picture_background_formatter.module in Picture Background Formatter 7

Hooks and functions for the Picture Background Formatter module.

File

picture_background_formatter.module

<?php

/**
 * @file
 * Hooks and functions for the Picture Background Formatter module.
 */

/**
 * Implements hook_field_formatter_info().
 */
function picture_background_formatter_field_formatter_info() {
  $formatters = array();
  $mappings = array_keys(picture_get_mapping_options());
  if ($mappings) {
    $formatters['picture_background_formatter'] = array(
      'label' => t('Picture Background Formatter'),
      'field types' => array(
        'image',
      ),
      'settings' => array(
        'picture_mapping' => reset($mappings),
        'selector' => '',
      ),
    );
  }
  return $formatters;
}

/**
 * Implements hook_field_formatter_settings_form().
 */
function picture_background_formatter_field_formatter_settings_form($field, $instance, $view_mode, $form, &$form_state) {
  $display = $instance['display'][$view_mode];
  $settings = $display['settings'];
  $options = picture_get_mapping_options();
  if ($options) {
    $element['picture_mapping'] = array(
      '#title' => t('Picture mapping'),
      '#type' => 'select',
      '#default_value' => isset($settings['picture_mapping']) ? $settings['picture_mapping'] : '',
      '#required' => TRUE,
      '#options' => picture_get_mapping_options(),
    );
    $element['selector'] = array(
      '#type' => 'textfield',
      '#title' => t('Selector'),
      '#description' => t('CSS Selector for background image.'),
      '#default_value' => $settings['selector'],
    );
  }
  else {
    $element['picture_mapping'] = array(
      '#title' => t('Picture mapping'),
      '#type' => 'item',
      '#markup' => t('There are no picture groups defined. !create_link.', array(
        '!create_link' => l(t('Create a picture mapping'), 'admin/config/media/picture/add'),
      )),
    );
  }
  return $element;
}

/**
 * Implements hook_field_formatter_settings_summary().
 */
function picture_background_formatter_field_formatter_settings_summary($field, $instance, $view_mode) {
  $display = $instance['display'][$view_mode];
  $settings = $display['settings'];
  $summary = array();
  $picture_mapping = picture_mapping_load($settings['picture_mapping']);
  if ($picture_mapping) {
    $summary[] = t('Picture mapping: @picture_mapping', array(
      '@picture_mapping' => $picture_mapping
        ->label(),
    ));
    $summary[] = t('Selector: @selector', array(
      '@selector' => $settings['selector'],
    ));
  }
  else {
    $summary[] = t('Select a responsive image mapping.');
  }
  return implode('<br />', $summary);
}

/**
 * Implements hook_field_formatter_view().
 */
function picture_background_formatter_field_formatter_view($entity_type, $entity, $field, $instance, $langcode, $items, $display) {
  $settings = $display['settings'];
  $element = array();
  $css = "";
  foreach ($items as $item) {
    $css .= picture_background_formatter_generate_background_css($item['uri'], $settings['picture_mapping'], $settings['selector']);
  }
  if (!empty($css)) {
    $element[0]['#attached']['css'][] = array(
      'data' => $css,
      'type' => 'inline',
    );
  }
  return $element;
}

/**
 * CSS Generator Helper Function.
 *
 * @param string $original_uri
 *   URI of the field image.
 * @param array $picture_mapping
 *   Desired picture mapping to generate CSS.
 * @param string $selector
 *   CSS selector to target.
 *
 * @return string
 *   Generated background image CSS.
 *
 * @see picture_background_formatter_field_formatter_view()
 */
function picture_background_formatter_generate_background_css($original_uri, $picture_mapping, $selector) {
  $breakpoints = picture_background_formatter_picture_breakpoint_data($picture_mapping);
  $css = "";
  foreach ($breakpoints as $breakpoint_size => $breakpoint_styles) {
    if ($breakpoint_size != "default") {
      $css .= '@media ' . $breakpoint_size . ' {';
    }
    foreach ($breakpoint_styles as $multiplier => $style_info) {
      $multiplier = rtrim($multiplier, ",");
      if ($style_info['image_style'] == "_original image_") {
        $url = file_create_url($original_uri);
      }
      else {
        $url = image_style_url($style_info['image_style'], $original_uri);
      }
      if ($multiplier != 1) {
        $css .= '@media (-webkit-min-device-pixel-ratio: ' . $multiplier . '), (min-resolution: ' . rtrim($multiplier, 'x') * 96 . 'dpi), (min-resolution: ' . $multiplier . 'dppx) {';
      }
      $css .= $selector . ' {background-image: url(' . $url . ');}';
      if ($multiplier != 1) {
        $css .= '}';
      }
    }
    if ($breakpoint_size != "default") {
      $css .= '}';
    }
  }
  return $css;
}

