Revamp printer activation settings

BACKEND_API.md

@@ -12,7 +12,7 @@ Alle Endpunkte erfordern einen Bearer Token (JWT oder API-Key):
 Authorization: Bearer {token}
 ```
 
-`/printers/register`, `/jobs/next`, `/jobs/:id/image`, `/jobs/:id/printed` und `/jobs/:id/error` benötigen keine spezifische Permission, nur einen gültigen Token. `POST /jobs` und `POST /preview` erfordern `VIEW_SCANNER`.
+`/printers/register`, `/printers/:printerId/deactivate`, `/jobs/next`, `/jobs/:id/image`, `/jobs/:id/printed` und `/jobs/:id/error` benötigen keine spezifische Permission, nur einen gültigen Token. `POST /jobs` und `POST /preview` erfordern `VIEW_SCANNER`.
 
 ## 1. Job manuell anlegen (Frontend -> Backend)
 
@@ -67,9 +67,9 @@ Content-Type: image/png
 
 Body: binäres PNG-Bild.
 
-## 3. Drucker registrieren (Agent-Start)
+## 3. Drucker aktivieren/deaktivieren (Benutzeraktion in den Agent-Einstellungen)
 
-Der Agent ruft diesen Endpunkt beim Start für jeden konfigurierten lokalen Windows-Drucker auf.
+Der Agent ruft diesen Endpunkt nicht automatisch beim Start auf. Der Benutzer aktiviert lokale Windows-Drucker bewusst über die Agent-Einstellungen.
 
 ```http
 POST /api/label-print-agent/printers/register
@@ -84,7 +84,8 @@ Content-Type: application/json
   "windowsPrinterName": "Zebra GK420d",
   "dpi": 203,
   "defaultWidthMm": 101,
-  "defaultHeightMm": 76
+  "defaultHeightMm": 76,
+  "active": true
 }
 ```
 
@@ -98,6 +99,15 @@ Content-Type: application/json
 { "ok": true }
 ```
 
+Zum Deaktivieren entfernt der Benutzer den Haken `Aktiv`; der Agent ruft standardmäßig folgenden Endpunkt auf:
+
+```http
+POST /api/label-print-agent/printers/{printerId}/deactivate
+Content-Type: application/json
+```
+
+Der Request Body entspricht dem Aktivieren, aber mit `"active": false`.
+
 ## 4. Nächsten Druckjob abrufen (Agent-Polling)
 
 ```http

README.md

@@ -108,6 +108,7 @@ Beispiel:
     "agentId": "PC-BUERO",
     "encryptedApiToken": "",
     "registerPrinterPath": "/api/label-print-agent/printers/register",
+    "deactivatePrinterPath": "/api/label-print-agent/printers/{printerId}/deactivate",
     "nextJobPath": "/api/label-print-agent/jobs/next",
     "imagePath": "/api/label-print-agent/jobs/{jobId}/image",
     "reportSuccessPath": "/api/label-print-agent/jobs/{jobId}/printed",
@@ -128,7 +129,8 @@ Beispiel:
       "windowsPrinterName": "DYMO LabelWriter 450",
       "dpi": 300,
       "defaultWidthMm": 57,
-      "defaultHeightMm": 32
+      "defaultHeightMm": 32,
+      "isActive": true
     },
     {
       "printerId": "PC-BUERO_ZEBRA_GK420D",
@@ -136,7 +138,8 @@ Beispiel:
       "windowsPrinterName": "Zebra GK420d",
       "dpi": 203,
       "defaultWidthMm": 101,
-      "defaultHeightMm": 76
+      "defaultHeightMm": 76,
+      "isActive": false
     }
   ],
   "worker": {
@@ -148,7 +151,7 @@ Beispiel:
 
 Der API-Token wird lokal mit Windows DPAPI verschlüsselt gespeichert.
 
-Beim Start registriert der Agent jeden Eintrag aus `printers` beim Backend. Das Feld `printer` bleibt als Kompatibilitätsfeld für ältere Einstellungen erhalten; neue Jobs werden anhand von `windowsPrinterName` aus der Backend-Antwort auf den passenden lokalen Windows-Drucker gedruckt.
+Der Agent registriert Drucker nicht automatisch. Im Tab `Drucker` steht links die Druckerliste; rechts werden Aktiv-Status, Breite, Höhe und DPI pro Drucker gepflegt. Wird `Aktiv` gesetzt, registriert der Agent den Drucker im Backend. Wird der Haken entfernt, ruft der Agent den Deaktivierungs-Endpunkt auf. Das Feld `printer` bleibt als Kompatibilitätsfeld für ältere Einstellungen erhalten; neue Jobs werden anhand von `windowsPrinterName` aus der Backend-Antwort auf den passenden lokalen Windows-Drucker gedruckt.
 
 ## Dymo-Druck
 
@@ -166,7 +169,7 @@ Wichtig:
 1. Anwendung starten.
 2. Tray-Symbol öffnen.
 3. Im Tab `Backend` BaseUrl, AgentId und optional API-Token eintragen.
-4. Im Tab `Drucker` den Dymo LabelWriter auswählen.
+4. Im Tab `Drucker` links einen Drucker auswählen und rechts `Aktiv`, Breite, Höhe und DPI setzen.
 5. Im Tab `Allgemein` Polling aktivieren und Intervall setzen.
 6. Mit `Jetzt prüfen` kann sofort ein Poll-Lauf ausgelöst werden; dabei werden alle aktuell verfügbaren Jobs verarbeitet.
 

src/LabelPrintAgent/App/Program.cs

@@ -28,7 +28,7 @@ internal static class Program
             using var backendWorker = new BackendPollingWorker(settingsStore, backendClient, printerService);
             backendWorker.Start();
 
-            Application.Run(new TrayApplicationContext(settingsStore, printerService, backendWorker, updateService));
+            Application.Run(new TrayApplicationContext(settingsStore, printerService, backendClient, backendWorker, updateService));
         }
         catch (Exception ex)
         {

src/LabelPrintAgent/App/SettingsForm.cs

@@ -14,9 +14,17 @@ internal sealed class SettingsForm : Form
 
     private readonly SettingsStore _settingsStore;
     private readonly PrinterService _printerService;
+    private readonly BackendClient _backendClient;
     private readonly BackendPollingWorker _backendWorker;
     private readonly UpdateService _updateService;
+    private readonly Dictionary<string, PrinterConfig> _printerConfigs = new(StringComparer.OrdinalIgnoreCase);
     private UpdateCheckResult? _lastUpdateCheck;
+    private bool _loadingPrinters;
+    private bool _loadingPrinterConfig;
+    private string? _selectedSharedPrinterName;
+    private decimal _defaultLabelWidthMm = 57;
+    private decimal _defaultLabelHeightMm = 32;
+    private int _defaultPrinterDpi = 203;
 
     private readonly CheckBox _autoStartCheckBox = new() { Text = "Autostart aktivieren", AutoSize = true };
     private readonly CheckBox _workerEnabled = new() { Text = "Backend automatisch abfragen", AutoSize = true };
@@ -26,6 +34,8 @@ internal sealed class SettingsForm : Form
     private readonly TextBox _backendBaseUrl = new() { Width = 420 };
     private readonly TextBox _agentId = new() { Width = 260 };
     private readonly TextBox _apiToken = new() { Width = 420, UseSystemPasswordChar = true };
+    private readonly TextBox _registerPrinterPath = new() { Width = 420 };
+    private readonly TextBox _deactivatePrinterPath = new() { Width = 420 };
     private readonly TextBox _nextJobPath = new() { Width = 420 };
     private readonly TextBox _imagePath = new() { Width = 420 };
     private readonly TextBox _reportSuccessPath = new() { Width = 420 };
@@ -40,9 +50,12 @@ internal sealed class SettingsForm : Form
     private readonly TextBox _updateAsset = new() { Width = 540, ReadOnly = true };
     private readonly Button _installUpdateButton;
 
-    private readonly ComboBox _printer = new() { Width = 360, DropDownStyle = ComboBoxStyle.DropDownList };
+    private readonly ListBox _printerList = new() { Width = 320, Height = 285 };
+    private readonly CheckBox _printerActive = new() { Text = "Aktiv", AutoSize = true };
+    private readonly TextBox _windowsPrinterName = new() { Width = 360, ReadOnly = true };
     private readonly NumericUpDown _labelWidth = new() { Minimum = 1, Maximum = 500, DecimalPlaces = 1, Value = 57, Width = 100 };
     private readonly NumericUpDown _labelHeight = new() { Minimum = 1, Maximum = 500, DecimalPlaces = 1, Value = 32, Width = 100 };
+    private readonly NumericUpDown _printerDpi = new() { Minimum = 50, Maximum = 2400, Value = 203, Width = 100 };
 
     private readonly TextBox _status = new()
     {
@@ -55,11 +68,13 @@ internal sealed class SettingsForm : Form
     public SettingsForm(
         SettingsStore settingsStore,
         PrinterService printerService,
+        BackendClient backendClient,
         BackendPollingWorker backendWorker,
         UpdateService updateService)
     {
         _settingsStore = settingsStore;
         _printerService = printerService;
+        _backendClient = backendClient;
         _backendWorker = backendWorker;
         _updateService = updateService;
         _installUpdateButton = ButtonAt("Update installieren", 340, 265, async (_, _) => await InstallUpdateFromUiAsync());
@@ -77,6 +92,11 @@ internal sealed class SettingsForm : Form
         tabs.TabPages.Add(CreateUpdatesTab());
         tabs.TabPages.Add(CreateStatusTab());
