RFC: New KWin effect for notifications

[Marco Martin]

On Thursday 26 November 2015, Martin Klapetek wrote:
> * setting an offset makes it appear out of nowhere;
>   that itself would be moreless fine, but the disappearing
>   animation makes it look really strange, it basically just
>   shrinks in height in place. This works fine when things
>   looks attached to the panel, then it looks like it slides
>   back to the panel, but with a detached popup it just
>   doesn't look good

for that it could just have a property that tells whether to clip during 
animation or not

> * the offset seems to be from screen edge rather than
>   from a strut edge

i don't think even attempting to make it from a strut edge makes sense or is 
manageable (as struts can have funky shapes in reality)

> * the popups are appearing in vertical stack and if one
>   of the bottom popups closes, the others are animated
>   to slide down; that's not entirely possible with slideWindow

that is the actually interesting point that makes it problematic that either 
justifies a different effect or even that may not be enough.

in brief the problem is:
* there is a window at a given position, like 10,10
* we want to move it to like 10, 20
* the movement has to "look" animated.

now, if i understood correctly, actual animation of the window position should 
be avoided, so would need after the window position is changed, for kwin to 
keep rendering it at the old position and then animate it still translated to 
the actual final position?

what would kwin need to do to do this third point in the best/smootest way 
possible? (note this would be utterly useful for plasma tooltips as well)

-- 
Marco Martin