WIP: Filling out controller APIs with commands

super_editor/lib/src/infrastructure/super_textfield/infrastructure/attributed_text_editing_value.dart

@@ -4,6 +4,15 @@ import 'package:flutter/services.dart';
 /// The logical value of a text editable that displays attributed
 /// text.
 class AttributedTextEditingValue {
+  factory AttributedTextEditingValue.empty() => AttributedTextEditingValue(
+        text: AttributedText(text: ""),
+      );
+
+  factory AttributedTextEditingValue.emptyWithCaret() => AttributedTextEditingValue(
+        text: AttributedText(text: ""),
+        selection: const TextSelection.collapsed(offset: 0),
+      );
+
   const AttributedTextEditingValue({
     required this.text,
     this.selection = const TextSelection.collapsed(offset: -1),

super_editor/lib/src/infrastructure/super_textfield/infrastructure/editing/commands.dart

@@ -1,17 +1,90 @@
 import 'package:attributed_text/attributed_text.dart';
 import 'package:flutter/painting.dart';
+import 'package:super_editor/src/infrastructure/attributed_text_styles.dart';
 import 'package:super_editor/src/infrastructure/super_textfield/infrastructure/attributed_text_editing_value.dart';
 
 import 'event_source_value.dart';
 
+/// Selects all text in the editable.
+class SelectAllCommand extends AttributedTextEditingValueCommand {
+  TextSelection? _previousSelection;
+
+  @override
+  AttributedTextEditingValue doExecute(AttributedTextEditingValue previousValue) {
+    _previousSelection = previousValue.selection;
+
+    return AttributedTextEditingValue(
+      text: previousValue.text.copy(),
+      selection: TextSelection(
+        baseOffset: 0,
+        extentOffset: previousValue.text.text.length,
+      ),
+    );
+  }
+
+  @override
+  AttributedTextEditingValue doUndo(AttributedTextEditingValue currentValue) {
+    return AttributedTextEditingValue(
+      text: currentValue.text,
+      selection: _previousSelection!,
+    );
+  }
+}
+
+/// Toggles the given attributions on/off within the selected text region.
+class ToggleSelectionAttributionsCommand extends AttributedTextEditingValueCommand {
+  ToggleSelectionAttributionsCommand(this.toggleAttributions);
+
+  /// The attributions that will be turned on/off within the current
+  /// text selection.
+  final Set<Attribution> toggleAttributions;
+
+  @override
+  AttributedTextEditingValue doExecute(AttributedTextEditingValue previousValue) {
+    final newText = previousValue.text.copy();
+    final selectionRange = previousValue.selection.toSpanRange();
+    for (final attribution in toggleAttributions) {
+      newText.toggleAttribution(attribution, selectionRange);
+    }
+
+    return AttributedTextEditingValue(
+      text: newText,
+      selection: previousValue.selection,
+      composingRegion: previousValue.composingRegion,
+    );
+  }
+
+  @override
+  AttributedTextEditingValue doUndo(AttributedTextEditingValue currentValue) {
+    final revertedText = currentValue.text.copy();
+    final selectionRange = currentValue.selection.toSpanRange();
+    for (final attribution in toggleAttributions) {
+      revertedText.toggleAttribution(attribution, selectionRange);
+    }
+
+    return AttributedTextEditingValue(
+      text: revertedText,
+      selection: currentValue.selection,
+      composingRegion: currentValue.composingRegion,
+    );
+  }
+}
+
 /// Inserts the given text at the current caret location.
 ///
 /// The [AttributedTextEditingValue] must have a collapsed selection.
-class TextFieldInsertTextCommand extends AttributedTextEditingValueCommand {
-  TextFieldInsertTextCommand(this.textToInsert);
+class InsertTextAtCaretCommand extends AttributedTextEditingValueCommand {
+  InsertTextAtCaretCommand(
+    this.textToInsert, {
+    this.composingRegion,
+  });
 
