sokhapkin wrote:When I hover mouse cursor over KDE taskbar, kwin shows tooltip for the application. If I hover over the tooltip, KDE hides all windows on the desktop except for the tooltiped application. How to disable this annoying behavior? I don't want windows hide when hover over tooltip.
You are correct. If you place your mouse over an application icon in the taskbar, provided that application is open, it will show a thumbnail preview of that application window. If you were to then move your mouse into the tooltip area and hover over the thumbnail preview of the associated application, then yes, you will be shown a full desktop preview of that application (essentially a type of zoom or enlarged preview). If you then click on that preview with the mouse it will then switch to that application on the desktop. If you do not wish to switch to that window or instance of that application, you simply move your mouse away and the enlarged fullscreen preview will disappear.
This is by design and is especially helpful when you have more than one instance or window open of the same application such as Firefox, Dolphin (file browser) or Konsole (terminal). This allows the user to get a thumbnail preview of each of those instances and then by moving the mouse over the thumbnail see a larger full screen preview. It lets the user get a peek at the thumbnail but also see a larger view when trying to work with multiple open windows, without having to go back and forth between the two windows. If you find this behavior annoying I would suggest not moving your mouse over the taskbar icons for running applications and then subsequently moving your mouse over the generated thumbnail previews that pop up. Problem solved.