vm: support disabling screenshots completely

Resolves #6620

Platform/macOS/SettingsView.swift

@@ -91,6 +91,7 @@ struct ApplicationSettingsView: View {
 }
 
 struct DisplaySettingsView: View {
+    @AppStorage("NoScreenshot") var isNoScreenshot = false
     @AppStorage("NoSaveScreenshot") var isNoSaveScreenshot = false
     @AppStorage("QEMURendererBackend") var qemuRendererBackend: UTMQEMURendererBackend = .qemuRendererBackendDefault
     @AppStorage("QEMURendererFPSLimit") var qemuRendererFpsLimit: Int = 0
@@ -98,9 +99,16 @@ struct DisplaySettingsView: View {
     var body: some View {
         Form {
             Section(header: Text("Display")) {
+                Toggle(isOn: $isNoScreenshot) {
+                    Text("Disable VM screenshot")
+                }.help("No VM screenshots will be taken.")
+                .onChange(of: isNoScreenshot) { newValue in
+                    isNoSaveScreenshot = newValue
+                }
                 Toggle(isOn: $isNoSaveScreenshot) {
                     Text("Do not save VM screenshot to disk")
                 }.help("If enabled, any existing screenshot will be deleted the next time the VM is started.")
+                .disabled(isNoScreenshot)
             }
             
             Section(header: Text("QEMU Graphics Acceleration")) {

Services/UTMAppleVirtualMachine.swift

@@ -326,9 +326,11 @@ final class UTMAppleVirtualMachine: UTMVirtualMachine {
                     continuation.resume(throwing: UTMAppleVirtualMachineError.operationNotAvailable)
                     return
                 }
-                Task { @MainActor in
-                    await self.takeScreenshot()
-                    try? self.saveScreenshot()
+                if self.isScreenshotEnabled {
+                    Task { @MainActor in
+                        await self.takeScreenshot()
+                        try? self.saveScreenshot()
+                    }
                 }
                 apple.pause { result in
                     continuation.resume(with: result)

Services/UTMQemuVirtualMachine.swift

@@ -538,7 +538,9 @@ extension UTMQemuVirtualMachine {
         guard let monitor = await monitor else {
             throw UTMQemuVirtualMachineError.invalidVmState
         }
-        await takeScreenshot()
+        if isScreenshotEnabled {
+            await takeScreenshot()
+        }
         try await monitor.qemuStop()
     }
     

Services/UTMVirtualMachine.swift

@@ -331,8 +331,12 @@ struct UTMVirtualMachineScreenshot {
 }
 
 extension UTMVirtualMachine {
-    private var isScreenshotSaveEnabled: Bool {
-        !UserDefaults.standard.bool(forKey: "NoSaveScreenshot")
+    nonisolated var isScreenshotEnabled: Bool {
+        !UserDefaults.standard.bool(forKey: "NoScreenshot")
+    }
+
+    nonisolated private var isScreenshotSaveEnabled: Bool {
+        isScreenshotEnabled && !UserDefaults.standard.bool(forKey: "NoSaveScreenshot")
     }
     
     private var screenshotUrl: URL {
@@ -349,6 +353,9 @@ extension UTMVirtualMachine {
                 timer.invalidate()
                 return
             }
+            guard self.isScreenshotEnabled else {
+                return
+            }
             if self.state == .started {
                 Task { @MainActor in
                     await self.takeScreenshot()