Add BG offset

packages/vitec/Configuration/TCA/Overrides/tt_content_vitec_shared.php

@@ -91,6 +91,8 @@ use TYPO3\CMS\Core\Utility\ExtensionManagementUtility;
         ],
         'tx_vitec_bg_position' => [
             'label' => $l . 'bg_position.label',
+            // Same reason as on bg_size: reveal the custom fields immediately.
+            'onChange' => 'reload',
             'config' => [
                 'type' => 'select',
                 'renderType' => 'selectSingle',
@@ -104,15 +106,43 @@ use TYPO3\CMS\Core\Utility\ExtensionManagementUtility;
                     ['label' => $l . 'bg_position.option.bottom_left',   'value' => 'left bottom'],
                     ['label' => $l . 'bg_position.option.bottom_center', 'value' => 'center bottom'],
                     ['label' => $l . 'bg_position.option.bottom_right',  'value' => 'right bottom'],
+                    ['label' => $l . 'bg_position.option.custom',        'value' => 'custom'],
                 ],
                 'default' => 'center center',
             ],
         ],
     ]);
 
+    // Custom position: four edge offsets in percent, shown only when the select
+    // is on "custom". `nullable` matters here - an empty field has to stay
+    // distinguishable from an explicit 0, which is a valid offset (flush against
+    // that edge). Empty means "centred on this axis".
+    //
+    // CSS cannot take a top AND a bottom offset at once, so these four are not
+    // written out literally; ContainerBackgroundRenderer folds them into the
+    // percentage form, where "10% from the right" is simply 90%.
+    $positionOffsets = [];
+    foreach (['top', 'bottom', 'left', 'right'] as $edge) {
+        $positionOffsets['tx_vitec_bg_pos_' . $edge] = [
+            'label' => $l . 'bg_pos.' . $edge,
+            'displayCond' => 'FIELD:tx_vitec_bg_position:=:custom',
+            'config' => [
+                'type' => 'number',
+                'size' => 5,
+                'nullable' => true,
+                'range' => [
+                    'lower' => 0,
+                    'upper' => 100,
+                ],
+            ],
+        ];
+    }
+    ExtensionManagementUtility::addTCAcolumns('tt_content', $positionOffsets);
+
     // One palette, so size and position sit on a single row under the image.
     $GLOBALS['TCA']['tt_content']['palettes']['vitec_background'] = [
-        'showitem' => 'tx_vitec_bg_image, --linebreak--, tx_vitec_bg_size, tx_vitec_bg_size_percent, tx_vitec_bg_position',
+        'showitem' => 'tx_vitec_bg_image, --linebreak--, tx_vitec_bg_size, tx_vitec_bg_size_percent, tx_vitec_bg_position,'
+            . ' --linebreak--, tx_vitec_bg_pos_top, tx_vitec_bg_pos_bottom, tx_vitec_bg_pos_left, tx_vitec_bg_pos_right',
     ];
 
     // -------------------------------------------------------------------------