         Controls.Add(tabs);
+        _printerList.SelectedIndexChanged += (_, _) => SelectPrinter(GetPrinterName(_printerList.SelectedItem));
+        _printerActive.CheckedChanged += async (_, _) => await SetSelectedPrinterActiveFromUiAsync();
+        _labelWidth.ValueChanged += (_, _) => SaveSelectedPrinterConfig();
+        _labelHeight.ValueChanged += (_, _) => SaveSelectedPrinterConfig();
+        _printerDpi.ValueChanged += (_, _) => SaveSelectedPrinterConfig();
 
         Load += (_, _) =>
         {
@@ -102,25 +122,41 @@ internal sealed class SettingsForm : Form
         panel.Controls.Add(Row(20, Label("BaseUrl", 160), _backendBaseUrl));
         panel.Controls.Add(Row(60, Label("AgentId", 160), _agentId));
         panel.Controls.Add(Row(100, Label("API Token", 160), _apiToken));
-        panel.Controls.Add(Row(140, Label("NextJobPath", 160), _nextJobPath));
-        panel.Controls.Add(Row(180, Label("ImagePath", 160), _imagePath));
-        panel.Controls.Add(Row(220, Label("ReportSuccessPath", 160), _reportSuccessPath));
-        panel.Controls.Add(Row(260, Label("ReportErrorPath", 160), _reportErrorPath));
-        panel.Controls.Add(Row(300, Label("SSE", 160), _useServerSentEvents));
-        panel.Controls.Add(Row(340, Label("EventsPath", 160), _eventsPath));
-        panel.Controls.Add(ButtonAt("Speichern", 180, 395, (_, _) => SaveBackend(showMessage: true)));
-        panel.Controls.Add(ButtonAt("Jetzt prüfen", 300, 395, async (_, _) => await PollOnceFromUiAsync()));
+        panel.Controls.Add(Row(140, Label("RegisterPrinterPath", 160), _registerPrinterPath));
+        panel.Controls.Add(Row(180, Label("DeactivatePrinterPath", 160), _deactivatePrinterPath));
+        panel.Controls.Add(Row(220, Label("NextJobPath", 160), _nextJobPath));
+        panel.Controls.Add(Row(260, Label("ImagePath", 160), _imagePath));
+        panel.Controls.Add(Row(300, Label("ReportSuccessPath", 160), _reportSuccessPath));
+        panel.Controls.Add(Row(340, Label("ReportErrorPath", 160), _reportErrorPath));
+        panel.Controls.Add(Row(380, Label("SSE", 160), _useServerSentEvents));
+        panel.Controls.Add(Row(420, Label("EventsPath", 160), _eventsPath));
+        panel.Controls.Add(ButtonAt("Speichern", 180, 475, (_, _) => SaveBackend(showMessage: true)));
+        panel.Controls.Add(ButtonAt("Jetzt prüfen", 300, 475, async (_, _) => await PollOnceFromUiAsync()));
         return new TabPage("Backend") { Controls = { panel } };
     }
 
     private TabPage CreatePrinterTab()
     {
         var panel = CreatePaddedPanel();
-        panel.Controls.Add(Row(20, Label("Drucker", 120), _printer));
-        panel.Controls.Add(Row(60, Label("Breite", 120), _labelWidth, Label("mm", 40)));
-        panel.Controls.Add(Row(100, Label("Höhe", 120), _labelHeight, Label("mm", 40)));
-        panel.Controls.Add(ButtonAt("Drucker neu laden", 140, 150, (_, _) => LoadPrinters()));
-        panel.Controls.Add(ButtonAt("Speichern", 300, 150, (_, _) => SavePrinter(showMessage: true)));
+        var listLabel = Label("Drucker", 120);
+        listLabel.Left = 20;
+        listLabel.Top = 20;
+        _printerList.Left = 20;
+        _printerList.Top = 55;
+        panel.Controls.Add(listLabel);
+        panel.Controls.Add(_printerList);
+
+        var detailLeft = 380;
+        _printerActive.Left = detailLeft;
+        _printerActive.Top = 55;
+        panel.Controls.Add(_printerActive);
+        panel.Controls.Add(RowAt(detailLeft, 95, Label("Windows-Name", 120), _windowsPrinterName));
+        panel.Controls.Add(RowAt(detailLeft, 135, Label("Breite", 120), _labelWidth, Label("mm", 40)));
+        panel.Controls.Add(RowAt(detailLeft, 175, Label("Höhe", 120), _labelHeight, Label("mm", 40)));
+        panel.Controls.Add(RowAt(detailLeft, 215, Label("DPI", 120), _printerDpi));
+
+        panel.Controls.Add(ButtonAt("Drucker neu laden", 20, 365, (_, _) => LoadPrinters()));
+        panel.Controls.Add(ButtonAt("Speichern", detailLeft, 365, (_, _) => SavePrinter(showMessage: true)));
         return new TabPage("Drucker") { Controls = { panel } };
     }
 
@@ -156,6 +192,8 @@ internal sealed class SettingsForm : Form
         _backendBaseUrl.Text = settings.Backend.BaseUrl;
         _agentId.Text = settings.Backend.AgentId;
         _apiToken.Text = _settingsStore.DecryptBackendApiToken(settings);
+        _registerPrinterPath.Text = settings.Backend.RegisterPrinterPath;
+        _deactivatePrinterPath.Text = settings.Backend.DeactivatePrinterPath;
         _nextJobPath.Text = settings.Backend.NextJobPath;
         _imagePath.Text = settings.Backend.ImagePath;
         _reportSuccessPath.Text = settings.Backend.ReportSuccessPath;
@@ -171,28 +209,54 @@ internal sealed class SettingsForm : Form
         _installUpdateButton.Enabled = false;
         _lastUpdateCheck = null;
 
-        var primaryPrinter = GetPrimaryPrinter(settings);
-        _labelWidth.Value = primaryPrinter?.DefaultWidthMm ?? settings.Printer.LabelWidthMm;
-        _labelHeight.Value = primaryPrinter?.DefaultHeightMm ?? settings.Printer.LabelHeightMm;
+        _defaultLabelWidthMm = settings.Printer.LabelWidthMm;
+        _defaultLabelHeightMm = settings.Printer.LabelHeightMm;
+        _defaultPrinterDpi = settings.Printer.Dpi > 0 ? settings.Printer.Dpi : 203;
+        SetPrinterEditorEnabled(false);
     }
 
     private void LoadPrinters()
     {
         var settings = _settingsStore.Load();
         var selected = GetPrimaryPrinter(settings)?.WindowsPrinterName ?? settings.Printer.PrinterName;
-        _printer.Items.Clear();
+        _loadingPrinters = true;
+        _selectedSharedPrinterName = null;
+        _printerConfigs.Clear();
+        foreach (var printer in settings.Printers.Where(printer => !string.IsNullOrWhiteSpace(printer.WindowsPrinterName)))
+        {
+            _printerConfigs[printer.WindowsPrinterName] = ClonePrinterConfig(printer);
+        }
+
+        _printerList.Items.Clear();
         var printers = _printerService.GetInstalledPrinters();
         foreach (var printer in printers)
         {
-            _printer.Items.Add(printer);
+            EnsurePrinterConfig(printer.Name);
+            _printerList.Items.Add(printer);
         }
 
-        var configuredPrinter = printers.FirstOrDefault(printer => string.Equals(printer.Name, selected, StringComparison.OrdinalIgnoreCase));
-        _printer.SelectedItem = configuredPrinter ?? printers.FirstOrDefault(printer => printer.IsDefault);
-        if (_printer.SelectedItem is null && _printer.Items.Count > 0)
+        foreach (var printerName in _printerConfigs.Keys
+            .Where(name => printers.All(printer => !string.Equals(printer.Name, name, StringComparison.OrdinalIgnoreCase)))
+            .OrderBy(name => name))
         {
-            _printer.SelectedIndex = 0;
+            _printerList.Items.Add(printerName);
         }
+
+        _loadingPrinters = false;
+        var selectedIndex = FindPrinterIndex(selected);
+        if (selectedIndex < 0 && _printerList.Items.Count > 0)
+        {
+            selectedIndex = 0;
+        }
+
+        if (selectedIndex >= 0)
+        {
+            _printerList.SelectedIndex = selectedIndex;
+            SelectPrinter(GetPrinterName(_printerList.SelectedItem));
+            return;
+        }
+
+        SetPrinterEditorEnabled(false);
     }
 
     private void SaveGeneral()
@@ -213,6 +277,8 @@ internal sealed class SettingsForm : Form
         var normalizedToken = SettingsStore.NormalizeBackendApiToken(_apiToken.Text);
         settings.Backend.EncryptedApiToken = _settingsStore.EncryptPassword(normalizedToken);
         _apiToken.Text = normalizedToken;
+        settings.Backend.RegisterPrinterPath = _registerPrinterPath.Text.Trim();
+        settings.Backend.DeactivatePrinterPath = _deactivatePrinterPath.Text.Trim();
         settings.Backend.NextJobPath = _nextJobPath.Text.Trim();
         settings.Backend.ImagePath = _imagePath.Text.Trim();
         settings.Backend.ReportSuccessPath = _reportSuccessPath.Text.Trim();
@@ -231,26 +297,19 @@ internal sealed class SettingsForm : Form
     {
         var settings = _settingsStore.Load();
         var selectedPrinterName = GetSelectedPrinterName() ?? string.Empty;
+        SaveSelectedPrinterConfig();
         settings.Printer.PrinterName = selectedPrinterName;
         settings.Printer.LabelWidthMm = _labelWidth.Value;
         settings.Printer.LabelHeightMm = _labelHeight.Value;
-        if (!string.IsNullOrWhiteSpace(selectedPrinterName))
+        settings.Printer.Dpi = (int)_printerDpi.Value;
+        settings.Printers = _printerConfigs.Keys
+            .OrderBy(printerName => printerName)
+            .Select(printerName => BuildPrinterConfig(settings, printerName, fallbackToEditor: false))
+            .ToList();
+
+        if (settings.Printers.Count == 0 && !string.IsNullOrWhiteSpace(selectedPrinterName))
         {
-            var existingPrinter = settings.Printers.FirstOrDefault(
-                printer => string.Equals(printer.WindowsPrinterName, selectedPrinterName, StringComparison.OrdinalIgnoreCase));
-            var printerConfig = existingPrinter ?? new PrinterConfig();
-            printerConfig.PrinterId = string.IsNullOrWhiteSpace(printerConfig.PrinterId)
-                ? SettingsStore.BuildPrinterId(settings.Backend.AgentId, selectedPrinterName)
-                : printerConfig.PrinterId;
-            printerConfig.Name = string.IsNullOrWhiteSpace(printerConfig.Name) ? selectedPrinterName : printerConfig.Name;
-            printerConfig.WindowsPrinterName = selectedPrinterName;
-            printerConfig.Dpi = settings.Printer.Dpi;
-            printerConfig.DefaultWidthMm = Math.Max(1, (int)Math.Round(_labelWidth.Value));
-            printerConfig.DefaultHeightMm = Math.Max(1, (int)Math.Round(_labelHeight.Value));
-            if (existingPrinter is null)
-            {
-                settings.Printers.Add(printerConfig);
-            }
+            settings.Printers.Add(BuildPrinterConfig(settings, selectedPrinterName, fallbackToEditor: true));
         }
 
         _settingsStore.Save(settings);
@@ -371,7 +430,150 @@ internal sealed class SettingsForm : Form
 
     private string? GetSelectedPrinterName()
     {
-        return _printer.SelectedItem switch
+        return GetPrinterName(_printerList.SelectedItem);
+    }
+
+    private void SelectPrinter(string? printerName)
+    {
+        if (_loadingPrinters)
+        {
+            return;
+        }
+
+        if (string.Equals(_selectedSharedPrinterName, printerName, StringComparison.OrdinalIgnoreCase))
+        {
+            return;
+        }
+
+        SaveSelectedPrinterConfig();
+        if (string.IsNullOrWhiteSpace(printerName) || !_printerConfigs.TryGetValue(printerName, out var config))
+        {
+            _selectedSharedPrinterName = null;
+            SetPrinterEditorEnabled(false);
+            return;
+        }
+
+        _selectedSharedPrinterName = printerName;
+        SetPrinterEditorEnabled(true);
+        _loadingPrinterConfig = true;
+        try
+        {
+            _windowsPrinterName.Text = config.WindowsPrinterName;
+            _printerActive.Checked = config.IsActive;
+            _labelWidth.Value = Math.Clamp(config.DefaultWidthMm, (int)_labelWidth.Minimum, (int)_labelWidth.Maximum);
+            _labelHeight.Value = Math.Clamp(config.DefaultHeightMm, (int)_labelHeight.Minimum, (int)_labelHeight.Maximum);
+            _printerDpi.Value = Math.Clamp(config.Dpi, (int)_printerDpi.Minimum, (int)_printerDpi.Maximum);
+        }
+        finally
+        {
+            _loadingPrinterConfig = false;
+        }
+    }
+
+    private void SaveSelectedPrinterConfig()
+    {
+        if (_loadingPrinters || _loadingPrinterConfig || string.IsNullOrWhiteSpace(_selectedSharedPrinterName))
+        {
+            return;
+        }
+
+        var config = EnsurePrinterConfig(_selectedSharedPrinterName);
+        config.DefaultWidthMm = Math.Max(1, (int)Math.Round(_labelWidth.Value));
+        config.DefaultHeightMm = Math.Max(1, (int)Math.Round(_labelHeight.Value));
+        config.Dpi = (int)_printerDpi.Value;
+        config.IsActive = _printerActive.Checked;
+    }
+
+    private async Task SetSelectedPrinterActiveFromUiAsync()
+    {
+        if (_loadingPrinters || _loadingPrinterConfig || string.IsNullOrWhiteSpace(_selectedSharedPrinterName))
+        {
+            return;
+        }
+
+        try
+        {
+            SaveBackend(showMessage: false);
+            SaveSelectedPrinterConfig();
+            var config = BuildPrinterConfig(_settingsStore.Load(), _selectedSharedPrinterName, fallbackToEditor: false);
+            config.IsActive = _printerActive.Checked;
+            SavePrinter(showMessage: false);
+            await _backendClient.SetPrinterActiveAsync(config, config.IsActive);
+            AppendStatus($"Drucker {config.WindowsPrinterName} {(config.IsActive ? "aktiviert" : "deaktiviert")}.");
+        }
+        catch (Exception ex)
+        {
+            Log.Error(ex, "Could not update printer active state");
+            AppendStatus($"Aktiv-Status konnte nicht synchronisiert werden: {ex.Message}");
+            MessageBox.Show($"Aktiv-Status konnte nicht synchronisiert werden: {ex.Message}", Text, MessageBoxButtons.OK, MessageBoxIcon.Error);
+        }
+    }
+
+    private PrinterConfig EnsurePrinterConfig(string printerName)
+    {
+        if (_printerConfigs.TryGetValue(printerName, out var config))
+        {
+            return config;
+        }
+
+        config = new PrinterConfig
+        {
+            PrinterId = SettingsStore.BuildPrinterId(_agentId.Text.Trim(), printerName),
+            Name = printerName,
+            WindowsPrinterName = printerName,
+            Dpi = _defaultPrinterDpi,
+            DefaultWidthMm = Math.Max(1, (int)Math.Round(_defaultLabelWidthMm)),
+            DefaultHeightMm = Math.Max(1, (int)Math.Round(_defaultLabelHeightMm)),
+            IsActive = false
+        };
+        _printerConfigs[printerName] = config;
+        return config;
+    }
+
+    private PrinterConfig BuildPrinterConfig(AppSettings settings, string printerName, bool fallbackToEditor)
+    {
+        var existingPrinter = _printerConfigs.TryGetValue(printerName, out var config)
+            ? config
+            : settings.Printers.FirstOrDefault(printer => string.Equals(printer.WindowsPrinterName, printerName, StringComparison.OrdinalIgnoreCase));
+        var width = fallbackToEditor ? (int)Math.Round(_labelWidth.Value) : existingPrinter?.DefaultWidthMm ?? (int)Math.Round(settings.Printer.LabelWidthMm);
+        var height = fallbackToEditor ? (int)Math.Round(_labelHeight.Value) : existingPrinter?.DefaultHeightMm ?? (int)Math.Round(settings.Printer.LabelHeightMm);
+        var dpi = fallbackToEditor ? (int)_printerDpi.Value : existingPrinter?.Dpi ?? settings.Printer.Dpi;
+        return new PrinterConfig
+        {
+            PrinterId = string.IsNullOrWhiteSpace(existingPrinter?.PrinterId)
+                ? SettingsStore.BuildPrinterId(settings.Backend.AgentId, printerName)
+                : existingPrinter.PrinterId,
+            Name = string.IsNullOrWhiteSpace(existingPrinter?.Name) ? printerName : existingPrinter.Name,
+            WindowsPrinterName = printerName,
+            Dpi = Math.Max(1, dpi),
+            DefaultWidthMm = Math.Max(1, width),
+            DefaultHeightMm = Math.Max(1, height),
+            IsActive = existingPrinter?.IsActive ?? false
+        };
+    }
+
+    private static PrinterConfig? GetPrimaryPrinter(AppSettings settings)
+    {
+        return settings.Printers.FirstOrDefault(printer => printer.IsActive && !string.IsNullOrWhiteSpace(printer.WindowsPrinterName))
+            ?? settings.Printers.FirstOrDefault(printer => !string.IsNullOrWhiteSpace(printer.WindowsPrinterName));
+    }
+
+    private int FindPrinterIndex(string printerName)
+    {
+        for (var index = 0; index < _printerList.Items.Count; index++)
+        {
+            if (string.Equals(GetPrinterName(_printerList.Items[index]), printerName, StringComparison.OrdinalIgnoreCase))
+            {
+                return index;
+            }
+        }
+
+        return -1;
+    }
+
+    private static string? GetPrinterName(object? item)
+    {
+        return item switch
         {
             PrinterInfo printerInfo => printerInfo.Name,
             string printerName => printerName,
@@ -379,9 +581,34 @@ internal sealed class SettingsForm : Form
         };
     }
 
-    private static PrinterConfig? GetPrimaryPrinter(AppSettings settings)
+    private static PrinterConfig ClonePrinterConfig(PrinterConfig printer)
     {
-        return settings.Printers.FirstOrDefault(printer => !string.IsNullOrWhiteSpace(printer.WindowsPrinterName));
+        return new PrinterConfig
+        {
+            PrinterId = printer.PrinterId,
+            Name = printer.Name,
+            WindowsPrinterName = printer.WindowsPrinterName,
+            Dpi = printer.Dpi,
+            DefaultWidthMm = printer.DefaultWidthMm,
+            DefaultHeightMm = printer.DefaultHeightMm,
+            IsActive = printer.IsActive
+        };
+    }
+
+    private void SetPrinterEditorEnabled(bool enabled)
+    {
+        _labelWidth.Enabled = enabled;
+        _labelHeight.Enabled = enabled;
+        _printerDpi.Enabled = enabled;
+        _printerActive.Enabled = enabled;
+        _windowsPrinterName.Enabled = enabled;
+        if (!enabled)
+        {
+            _loadingPrinterConfig = true;
+            _windowsPrinterName.Text = string.Empty;
+            _printerActive.Checked = false;
+            _loadingPrinterConfig = false;
+        }
     }
 
     private void AppendStatus(string message)
@@ -413,10 +640,15 @@ internal sealed class SettingsForm : Form
     private static Label Label(string text, int width) => new() { Text = text, Width = width, TextAlign = ContentAlignment.MiddleLeft };
 
