opt text selection

Signed-off-by: dom <githubaccount56556@proton.me>

lib/scripts/selectable_region.patch

@@ -119,10 +119,18 @@ index 09fba7fc4fb..57ee469358e 100644
    void computeSemanticsInformation(
      List<InlineSpanSemanticsInformation> collector, {
 diff --git a/packages/flutter/lib/src/rendering/paragraph.dart b/packages/flutter/lib/src/rendering/paragraph.dart
-index 97a41dafb8d..266dd6f0283 100644
+index 97a41dafb8d..15e7ce055e9 100644
 --- a/packages/flutter/lib/src/rendering/paragraph.dart
 +++ b/packages/flutter/lib/src/rendering/paragraph.dart
-@@ -502,27 +502,17 @@ class RenderParagraph extends RenderBox
+@@ -7,6 +7,7 @@
+ /// @docImport 'editable.dart';
+ library;
+ 
++import 'dart:io' show Platform;
+ import 'dart:math' as math;
+ import 'dart:ui'
+     as ui
+@@ -502,27 +503,17 @@ class RenderParagraph extends RenderBox
    }
  
    List<_SelectableFragment> _getSelectableFragments() {
@@ -161,7 +169,7 @@ index 97a41dafb8d..266dd6f0283 100644
    }
  
    /// Determines whether the given [Selectable] was created by this
-@@ -1467,7 +1457,7 @@ class RenderParagraph extends RenderBox
+@@ -1467,7 +1458,7 @@ class RenderParagraph extends RenderBox
  class _SelectableFragment
      with Selectable, Diagnosticable, ChangeNotifier
      implements TextLayoutMetrics {
@@ -170,7 +178,7 @@ index 97a41dafb8d..266dd6f0283 100644
      : assert(range.isValid && !range.isCollapsed && range.isNormalized) {
      if (kFlutterMemoryAllocationsEnabled) {
        ChangeNotifier.maybeDispatchObjectCreation(this);
-@@ -1478,6 +1468,7 @@ class _SelectableFragment
+@@ -1478,6 +1469,7 @@ class _SelectableFragment
    final TextRange range;
    final RenderParagraph paragraph;
    final String fullText;
@@ -178,7 +186,7 @@ index 97a41dafb8d..266dd6f0283 100644
  
    TextPosition? _textSelectionStart;
    TextPosition? _textSelectionEnd;
-@@ -1509,18 +1500,36 @@ class _SelectableFragment
+@@ -1509,18 +1501,36 @@ class _SelectableFragment
      final int selectionStart = _textSelectionStart!.offset;
      final int selectionEnd = _textSelectionEnd!.offset;
      final bool isReversed = selectionStart > selectionEnd;
@@ -222,11 +230,12 @@ index 97a41dafb8d..266dd6f0283 100644
      final selectionCollapsed = selectionStart == selectionEnd;
      final (
        TextSelectionHandleType startSelectionHandleType,
-@@ -1564,12 +1573,14 @@ class _SelectableFragment
+@@ -1564,12 +1574,15 @@ class _SelectableFragment
              result = _updateSelectionEdge(
                edgeUpdate.globalPosition,
                isEnd: edgeUpdate.type == SelectionEventType.endEdgeUpdate,
 +              isSingle: edgeUpdate.isSingle,
++              fromDrag: edgeUpdate.fromDrag,
              );
            case TextGranularity.word:
              result = _updateSelectionEdgeByTextBoundary(
@@ -237,7 +246,7 @@ index 97a41dafb8d..266dd6f0283 100644
              );
            case TextGranularity.paragraph:
              result = _updateSelectionEdgeByMultiSelectableTextBoundary(
-@@ -1626,9 +1637,33 @@ class _SelectableFragment
+@@ -1626,9 +1639,33 @@ class _SelectableFragment
      if (_textSelectionStart == null || _textSelectionEnd == null) {
        return null;
      }
@@ -273,7 +282,7 @@ index 97a41dafb8d..266dd6f0283 100644
    }
  
    @override
-@@ -1848,6 +1883,7 @@ class _SelectableFragment
+@@ -1848,6 +1885,7 @@ class _SelectableFragment
      Offset globalPosition, {
      required bool isEnd,
      required _TextBoundaryAtPosition getTextBoundary,
@@ -281,7 +290,7 @@ index 97a41dafb8d..266dd6f0283 100644
    }) {
      // When the start/end edges are swapped, i.e. the start is after the end, and
      // the scrollable synthesizes an event for the opposite edge, this will potentially
-@@ -1866,6 +1902,7 @@ class _SelectableFragment
+@@ -1866,6 +1904,7 @@ class _SelectableFragment
        _rect,
        localPosition,
        direction: paragraph.textDirection,
@@ -289,25 +298,26 @@ index 97a41dafb8d..266dd6f0283 100644
      );
  
      final TextPosition position = paragraph.getPositionForOffset(adjustedOffset);
-@@ -1920,7 +1957,7 @@ class _SelectableFragment
+@@ -1920,7 +1959,7 @@ class _SelectableFragment
      return SelectionUtils.getResultBasedOnRect(_rect, localPosition);
    }
  
 -  SelectionResult _updateSelectionEdge(Offset globalPosition, {required bool isEnd}) {
-+  SelectionResult _updateSelectionEdge(Offset globalPosition, {required bool isEnd, bool isSingle = false}) {
++  SelectionResult _updateSelectionEdge(Offset globalPosition, {required bool isEnd, bool isSingle = false, bool fromDrag = false}) {
      _setSelectionPosition(null, isEnd: isEnd);
      final Matrix4 transform = paragraph.getTransformTo(null);
      transform.invert();
-@@ -1932,11 +1969,21 @@ class _SelectableFragment
+@@ -1932,11 +1971,30 @@ class _SelectableFragment
        _rect,
        localPosition,
        direction: paragraph.textDirection,
 +      isSingle: isSingle,
      );
  
-     final TextPosition position = _clampTextPosition(
+-    final TextPosition position = _clampTextPosition(
-       paragraph.getPositionForOffset(adjustedOffset),
+-      paragraph.getPositionForOffset(adjustedOffset),
-     );
+-    );
++    TextPosition position = _clampTextPosition(paragraph.getPositionForOffset(adjustedOffset));
 +    // if (rawText != null) {
 +    //   position = _clampTextPosition(
 +    //     adjustedOffset.dx * 2 > _rect.left + _rect.right
@@ -317,10 +327,21 @@ index 97a41dafb8d..266dd6f0283 100644
 +    // } else {
 +    //   position = _clampTextPosition(paragraph.getPositionForOffset(adjustedOffset));
 +    // }
++    if (fromDrag && isSingle && !Platform.isIOS) {
++      if (isEnd) {
++        if (position.offset <= _textSelectionStart!.offset) {
++          position = TextPosition(offset: _textSelectionStart!.offset + 1);
++        }
++      } else {
++        if (position.offset >= _textSelectionEnd!.offset) {
++          position = TextPosition(offset: _textSelectionEnd!.offset - 1);
++        }
++      }
++    }
      _setSelectionPosition(position, isEnd: isEnd);
      if (position.offset == range.end) {
        return SelectionResult.next;
-@@ -3568,7 +3615,10 @@ class _SelectableFragment
+@@ -3568,7 +3626,10 @@ class _SelectableFragment
        final selectionPaint = Paint()
          ..style = PaintingStyle.fill
          ..color = paragraph.selectionColor!;
@@ -333,7 +354,7 @@ index 97a41dafb8d..266dd6f0283 100644
        }
      }
 diff --git a/packages/flutter/lib/src/rendering/selection.dart b/packages/flutter/lib/src/rendering/selection.dart
-index a813e141dc4..e5ef2103645 100644
+index a813e141dc4..d045236d031 100644
 --- a/packages/flutter/lib/src/rendering/selection.dart
 +++ b/packages/flutter/lib/src/rendering/selection.dart
 @@ -6,6 +6,8 @@
@@ -383,7 +404,7 @@ index a813e141dc4..e5ef2103645 100644
      if (point.dy <= targetRect.top ||
          point.dy <= targetRect.bottom && point.dx <= targetRect.left) {
        // Area 1
-@@ -520,7 +535,7 @@ class SelectionEdgeUpdateEvent extends SelectionEvent {
+@@ -520,9 +535,10 @@ class SelectionEdgeUpdateEvent extends SelectionEvent {
    ///
    /// The [granularity] contains the granularity which the selection edge should move by.
    /// This value defaults to [TextGranularity.character].
@@ -391,8 +412,11 @@ index a813e141dc4..e5ef2103645 100644
 +  SelectionEdgeUpdateEvent.forStart({
      required this.globalPosition,
      TextGranularity? granularity,
++    this.fromDrag = false,
    }) : granularity = granularity ?? TextGranularity.character,
-@@ -532,7 +547,7 @@ class SelectionEdgeUpdateEvent extends SelectionEvent {
+        super._(SelectionEventType.startEdgeUpdate);
+ 
+@@ -532,9 +548,10 @@ class SelectionEdgeUpdateEvent extends SelectionEvent {
    ///
    /// The [granularity] contains the granularity which the selection edge should move by.
    /// This value defaults to [TextGranularity.character].
@@ -400,18 +424,23 @@ index a813e141dc4..e5ef2103645 100644
 +  SelectionEdgeUpdateEvent.forEnd({
      required this.globalPosition,
      TextGranularity? granularity,
++    this.fromDrag = false,
    }) : granularity = granularity ?? TextGranularity.character,
-@@ -547,6 +562,8 @@ class SelectionEdgeUpdateEvent extends SelectionEvent {
+        super._(SelectionEventType.endEdgeUpdate);
+ 
+@@ -547,6 +564,10 @@ class SelectionEdgeUpdateEvent extends SelectionEvent {
    ///
    /// Defaults to [TextGranularity.character].
    final TextGranularity granularity;
 +
 +  bool isSingle = false;
++
++  final bool fromDrag;
  }
  
  /// Extends the start or end of the selection by a given [TextGranularity].
 diff --git a/packages/flutter/lib/src/widgets/scrollable.dart b/packages/flutter/lib/src/widgets/scrollable.dart
-index 9df2d633f16..54d30883245 100644
+index 9df2d633f16..c6a43cc97a3 100644
 --- a/packages/flutter/lib/src/widgets/scrollable.dart
 +++ b/packages/flutter/lib/src/widgets/scrollable.dart
 @@ -1177,6 +1177,9 @@ class _ScrollableSelectionContainerDelegate extends MultiSelectableSelectionCont
@@ -424,8 +453,24 @@ index 9df2d633f16..54d30883245 100644
    // Pointer drag is a single point, it should not have a size.
    static const double _kDefaultDragTargetSize = 0;
  
+@@ -1276,6 +1279,7 @@ class _ScrollableSelectionContainerDelegate extends MultiSelectableSelectionCont
+       event = SelectionEdgeUpdateEvent.forEnd(
+         globalPosition: endOffset,
+         granularity: event.granularity,
++        fromDrag: event.fromDrag,
+       );
+     } else {
+       _currentDragStartRelatedToOrigin = _inferPositionRelatedToOrigin(event.globalPosition);
+@@ -1286,6 +1290,7 @@ class _ScrollableSelectionContainerDelegate extends MultiSelectableSelectionCont
+       event = SelectionEdgeUpdateEvent.forStart(
+         globalPosition: startOffset,
+         granularity: event.granularity,
++        fromDrag: event.fromDrag,
+       );
+     }
+     final SelectionResult result = super.handleSelectionEdgeUpdate(event);
 diff --git a/packages/flutter/lib/src/widgets/selectable_region.dart b/packages/flutter/lib/src/widgets/selectable_region.dart
-index 59de8bae20b..9ce4810aa68 100644
+index 59de8bae20b..2084a40b24d 100644
 --- a/packages/flutter/lib/src/widgets/selectable_region.dart
 +++ b/packages/flutter/lib/src/widgets/selectable_region.dart
 @@ -401,9 +401,11 @@ class SelectableRegionState extends State<SelectableRegion>
@@ -549,7 +594,59 @@ index 59de8bae20b..9ce4810aa68 100644
            // Restore _lastSecondaryTapDownPosition since it may be cleared if a user
            // accesses contextMenuAnchors.
            _lastSecondaryTapDownPosition = details.globalPosition;
-@@ -1957,6 +1929,8 @@ class SelectableRegionState extends State<SelectableRegion>
+@@ -1105,7 +1077,7 @@ class SelectableRegionState extends State<SelectableRegion>
+   /// If the selectable subtree returns a [SelectionResult.pending], this method
+   /// continues to send [SelectionEdgeUpdateEvent]s every frame until the result
+   /// is not pending or users end their gestures.
+-  void _triggerSelectionEndEdgeUpdate({TextGranularity? textGranularity}) {
++  void _triggerSelectionEndEdgeUpdate({TextGranularity? textGranularity, bool fromDrag = false}) {
+     // This method can be called when the drag is not in progress. This can
+     // happen if the child scrollable returns SelectionResult.pending, and
+     // the selection area scheduled a selection update for the next frame, but
+@@ -1117,6 +1089,7 @@ class SelectableRegionState extends State<SelectableRegion>
+           SelectionEdgeUpdateEvent.forEnd(
+             globalPosition: _selectionEndPosition!,
+             granularity: textGranularity,
++            fromDrag: fromDrag,
+           ),
+         ) ==
+         SelectionResult.pending) {
+@@ -1159,7 +1132,7 @@ class SelectableRegionState extends State<SelectableRegion>
+   /// If the selectable subtree returns a [SelectionResult.pending], this method
+   /// continues to send [SelectionEdgeUpdateEvent]s every frame until the result
+   /// is not pending or users end their gestures.
+-  void _triggerSelectionStartEdgeUpdate({TextGranularity? textGranularity}) {
++  void _triggerSelectionStartEdgeUpdate({TextGranularity? textGranularity, bool fromDrag = false}) {
+     // This method can be called when the drag is not in progress. This can
+     // happen if the child scrollable returns SelectionResult.pending, and
+     // the selection area scheduled a selection update for the next frame, but
+@@ -1171,6 +1144,7 @@ class SelectableRegionState extends State<SelectableRegion>
+           SelectionEdgeUpdateEvent.forStart(
+             globalPosition: _selectionStartPosition!,
+             granularity: textGranularity,
++            fromDrag: fromDrag,
+           ),
+         ) ==
+         SelectionResult.pending) {
+@@ -1216,7 +1190,7 @@ class SelectableRegionState extends State<SelectableRegion>
+     _selectionStartPosition =
+         _selectionStartHandleDragPosition -
+         Offset(0, _selectionDelegate.value.startSelectionPoint!.lineHeight / 2);
+-    _triggerSelectionStartEdgeUpdate();
++    _triggerSelectionStartEdgeUpdate(fromDrag: true);
+ 
+     _selectionOverlay!.updateMagnifier(
+       _buildInfoForMagnifier(details.globalPosition, _selectionDelegate.value.startSelectionPoint!),
+@@ -1244,7 +1218,7 @@ class SelectableRegionState extends State<SelectableRegion>
+     _selectionEndPosition =
+         _selectionEndHandleDragPosition -
+         Offset(0, _selectionDelegate.value.endSelectionPoint!.lineHeight / 2);
+-    _triggerSelectionEndEdgeUpdate();
++    _triggerSelectionEndEdgeUpdate(fromDrag: true);
+ 
+     _selectionOverlay!.updateMagnifier(
+       _buildInfoForMagnifier(details.globalPosition, _selectionDelegate.value.endSelectionPoint!),
+@@ -1957,6 +1931,8 @@ class SelectableRegionState extends State<SelectableRegion>
          // the region on non-web platforms.
          if (kIsWeb) {
            _focusNode.unfocus();
@@ -558,7 +655,7 @@ index 59de8bae20b..9ce4810aa68 100644
          }
        },
        child: CompositedTransformTarget(
-@@ -2087,6 +2061,11 @@ class _DirectionallyExtendCaretSelectionAction<T extends DirectionalCaretMovemen
+@@ -2087,6 +2063,11 @@ class _DirectionallyExtendCaretSelectionAction<T extends DirectionalCaretMovemen
  ///  * [MultiSelectableSelectionContainerDelegate], for the class that provides
  ///  the main implementation details of this [SelectionContainerDelegate].
  class StaticSelectionContainerDelegate extends MultiSelectableSelectionContainerDelegate {
@@ -570,26 +667,7 @@ index 59de8bae20b..9ce4810aa68 100644
    /// The set of [Selectable]s that have received start events.
    final Set<Selectable> _hasReceivedStartEvent = <Selectable>{};
  
-@@ -2271,6 +2250,18 @@ class StaticSelectionContainerDelegate extends MultiSelectableSelectionContainer
+@@ -2367,6 +2348,8 @@ abstract class MultiSelectableSelectionContainerDelegate extends SelectionContai
-     super.dispose();
-   }
- 
-+  void handleSelectionEdgeUpdateEvent(SelectionEdgeUpdateEvent event) {
-+    event.isSingle = isSingle;
-+  }
-+
-+  @override
-+  SelectionResult dispatchSelectionEvent(SelectionEvent event) {
-+    if (event is SelectionEdgeUpdateEvent) {
-+      handleSelectionEdgeUpdateEvent(event);
-+    }
-+    return super.dispatchSelectionEvent(event);
-+  }
-+
-   @override
-   SelectionResult dispatchSelectionEventToChild(Selectable selectable, SelectionEvent event) {
-     switch (event.type) {
-@@ -2367,6 +2358,8 @@ abstract class MultiSelectableSelectionContainerDelegate extends SelectionContai
    /// Gets the list of [Selectable]s this delegate is managing.
    List<Selectable> selectables = <Selectable>[];
  
@@ -598,7 +676,7 @@ index 59de8bae20b..9ce4810aa68 100644
    /// The number of additional pixels added to the selection handle drawable
    /// area.
    ///
-@@ -2822,8 +2815,17 @@ abstract class MultiSelectableSelectionContainerDelegate extends SelectionContai
+@@ -2822,8 +2805,17 @@ abstract class MultiSelectableSelectionContainerDelegate extends SelectionContai
        return null;
      }
      final buffer = StringBuffer();
@@ -618,6 +696,25 @@ index 59de8bae20b..9ce4810aa68 100644
      }
      return SelectedContent(plainText: buffer.toString());
    }
+@@ -3129,6 +3121,7 @@ abstract class MultiSelectableSelectionContainerDelegate extends SelectionContai
+   /// Updates the selection edges.
+   @protected
+   SelectionResult handleSelectionEdgeUpdate(SelectionEdgeUpdateEvent event) {
++    handleSelectionEdgeUpdateEvent(event);
+     if (event.type == SelectionEventType.endEdgeUpdate) {
+       return currentSelectionEndIndex == -1
+           ? _initSelection(event, isEnd: true)
+@@ -3139,6 +3132,10 @@ abstract class MultiSelectableSelectionContainerDelegate extends SelectionContai
+         : _adjustSelection(event, isEnd: false);
+   }
+ 
++  void handleSelectionEdgeUpdateEvent(SelectionEdgeUpdateEvent event) {
++    event.isSingle = isSingle;
++  }
++
+   @override
+   SelectionResult dispatchSelectionEvent(SelectionEvent event) {
+     final selectionWillBeInProgress = event is! ClearSelectionEvent;
 diff --git a/packages/flutter/lib/src/widgets/selection_container.dart b/packages/flutter/lib/src/widgets/selection_container.dart
 index 5d5a2386a7a..92e7d1eb70a 100644
 --- a/packages/flutter/lib/src/widgets/selection_container.dart