Please describe the problem:
The x, y params should be of the type "out" 

get_tooltip_context (int x, int y, bool keyboard_tip, out unowned Gtk.TreeModel model, out unowned Gtk.TreePath path, out Gtk.TreeIter iter)

Should be:
get_tooltip_context (out int x,out int y, bool keyboard_tip, out unowned Gtk.TreeModel model, out unowned Gtk.TreePath path, out Gtk.TreeIter iter)

This for both GtkTreeView as GtkIconView.

(this is the gtk doc:
gboolean            gtk_tree_view_get_tooltip_context   (GtkTreeView *tree_view,
                                                         gint *x,
                                                         gint *y,
                                                         gboolean keyboard_tip,
                                                         GtkTreeModel **model,
                                                         GtkTreePath **path,
                                                         GtkTreeIter *iter);
This function is supposed to be used in a "query-tooltip" signal handler for GtkTreeView. The x, y and keyboard_tip values which are received in the signal handler, should be passed to this function without modification.

The return value indicates whether there is a tree view row at the given coordinates (TRUE) or not (FALSE) for mouse tooltips. For keyboard tooltips the row returned will be the cursor row. When TRUE, then any of model, path and iter which have been provided will be set to point to that row and the corresponding model. x and y will always be converted to be relative to tree_view's bin_window if keyboard_tooltip is FALSE.

tree_view :

a GtkTreeView
x :

the x coordinate (relative to widget coordinates)
y :

the y coordinate (relative to widget coordinates)
keyboard_tip :

whether this is a keyboard tooltip or not
model :

a pointer to receive a GtkTreeModel or NULL
path :

a pointer to receive a GtkTreePath or NULL
iter :

a pointer to receive a GtkTreeIter or NULL
Returns :

whether or not the given tooltip context points to a row.
)

Steps to reproduce:
1. 
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Actual results:


Expected results:


Does this happen every time?


Other information: