Gtk.TreeView.prototype.get_background_area

function get_background_area(path:Gtk.TreePath, column:Gtk.TreeViewColumn):void {
    // Gjs wrapper for gtk_tree_view_get_background_area()
}

Fills the bounding rectangle in bin_window coordinates for the cell at the row specified by path and the column specified by column. If path is null, or points to a node not found in the tree, the @y and @height fields of the rectangle will be filled with 0. If column is null, the @x and @width fields will be filled with 0. The returned rectangle is equivalent to the @background_area passed to Gtk.CellRenderer.prototype.render. These background areas tile to cover the entire bin window. Contrast with the @cell_area, returned by Gtk.get_cell_area, which returns only the cell itself, excluding surrounding borders and the tree expander area.