/**
 * Queries the breakpoint data for the requested picture mapping.
 *
 * @param array $picture_mapping
 *   Desired Picture Mapping to pull Breakpoint Data from.
 *
 * @return array
 *   An array of breakpoints, their sizes, and multipliers.
 *
 * @see picture_background_formatter_generate_background_css()
 */
function picture_background_formatter_picture_breakpoint_data($picture_mapping) {
  $mapping = picture_mapping_load($picture_mapping);
  $mapping_breakpoints = array_reverse(picture_get_mapping_breakpoints($mapping));
  $picture_breakpoint_data = array();
  reset($mapping_breakpoints);
  $first = key($mapping_breakpoints);
  foreach ($mapping_breakpoints as $breakpoint_name => $breakpoint_values) {

    // Mark breakpoint as invalid if it consists of a type other than an
    // image_style type.
    $invalid = FALSE;
    foreach ($breakpoint_values as $values) {
      if ($values['mapping_type'] != "image_style") {
        $invalid = TRUE;
      }
    }

    // Skip invalid breakpoints.
    if ($invalid) {
      watchdog('picture_background_formatter', 'Breakpoint %breakpoint was skipped due to the misconfigured %mapping Picture Mapping.', array(
        '%breakpoint' => $breakpoint_name,
        '%mapping' => $mapping
          ->label(),
      ), WATCHDOG_NOTICE, NULL);
      continue;
    }
    if ($breakpoint_name === $first) {
      $picture_breakpoint_data["default"] = $mapping_breakpoints[$breakpoint_name];
    }
    else {
      $breakpoint_data = breakpoints_breakpoint_load_by_fullkey($breakpoint_name);
      $picture_breakpoint_data[$breakpoint_data->breakpoint] = $mapping_breakpoints[$breakpoint_name];
    }
  }
  return $picture_breakpoint_data;
}

/**
 * Implements hook_help().
 */
function picture_background_formatter_help($path, $arg) {
  switch ($path) {
    case 'admin/help#picture_background_formatter':
      $filepath = dirname(__FILE__) . '/README.md';
      if (file_exists($filepath)) {
        $readme = file_get_contents($filepath);
      }
      else {
        $filepath = dirname(__FILE__) . '/README.txt';
        if (file_exists($filepath)) {
          $readme = file_get_contents($filepath);
        }
      }
      if (!isset($readme)) {
        return NULL;
      }
      if (module_exists('markdown')) {
        $filters = module_invoke('markdown', 'filter_info');
        $info = $filters['filter_markdown'];
        if (function_exists($info['process callback'])) {
          $output = $info['process callback']($readme, NULL);
        }
        else {
          $output = '<pre>' . $readme . '</pre>';
        }
      }
      else {
        $output = '<pre>' . $readme . '</pre>';
      }
      return $output;
  }
}

Functions

Name	Description
picture_background_formatter_field_formatter_info	Implements hook_field_formatter_info().
picture_background_formatter_field_formatter_settings_form	Implements hook_field_formatter_settings_form().
picture_background_formatter_field_formatter_settings_summary	Implements hook_field_formatter_settings_summary().
picture_background_formatter_field_formatter_view	Implements hook_field_formatter_view().
picture_background_formatter_generate_background_css	CSS Generator Helper Function.
picture_background_formatter_help	Implements hook_help().
picture_background_formatter_picture_breakpoint_data	Queries the breakpoint data for the requested picture mapping.