/// <summary>
/// Creates a new AnchorSegment that creates new anchors.
/// </summary>
public AnchorSegment(TextDocument document, int offset, int length)
{
_start = document?.CreateAnchor(offset) ?? throw new ArgumentNullException(nameof(document));
_start.SurviveDeletion = true;
_start.MovementType = AnchorMovementType.AfterInsertion;
_end = document.CreateAnchor(offset + length);
_end.SurviveDeletion = true;
_end.MovementType = AnchorMovementType.BeforeInsertion;
}
public void AnchorInEmptyDocument()
{
TextAnchor a1 = document.CreateAnchor(0);
TextAnchor a2 = document.CreateAnchor(0);
a1.MovementType = AnchorMovementType.BeforeInsertion;
a2.MovementType = AnchorMovementType.AfterInsertion;
Assert.AreEqual(0, a1.Offset);
Assert.AreEqual(0, a2.Offset);
document.Insert(0, "x");
Assert.AreEqual(0, a1.Offset);
Assert.AreEqual(1, a2.Offset);
}