[news.eclipse.tools.gef] Re: Editparts, Figures and children

[Pat <spam@xxxxxxxxxx>]

Hi Randy,

this would be fine for the simple example I cited. However, sometimes I 
need to build up more complex figures for layout reasons. I.e. one 
editpart has a figure with any number of nested figures to lay out the 
EditPart. In this case I might not actually be adding to the EditPart's 
top level figure, but to one of its children. It also isn't necessarily 
a case of having a 'content pane' to which child visuals are added. They 
can be placed anywhere in the figure hierarchy.

I've worked round the problem by having a superclass EditPart which 
allows 'placeholders' to be added to a figure by subclasses. The 
placeholders are stored in a List for retrieval later. The signature for 
the method is

	protected void addPlaceholder(Figure container)

This allows the subclass to determine where the child EditPart's figure 
will ultimately be placed. The superclass overrides 
addChildVisual/removeChildVisual to look up the placeholder by index and 
replaces it with the child editpart's figure. Seems to work well.

BTW as I'm sure you know, overriding add/removeChildVisual to do nothing 
was not a solution. When createFigure() is called, the parent EditPart 
doesn't have any child EditParts so it can't add them at that point.

Thanks for the help.

Pat


Randy Hudson wrote:
> It sounds like you want 2 children figures to be at figure indexes 0 and 2.
> Why not just extend the method and correct the indexed?  In other words, if
> index==1, set index := 2.