evdev: add evdev monitor for caps lock state

quickshell/DMSShell.qml

@@ -600,6 +600,14 @@ Item {
         }
     }
 
+    Variants {
+        model: SettingsData.getFilteredScreens("osd")
+
+        delegate: CapsLockOSD {
+            modelData: item
+        }
+    }
+
     LazyLoader {
         id: hyprlandOverviewLoader
         active: CompositorService.isHyprland

quickshell/Modules/Lock/LockScreenContent.qml

@@ -332,6 +332,7 @@ Item {
         }
 
         ColumnLayout {
+            id: passwordLayout
             anchors.centerIn: parent
             anchors.verticalCenterOffset: 50
             spacing: Theme.spacingM
@@ -740,6 +741,35 @@ Item {
             }
         }
 
+        Row {
+            anchors.top: passwordLayout.bottom
+            anchors.topMargin: Theme.spacingS
+            anchors.horizontalCenter: passwordLayout.horizontalCenter
+            spacing: 4
+            opacity: DMSService.capsLockState ? 1 : 0
+
+            DankIcon {
+                name: "shift_lock"
+                size: 14
+                color: Theme.error
+                anchors.verticalCenter: parent.verticalCenter
+            }
+
+            StyledText {
+                text: "Caps Lock is on"
+                font.pixelSize: Theme.fontSizeSmall
+                color: Theme.error
+                anchors.verticalCenter: parent.verticalCenter
+            }
+
+            Behavior on opacity {
+                NumberAnimation {
+                    duration: Theme.shortDuration
+                    easing.type: Theme.standardEasing
+                }
+            }
+        }
+
         StyledText {
             anchors.top: parent.top
             anchors.left: parent.left

quickshell/Modules/OSD/CapsLockOSD.qml

@@ -0,0 +1,37 @@
+import QtQuick
+import qs.Common
+import qs.Services
+import qs.Widgets
+
+DankOSD {
+    id: root
+
+    osdWidth: Theme.iconSize + Theme.spacingS * 2
+    osdHeight: Theme.iconSize + Theme.spacingS * 2
+    autoHideInterval: 2000
+    enableMouseInteraction: false
+
+    property bool lastCapsLockState: false
+
+    Connections {
+        target: DMSService
+
+        function onCapsLockStateChanged() {
+            if (lastCapsLockState !== DMSService.capsLockState) {
+                root.show()
+            }
+            lastCapsLockState = DMSService.capsLockState
+        }
+    }
+
+    Component.onCompleted: {
+        lastCapsLockState = DMSService.capsLockState
+    }
+
+    content: DankIcon {
+        anchors.centerIn: parent
+        name: DMSService.capsLockState ? "shift_lock" : "shift_lock_off"
+        size: Theme.iconSize
+        color: Theme.primary
+    }
+}

quickshell/Services/DMSService.qml

@@ -49,8 +49,11 @@ Singleton {
     signal brightnessDeviceUpdate(var device)
     signal extWorkspaceStateUpdate(var data)
     signal wlrOutputStateUpdate(var data)
+    signal evdevStateUpdate(var data)
 
-    property var activeSubscriptions: ["network", "network.credentials", "loginctl", "freedesktop", "gamma", "bluetooth", "bluetooth.pairing", "dwl", "brightness", "wlroutput"]
+    property bool capsLockState: false
+
+    property var activeSubscriptions: ["network", "network.credentials", "loginctl", "freedesktop", "gamma", "bluetooth", "bluetooth.pairing", "dwl", "brightness", "wlroutput", "evdev"]
 
     Component.onCompleted: {
         if (socketPath && socketPath.length > 0) {
@@ -349,6 +352,11 @@ Singleton {
             extWorkspaceStateUpdate(data)
         } else if (service === "wlroutput") {
             wlrOutputStateUpdate(data)
+        } else if (service === "evdev") {
+            if (data.capsLock !== undefined) {
+                capsLockState = data.capsLock
+            }
+            evdevStateUpdate(data)
         }
     }