olivesimagined/theme-settings.php

<?php

/**
 * @file
 * Functions to support Olivesimagined theme settings.
 */

use Drupal\Core\Form\FormStateInterface;

/**
 * Implements hook_form_FORM_ID_alter() for system_theme_settings.
 */
function olivesimagined_form_system_theme_settings_alter(&$form, FormStateInterface $form_state) {
  $form['#validate'][] = 'olivesimagined_theme_settings_validate';
  $form['#attached']['library'][] = 'olivesimagined/color-picker';

  $color_config = [
    'colors' => [
      'base_primary_color' => 'Primary base color',
    ],
    'schemes' => [
      'default' => [
        'label' => 'Blue Lagoon',
        'colors' => [
          'base_primary_color' => '#1b9ae4',
        ],
      ],
      'firehouse' => [
        'label' => 'Firehouse',
        'colors' => [
          'base_primary_color' => '#a30f0f',
        ],
      ],
      'ice' => [
        'label' => 'Ice',
        'colors' => [
          'base_primary_color' => '#57919e',
        ],
      ],
      'plum' => [
        'label' => 'Plum',
        'colors' => [
          'base_primary_color' => '#7a4587',
        ],
      ],
      'slate' => [
        'label' => 'Slate',
        'colors' => [
          'base_primary_color' => '#47625b',
        ],
      ],
    ],
  ];

  $form['#attached']['drupalSettings']['olivesimagined']['colorSchemes'] = $color_config['schemes'];

  $form['olivesimagined_settings']['olivesimagined_utilities'] = [
    '#type' => 'fieldset',
    '#title' => t('Olivesimagined Utilities'),
  ];
  $form['olivesimagined_settings']['olivesimagined_utilities']['mobile_menu_all_widths'] = [
    '#type' => 'checkbox',
    '#title' => t('Enable mobile menu at all widths'),
    '#default_value' => theme_get_setting('mobile_menu_all_widths'),
    '#description' => t('Enables the mobile menu toggle at all widths.'),
  ];
  $form['olivesimagined_settings']['olivesimagined_utilities']['site_branding_bg_color'] = [
    '#type' => 'select',
    '#title' => t('Header site branding background color'),
    '#options' => [
      'default' => t('Primary Branding Color'),
      'gray' => t('Gray'),
      'white' => t('White'),
    ],
    '#default_value' => theme_get_setting('site_branding_bg_color'),
  ];
  $form['olivesimagined_settings']['olivesimagined_utilities']['olivesimagined_color_scheme'] = [
    '#type' => 'fieldset',
    '#title' => t('Olivesimagined Color Scheme Settings'),
  ];
  $form['olivesimagined_settings']['olivesimagined_utilities']['olivesimagined_color_scheme']['description'] = [
    '#type' => 'html_tag',
    '#tag' => 'p',
    '#value' => t('These settings adjust the look and feel of the Olivesimagined theme. Changing the color below will change the base hue, saturation, and lightness values the Olivesimagined theme uses to determine its internal colors.'),
  ];
  $form['olivesimagined_settings']['olivesimagined_utilities']['olivesimagined_color_scheme']['color_scheme'] = [
    '#type' => 'select',
    '#title' => t('Olivesimagined Color Scheme'),
    '#empty_option' => t('Custom'),
    '#empty_value' => '',
    '#options' => [
      'default' => t('Blue Lagoon (Default)'),
      'firehouse' => t('Firehouse'),
      'ice' => t('Ice'),
      'plum' => t('Plum'),
      'slate' => t('Slate'),
    ],
    '#input' => FALSE,
    '#wrapper_attributes' => [
      'style' => 'display:none;',
    ],
  ];

  foreach ($color_config['colors'] as $key => $title) {
    $form['olivesimagined_settings']['olivesimagined_utilities']['olivesimagined_color_scheme'][$key] = [
      '#type' => 'textfield',
      '#maxlength' => 7,
      '#size' => 10,
      '#title' => t($title),
      '#description' => t('Enter color in full hexadecimal format (#abc123).') . '<br/>' . t('Derivatives will be formed from this color.'),
      '#default_value' => theme_get_setting($key),
      '#attributes' => [
        'pattern' => '^#[a-fA-F0-9]{6}',
      ],
      '#wrapper_attributes' => [
        'data-drupal-selector' => 'olivesimagined-color-picker',
      ],
    ];
  }
}

/**
 * Validation handler for the Olivesimagined system_theme_settings form.
 */
function olivesimagined_theme_settings_validate($form, FormStateInterface $form_state) {
  if (!preg_match('/^#[a-fA-F0-9]{6}$/', $form_state->getValue('base_primary_color'))) {
    $form_state->setErrorByName('base_primary_color', t('Colors must be 7-character string specifying a color hexadecimal format.'));
  }
}