feat(Android): add registered flag to screen protector

Author: tompsota

android/src/main/java/com/aheaditec/freerasp/ScreenProtector.kt

@@ -18,7 +18,7 @@ internal object ScreenProtector {
     private const val TAG = "TalsecScreenProtector"
     private const val SCREEN_CAPTURE_PERMISSION = "android.permission.DETECT_SCREEN_CAPTURE"
     private const val SCREEN_RECORDING_PERMISSION = "android.permission.DETECT_SCREEN_RECORDING"
-
+    private var registered = false
     private val screenCaptureCallback = ScreenCaptureCallback { Talsec.onScreenshotDetected() }
     private val screenRecordCallback: Consumer<Int> = Consumer<Int> { state ->
         if (state == SCREEN_RECORDING_STATE_VISIBLE) {
@@ -34,7 +34,7 @@ internal object ScreenProtector {
      * granted for the app in the AndroidManifest.xml
      */
     internal fun register(activity: Activity) {
-        if (!FreeraspPlugin.talsecStarted) {
+        if (!FreeraspPlugin.talsecStarted || registered) {
             return
         }
 
@@ -45,7 +45,7 @@ internal object ScreenProtector {
         if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.VANILLA_ICE_CREAM) {
             registerScreenRecording(activity)
         }
-
+        registered = true
     }
 
     /**
@@ -108,7 +108,7 @@ internal object ScreenProtector {
     @SuppressLint("MissingPermission")
     @RequiresApi(Build.VERSION_CODES.UPSIDE_DOWN_CAKE)
     internal fun unregister(activity: Activity) {
-        if (!FreeraspPlugin.talsecStarted) {
+        if (!FreeraspPlugin.talsecStarted || !registered) {
             return
         }
 
@@ -119,6 +119,7 @@ internal object ScreenProtector {
         if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.VANILLA_ICE_CREAM) {
             unregisterScreenRecording(activity)
         }
+        registered = false
     }
 
     // Missing permission is suppressed because the decision to use the screen capture API is made