With no titlebar in KDE for okular, Could there be on option to have (Minimize, Maximize, Close) in the toolbar? Reproducible: Always
How do you remove the titlebar?
(In reply to comment #1) > How do you remove the titlebar? KDE -> System Settings -> Window Behaviour -> Window Rules New -> 'Application settings for okular' Appearance & Fixes -> No titlebar and frame = Force Yes
Have you tried using the Alt+F3 menu?
(In reply to comment #3) I mean the setup as in Oxygen KDE <https://addons.mozilla.org/en-US/firefox/addon/oxygen-kde/> like to top right hand corner of https://static-ssl-cdn.addons.mozilla.net/img/uploads/previews/full/63/63909.png The titlebar is removed in the setup, and (Minimize, Maximize, Close) is added to the toolbar.
Then you are explaining yourself very badly. Why didn't you attach the screenshot on the first time? This has nothing to do with Okular, what you want is a KWin (i guess) feature.
KWin can and does not stuff items into the application. What you describe here is called client-side decoration, and has to be provided by the client entirely and only (which will likely rely on the UI style and abuse the MDI buttons or this is a FF specific theme. -> either kdelibs / KMainWindow or the application itself has to provide these buttons.. Notice that i happen to know that the KWin maintainer is not too excited about client-side decorations - and i'm neither. passing to kdelibs
kdelibs developers are not interested in client side decorations either.