Semantic Sticky Function minor mode displays a header line that shows the declaration line of the function or tag on the topmost line in the text area. This allows you to keep that declaration line in view at all times, even if it is scrolls off the “top” of the screen.
In addition, clicking Mouse-1 on the header line opens a context menu that contains menu items for copying, killing, or narrowing to that tag.
Toggle Semantic Sticky Function mode in all Semantic-enabled buffers. With an optional argument arg, enable if arg is positive, and disable otherwise.