onSingleTapUp method

Implementation

@protected
void onSingleTapUp(TapDragUpDetails details) {
  if (delegate.selectionEnabled) {
    // It is impossible to extend the selection when the shift key is pressed, if the
    // renderEditable.selection is invalid.
    final bool isShiftPressedValid = _isShiftPressed && renderEditable.selection?.baseOffset != null;
    switch (defaultTargetPlatform) {
      case TargetPlatform.linux:
      case TargetPlatform.macOS:
      case TargetPlatform.windows:
        break;
        // On desktop platforms the selection is set on tap down.
      case TargetPlatform.android:
        if (isShiftPressedValid) {
          _extendSelection(details.globalPosition, SelectionChangedCause.tap);
          return;
        }
        renderEditable.selectPosition(cause: SelectionChangedCause.tap);
        editableText.showSpellCheckSuggestionsToolbar();
      case TargetPlatform.fuchsia:
        if (isShiftPressedValid) {
          _extendSelection(details.globalPosition, SelectionChangedCause.tap);
          return;
        }
        renderEditable.selectPosition(cause: SelectionChangedCause.tap);
      case TargetPlatform.iOS:
        if (isShiftPressedValid) {
          // On iOS, a shift-tapped unfocused field expands from 0, not from
          // the previous selection.
          final TextSelection? fromSelection = renderEditable.hasFocus
              ? null
              : const TextSelection.collapsed(offset: 0);
          _expandSelection(
            details.globalPosition,
            SelectionChangedCause.tap,
            fromSelection,
          );
          return;
        }
        switch (details.kind) {
          case PointerDeviceKind.mouse:
          case PointerDeviceKind.trackpad:
          case PointerDeviceKind.stylus:
          case PointerDeviceKind.invertedStylus:
            // TODO(camsim99): Determine spell check toolbar behavior in these cases:
            // https://github.com/flutter/flutter/issues/119573.
            // Precise devices should place the cursor at a precise position if the
            // word at the text position is not misspelled.
            renderEditable.selectPosition(cause: SelectionChangedCause.tap);
          case PointerDeviceKind.touch:
          case PointerDeviceKind.unknown:
            // If the word that was tapped is misspelled, select the word and show the spell check suggestions
            // toolbar once. If additional taps are made on a misspelled word, toggle the toolbar. If the word
            // is not misspelled, default to the following behavior:
            //
            // Toggle the toolbar if the `previousSelection` is collapsed, the tap is on the selection, the
            // TextAffinity remains the same, and the editable is focused. The TextAffinity is important when the
            // cursor is on the boundary of a line wrap, if the affinity is different (i.e. it is downstream), the
            // selection should move to the following line and not toggle the toolbar.
            //
            // Toggle the toolbar when the tap is exclusively within the bounds of a non-collapsed `previousSelection`,
            // and the editable is focused.
            //
            // Selects the word edge closest to the tap when the editable is not focused, or if the tap was neither exclusively
            // or inclusively on `previousSelection`. If the selection remains the same after selecting the word edge, then we
            // toggle the toolbar. If the selection changes then we hide the toolbar.
            final TextSelection previousSelection = renderEditable.selection ?? editableText.textEditingValue.selection;
            final TextPosition textPosition = renderEditable.getPositionForPoint(details.globalPosition);
            final bool isAffinityTheSame = textPosition.affinity == previousSelection.affinity;
            final bool wordAtCursorIndexIsMisspelled = editableText.findSuggestionSpanAtCursorIndex(textPosition.offset) != null;

            if (wordAtCursorIndexIsMisspelled) {
              renderEditable.selectWord(cause: SelectionChangedCause.tap);
              if (previousSelection != editableText.textEditingValue.selection) {
                editableText.showSpellCheckSuggestionsToolbar();
              } else {
                editableText.toggleToolbar(false);
              }
            } else if (((_positionWasOnSelectionExclusive(textPosition) && !previousSelection.isCollapsed) || (_positionWasOnSelectionInclusive(textPosition) && previousSelection.isCollapsed && isAffinityTheSame)) && renderEditable.hasFocus) {
              editableText.toggleToolbar(false);
            } else {
              renderEditable.selectWordEdge(cause: SelectionChangedCause.tap);
              if (previousSelection == editableText.textEditingValue.selection && renderEditable.hasFocus) {
                editableText.toggleToolbar(false);
              } else {
                editableText.hideToolbar(false);
              }
            }
        }
    }
  }
}