the #GtkCellAreaContext which has already been requested for widths.
the #GtkWidget where @area will be rendering
the height for which to check the width of this area
location to store the minimum width, or %NULL
location to store the natural width, or %NULL
Retrieves a cell area’s minimum and natural width if it would be given the specified @height.
@area stores some geometrical information in @context along the way while calling gtk_cell_area_get_preferred_height(). It’s important to perform a series of gtk_cell_area_get_preferred_height() requests with @context first and then call gtk_cell_area_get_preferred_width_for_height() on each cell area individually to get the height for width of each fully requested row.
If at some point, the height of a single row changes, it should be requested with gtk_cell_area_get_preferred_height() again and then the full height of the requested rows checked again with gtk_cell_area_context_get_preferred_height().