comment control

[TheTree]

Hi,

I´m working on a comment control. I mean a control, that has an input area for text and images and a line or an arrow for pointing to something. It should a bit look like the comment control in Adobe Acrobat.

My first idea is to put four standard controls together:
1) a RichTextBox to hold text and images
2) a Panel to hold the RichTextBox and some GrabRectangles around it (the Panel needs to be a bit greater than the RTB for the GrabRectangles)
3) a little Panel (3x3 or 4x4 Pixel) to hold another GrabRectangle for placing and resizing the line (the arrow)
4) a LineShape for pointing (its startpoint on the RTB and endpoint on the little Panel)

I have added a drawing.

My question is: what can I use to put these controls together? Another Panel would probably do a good job. But it would cover a lot of additional area around the contained controls and hide other controls, so that they don´t get mouse clicks. Any other idea?

Is there a better way to create such a control?

Links and articles would also be helpful.

Greetings,

TheTree