TextSelectionToolbarAnchors.fromSelection constructor Null safety

TextSelectionToolbarAnchors.fromSelection(
  1. {required RenderBox renderBox,
  2. required double startGlyphHeight,
  3. required double endGlyphHeight,
  4. required List<TextSelectionPoint> selectionEndpoints}
)

Creates an instance of TextSelectionToolbarAnchors for some selection.

Implementation

factory TextSelectionToolbarAnchors.fromSelection({
  required RenderBox renderBox,
  required double startGlyphHeight,
  required double endGlyphHeight,
  required List<TextSelectionPoint> selectionEndpoints,
}) {
  final Rect editingRegion = Rect.fromPoints(
    renderBox.localToGlobal(Offset.zero),
    renderBox.localToGlobal(renderBox.size.bottomRight(Offset.zero)),
  );
  final bool isMultiline = selectionEndpoints.last.point.dy - selectionEndpoints.first.point.dy >
      endGlyphHeight / 2;

  final Rect selectionRect = Rect.fromLTRB(
    isMultiline
        ? editingRegion.left
        : editingRegion.left + selectionEndpoints.first.point.dx,
    editingRegion.top + selectionEndpoints.first.point.dy - startGlyphHeight,
    isMultiline
        ? editingRegion.right
        : editingRegion.left + selectionEndpoints.last.point.dx,
    editingRegion.top + selectionEndpoints.last.point.dy,
  );

  return TextSelectionToolbarAnchors(
    primaryAnchor: Offset(
      selectionRect.left + selectionRect.width / 2,
      clampDouble(selectionRect.top, editingRegion.top, editingRegion.bottom),
    ),
    secondaryAnchor: Offset(
      selectionRect.left + selectionRect.width / 2,
      clampDouble(selectionRect.bottom, editingRegion.top, editingRegion.bottom),
    ),
  );
}