[SuperEditor][SuperReader] - Added font family attribution, superscript and subscript, and paragraph indentation (Resolves #2107) (#2111)

Author: matthew-carroll

super_editor/example/lib/demos/example_editor/_toolbar.dart

@@ -282,6 +282,26 @@ class _EditorToolbarState extends State<EditorToolbar> {
     ]);
   }
 
+  /// Toggles superscript styling for the current selected text.
+  void _toggleSuperscript() {
+    widget.editor!.execute([
+      ToggleTextAttributionsRequest(
+        documentRange: widget.composer.selection!,
+        attributions: {superscriptAttribution},
+      ),
+    ]);
+  }
+
+  /// Toggles subscript styling for the current selected text.
+  void _toggleSubscript() {
+    widget.editor!.execute([
+      ToggleTextAttributionsRequest(
+        documentRange: widget.composer.selection!,
+        attributions: {subscriptAttribution},
+      ),
+    ]);
+  }
+
   /// Returns true if the current text selection includes part
   /// or all of a single link, returns false if zero links are
   /// in the selection or if 2+ links are in the selection.
@@ -571,6 +591,22 @@ class _EditorToolbarState extends State<EditorToolbar> {
                   tooltip: AppLocalizations.of(context)!.labelStrikethrough,
                 ),
               ),
+              Center(
+                child: IconButton(
+                  onPressed: _toggleSuperscript,
+                  icon: const Icon(Icons.superscript),
+                  splashRadius: 16,
+                  tooltip: AppLocalizations.of(context)!.labelSuperscript,
+                ),
+              ),
+              Center(
+                child: IconButton(
+                  onPressed: _toggleSubscript,
+                  icon: const Icon(Icons.subscript),
+                  splashRadius: 16,
+                  tooltip: AppLocalizations.of(context)!.labelSubscript,
+                ),
+              ),
               Center(
                 child: IconButton(
                   onPressed: _areMultipleLinksSelected() ? null : _onLinkPressed,

super_editor/example/lib/l10n/app_en.arb

@@ -3,6 +3,8 @@
   "labelBold": "Bold",
   "labelItalics": "Italics",
   "labelStrikethrough": "Strikethrough",
+  "labelSuperscript": "Superscript",
+  "labelSubscript": "Subscript",
   "labelLink": "Link",
   "labelTextAlignment": "Text Alignment",
   "labelMoreOptions": "More Options (not implemented)",

super_editor/example_docs/lib/editor.dart

@@ -105,39 +105,6 @@ class _DocsEditorState extends State<DocsEditor> {
   }
 }
 
-/// Attribution to be used within [AttributedText] to
-/// represent an inline span of a font family change.
-///
-/// Every [FontFamilyAttribution] is considered equivalent so
-/// that [AttributedText] prevents multiple [FontFamilyAttribution]s
-/// from overlapping.
-class FontFamilyAttribution implements Attribution {
-  FontFamilyAttribution(this.fontFamily);
-
-  @override
-  String get id => fontFamily;
-
-  final String fontFamily;
-
-  @override
-  bool canMergeWith(Attribution other) {
-    return this == other;
-  }
-
-  @override
-  bool operator ==(Object other) =>
-      identical(this, other) ||
-      other is FontFamilyAttribution && runtimeType == other.runtimeType && fontFamily == other.fontFamily;
-
-  @override
-  int get hashCode => fontFamily.hashCode;
-
-  @override
-  String toString() {
-    return '[FontFamilyAttribution]: $fontFamily';
-  }
-}
-
 // Selection styles when the editor has focus.
 const _standardEditorSelectionStyle = defaultSelectionStyle;
 

super_editor/lib/src/default_editor/attributions.dart

@@ -38,9 +38,35 @@ const underlineAttribution = NamedAttribution('underline');
 /// Strikethrough style attribution.
 const strikethroughAttribution = NamedAttribution('strikethrough');
 
+/// Superscript style attribution.
+const superscriptAttribution = ScriptAttribution.superscript();
+
+/// Subscript style attribution.
+const subscriptAttribution = ScriptAttribution.subscript();
+
 /// Code style attribution.
 const codeAttribution = NamedAttribution('code');
 
+/// An attribution for superscript and subscript text.
+class ScriptAttribution implements Attribution {
+  static const typeSuper = "superscript";
+  static const typeSub = "subscript";
+
+  const ScriptAttribution.superscript() : type = typeSuper;
+
+  const ScriptAttribution.subscript() : type = typeSub;
+
+  @override
+  String get id => "script";
+
+  final String type;
+
+  @override
+  bool canMergeWith(Attribution other) {
+    return other is ScriptAttribution && type == other.type;
+  }
+}
+
 /// Attribution to be used within [AttributedText] to
 /// represent an inline span of a text color change.
 ///
@@ -139,6 +165,39 @@ class FontSizeAttribution implements Attribution {
   }
 }
 
+/// Attribution that says the text within it should use the given
+/// [fontFamily].
+///
+/// Every [FontFamilyAttribution] is considered equivalent so
+/// that [AttributedText] prevents multiple [FontFamilyAttribution]s
+/// from overlapping.
+class FontFamilyAttribution implements Attribution {
+  const FontFamilyAttribution(this.fontFamily);
+
+  @override
+  String get id => 'font_family';
+
+  final String fontFamily;
+
+  @override
+  bool canMergeWith(Attribution other) {
+    return this == other;
+  }
+
+  @override
+  bool operator ==(Object other) =>
+      identical(this, other) ||
+      other is FontFamilyAttribution && runtimeType == other.runtimeType && fontFamily == other.fontFamily;
+
+  @override
+  int get hashCode => fontFamily.hashCode;
+
+  @override
+  String toString() {
+    return '[FontFamilyAttribution]: $fontFamily';
+  }
+}
+
 /// Attribution to be used within [AttributedText] to
 /// represent a link.
 ///

super_editor/lib/src/default_editor/default_document_editor.dart

@@ -134,6 +134,22 @@ final defaultRequestHandlers = List.unmodifiable(<EditRequestHandler>[
           alignment: request.alignment,
         )
       : null,
+  (request) => request is IndentParagraphRequest
+      ? IndentParagraphCommand(
+          request.nodeId,
+        )
+      : null,
+  (request) => request is UnIndentParagraphRequest
+      ? UnIndentParagraphCommand(
+          request.nodeId,
+        )
+      : null,
+  (request) => request is SetParagraphIndentRequest
+      ? SetParagraphIndentCommand(
+          request.nodeId,
+          level: request.level,
+        )
+      : null,
   (request) => request is ChangeParagraphBlockTypeRequest
       ? ChangeParagraphBlockTypeCommand(
           nodeId: request.nodeId,