Resets any previously cached request and allocation
data.
When underlying #GtkTreeModel data changes its
important to reset the context if the content
size is allowed to shrink. If the content size
is only allowed to grow (this is usually an option
for views rendering large data stores as a measure
of optimization), then only the row that changed
or was inserted needs to be (re)requested with
gtk_cell_area_get_preferred_width().
When the new overall size of the context requires
that the allocated size changes (or whenever this
allocation changes at all), the variable row
sizes need to be re-requested for every row.
For instance, if the rows are displayed all with
the same width from top to bottom then a change
in the allocated width necessitates a recalculation
of all the displayed row heights using
gtk_cell_area_get_preferred_height_for_width().
Resets any previously cached request and allocation data.
When underlying #GtkTreeModel data changes its important to reset the context if the content size is allowed to shrink. If the content size is only allowed to grow (this is usually an option for views rendering large data stores as a measure of optimization), then only the row that changed or was inserted needs to be (re)requested with gtk_cell_area_get_preferred_width().
When the new overall size of the context requires that the allocated size changes (or whenever this allocation changes at all), the variable row sizes need to be re-requested for every row.
For instance, if the rows are displayed all with the same width from top to bottom then a change in the allocated width necessitates a recalculation of all the displayed row heights using gtk_cell_area_get_preferred_height_for_width().
Since 3.0