GtkStatusbar::pop
void pop(int context_id);
pop() removes the message
that is currently at the top of the statusbar's stack, using the
context_id to identify the message.
When a message is removed from the stack, the memory that was allocated
to it is freed. Given that all messages are generated uniquely, it is
good practice to pop() the
current message before appending the next. Allowing the stack to build
up can add considerably to processing time.
This method causes the
"text-popped" signal to be
emitted.