Searching in a GtkSourceBuffer @GTK_SOURCE_SEARCH_VISIBLE_ONLY: @GTK_SOURCE_SEARCH_TEXT_ONLY: @GTK_SOURCE_SEARCH_CASE_INSENSITIVE: @iter: @str: @flags: @match_start: @match_end: @limit: @Returns: @iter: @str: @flags: @match_start: @match_end: @limit: @Returns: @iter: @Returns: