic backgrounds',
    ),
    'file' => 'includes/backgrounds.admin.inc',
  );
  $items['admin/build/backgrounds/images'] = array(
    'title' => 'Background images',
    'description' => t('Upload background images and select current active background.'),
    'type' => MENU_DEFAULT_LOCAL_TASK,
    'weight' => -10,
  );
  $items['admin/build/backgrounds/settings'] = array(
    'title' => 'Settings',
    'description' => t('Configure dynamic backgrounds settings'),
    'page callback' => 'drupal_get_form',
    'page arguments' => array(
      'dynamic_background_admin_settings',
    ),
    'access arguments' => array(
      'configure dynamic backgrounds',
    ),
    'type' => MENU_LOCAL_TASK,
    'weight' => -5,
    'file' => 'includes/settings.admin.inc',
  );
  $items['background.css'] = array(
    'page callback' => 'dynamic_background_css',
    'access arguments' => array(
      'dynamic backgrounds css',
    ),
    'type' => MENU_CALLBACK,
  );
  return $items;
}

/**
 * Helper function that creates CSS based on user supplied css.
 *
 * @param array $images_conf
 * @param boolean $reset optional
 * @return string $css or FALSE if custom CSS have not been defined
 */
function dynamic_background_create_css($images_conf, $reset = FALSE) {
  static $css;
  if (!isset($css) || $reset) {

    // Build style array based on weight, this will allow weight base override
    // at the same time allowing different selectors.
    $style_array = array();
    foreach ($images_conf as $image_conf) {

      // Only use image if css behaviour have be set.
      if (!empty($image_conf['configuration'])) {

        // Add imagecache preset, if one have been defined.
        $image = $image_conf['image'];
        if (isset($image_conf['imagecache']) && $image_conf['imagecache']) {

          // Imagecache preset found, so update the image path with a
          // imagecache based one.
          $image = imagecache_create_path($image_conf['imagecache'], $image);
        }

        // Check if selector have been used, if it have and has a higher weight
        // override it.
        if (isset($style_array[$image_conf['configuration']['selector']])) {
          if ($style_array[$image_conf['configuration']['selector']]['weight'] < $image_conf['weight']) {

            // This css selector have been used before and the new whan was
            // fater, so override the select in the style array.
            $style_array[$image_conf['configuration']['selector']] = array(
              'css' => $image_conf['configuration']['css'],
              'image' => $image,
              'weight' => $image_conf['weight'],
            );
          }
        }
        else {

          // This selector have not been used before, so add it to the array.
          $style_array[$image_conf['configuration']['selector']] = array(
            'css' => $image_conf['configuration']['css'],
            'image' => $image,
            'weight' => $image_conf['weight'],
          );
        }
      }
    }

    // Build css based on weighted style array.
    $css = '';
    foreach ($style_array as $selector => $style) {
      $css .= $selector . " {\n        background-image: url('" . file_create_url($style['image']) . "');\n        " . $style['css'] . "\n      }\n";
    }
  }
  return $css;
}

/**
 * Page preprocess function used to create the $background variable, so it
 * can be used in page.tpl.
 *
 */
function dynamic_background_preprocess_page(&$vars) {

  // Load image configuration.
  $images_conf = dynamic_background_load_image_configuration($vars);

  // Generate the css and add it to the site.
  if (isset($images_conf)) {
    $css = dynamic_background_create_css($images_conf);
    if ($css) {
      $vars['styles'] .= '<style type="text/css">' . $css . '</style>';
    }
    $image = array_pop($images_conf);
    $vars['background'] = 'style="background-image: url(\'' . file_create_url($image['image']) . '\')"';
  }
}

/**
 * Menu callback function used to generate an body style css with the selected
 * background image. The callback is /background.css.
 */
function dynamic_background_css() {

  // Load image configuration.
  $images_conf = dynamic_background_load_image_configuration($vars);

  // Generate the css and add it to the site.
  if (isset($images_conf)) {
    $css = dynamic_background_create_css($images_conf);
    if ($css) {
      echo $css;
    }
  }
}

/**
 * Implementation of hook_dynamic_background_css().
 */
function dynamic_background_dynamic_background_css($vars) {
  $image = variable_get('dynamic_background_active', FALSE);
  $imagecache = variable_get('dynamic_background_imagecache', FALSE);
  if ($image) {
    return array(
      'image' => $image,
      'configuration' => variable_get('dynamic_background_css', array()),
      'imagecache' => $imagecache ? $imagecache['present'] : FALSE,
      'weight' => 200,
    );
  }
}

/**
 * Builds the CSS behaviour part of the form, this should be used by every
 * sub-module. The parameter is the variable name in which the css behaviour is
 * stored.
 *
 * @param string $form_key
 * @return array $form
 */
function dynamic_background_css_behaviour_form($form_key) {
  $form = array();

  // Add CSS behaviour options
  $default = variable_get($form_key, array());
  $form[$form_key] = array(
    '#type' => 'fieldset',
    '#title' => t('CSS behaviour'),
    '#collapsed' => FALSE,
    '#collapsible' => TRUE,
    '#tree' => TRUE,
  );
  $form[$form_key]['selector'] = array(
    '#type' => 'textfield',
    '#title' => t('CSS selector'),
    '#required' => TRUE,
    '#description' => t('The CSS selector string to target with the background image e.g. body #container.'),
    '#default_value' => isset($default['selector']) ? $default['selector'] : '',
  );
  $form[$form_key]['css'] = array(
    '#type' => 'textarea',
    '#title' => t('CSS'),
    '#description' => t('The CSS to insert with the background image e.g background-size: cover;.'),
    '#default_value' => isset($default['css']) ? $default['css'] : '',
  );
  return $form;
}

/**
 * Build the imagecahce present selection form, which can be used in sub-modules
 * to add support for image manipulation.
 *
 * @param type $form_key
 * @return type
 */
function dynamic_background_image_presents_form($form_key) {
  $form = array();
  $form[$form_key] = array(
    '#type' => 'fieldset',
    '#title' => t('Imagecache preset'),
    '#description' => 'You can apply differect effects to your background image using imagecahce presets. If you don\'t want to add effects to the selected background image, just select "No preset".',
    '#collapsed' => FALSE,
    '#collapsible' => TRUE,
    '#tree' => TRUE,
  );

  // Get imagechache presets information, there will a least be one as this
  // module have implemented on for background image thumbnails.
  $options = array(
    0 => t('No preset'),
  );
  $presets = imagecache_presets(TRUE);
  foreach ($presets as $id => $preset) {
    $options[$preset['presetname']] = $preset['presetname'];
  }

  // Load default form values (current selected image present)
  $default = variable_get($form_key, array());
  $form[$form_key]['present'] = array(
    '#type' => 'select',
    '#title' => t('Choose a preset to apply to background images.'),
    '#description' => t('To create am imagecache preset, go to <a href="@url">image cache settings</a>.', array(
      '@url' => '/admin/build/imagecache/list',
    )),
    '#options' => $options,
    '#default_value' => isset($default['present']) ? $default['present'] : 0,
  );
  return $form;
}

/**
 * Helper function that calls hook_dynamic_background_css() and sorts the
 * returned image configurations based on weight. This function may be called
 * by more then one preprocessor function, so a static cache applied.
 *
 * @staticvar type $images
 * @param type $reset
 * @return type
 */
function dynamic_background_load_image_configuration(&$vars, $reset = FALSE) {
  static $images;
  if (!isset($images) || $reset) {

    // If images is null, create empty array (as no images may be selected).
    if (is_null($images)) {
      $images = array();
    }

    // Implementation of hook_dynamic_background_css().
    foreach (module_implements('dynamic_background_css') as $module) {
      $function = $module . '_dynamic_background_css';
      $result = $function($vars);
      if ($result && is_array($result)) {
        $images[$module] = $result;
      }
    }

    // Sort images based on weight and get images with highest weight.
    usort($images, '_dynamic_background_cmp');
  }
  return $images;
}

/**
 * Helper function to sort image configuration arrays based on module weight.
 *
 * @param array $a
 * @param array $b
 * @return int
 */
function _dynamic_background_cmp($a, $b) {
  if ($a['weight'] == $b['weight']) {
    return 0;
  }
  return $a['weight'] < $b['weight'] ? -1 : 1;
}

/**
 * Builds image selection part of a form to be used by sub-moduels, where the
 * user may select background images.
 *
 * @param int $selected_image_id
 * @return array $form
 */
function dynamic_background_image_selector_form($selected_image_id) {
  $form = array(
    '#tree' => TRUE,
  );

  // Get all uploaded images
  $images = variable_get('dynamic_background_images', array());
  foreach ($images as $id => $image) {
    if (!empty($image['default'])) {

      // Create image thumbnail.
      $picture = theme('imagecache', 'dynamic_background_thumb', $image['default'], basename($image['default']), basename($image['default']), NULL);
      $form[$id]['image'] = array(
        '#value' => $picture,
        '#prefix' => '<div class="dynamic-background-picture">',
      );
      $form[$id]['selected'] = array(
        '#type' => 'checkbox',
        '#title' => t('Use background'),
        '#default_value' => !is_null($selected_image_id) && $id == $selected_image_id ? 1 : 0,
        '#suffix' => '</div>',
      );
    }
  }

  // Add some default styling to the image selector.
  drupal_add_css(drupal_get_path('module', 'dynamic_background') . '/css/dynamic_background.theme.css', 'module');
  drupal_add_js(drupal_get_path('module', 'dynamic_background') . '/js/dynamic_background_selector.js', 'file');
  return $form;
}

Functions

Name	Description
dynamic_background_create_css	Helper function that creates CSS based on user supplied css.
dynamic_background_css	Menu callback function used to generate an body style css with the selected background image. The callback is /background.css.
dynamic_background_css_behaviour_form	Builds the CSS behaviour part of the form, this should be used by every sub-module. The parameter is the variable name in which the css behaviour is stored.
dynamic_background_dynamic_background_css	Implementation of hook_dynamic_background_css().
dynamic_background_image_presents_form	Build the imagecahce present selection form, which can be used in sub-modules to add support for image manipulation.
dynamic_background_image_selector_form	Builds image selection part of a form to be used by sub-moduels, where the user may select background images.
dynamic_background_load_image_configuration	Helper function that calls hook_dynamic_background_css() and sorts the returned image configurations based on weight. This function may be called by more then one preprocessor function, so a static cache applied.
dynamic_background_menu	Implementation of hook_menu().
dynamic_background_perm	Implementation of hook_perm().
dynamic_background_preprocess_page	Page preprocess function used to create the $background variable, so it can be used in page.tpl.
_dynamic_background_cmp	Helper function to sort image configuration arrays based on module weight.