the GtkWidget that @area is rendering onto
the GtkCellRenderer in @area to activate
the GdkEvent for which cell activation should occur
the GdkRectangle in @widget relative coordinates of @renderer for the current row.
the GtkCellRendererState for @renderer
whether cell activation was successful
This is used by GtkCellArea subclasses when handling events to activate cells, the base GtkCellArea class activates cells for keyboard events for free in its own GtkCellArea->activate() implementation.