     private static FlowLayoutPanel Row(int top, params Control[] controls)
+    {
+        return RowAt(20, top, controls);
+    }
+
+    private static FlowLayoutPanel RowAt(int left, int top, params Control[] controls)
     {
         var row = new FlowLayoutPanel
         {
-            Left = 20,
+            Left = left,
             Top = top,
             Width = 760,
             Height = 32,

src/LabelPrintAgent/App/TrayApplicationContext.cs

@@ -11,6 +11,7 @@ internal sealed class TrayApplicationContext : ApplicationContext
     private readonly NotifyIcon _notifyIcon;
     private readonly SettingsStore _settingsStore;
     private readonly PrinterService _printerService;
+    private readonly BackendClient _backendClient;
     private readonly BackendPollingWorker _backendWorker;
     private readonly UpdateService _updateService;
     private readonly Icon _healthyIcon;
@@ -21,11 +22,13 @@ internal sealed class TrayApplicationContext : ApplicationContext
     public TrayApplicationContext(
         SettingsStore settingsStore,
         PrinterService printerService,
+        BackendClient backendClient,
         BackendPollingWorker backendWorker,
         UpdateService updateService)
     {
         _settingsStore = settingsStore;
         _printerService = printerService;
+        _backendClient = backendClient;
         _backendWorker = backendWorker;
         _updateService = updateService;
         _healthyIcon = TrayIconFactory.CreatePrinterIcon(Color.FromArgb(36, 160, 72));
@@ -62,7 +65,7 @@ internal sealed class TrayApplicationContext : ApplicationContext
         {
             if (_settingsForm is null || _settingsForm.IsDisposed)
             {
-                _settingsForm = new SettingsForm(_settingsStore, _printerService, _backendWorker, _updateService);
+                _settingsForm = new SettingsForm(_settingsStore, _printerService, _backendClient, _backendWorker, _updateService);
             }
 
             _settingsForm.Show();
@@ -113,7 +116,7 @@ internal sealed class TrayApplicationContext : ApplicationContext
             }
 
             var configuredPrinters = settings.Printers
-                .Where(printer => !string.IsNullOrWhiteSpace(printer.WindowsPrinterName))
+                .Where(printer => printer.IsActive && !string.IsNullOrWhiteSpace(printer.WindowsPrinterName))
                 .ToList();
             if (configuredPrinters.Count == 0)
             {

src/LabelPrintAgent/Backend/BackendClient.cs

@@ -38,34 +38,18 @@ public sealed class BackendClient
     public async Task RegisterPrintersAsync(CancellationToken cancellationToken = default)
     {
         var settings = _settingsStore.Load();
-        foreach (var printer in settings.Printers.Where(IsRegisterablePrinter))
+        foreach (var printer in settings.Printers.Where(printer => printer.IsActive).Where(IsRegisterablePrinter))
         {
-            var body = new
-            {
-                printerId = printer.PrinterId,
-                agentId = settings.Backend.AgentId,
-                name = printer.Name,
-                windowsPrinterName = printer.WindowsPrinterName,
-                dpi = printer.Dpi,
-                defaultWidthMm = printer.DefaultWidthMm,
-                defaultHeightMm = printer.DefaultHeightMm
-            };
-
-            using var request = CreateRequest(
-                HttpMethod.Post,
-                MakeAbsoluteUrl(settings.Backend.BaseUrl, settings.Backend.RegisterPrinterPath),
-                settings);
-            request.Content = JsonContent.Create(body);
-            using var response = await _httpClient.SendAsync(request, cancellationToken);
-            await EnsureSuccessWithDiagnosticsAsync(response, request, cancellationToken);
-            Log.Information(
-                "Registered printer {PrinterId} ({WindowsPrinterName}) for agent {AgentId}",
-                printer.PrinterId,
-                printer.WindowsPrinterName,
-                settings.Backend.AgentId);
+            await SetPrinterActiveAsync(settings, printer, active: true, cancellationToken);
         }
     }
 
+    public async Task SetPrinterActiveAsync(PrinterConfig printer, bool active, CancellationToken cancellationToken = default)
+    {
+        var settings = _settingsStore.Load();
+        await SetPrinterActiveAsync(settings, printer, active, cancellationToken);
+    }
+
     public async Task<Bitmap> GetLabelImageAsync(BackendLabelJob job, CancellationToken cancellationToken = default)
