the GtkCellAreaContext in context with the current row data
the GtkWidget that area is rendering on
the size and location of area relative to widget's allocation
the GtkCellRendererState flags for area for this row of data.
if TRUE then only cell renderers that are GTK_CELL_RENDERER_MODE_EDITABLE will be activated.
Whether area was successfully activated. Since 3.0
Activates area, usually by activating the currently focused cell, however some subclasses which embed widgets in the area can also activate a widget if it currently has the focus.