feat: add per stream volume page

modules/nexus/PageCompRegistry.qml

@@ -3,6 +3,7 @@ pragma Singleton
 import QtQuick
 import qs.modules.nexus.common
 import qs.modules.nexus.pages
+import qs.modules.nexus.pages.audio
 import qs.modules.nexus.pages.bluetooth
 import qs.modules.nexus.pages.wallandstyle
 
@@ -58,6 +59,9 @@ QtObject {
                 Component {
                     AudioPage {}
                 }
+                Component {
+                    AppVolumes {}
+                }
             }
         }
     ]

modules/nexus/pages/audio/AppVolumes.qml

@@ -0,0 +1,69 @@
+pragma ComponentBehavior: Bound
+
+import QtQuick
+import QtQuick.Layouts
+import Quickshell
+import Quickshell.Services.Pipewire
+import Caelestia.Config
+import qs.components
+import qs.services
+import qs.utils
+import qs.modules.nexus.common
+
+PageBase {
+    id: root
+
+    title: qsTr("App volumes")
+    isSubPage: true
+
+    ColumnLayout {
+        anchors.horizontalCenter: parent.horizontalCenter
+        anchors.top: parent.top
+        width: root.cappedWidth
+        spacing: Tokens.spacing.extraSmall / 2
+
+        StyledText {
+            Layout.fillWidth: true
+            Layout.bottomMargin: Tokens.spacing.medium
+            text: qsTr("Adjust the volume of individual apps currently playing audio.")
+            color: Colours.palette.m3outline
+            font: Tokens.font.body.small
+            wrapMode: Text.WordWrap
+        }
+
+        ItemList {
+            id: streamList
+
+            first: true
+            last: true
+            showList: true
+            placeholderIcon: "music_off"
+            placeholderText: qsTr("No apps playing audio")
+            color: list.count === 0 ? Colours.tPalette.m3surfaceContainer : "transparent"
+            list.spacing: Tokens.spacing.extraSmall / 2
+
+            model: ScriptModel {
+                values: [...Audio.streams]
+            }
+
+            delegate: SliderRow {
+                id: stream
+
+                required property PwNode modelData
+                required property int index
+
+                anchors.left: streamList.list.contentItem.left
+                anchors.right: streamList.list.contentItem.right
+                first: index === 0
+                last: index === streamList.list.count - 1
+
+                icon: Icons.getVolumeIcon(stream.modelData?.audio?.volume ?? 0, stream.modelData?.audio?.muted ?? false)
+                label: Audio.getStreamName(stream.modelData)
+                valueLabel: Math.round(value * 100) + "%"
+                value: stream.modelData?.audio?.volume ?? 0
+                enabled: !stream.modelData?.audio?.muted
+                onMoved: v => Audio.setStreamVolume(stream.modelData, v)
+            }
+        }
+    }
+}