gboolean gtk_text_buffer_delete_selection ( GtkTextBuffer* buffer, gboolean interactive, gboolean default_editable )
Deletes the range between the “insert” and “selection_bound” marks, that is, the currently-selected text.
TRUE, the editability of the selection will be
considered (users can’t delete uneditable text).
Whether the deletion is caused by user interaction.
Whether the buffer is editable by default.