Hi, I'm writing an application with gtkmm. I write my own derived TreeModel (derived from GtkTreeStore), and in the process I've been reading GTK source code a lot, gtktreeview.c and gtktreestore.c, because that's where things are actually implemented.
I've been looking for a way to disable drag-n-drop between rows. As you probably know, a drop can happen between rows (then the GUI shows a thin line where the drop would happen) or on a row (then the GUI highlights the drop destination row). The automatic DnD doesn't work with sorting, so it's currently off, but even if I eventually use my own sorting code, the model will be sorted. Just like when I open Nautilus and watch a folder's contents in the list-view mode - it doesn't make sense to drop between rows because the order is determined by the sorting code, not by the user. I found several locations in the code, which I believe are responsible to start the graphical highlight when the cursor moves while dragging a row. But I'm not sure I covered all cases and found everything I need, so I'd like to know: Basically, which signal handlers do I need to override, and/or which stages of DnD process require my intervension, in order to avoid any highlighting of drop-between-rows (i.e. never draw that thin line between the rows) ? I figured out overriding drag_dest_row_drop_possible (), i.e. in the gtkmm case overriding Gtk::TreeDragDest::row_drop_possible_vfunc(), can help avoid the drop itself, but does it also mean the lines aren't drawn in the first place? Do I also need to override TreeView signal handlers, e.g. gtk_tree_view_drag_motion() ? I found an internal function set_destination_row() which seems to be responsible for highlighting the rows by calling public method gtk_tree_view_set_drag_dest_row() but I can't override either, so I guess the workaround, if it's really the solution, is to find all the places where these methods are called and make sure the drop-between-rows case is ignored. Thanks in advance, Tom _______________________________________________ gtk-app-devel-list mailing list gtk-app-devel-list@gnome.org https://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
