void begin_user_action ( GtkTextBuffer* buffer )
Called to indicate that the buffer operations between here and a
gtk_text_buffer_end_user_action() are part of a single
user-visible operation. The operations between
gtk_text_buffer_end_user_action() can then be grouped when creating
an undo stack.
GtkTextBuffer maintains a count of calls to
gtk_text_buffer_begin_user_action() that have not been closed with
a call to gtk_text_buffer_end_user_action(), and emits the
“begin-user-action” and “end-user-action” signals only for the
outermost pair of calls. This allows you to build user actions
from other user actions.
The “interactive” buffer mutation functions, such as gtk_text_buffer_insert_interactive(), automatically call begin/end user action around the buffer operations they perform, so there’s no need to add extra calls if you user action consists solely of a single call to one of those functions.