[effects/fadingpopups] Don't animate KDE Plasma splash screen

Summary:
In order to be compatible with the monolithic Fade effect, this effect
animates special windows (e.g. notifications, etc) as well, but some
of those special windows shouldn't be animated by this effect (e.g.
KDE Plasma splash screen).

Test Plan:
Started new Plasma on Wayland session, the KDE Plasma splash screen
smoothly faded out without flickering/blinking, etc.

Reviewers: #kwin, davidedmundson

Reviewed By: #kwin, davidedmundson

Subscribers: davidedmundson, kwin

Tags: #kwin

Differential Revision: https://phabricator.kde.org/D17209

effects/fadingpopups/package/contents/code/main.js

@@ -20,7 +20,23 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 "use strict";
 
+var blacklist = [
+    // The logout screen has to be animated only by the logout effect.
+    "ksmserver ksmserver",
+    "ksmserver-logout-greeter ksmserver-logout-greeter",
+
+    // KDE Plasma splash screen has to be animated only by the login effect.
+    "ksplashqml ksplashqml",
+    "ksplashsimple ksplashsimple",
+    "ksplashx ksplashx"
+];
+
 function isPopupWindow(window) {
+    // If the window is blacklisted, don't animate it.
+    if (blacklist.indexOf(window.windowClass) != -1) {
+        return false;
+    }
+
     // Animate combo box popups, tooltips, popup menus, etc.
     if (window.popupWindow) {
         return true;