Before we take a closer look at how the Drag & Drop framework operates, let’s first go through what the capabilities are. The Drag & Drop framework allows you to add logic to your view to extend existing controls with Drag & Drop functionality. While almost all controls will support it in some form, it’s good to know beforehand what you can expect.
We can split the functionality in 2 main categories: Drag actions and Drop actions. A control is capable of a subset of these actions.
Drag actions determine what pieces of a control can be picked up and moved. At the moment, dragging is enabled for the WebList, WebTreeView and WebTagsForm.
Next are Drop Actions. Drop Actions determine where on a control a dragged element can be dropped.
Note that I keep using the term ‘element’ here, for lack of a better word. An element is a piece of a control that you picked up earlier, like a list row or a Tagsform tag.
This doesn’t necessarily have to be from a different control. You can also program the logic in such a way, that you can pick up items and drop them within the same control.
Finally, each drop action also works for files from your filesystem. We’ll go into more detail on this later.