activateCell 
  open fun activateCell(widget: Widget, renderer: CellRenderer, event: <Error class: unknown class>, cellArea: <Error class: unknown class>, flags: CellRendererState): Boolean(source)
⚠️ Deprecated ⚠️
This is deprecated since version 4.10.
---This is used by GtkCellArea subclasses when handling events to activate cells, the base GtkCellArea class activates cells for keyboard events for free in its own GtkCellArea->activate() implementation.
Return
whether cell activation was successful
Parameters
widget
the GtkWidget that @area is rendering onto
renderer
the GtkCellRenderer in @area to activate
event
the GdkEvent for which cell activation should occur
cellArea 
the GdkRectangle in @widget relative coordinates     of @renderer for the current row.
flags
the GtkCellRendererState for @renderer