[SuperEditor][iOS] Fix selecting all document when using the native toolbar (Resolves #2579) (#2582)

Author: angelosilvestre

super_editor/lib/src/default_editor/document_ime/document_delta_editing.dart

@@ -258,7 +258,11 @@ class TextDeltasDocumentEditor {
     if (docSelection != null) {
       // We got a selection from the platform.
       // This could happen in some software keyboards, like GBoard,
-      // where the user can swipe over the spacebar to change the selection.
+      // where the user can swipe over the spacebar to change the selection. This also happens
+      // when the app uses the native iOS text selection toolbar and the user presses "Select all".
+
+      docSelection = _maybeSelectAllOnIos(docSelection);
+
       editor.execute([
         ChangeSelectionRequest(
           docSelection,
@@ -273,6 +277,44 @@ class TextDeltasDocumentEditor {
     _previousImeValue = delta.apply(_previousImeValue);
   }
 
+  /// Performs a workaround to select all text in the document on iOS when the user presses "Select all".
+  ///
+  /// On iOS, when the app uses the native text selection toolbar and the user presses "Select all",
+  /// Flutter sends us a non-text delta with the selection change. However, since we only send to the IME the text
+  /// of the currently selected nodes, the delta reports the node being selected, not the entire
+  /// document.
+  ///
+  /// To workaroud this, whenever iOS reports a selection change that selects an entire node,
+  /// we select the entire document instead.
+  DocumentSelection _maybeSelectAllOnIos(DocumentSelection documentSelection) {
+    if (defaultTargetPlatform != TargetPlatform.iOS) {
+      return documentSelection;
+    }
+
+    final extentNode = document.getNodeById(documentSelection.extent.nodeId)!;
+    final isWholeNodeSelected = documentSelection.start.nodeId == documentSelection.end.nodeId &&
+        documentSelection.start.nodePosition == extentNode.beginningPosition &&
+        documentSelection.end.nodePosition == extentNode.endPosition;
+
+    if (!isWholeNodeSelected) {
+      // The selection is either across multiple nodes or not the entire node.
+      // The user didn't press "Select all".
+      return documentSelection;
+    }
+
+    // The IME reported a selection that selects an entire node. Select the entire document instead.
+    return DocumentSelection(
+      base: DocumentPosition(
+        nodeId: document.first.id,
+        nodePosition: document.first.beginningPosition,
+      ),
+      extent: DocumentPosition(
+        nodeId: document.last.id,
+        nodePosition: document.last.endPosition,
+      ),
+    );
+  }
+
   void insert(DocumentSelection insertionSelection, String textInserted) {
     editorImeLog.fine('Inserting "$textInserted" at position "$insertionSelection"');
     editorImeLog

super_editor/test/super_editor/mobile/super_editor_ios_selection_test.dart

@@ -1,6 +1,8 @@
 import 'package:flutter/gestures.dart';
+import 'package:flutter/services.dart';
 import 'package:flutter/widgets.dart';
 import 'package:flutter_test/flutter_test.dart';
+import 'package:flutter_test_robots/flutter_test_robots.dart';
 import 'package:flutter_test_runners/flutter_test_runners.dart';
 import 'package:super_editor/src/infrastructure/platforms/ios/selection_handles.dart';
 import 'package:super_editor/super_editor.dart';
@@ -496,6 +498,60 @@ void main() {
           await tester.pumpAndSettle();
         });
       });
+
+      testWidgetsOnIos("converts entire paragraph selection to entire document selection", (tester) async {
+        // This test locks the behavior of a workaround for https://github.com/superlistapp/super_editor/issues/2579.
+        //
+        // When using the native text selection toolbar to select all text in a document, the IME sends a delta
+        // that selects only the text of the currently selected nodes. This is because we only send the text of the
+        // currently selected nodes to the IME. This test ensures that we select the entire document when we
+        // receive a delta that selects an entire node.
+
+        await tester //
+            .createDocument()
+            .withCustomContent(MutableDocument(
+              nodes: [
+                ParagraphNode(
+                  id: '1',
+                  text: AttributedText('First paragraph'),
+                ),
+                ParagraphNode(
+                  id: '2',
+                  text: AttributedText('Second paragraph'),
+                ),
+              ],
+            ))
+            .pump();
+
+        // Place the caret at the beginning of the document.
+        await tester.placeCaretInParagraph('1', 0);
+
+        // Simulate the user pressing "Select all" on the native text selection toolbar.
+        // Since we send only the text of the currently selected nodes to the IME, this results in a delta
+        // that selects only the first paragraph.
+        await tester.ime.sendDeltas(const [
+          TextEditingDeltaNonTextUpdate(
+            oldText: '. First paragraph',
+            selection: TextSelection(baseOffset: 0, extentOffset: 17),
+            composing: TextRange(start: -1, end: -1),
+          ),
+        ], getter: imeClientGetter);
+
+        // Ensure that we selected the entire document.
+        expect(
+          SuperEditorInspector.findDocumentSelection(),
+          const DocumentSelection(
+            base: DocumentPosition(
+              nodeId: '1',
+              nodePosition: TextNodePosition(offset: 0),
+            ),
+            extent: DocumentPosition(
+              nodeId: '2',
+              nodePosition: TextNodePosition(offset: 16),
+            ),
+          ),
+        );
+      });
     });
 
     group('within ancestor scrollable', () {