[SuperEditor] - Tasks are now indentable (Resolves #1895) (#2101)

Author: matthew-carroll

super_editor/lib/src/default_editor/blocks/indentation.dart

@@ -0,0 +1,7 @@
+import 'package:flutter/painting.dart';
+
+/// A function that calculates the pixels to indent a text block in a document, given
+/// the [blockTextStyle], and the [indent] level.
+///
+/// A text block is a document block that contains text, e.g., paragraph, list item, task.
+typedef TextBlockIndentCalculator = double Function(TextStyle blockTextStyle, int indent);

super_editor/lib/src/default_editor/default_document_editor.dart

@@ -164,6 +164,15 @@ final defaultRequestHandlers = List.unmodifiable(<EditRequestHandler>[
           isComplete: request.isComplete,
         )
       : null,
+  (request) => request is IndentTaskRequest //
+      ? IndentTaskCommand(request.nodeId)
+      : null,
+  (request) => request is UnIndentTaskRequest //
+      ? UnIndentTaskCommand(request.nodeId)
+      : null,
+  (request) => request is SetTaskIndentRequest //
+      ? SetTaskIndentCommand(request.nodeId, request.indent)
+      : null,
   (request) => request is SplitExistingTaskRequest
       ? SplitExistingTaskCommand(
           nodeId: request.existingNodeId,
@@ -234,4 +243,6 @@ final defaultEditorReactions = List.unmodifiable([
   const ImageUrlConversionReaction(),
   const DashConversionReaction(),
   //---- End Content Conversions ---
+
+  UpdateSubTaskIndentAfterTaskDeletionReaction(),
 ]);

super_editor/lib/src/default_editor/list_items.dart

@@ -6,6 +6,7 @@ import 'package:super_editor/src/core/edit_context.dart';
 import 'package:super_editor/src/core/editor.dart';
 import 'package:super_editor/src/core/styles.dart';
 import 'package:super_editor/src/default_editor/attributions.dart';
+import 'package:super_editor/src/default_editor/blocks/indentation.dart';
 import 'package:super_editor/src/infrastructure/_logging.dart';
 import 'package:super_editor/src/infrastructure/attributed_text_styles.dart';
 import 'package:super_editor/src/infrastructure/keyboard.dart';
@@ -399,7 +400,7 @@ class UnorderedListItemComponent extends StatefulWidget {
     this.dotBuilder = _defaultUnorderedListItemDotBuilder,
     this.dotStyle,
     this.indent = 0,
-    this.indentCalculator = _defaultIndentCalculator,
+    this.indentCalculator = defaultListItemIndentCalculator,
     this.textSelection,
     this.selectionColor = Colors.lightBlueAccent,
     this.showCaret = false,
@@ -563,7 +564,7 @@ class OrderedListItemComponent extends StatefulWidget {
     this.numeralBuilder = _defaultOrderedListItemNumeralBuilder,
     this.numeralStyle = OrderedListNumeralStyle.arabic,
     this.indent = 0,
-    this.indentCalculator = _defaultIndentCalculator,
+    this.indentCalculator = defaultListItemIndentCalculator,
     this.textSelection,
     this.selectionColor = Colors.lightBlueAccent,
     this.showCaret = false,
@@ -581,7 +582,7 @@ class OrderedListItemComponent extends StatefulWidget {
   final OrderedListItemNumeralBuilder numeralBuilder;
   final OrderedListNumeralStyle numeralStyle;
   final int indent;
-  final double Function(TextStyle, int indent) indentCalculator;
+  final TextBlockIndentCalculator indentCalculator;
   final TextSelection? textSelection;
   final Color selectionColor;
   final bool showCaret;
@@ -659,7 +660,8 @@ class _OrderedListItemComponentState extends State<OrderedListItemComponent> {
 
 typedef OrderedListItemNumeralBuilder = Widget Function(BuildContext, OrderedListItemComponent);
 
-double _defaultIndentCalculator(TextStyle textStyle, int indent) {
+/// The standard [TextBlockIndentCalculator] used by list items in `SuperEditor`.
+double defaultListItemIndentCalculator(TextStyle textStyle, int indent) {
   return (textStyle.fontSize! * 0.60) * 4 * (indent + 1);
 }
 

super_editor/lib/src/default_editor/super_editor.dart

@@ -1207,6 +1207,9 @@ final defaultKeyboardActions = <DocumentKeyboardAction>[
   tabToIndentListItem,
   shiftTabToUnIndentListItem,
   backspaceToUnIndentListItem,
+  tabToIndentTask,
+  shiftTabToUnIndentTask,
+  backspaceToUnIndentTask,
   backspaceToConvertTaskToParagraph,
   backspaceToClearParagraphBlockType,
   cmdBToToggleBold,
@@ -1244,6 +1247,9 @@ final defaultImeKeyboardActions = <DocumentKeyboardAction>[
   cmdIToToggleItalics,
   doNothingWithBackspaceOnWeb,
   doNothingWithCtrlOrCmdAndZOnWeb,
+  tabToIndentTask,
+  shiftTabToUnIndentTask,
+  backspaceToUnIndentTask,
   backspaceToConvertTaskToParagraph,
   backspaceToUnIndentListItem,
   backspaceToClearParagraphBlockType,