On Tue, 4 Sep 2018 at 00:09, c.buhtz--- via gtk-app-devel-list < gtk-app-devel-list@gnome.org> wrote:
> Dear Emmanuele, > > you describe how to set a drag icon. I know how to do this. > https://stackoverflow.com/q/51975256/4865723 > > But the question is how do I create my icon? > That's what I wrote in my email: > If you want to override that, you should call > gtk_drag_set_icon_surface(), using a Cairo surface you created: > > https://developer.gnome.org/gtk3/stable/gtk3-Drag-and-Drop.html#gtk-drag-set-icon-surface > > The GtkTreeView uses the default handler of the GtkWidget::drag-begin > signal to set the drag icon; you want your own handler to be called > after that, so you can override the drag icon with your own. Icons are Cairo surfaces; this means you need to create a Cairo surface and render on it using the Cairo API. > e.g. TreeView create it's own one, too. It is based on the row content. > I can I do the same? e.g. I only want the content of the second > column/cell and not the complete row? > You can get the contents of the model and render them as you wish, using the gtk_render_* API. Ciao, Emmanuele. On 2018-09-02 02:33 Emmanuele Bassi > <eba...@gmail.com> wrote: > > On Sat, 1 Sep 2018 at 22:20, c.buhtz--- via gtk-app-devel-list < > > gtk-app-devel-list@gnome.org> wrote: > > > > > I want to use my own drag-icon in a Gtk.TreeView where this is set > > > as an instance of GdkPixbuf.Pixbuf. > > > > > > I can I create/draw a pixbuf and create Text, background and border > > > color in it? > > > > > > > Typically, GtkTreeView will call gtk_tree_view_create_row_drag_icon() > > for the default drag surface — a box with the contents of the row. > > > > > https://developer.gnome.org/gtk3/stable/GtkTreeView.html#gtk-tree-view-create-row-drag-icon > > > > If you want to override that, you should call > > gtk_drag_set_icon_surface(), using a Cairo surface you created: > > > > > https://developer.gnome.org/gtk3/stable/gtk3-Drag-and-Drop.html#gtk-drag-set-icon-surface > > > > The GtkTreeView uses the default handler of the GtkWidget::drag-begin > > signal to set the drag icon; you want your own handler to be called > > after that, so you can override the drag icon with your own. To do > > that, you can: > > > > - call gtk_tree_view_unset_model_drag_source() or > > gtk_tree_view_unset_model_drag_dest() and implement your own drag and > > drop handling > > - call g_signal_stop_emission_by_name() in your drag-begin callback > > to stop the signal emission chain, and prevent the default handler > > from running > > - use g_signal_connect_after() to connect your callback, and have > > your handler run after the default one > > - subclass GtkTreeView and override the drag_begin() virtual function > > without chaining up, to implement your own handler > > > > Ciao, > > Emmanuele. > > > > _______________________________________________ > gtk-app-devel-list mailing list > gtk-app-devel-list@gnome.org > https://mail.gnome.org/mailman/listinfo/gtk-app-devel-list -- https://www.bassi.io [@] ebassi [@gmail.com] _______________________________________________ gtk-app-devel-list mailing list gtk-app-devel-list@gnome.org https://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
