No tooltip on hover on min/maximise/close buttons

Project:Linux software
Component:Documentation
Category:feature request
Priority:normal
Assigned:Unassigned
Status:active
Related pages:#9134: kwin
Tags:Resizing, Windowing system
Description

As a usability feature, I'd like to have a tooltip appearing when hovering on minimize/maximize/close window buttons.
The tooltip would display the shortcuts affected to those buttons, as well as the ALT/CTRL modifiers, and a link to where the behaviour of the button can be changed.