keep some types (e.g. mermaid diagrams) of notes full width

src/public/app/widgets/note_wrapper.js

@@ -0,0 +1,39 @@
+import FlexContainer from "./containers/flex_container.js";
+
+export default class NoteWrapperWidget extends FlexContainer {
+    constructor() {
+        super('column');
+
+        this.css("flex-grow", "1")
+            .collapsible();
+    }
+
+    doRender() {
+        super.doRender();
+
+        this.$widget.addClass("note-split");
+    }
+
+    setNoteContextEvent({noteContext}) {
+        this.refresh(noteContext);
+    }
+
+    noteSwitchedAndActivatedEvent({noteContext}) {
+        this.refresh(noteContext);
+    }
+
+    noteSwitchedEvent({noteContext}) {
+        this.refresh(noteContext);
+    }
+
+    activeContextChangedEvent({noteContext}) {
+        this.refresh(noteContext);
+    }
+
+    refresh(noteContext) {
+        this.$widget.toggleClass("full-content-width",
+            ['image', 'mermaid', 'book', 'render'].includes(noteContext?.note?.type)
+            || !!noteContext?.note?.hasLabel('fullContentWidth')
+        );
+    }
+}