You would need to look at the drag vector (the vector between the points in each drag delta) and determine whether the user is trying to scroll the panel (drag in the scrolling direction) or move an item out of it (drag in the non-scrolling direction). In the case that its not a scroll gesture, you might want to release mouse capture and fire an event with the item being dragged. In your app, you can handle that event by grabbing capture from another element. You can then use an adorner to render the item being dragged until it is released. I’ve used this exact approach and it works quite well.

Honestly, drag & drop code is probably too involved to try to explain well in a comment here, but hopefully you get the gist. I don’t currently have the bandwidth to put together a sample, but I’ll add it to my huge list of potential future posts. :S

Cheers,
-dw

First of all, thank you so much for this great article which spared me a looot of time at work and allowed me to understand many things about WPF.

However, I was wondering how I could implement drag&drop operations on the looping listbox, while keeping the already implemented and working drag events ?

I.E, I want to be able to drag&drop the source of my click on the looping list box into another control, while dragging this item will still continue to scroll the listbox.

Many many many thanks,
Laurent

This is a truly fantastic article, well laid out, clear, understandable and extremely useful. Thank you so much for the effort you put into it.

I do hope you get those extra hours to add the enhancements…if I had the power to make them I’d definitely be sending some your way!

Thanks again,
Richard

The updated sample is really available now! Thanks for the heads up.

Another approach I sometimes advocate (less invasive, but a little more work for the person using your control) is to have the parent control set attached properties on its children (like ChildAngle, ChildScaleX, ChildScaleY, etc). This creates more of an “opt in” mechanism where the item container can specify its own RenderTransform with child transforms each binding to the attached properties it cares about.

I like both approaches.

Cheers,
-dw

For example, I have a carousel control which wraps the user-provided ItemTemplate in a ContentPresenter, and sets a render transform on the ContentPresenter to produce a pop-out effect when the mouse is over the item. Another example is a drawing canvas, which provides pan, zoom and rotate with mouse gestures. In this case the user control manipulates the render transform of a child canvas, and exposes the items in the canvas indirectly.