Issue #2982202 by bojanz: Update promotion offer UX

Author: bojanz

modules/promotion/src/Entity/Promotion.php

@@ -618,7 +618,7 @@ public static function baseFieldDefinitions(EntityTypeInterface $entity_type) {
       ]);
 
     $fields['offer'] = BaseFieldDefinition::create('commerce_plugin_item:commerce_promotion_offer')
-      ->setLabel(t('Offer'))
+      ->setLabel(t('Offer type'))
       ->setCardinality(1)
       ->setRequired(TRUE)
       ->setDisplayOptions('form', [

modules/promotion/src/Plugin/Commerce/PromotionOffer/FixedAmountOffTrait.php

@@ -33,9 +33,10 @@ public function buildConfigurationForm(array $form, FormStateInterface $form_sta
 
     $form['amount'] = [
       '#type' => 'commerce_price',
-      '#title' => $this->t('Amount'),
+      '#title' => $this->t('Amount off'),
       '#default_value' => $amount,
       '#required' => TRUE,
+      '#weight' => -1,
     ];
 
     return $form;

modules/promotion/src/Plugin/Commerce/PromotionOffer/PercentageOffTrait.php

@@ -40,14 +40,15 @@ public function buildConfigurationForm(array $form, FormStateInterface $form_sta
 
     $form['percentage'] = [
       '#type' => 'commerce_number',
-      '#title' => $this->t('Percentage'),
+      '#title' => $this->t('Percentage off'),
       '#default_value' => Calculator::multiply($this->getPercentage(), '100'),
       '#maxlength' => 255,
       '#min' => 0,
       '#max' => 100,
       '#size' => 4,
       '#field_suffix' => $this->t('%'),
       '#required' => TRUE,
+      '#weight' => -1,
     ];
 
     return $form;

modules/promotion/src/Plugin/Commerce/PromotionOffer/PromotionOfferBase.php

@@ -86,6 +86,11 @@ public function setConfiguration(array $configuration) {
    * {@inheritdoc}
    */
   public function buildConfigurationForm(array $form, FormStateInterface $form_state) {
+    // Wrap the offer configuration in a fieldset by default.
+    $form['#type'] = 'fieldset';
+    $form['#title'] = $this->t('Offer');
+    $form['#collapsible'] = FALSE;
+
     return $form;
   }