plugin/cutils: add getAverageLuminance

Fixes stutters in wallpaper list

Also fix crash when saveItem target doesn't have a window

1 files changed, 11 insertions, 7 deletions

diff --git a/services/Colours.qml b/services/Colours.qml
index 8470cfa..ca78abc 100644
--- a/services/Colours.qml
+++ b/services/Colours.qml
@@ -3,6 +3,7 @@ pragma ComponentBehavior: Bound
 
 import qs.config
 import qs.utils
+import Caelestia
 import Quickshell
 import Quickshell.Io
 import QtQuick
@@ -21,7 +22,7 @@ Singleton {
     readonly property M3Palette current: M3Palette {}
     readonly property M3Palette preview: M3Palette {}
     readonly property Transparency transparency: Transparency {}
-    readonly property color wallColour: quantizer.colors[0] ?? "black"
+    property real wallLuminance
 
     function getLuminance(c: color): real {
         if (c.r == 0 && c.g == 0 && c.b == 0)
@@ -30,7 +31,6 @@ Singleton {
     }
 
     function alterColour(c: color, a: real, layer: int): color {
-        const wallLuminance = getLuminance(wallColour);
         const luminance = getLuminance(c);
 
         const offset = (!light || layer == 1 ? 1 : -layer / 2) * (light ? 0.2 : 0.3) * (1 - transparency.base) * (1 + wallLuminance * (light ? (layer == 1 ? 3 : 1) : 2.5));
@@ -85,12 +85,16 @@ Singleton {
         onLoaded: root.load(text(), false)
     }
 
-    ColorQuantizer {
-        id: quantizer
+    Connections {
+        target: Wallpapers
 
-        source: Qt.resolvedUrl(Wallpapers.current)
-        depth: 0
-        rescaleSize: 128
+        function onCurrentChanged(): void {
+            const current = Wallpapers.current;
+            CUtils.getAverageLuminance(current, l => {
+                if (Wallpapers.current == current)
+                    root.wallLuminance = l;
+            });
+        }
     }
 
     component Transparency: QtObject {