There are three options for autocheck when a doc is loaded:
Always autocheck, Never autocheck and Remember the autocheck setting for each document
The chosen option is stored in the gsettings schema.
The default setting is to remember by document as this is what Pluma did previously.
The replacement functions are available since 2.18
GTK_WIDGET_HAS_FOCUS -> gtk_widget_has_focus
GTK_WIDGET_VISIBLE -> gtk_widget_get_visible
GTK_WIDGET_SET_FLAGS -> gtk_widget_set_*