The Dim Inactive effect was rewritten mostly to fix most of issues with
it, e.g. after leaving a full screen effect(e.g. Desktop Grid) windows
sometimes are not dimmed back, or when a window becomes inactive there
is no smooth transition, etc.
Before: the window is not smoothly dimmed.
After: the window is smoothly dimmed.
In combination with an effect that animates the disappearing of windows,
e.g. Glide, the rewritten Dim Inactive effect doesn't "flash" windows.
If an active window has been closed, it will stay bright. If an inactive
window has been closed, it will stay dimmed.
Among other changes, the KCM has been re-designed to follow common KCM
design in Plasma:
The way the rewritten Dim Inactive effect handles flashing/flickering problem can be
reused in the Dialog Parent effect.
Before: dimming of a window group.
After: Dimming of a window group.
Depends on D13740