Drag&Drop a debug arrow like in visual studio

    Private Sub SyntaxEditor1_MouseDown(ByVal sender As System.Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles SyntaxEditor1.MouseDown
        If IsMouseHoveringDebugArrow(e.location) Then
            Me.DoDragDrop(Me.mArrowIndicator, DragDropEffects.Move)
        End If
    End Sub

    Private Function IsMouseHoveringDebugArrow(ByVal mouseLocation As Point) As Boolean
        If mouseLocation.X > SyntaxEditor1.IndicatorMarginWidth Then Return False

        Dim position As Position = SyntaxEditor1.SelectedView.PositionFromLocation(mouseLocation, LocationToOffsetAlgorithm.BestFit)
        Dim offset As Integer = SyntaxEditor1.Document.PositionToOffset(position)
        Dim nextOffset As Integer = SyntaxEditor1.Document.PositionToOffset(New Position(Math.Min(position.Line + 1, SyntaxEditor1.Document.Lines.Count - 1), 0))

        If mArrowIndicator.Offset >= offset AndAlso mArrowIndicator.Offset <= nextOffset Then Return True
       
        Return False
    End Function

    Private Sub SyntaxEditor1_PasteDragDrop(ByVal sender As System.Object, ByVal e As ActiproSoftware.SyntaxEditor.PasteDragDropEventArgs) Handles SyntaxEditor1.PasteDragDrop
        If e.Source = PasteDragDropSource.DragEnter Then
            If e.DragEventArgs.Data.GetDataPresent(mArrowIndicator.GetType()) Then
                e.DragEventArgs.Effect = DragDropEffects.Move
            End If
        End If
    End Sub