busy app icon defaults to "Bouncing cursor". It represents a happy way to notify the user if an app has been launched and which. Currently systemsettings offers other 2 cursors animations, "Passive" and "Blinking", and the latter is broken when compositing is turned on.
"Passive busy cursor" produces a still app icon beside cursor as app launch feedback, and this is misleading. In modern UIs where everything is gracefully animated, it feels more "natural" (even rocks in nature remain never the same) to have animations, and feels extraneous and broken something that is still.
So maybe better that having 3 ways or doing busy cursors, whose two aren't working for different causes, it's better to leave the user the choice between the default "Bouncing" animation, and no busy effect. Notification kcm should reflect the change with a checkbox instead of the dropdown button.
More, there is an ambiguity in systemsettings: while you can configure and turn off busy cursors in Notifications kcm, in Desktop Effects kcm you can turn off the effect too. I don't think it's a good idea to control one whole thing in a place (the proper one), and a part of it in another. That is to say, probably it's better to cancel the "Candy: Startup Feedback" entry in kwin kcm and leave the effect active for user using compositing.
The very same reasoning could be applied for other effects too, like "Highlight windows" (Alt-Tab effect can use it).
Steps to Reproduce:
1. System settings > Launch Feedback > Busy Cursor, select "Passive busy cursor" or "Blinking cursor"
still, not animated, busy app icon if compositing is on.
always animated busy app icon, if ON.
Passive cursor bug (leaving traces) is bug #260727
OP suggests to drop all but bouncing and make startup feedback a toggle.
IIRC Fredrik had once mentioned to have a completely different replacement for the startup feedback mechanism (no mouse cursor icon shape stuff)
The entry in the effect lists exists, because it lists *all* effects and the effect only overtakes painting whe using GL compositing (because those littly things create a pretty huge overhead in that case)
It has no direct impact on whether startup feedback is used or not.
There's a bug about the effect configuration being to complex (and the idea was to completely dissamble it, have effects align to some regular settings and only allow direct manipulation of effect loading through a dedicated dialog)
Reg. the idea to reduce startup feedback mechanisms:
a) that's actually not a KWin topic ("you're on the wrong product")
b) this is likely best discussed at the KDE brainstorm forum  - at least the KWin maintainer/developers are unlikely in position to decide such on their own.
I changed the target of my bug report to something humbler, so opened it again.
Surprisingly, the whole thing changed after upgrading from 4.10.90 to 4.10.95.
1. Passive effect started to show same bug tracked in https://bugs.kde.org/show_bug.cgi?id=260727
2. Blinking effect works again (even if it's ugly:)
3. Bouncy effect now desaturates when moving cursor. This happens only when OpenGL 2.0 or 3.1 is selected. Works in 1.2 mode. VSync doesn't change things.
please attach the output of "qdbus org.kde.kwin /KWin supportInformation"
(In reply to comment #2)
> 3. Bouncy effect now desaturates when moving cursor. This happens only when
> OpenGL 2.0 or 3.1 is selected. Works in 1.2 mode. VSync doesn't change
Dirty shader state, but color correction is disabled.
- Does it "desaturate" slowely or instanly?
- Does it matter where you move it?
- Does it really "desaturate" or rather "darken" or "get translucent"?
- Does it happen when deactivating either
(and restart the compositor afterwards, ie. press "Shift+Alt+F12" twice)
- Can you record a video / make one or two screenshot(s)?
> Dirty shader state, but color correction is disabled.
> - Does it "desaturate" slowely or instanly?
> - Does it matter where you move it?
> - Does it really "desaturate" or rather "darken" or "get translucent"?
desaturate, as far as i can see
> - Does it happen when deactivating either
> * blurring
> * translucency
> * dialogparent
> * fade
> (and restart the compositor afterwards, ie. press "Shift+Alt+F12" twice)
> - Can you record a video / make one or two screenshot(s)?
(In reply to comment #6)
> > - Can you record a video / make one or two screenshot(s)?
Could this be the diabled icon look (or whatever causes the desaturated & translucent icon on the taskbar)
no, it happens on every launcher, e.g. kickoff too.
I meant the effect you can configure in "kcmshell4 icons" / "Advanced" tab
> Could this be the diabled icon look (or whatever causes the desaturated &
> translucent icon on the taskbar)
ok, got it. No, doesn't change anything.
But i've just found something funny. I was noticing that bouncy cursor sometimes is working as expected: when? When non-qt windows have focus, it works. When a qt window is on top (not necessarily active), is see the bug.
Any impact of either GUI style ("kwrite --style plastique") or window opacity?
> Any impact of either GUI style ("kwrite --style plastique") or window
should change title like
"Bouncy" busy cursor: desaturated app icon when moving cursor and qt app has focus"
don't ask me why, but in 4.11 final it just works :)
simply great release guys, you rock!