     {
         if (!string.IsNullOrWhiteSpace(job.LabelImageBase64))
@@ -120,6 +104,40 @@ public sealed class BackendClient
         await EnsureSuccessWithDiagnosticsAsync(response, request, cancellationToken);
     }
 
+    private async Task SetPrinterActiveAsync(AppSettings settings, PrinterConfig printer, bool active, CancellationToken cancellationToken)
+    {
+        if (!IsRegisterablePrinter(printer))
+        {
+            throw new InvalidOperationException("Drucker kann ohne PrinterId und WindowsPrinterName nicht synchronisiert werden.");
+        }
+
+        var body = new
+        {
+            printerId = printer.PrinterId,
+            agentId = settings.Backend.AgentId,
+            name = printer.Name,
+            windowsPrinterName = printer.WindowsPrinterName,
+            dpi = printer.Dpi,
+            defaultWidthMm = printer.DefaultWidthMm,
+            defaultHeightMm = printer.DefaultHeightMm,
+            active
+        };
+
+        var path = active
+            ? settings.Backend.RegisterPrinterPath
+            : settings.Backend.DeactivatePrinterPath.Replace("{printerId}", Uri.EscapeDataString(printer.PrinterId), StringComparison.OrdinalIgnoreCase);
+        using var request = CreateRequest(HttpMethod.Post, MakeAbsoluteUrl(settings.Backend.BaseUrl, path), settings);
+        request.Content = JsonContent.Create(body);
+        using var response = await _httpClient.SendAsync(request, cancellationToken);
+        await EnsureSuccessWithDiagnosticsAsync(response, request, cancellationToken);
+        Log.Information(
+            "{Action} printer {PrinterId} ({WindowsPrinterName}) for agent {AgentId}",
+            active ? "Activated" : "Deactivated",
+            printer.PrinterId,
+            printer.WindowsPrinterName,
+            settings.Backend.AgentId);
+    }
+
     public async Task WatchServerSentEventsAsync(Func<CancellationToken, Task> onLabelJobAvailable, CancellationToken cancellationToken = default)
     {
         var settings = _settingsStore.Load();

src/LabelPrintAgent/Backend/BackendPollingWorker.cs

@@ -55,7 +55,7 @@ public sealed class BackendPollingWorker : IDisposable
             }
 
             var configuredPrinters = settings.Printers
-                .Where(printer => !string.IsNullOrWhiteSpace(printer.WindowsPrinterName))
+                .Where(printer => printer.IsActive && !string.IsNullOrWhiteSpace(printer.WindowsPrinterName))
                 .ToList();
             if (configuredPrinters.Count == 0)
             {
@@ -64,8 +64,6 @@ public sealed class BackendPollingWorker : IDisposable
                 return;
             }
 
-            await _backendClient.RegisterPrintersAsync(cancellationToken);
-
             var unavailablePrinters = configuredPrinters
                 .Where(printer => !_printerService.IsPrinterAvailable(printer.WindowsPrinterName))
                 .Select(printer => printer.WindowsPrinterName)

src/LabelPrintAgent/Configuration/AppSettings.cs

@@ -22,6 +22,7 @@ public sealed class BackendSettings
     public string AgentId { get; set; } = Environment.MachineName;
     public string EncryptedApiToken { get; set; } = string.Empty;
     public string RegisterPrinterPath { get; set; } = "/api/label-print-agent/printers/register";
+    public string DeactivatePrinterPath { get; set; } = "/api/label-print-agent/printers/{printerId}/deactivate";
     public string NextJobPath { get; set; } = "/api/label-print-agent/jobs/next";
     public string ImagePath { get; set; } = "/api/label-print-agent/jobs/{jobId}/image";
     public string ReportSuccessPath { get; set; } = "/api/label-print-agent/jobs/{jobId}/printed";
@@ -53,6 +54,7 @@ public sealed class PrinterConfig
     public int Dpi { get; set; } = 203;
     public int DefaultWidthMm { get; set; } = 57;
     public int DefaultHeightMm { get; set; } = 32;
+    public bool IsActive { get; set; } = true;
 }
 
 public sealed class WorkerSettings

src/LabelPrintAgent/Configuration/SettingsStore.cs

@@ -101,7 +101,8 @@ public sealed class SettingsStore
             WindowsPrinterName = settings.Printer.PrinterName,
             Dpi = settings.Printer.Dpi,
             DefaultWidthMm = Math.Max(1, (int)Math.Round(settings.Printer.LabelWidthMm)),
-            DefaultHeightMm = Math.Max(1, (int)Math.Round(settings.Printer.LabelHeightMm))
+            DefaultHeightMm = Math.Max(1, (int)Math.Round(settings.Printer.LabelHeightMm)),
+            IsActive = true
         });
     }