Handling the parent's events

[boops boops]

I am trying to make a UserControl or Component which can be dragged from the Toolbox onto a container control such as a Form or a Panel. Its purpose is to change the behaviour of that container. In particular, I would like to add functions to the container's painting and mouse actions. I DO NOT want to have to write code for the container itself -- that's the whole point of the Toolbox object.

I can do this by getting a reference to the object's Parent (or Host in the case of a Component) and handling its events, as this example illustrates:

Public Class DeformablePolygon
    Inherits Windows.Forms.UserControl
 
    Private WithEvents _Parent As Windows.Forms.Control
    Public Property VertexCollection As System.Drawing.PointF()
 
    Protected Overrides Sub OnParentChanged(e As System.EventArgs)
        _Parent = Me.Parent
        MyBase.OnParentChanged(e)
    End Sub
 
    Private Sub _Parent_Paint(sender As Object, e As System.Windows.Forms.PaintEventArgs) Handles _Parent.Paint
        If _VertexCollection IsNot Nothing Then
            e.Graphics.DrawPolygon(System.Drawing.Pens.Black, _VertexCollection)
        End If
    End Sub
 
'+ mouse events etc.
 
End Class

However, I have heard that handling the events of a parent control conflicts with OOP principles. So I would like to know, does that objection apply in a case like my example? If so, what are the drawbacks? And what alternative techniques are available?

BB