action center: scrollable quick sliders (#2536)

dots/.config/quickshell/ii/modules/waffle/actionCenter/mainPage/MainPageBodySliders.qml

@@ -33,6 +33,7 @@ ColumnLayout {
         WSlider {
             Layout.fillWidth: true
             value: root.brightnessMonitor?.brightness ?? 0
+            scrollable: true
             onMoved: {
                 root.brightnessMonitor?.setBrightness(value)
             }
@@ -54,6 +55,7 @@ ColumnLayout {
         WSlider {
             Layout.fillWidth: true
             value: Audio.sink.audio.volume
+            scrollable: true
             onMoved: {
                 Audio.sink.audio.volume = value;
             }

dots/.config/quickshell/ii/modules/waffle/looks/WSlider.qml

@@ -11,6 +11,8 @@ Slider {
 
     property real trackWidth: 4
     property string tooltipContent: `${Math.round(value * 100)}`
+    property bool scrollable: false
+    stepSize: 0.02
     leftPadding: 0
     rightPadding: 0
 
@@ -22,10 +24,24 @@ Slider {
         }
     }
 
-    background: Item {
+    background: MouseArea {
         id: background
         anchors.fill: parent
 
+        onWheel: (event) => {
+            if (!root.scrollable) {
+                event.accepted = false;
+                return;
+            }
+            if (event.angleDelta.y > 0) {
+                root.value = Math.min(root.value + root.stepSize, 1)
+                root.moved()
+            } else {
+                root.value = Math.max(root.value - root.stepSize, 0)
+                root.moved()
+            }
+        }
+
         Rectangle {
             id: trackHighlight
             anchors {