> Say I've got a class containing a list of values. For example, a
> Palette class containing a list of colors (something like the
> following incomplete class declaration):
>
> class Palette
> {
> public:
> typedef std::vector<rgb_t> color_list_type;
> // snipped other methods
> color_list_type& colors(void);
>
> private:
> color_list_type m_colors;
> };
>
> Now say I want to display these values in a treeview. One option is
> obviously to copy all of the values from m_colors into a
> Gtk::ListModel. But this has a rather large disadvantage in that when
> I make some changes in the treeview (i.e. add a new item, re-order
> items, remove items), I would need to copy these items out of the
> listmodel into a Palette whenever I want to use this group of items as
> a Palette type.
Maybe you should just store the Palette in the list model and use
cell_data_func callbacks to show it in the treeview.
> I'd rather just have the treeview display data directly from the
> Palette class so that I don't need to copy / synchronize things back
> and forth. So in order to display data directly from the Palette
> class, I'd need to have Palette inherit from Gtk::TreeModel (i.e.
> implement a custom TreeModel). There is an example in gtkmm CVS that
> shows how to implement a custom TreeModel, but unfortunately I haven't
> had much luck deciphering it (especially the GlueItem stuff). And
> besides the example, the documentation on implementing custom
> TreeModels is pretty sparse, Has anybody really done this before?
I've done it in Glom, but the gtkmm example is simpler.
> Does anybody know of other examples I could look at? Is there a
> better way to solve this problem than implementing a custom TreeModel?
>
> What I think would be helpful is some guidance on what methods need to
> be implemented / overridden and approximately what they're supposed to
> do, etc. I'd be willing to put together a document like this (maybe
> as a section in the tutorial) if I can get it figured out.
Murray Cumming
[EMAIL PROTECTED]
www.murrayc.com
www.openismus.com
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