+  /// The text to insert into the [AttributedTextEditingValue].
   final AttributedText textToInsert;
 
+  /// The new composing region after the text is inserted.
+  final TextRange? composingRegion;
+
   TextRange? _previousComposingRegion;
 
   @override
@@ -29,6 +102,7 @@ class TextFieldInsertTextCommand extends AttributedTextEditingValueCommand {
       selection: TextSelection.collapsed(
         offset: previousValue.selection.extentOffset + textToInsert.text.length,
       ),
+      composingRegion: composingRegion ?? TextRange.empty,
     );
 
     return newValue;
@@ -53,3 +127,110 @@ class TextFieldInsertTextCommand extends AttributedTextEditingValueCommand {
     return newValue;
   }
 }
+
+/// Inserts the given text at a desired text offset.
+class InsertTextAtOffsetCommand extends AttributedTextEditingValueCommand {
+  InsertTextAtOffsetCommand({
+    required this.textToInsert,
+    required this.insertionOffset,
+    required this.selectionAfter,
+    this.composingRegion,
+  });
+
+  /// The text to insert into the [AttributedTextEditingValue].
+  final AttributedText textToInsert;
+
+  /// The text offset where the new text should be inserted.
+  final int insertionOffset;
+
+  /// The selection that should be present after inserting the new text.
+  final TextSelection selectionAfter;
+
+  /// The new composing region after the text is inserted.
+  final TextRange? composingRegion;
+
+  TextSelection? _previousSelection;
+  TextRange? _previousComposingRegion;
+
+  @override
+  AttributedTextEditingValue doExecute(AttributedTextEditingValue previousValue) {
+    _previousSelection = previousValue.selection;
+    _previousComposingRegion = previousValue.composingRegion;
+
+    final newValue = AttributedTextEditingValue(
+      text: previousValue.text.insert(
+        textToInsert: textToInsert,
+        startOffset: insertionOffset,
+      ),
+      selection: selectionAfter,
+      composingRegion: composingRegion ?? TextRange.empty,
+    );
+
+    return newValue;
+  }
+
+  @override
+  AttributedTextEditingValue doUndo(AttributedTextEditingValue currentValue) {
+    final newValue = AttributedTextEditingValue(
+      text: currentValue.text.removeRegion(
+        startOffset: insertionOffset - textToInsert.text.length,
+        endOffset: insertionOffset,
+      ),
+      selection: _previousSelection!,
+      composingRegion: _previousComposingRegion!,
+    );
+
+    _previousSelection = null;
+    _previousComposingRegion = null;
+
+    return newValue;
+  }
+}
+
+extension on AttributedText {
+  AttributedText copy() {
+    return AttributedText(
+      text: text,
+      spans: spans.copy(),
+    );
+  }
+}
+
+/// Replaces the text, selection, and composing region in the editable.
+class ReplaceContentCommands extends AttributedTextEditingValueCommand {
+  ReplaceContentCommands({
+    required this.newText,
+    required this.newSelection,
+    this.newComposingRegion = TextRange.empty,
+  });
+
+  final AttributedText newText;
+  final TextSelection newSelection;
+  final TextRange newComposingRegion;
+
+  AttributedTextEditingValue? _previousValue;
+
+  @override
+  AttributedTextEditingValue doExecute(AttributedTextEditingValue previousValue) {
+    _previousValue = AttributedTextEditingValue(
+      text: previousValue.text.copy(),
+      selection: previousValue.selection,
+      composingRegion: previousValue.composingRegion,
+    );
+
+    return AttributedTextEditingValue(
+      text: newText,
+      selection: newSelection,
+      composingRegion: newComposingRegion,
+    );
+  }
+
+  @override
+  AttributedTextEditingValue doUndo(AttributedTextEditingValue currentValue) {
+    return AttributedTextEditingValue(
+      text: _previousValue!.text.copy(),
+      selection: _previousValue!.selection,
+      composingRegion: _previousValue!.composingRegion,
+    );
+  }
+}