The type of the callback functions used for iterating over the cell renderers and their allocated areas inside a #GtkCellArea, see gtk_cell_area_foreach_alloc().
the cell renderer to operate on
the area allocated to renderer inside the rectangle provided to gtk_cell_area_foreach_alloc().
renderer
the background area for renderer inside the background area provided to gtk_cell_area_foreach_alloc().
The type of the callback functions used for iterating over the cell renderers and their allocated areas inside a #GtkCellArea, see gtk_cell_area_foreach_alloc().