Add default section appearance setting

Allow editors to configure the default text background style
(shadow, cards, or transparent) for new sections.

Author: tf

entry_types/scrolled/config/locales/de.yml

@@ -1478,6 +1478,13 @@ de:
               centerRagged: Zentriert
               left: Links
               right: Rechts
+          defaultSectionAppearance:
+            label: Abblendung
+            inline_help: Standard-Erscheinung neuer Abschnitte.
+            values:
+              cards: Karte
+              shadow: Schatten
+              transparent: Keine
           topPaddingVisualization:
             label: Abstand oben
           defaultSectionPaddingTop:

entry_types/scrolled/config/locales/en.yml

@@ -1461,6 +1461,13 @@ en:
               centerRagged: Centered (Ragged)
               left: Left
               right: Right
+          defaultSectionAppearance:
+            label: Text background
+            inline_help: Default appearance of new sections.
+            values:
+              cards: Card
+              shadow: Shadow
+              transparent: Transparent
           topPaddingVisualization:
             label: Top padding
           defaultSectionPaddingTop:

entry_types/scrolled/doc/creating_content_element_types.md

@@ -379,6 +379,57 @@ pageflow_scrolled:
             inline_help: "..."
 ```
 
+## Defaults Inputs
+
+Content element types can contribute inputs to the entry defaults
+settings. These inputs allow editors to configure default values that
+are applied when creating new content elements of that type.
+
+To define defaults inputs, provide a `defaultsInputs` function when
+registering your content element type:
+
+```javascript
+import {editor} from 'pageflow-scrolled/editor';
+import {CheckBoxInputView} from 'pageflow/ui';
+
+editor.contentElementTypes.register('inlineImage', {
+  configurationEditor({entry}) {
+    // ...
+  },
+
+  defaultsInputs() {
+    this.input('enableFullscreen', CheckBoxInputView);
+  }
+});
+```
+
+The `defaultsInputs` function is called in a similar context as the
+`this.tab` callback in `configurationEditor`. Property names are
+automatically prefixed with `default-{typeName}-` when stored in the
+entry metadata configuration.
+
+For translations, Pageflow first looks for keys under a `defaults`
+namespace, then falls back to normal attribute translations:
+
+```
+pageflow_scrolled:
+  editor:
+    content_elements:
+      inlineImage:
+        defaults:
+          attributes:
+            enableFullscreen:
+              label: "..."
+              inline_help: "..."
+        attributes:
+          enableFullscreen:
+            label: "..."
+            inline_help: "..."
+```
+
+If the `defaults.attributes` translation is not found, the normal
+`attributes` translation is used as a fallback.
+
 ## Using Palette Colors
 
 [Palette

entry_types/scrolled/package/spec/editor/models/Chapter-spec.js

@@ -59,6 +59,15 @@ describe('Chapter', () => {
       expect(section.configuration.get('layout')).toEqual('right');
     });
 
+    it('uses default appearance from entry metadata configuration', () => {
+      const {entry} = testContext;
+
+      entry.metadata.configuration.set('defaultSectionAppearance', 'cards');
+      const section = entry.chapters.first().addSection();
+
+      expect(section.configuration.get('appearance')).toEqual('cards');
+    });
+
     it('handles sparse positions correctly', () => {
       const {entry} = testContext;
 

entry_types/scrolled/package/src/editor/models/Chapter.js

@@ -65,6 +65,7 @@ export const Chapter = Backbone.Model.extend({
     const defaultConfiguration = options.skipDefaults ? {} : {
       transition: this.entry.metadata.configuration.get('defaultTransition'),
       layout: this.entry.metadata.configuration.get('defaultSectionLayout'),
+      appearance: this.entry.metadata.configuration.get('defaultSectionAppearance'),
       paddingTop: this.entry.metadata.configuration.get('defaultSectionPaddingTop'),
       paddingBottom: this.entry.metadata.configuration.get('defaultSectionPaddingBottom')
     };

entry_types/scrolled/package/src/editor/views/EditDefaultsView.js

@@ -28,6 +28,10 @@ export const EditDefaultsView = EditConfigurationView.extend({
         values: ['left', 'right', 'center', 'centerRagged']
       });
 
+      this.input('defaultSectionAppearance', SelectInputView, {
+        values: ['shadow', 'cards', 'transparent']
+      });
+
       if (features.isEnabled('section_paddings')) {
         const paddingTopScale = entry.getScale('sectionPaddingTop');
         const paddingBottomScale = entry.getScale('sectionPaddingBottom');