handle new ConfigReloaded event

Services/NiriService.qml

@@ -26,6 +26,10 @@ Singleton {
   // Overview state
   property bool inOverview: false
 
+  // Config validation
+  property string configValidationOutput: ""
+  property bool hasInitialConnection: false
+
   signal windowOpenedOrChanged(var windowData)
 
   // Feature availability
@@ -97,6 +101,8 @@ Singleton {
       handleWindowOpenedOrChanged(event.WindowOpenedOrChanged)
     } else if (event.OverviewOpenedOrClosed) {
       handleOverviewChanged(event.OverviewOpenedOrClosed)
+    } else if (event.ConfigLoaded) {
+      handleConfigLoaded(event.ConfigLoaded)
     }
   }
 
@@ -248,6 +254,48 @@ Singleton {
     inOverview = data.is_open
   }
 
+  function handleConfigLoaded(data) {
+    if (data.failed) {
+      validateProcess.running = true
+    } else {
+      configValidationOutput = ""
+      if (ToastService.toastVisible && ToastService.currentLevel === ToastService.levelError) {
+        ToastService.hideToast()
+      }
+      if (hasInitialConnection) {
+        ToastService.showInfo("niri: config reloaded")
+      }
+    }
+    
+    if (!hasInitialConnection) {
+      hasInitialConnection = true
+    }
+  }
+
+  Process {
+    id: validateProcess
+    command: ["niri", "validate"]
+    running: false
+
+    stderr: StdioCollector {
+      onStreamFinished: {
+        const lines = text.split('\n')
+        const trimmedLines = lines.map(line => line.replace(/\s+$/, ''))
+                                  .filter(line => line.length > 0)
+        configValidationOutput = trimmedLines.join('\n').trim()
+        if (hasInitialConnection) {
+          ToastService.showError("niri: failed to load config", configValidationOutput)
+        }
+      }
+    }
+
+    onExited: exitCode => {
+      if (exitCode === 0) {
+        configValidationOutput = ""
+      }
+    }
+  }
+
   function updateCurrentOutputWorkspaces() {
     if (!currentOutput) {
       currentOutputWorkspaces = allWorkspaces

Services/ToastService.qml

@@ -15,34 +15,40 @@ Singleton {
   property int currentLevel: levelInfo
   property bool toastVisible: false
   property var toastQueue: []
+  property string currentDetails: ""
+  property bool hasDetails: false
   property string wallpaperErrorStatus: ""
 
-  function showToast(message, level = levelInfo) {
+  function showToast(message, level = levelInfo, details = "") {
     toastQueue.push({
                       "message": message,
-                      "level": level
+                      "level": level,
+                      "details": details
                     })
     if (!toastVisible)
       processQueue()
   }
 
-  function showInfo(message) {
-    showToast(message, levelInfo)
+  function showInfo(message, details = "") {
+    showToast(message, levelInfo, details)
   }
 
-  function showWarning(message) {
-    showToast(message, levelWarn)
+  function showWarning(message, details = "") {
+    showToast(message, levelWarn, details)
   }
 
-  function showError(message) {
-    showToast(message, levelError)
+  function showError(message, details = "") {
+    showToast(message, levelError, details)
   }
 
   function hideToast() {
     toastVisible = false
     currentMessage = ""
+    currentDetails = ""
+    hasDetails = false
     currentLevel = levelInfo
     toastTimer.stop()
+    resetToastState()
     if (toastQueue.length > 0)
       processQueue()
   }
@@ -54,10 +60,31 @@ Singleton {
     const toast = toastQueue.shift()
     currentMessage = toast.message
     currentLevel = toast.level
+    currentDetails = toast.details || ""
+    hasDetails = currentDetails.length > 0
     toastVisible = true
-    toastTimer.interval = toast.level
-        === levelError ? 5000 : toast.level === levelWarn ? 4000 : 3000
-    toastTimer.start()
+    resetToastState()
+    
+    if (toast.level === levelError && hasDetails) {
+      toastTimer.interval = 8000
+      toastTimer.start()
+    } else {
+      toastTimer.interval = toast.level === levelError ? 5000 : toast.level === levelWarn ? 4000 : 3000
+      toastTimer.start()
+    }
+  }
+
+  signal resetToastState
+  
+  function stopTimer() {
+    toastTimer.stop()
+  }
+  
+  function restartTimer() {
+    if (hasDetails && currentLevel === levelError) {
+      toastTimer.interval = 8000
+      toastTimer.restart()
+    }
   }
 
   function clearWallpaperError() {