Re: Drag and drop mysteries

[Matthias Kaeppler <nospam digitalraid com>]

Chris Vine wrote:

> On Wednesday 18 May 2005 09:57, Matthias Kaeppler wrote:
>
>  
>
> > Okay, I have finished reading and I'm not really satisfied. My program
> > still doesn't work.
> >     // enable drag and drop
> >     m_target_entries.push_back( Gtk::TargetEntry("FILE") );
> >     m_target_entries.push_back( Gtk::TargetEntry("DIR") );
> >    
>
>  
>
> >     m_view.drag_source_set(
> > m_target_entries,
> > Gdk::ModifierType( Gdk::BUTTON1_MASK | Gdk::BUTTON2_MASK ),
> > Gdk::DragAction( Gdk::ACTION_COPY | Gdk::ACTION_MOVE | Gdk::ACTION_LINK )
> > );
> >     m_view.drag_dest_set(
> > m_target_entries,
> > Gtk::DEST_DEFAULT_ALL,
> > Gdk::DragAction( Gdk::ACTION_COPY | Gdk::ACTION_MOVE | Gdk::ACTION_LINK )
> > );
> >
> >     m_view.signal_drag_data_get()
> > .connect( sigc::mem_fun( *this, &DirBrowser::on_drag_data_get ) );
> >     m_view.signal_drag_data_received()
> > .connect( sigc::mem_fun( *this, &DirBrowser::on_drag_data_received ) );
> >
> > [...]
> >
> > ##############################################################
> >
> > The signal handlers:
> >
> > ##############################################################
> >
> > void DirBrowser::on_drag_data_get
> > ( const Glib::RefPtr<Gdk::DragContext>&, const Gtk::SelectionData&,
> > guint, guint )
> > {
> >     std::cout << "getting data" << std::endl;
> > }
> >
> > void DirBrowser::on_drag_data_received
> > ( const Glib::RefPtr<Gdk::DragContext>& context, int, int, const
> > Gtk::SelectionData& data, guint, guint time )
> > {
> >     std::cout << "data received" << std::endl;
> > }
> >
> > ##############################################################
> >
> > The on_drag_data_received is never called. Something is still wrong here.
> >    
>
> It is quite difficult to comment on this as it is not complete.  I assume you 
> have a tree model, and I assume you have tree view columns for the tree view.  
> Apart from that, what I can see is:
>
> 1.  Your targets should be:
>
>  m_target_entries.push_back(Gtk::TargetEntry("STRING"));
>  m_target_entries.push_back(Gtk::TargetEntry("text/plain"));
>
> 2.  If, as I assume, DirBrowser is derived from Gtk::Widget you have connected 
> signals to the virtual protected member functions which also dispatch those 
> signals.
>
> Chris
>
>  

at 1) How is one supposed to know this stuff with the "STRING" and 
"text/plain"?
It's nowhere documented, it only appears in the examples without further 
explanation,
so it looked completely random to me.
What other "types" are there for drag and drop targets?

at 2) I'm not sure what you mean here. I have a TreeView which is 
supposed to be dnd enabled.
What does this have to do with the underlying window?