Here you can see the popup KDevelop 4 shows when hovering a declaration, a definition or use of one of these. It displays useful information about the symbol like where it is defined. All links can be clicked on to jump to the related location.
Tip: You can use the tooltip without any mouse interaction. Place the text cursor in a symbol and press
ALT and keep it pressed. The tooltip will shop up. You can now use the arrow keys to navigate in the tooltip. Press
Return to activate a link.