B4J Question Drag & Drop many panes

[LucaMs]

This question is meant to drive @stevel05 crazy


With a lot of "hard work", I managed to modify his jDragAndDrop2 project so that a Pane is dragged onto another and the latter becomes its parent.

Having N Panes and wanting to move one of them, how do I detect on which of them I release the moved Pane?


Goal (not easy): use the native TreeView giving the user the ability to move nodes, modify the TreeView structure.

 

[MicroDrie]

I don't know how exactly you created the layout, nor how you detect drops, but for those initial panels you may be able to determine the order of which panel is being dragged based on a panel tag.

 

[stevel05]

In the _DragDropped sub you can use e.GetEventTarget method to get the view that was dropped on.

 

[LucaMs]

In the _DragDropped sub you can use e.GetEventTarget method to get the view that was dropped on.

I stopped at the first property that seemed the most suitable:
e.GetAcceptingObject
which returns a very strange thing.

e.GetEventTarget is very useful but the problem remains that you have to set MakeDragSource and MakeDragTarget for a single DragAndDrop object.

I'm afraid I should create a DragAndDrop object for every existing node pair.

 

[stevel05]

I'm afraid I should create a DragAndDrop object for every existing node pair

Yes a daunting task indeed. The most straightforward way to achieve this, although by no means simple, would be to create a Cell Factory for the Treeview and handle that in there.

You would need to delve into Java to achieve this method.

 

[LucaMs]

would be to create a Cell Factory for the Treeview and handle that in there.

You would need to delve into Java to achieve this method.

Thanks, but I should study for about 88 days (just because I like the number 88)

I could try using my library:
https://www.b4x.com/android/forum/threads/b4x-b4xlib-lmb4xpermutations.165073/#content

but I still don't know if it would work, detecting everything, which DragAndDrop object is "running", which nodes and who knows what else.

By the way, I should do the first test on a TreeView, directly setting the source and target node.

 

[LucaMs]

I could not get the base node of a TreeItem (I assume it exists).

So I'll have to create a TreeView from scratch.

 

[LucaMs]

I could not get the base node of a TreeItem (I assume it exists).

So I'll have to create a TreeView from scratch.

I had forgotten that I have to create a TreeView anyway from scratch, because I want it to have another type of view in addition to the nodes (branches-leaves), which allows me to place "AND" or "OR" between branches and/or leaves.