Any ideas for a "scene builder" control?

[Werner Lehmann]

Hi,

I am looking for options to create a custom container control or pane 
with absolute-position layouting which allows users at runtime to 
select, resize, drag, or drag-select children - similar to SceneBuilder.

Absolute layouting would probably be achieved by j.s.layout.Pane. The 
hard part is how to display interactive selections with...
- selection border on selected controls,
- resizing-handles in the border corners,
- a drag-selection rectangle,

while still keeping this a private implementation detail...
- cannot change parent hierarchy of contained child nodes,
- cannot add private nodes like a selection rectangle to the public 
children property.

So far I am stuck on the prototyping phase because nothing satisfied the 
above:

1. Using CSS to draw selection borders: does not work because I could 
not display those 8 resizing-handles (on top yes, on bottom no), plus it 
may override existing control styles, plus it does not help with a 
drag-selection rectangle.

2. Extending Region and implement Skinnable, and the Skin has a 
stackpane for the private nodes: skins are intended for Control, not 
Region, need to use/copy some com.sun.* and impl and private code, and 
the layouting seems off (leaving out details here).

3. Extending Region with a nested substructure of StackPane and Panes, 
and returning only part of that substructure as public children. Does 
not work well either (not surprisingly because I have different public 
and private children lists then), and it violates the "cannot change 
parent hierarchy" requirement.

Am I missing something obvious? How is this done in SceneBuilder? Maybe 
it extends Control and lays out the children in a Skin?

Rgds
Werner