Merge pull request #2 from TheCodeDaniel/fix/crash_issue

fix: crashing issues on IOS version

Author: TheCodeDaniel

example/lib/main.dart

@@ -23,6 +23,7 @@ class _MyAppState extends State<MyApp> {
   void initState() {
     super.initState();
     initPlatformState();
+    _screenshotGuardPlugin.enableSecureFlag(enable: true);
   }
 
   // Platform messages are asynchronous, so we initialize in an async method.

ios/Classes/ScreenshotGuardPlugin.swift

@@ -5,42 +5,85 @@ import ScreenProtectorKit
 public class ScreenshotGuardPlugin: NSObject, FlutterPlugin {
 
     private var screenProtectorKit: ScreenProtectorKit?
+    private var isScreenshotPreventionActive = false // Track the current state
+    private var blackOverlay: UIView? // Black overlay for recent apps protection
 
     public static func register(with registrar: FlutterPluginRegistrar) {
         let channel = FlutterMethodChannel(name: "screenshot_guard", binaryMessenger: registrar.messenger())
         let instance = ScreenshotGuardPlugin()
         registrar.addMethodCallDelegate(instance, channel: channel)
+        registrar.addApplicationDelegate(instance) // Register lifecycle events
     }
 
     public func handle(_ call: FlutterMethodCall, result: @escaping FlutterResult) {
         switch call.method {
         case "enableSecureFlag":
-            if let args = call.arguments as? [String: Any], let enable = args["enable"] as? Bool {
-                toggleScreenshotProtection(enable)
-                result(nil)
-            } else {
+            guard let args = call.arguments as? [String: Any],
+                  let enable = args["enable"] as? Bool else {
                 result(FlutterError(code: "INVALID_ARGUMENT", message: "Expected 'enable' boolean argument", details: nil))
+                return
             }
+            toggleScreenshotPrevention(enable)
+            result(nil)
         case "getPlatformVersion":
-            result("iOS " + UIDevice.current.systemVersion)
+            result("iOS " + UIDevice.current.systemVersion)    
         default:
             result(FlutterMethodNotImplemented)
         }
     }
 
-    private func toggleScreenshotProtection(_ enable: Bool) {
+    private func toggleScreenshotPrevention(_ enable: Bool) {
+        isScreenshotPreventionActive = enable
         if enable {
-            // Initialize screenProtectorKit only when needed
+            // Initialize and enable screenshot prevention
             if screenProtectorKit == nil {
-                // Use the current window context to initialize ScreenProtectorKit
-                screenProtectorKit = ScreenProtectorKit(window: UIApplication.shared.delegate?.window as? UIWindow)
+                guard let window = UIApplication.shared.windows.first else {
+                    print("Failed to retrieve the main window")
+                    return
+                }
+                screenProtectorKit = ScreenProtectorKit(window: window)
+                screenProtectorKit?.configurePreventionScreenshot()
             }
-            screenProtectorKit?.configurePreventionScreenshot() // Configure prevention
-            screenProtectorKit?.enabledPreventScreenshot() // Enable screenshot prevention
+            screenProtectorKit?.enabledPreventScreenshot()
         } else {
-            screenProtectorKit?.disablePreventScreenshot() // Disable screenshot protection
-            screenProtectorKit = nil // Reset the screenProtectorKit instance
+            // Disable screenshot prevention
+            screenProtectorKit?.disablePreventScreenshot()
+        }
+    }
+
+    // MARK: - App Lifecycle Management
+
+    public func applicationWillResignActive(_ application: UIApplication) {
+        // App is about to move to the background
+        if isScreenshotPreventionActive {
+            addBlackOverlay() // Protect app content in "Recent Apps"
+            screenProtectorKit?.disablePreventScreenshot() // Avoid black screen
+        }
+    }
+
+    public func applicationDidBecomeActive(_ application: UIApplication) {
+        // App has moved to the foreground
+        if isScreenshotPreventionActive {
+            removeBlackOverlay() // Restore visibility
+            screenProtectorKit?.enabledPreventScreenshot() // Re-enable prevention
         }
     }
-}
 
+    // MARK: - Black Overlay for "Recent Apps"
+
+    private func addBlackOverlay() {
+        guard let window = UIApplication.shared.windows.first else { return }
+        if blackOverlay == nil {
+            blackOverlay = UIView(frame: window.bounds)
+            blackOverlay?.backgroundColor = UIColor.black
+            blackOverlay?.autoresizingMask = [.flexibleWidth, .flexibleHeight]
+        }
+        if let blackOverlay = blackOverlay, blackOverlay.superview == nil {
+            window.addSubview(blackOverlay)
+        }
+    }
+
+    private func removeBlackOverlay() {
+        blackOverlay?.removeFromSuperview()
+    }
+}