Fix pressing back on AuthenticationFragment

If login request isn't disabled when user presses
back then they might get navigated back to
authentication again.

app/src/main/java/gq/kirmanak/mealient/extensions/FragmentExtensions.kt

@@ -0,0 +1,30 @@
+package gq.kirmanak.mealient.extensions
+
+import androidx.activity.OnBackPressedDispatcher
+import androidx.activity.addCallback
+import androidx.fragment.app.Fragment
+import androidx.lifecycle.lifecycleScope
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.channels.awaitClose
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.callbackFlow
+import kotlinx.coroutines.flow.first
+import kotlinx.coroutines.launch
+
+fun Fragment.executeOnceOnBackPressed(action: () -> Unit) {
+    val onBackPressedDispatcher = requireActivity().onBackPressedDispatcher
+    lifecycleScope.launch {
+        onBackPressedDispatcher.backPressedFlow().first()
+        action()
+        onBackPressedDispatcher.onBackPressed() // Execute other callbacks now
+    }
+}
+
+@OptIn(ExperimentalCoroutinesApi::class)
+fun OnBackPressedDispatcher.backPressedFlow(): Flow<Unit> = callbackFlow {
+    val callback = addCallback { trySend(Unit) }
+    awaitClose {
+        callback.isEnabled = false
+        callback.remove()
+    }
+}

app/src/main/java/gq/kirmanak/mealient/extensions/ViewExtensions.kt

@@ -1,4 +1,4 @@
-package gq.kirmanak.mealient.ui
+package gq.kirmanak.mealient.extensions
 
 import android.app.Activity
 import android.os.Build

app/src/main/java/gq/kirmanak/mealient/ui/auth/AuthenticationFragment.kt

@@ -13,7 +13,8 @@ import dagger.hilt.android.AndroidEntryPoint
 import gq.kirmanak.mealient.R
 import gq.kirmanak.mealient.data.network.NetworkError.Unauthorized
 import gq.kirmanak.mealient.databinding.FragmentAuthenticationBinding
-import gq.kirmanak.mealient.ui.checkIfInputIsEmpty
+import gq.kirmanak.mealient.extensions.checkIfInputIsEmpty
+import gq.kirmanak.mealient.extensions.executeOnceOnBackPressed
 import timber.log.Timber
 
 @AndroidEntryPoint
@@ -28,6 +29,7 @@ class AuthenticationFragment : Fragment(R.layout.fragment_authentication) {
         super.onCreate(savedInstanceState)
         Timber.v("onCreate() called with: savedInstanceState = $savedInstanceState")
         authStatuses.observe(this, ::onAuthStatusChange)
+        executeOnceOnBackPressed { viewModel.disableLoginRequest() }
     }
 
     override fun onViewCreated(view: View, savedInstanceState: Bundle?) {

app/src/main/java/gq/kirmanak/mealient/ui/auth/AuthenticationViewModel.kt

@@ -45,8 +45,17 @@ class AuthenticationViewModel @Inject constructor(
         }
     }
 
-    fun login() {
-        Timber.v("login() called")
-        viewModelScope.launch { loginRequestsFlow.emit(true) }
+    fun enableLoginRequest() {
+        Timber.v("enableLoginRequest() called")
+        updateIsLoginRequested(true)
+    }
+
+    fun disableLoginRequest() {
+        Timber.v("disableLoginRequest() called")
+        updateIsLoginRequested(false)
+    }
+
+    private fun updateIsLoginRequested(isRequested: Boolean) {
+        viewModelScope.launch { loginRequestsFlow.emit(isRequested) }
     }
 }

app/src/main/java/gq/kirmanak/mealient/ui/baseurl/BaseURLFragment.kt

@@ -11,7 +11,7 @@ import dagger.hilt.android.AndroidEntryPoint
 import gq.kirmanak.mealient.R
 import gq.kirmanak.mealient.data.network.NetworkError
 import gq.kirmanak.mealient.databinding.FragmentBaseUrlBinding
-import gq.kirmanak.mealient.ui.checkIfInputIsEmpty
+import gq.kirmanak.mealient.extensions.checkIfInputIsEmpty
 import timber.log.Timber
 
 @AndroidEntryPoint

app/src/main/java/gq/kirmanak/mealient/ui/recipes/RecipesFragment.kt

@@ -13,9 +13,9 @@ import dagger.hilt.android.AndroidEntryPoint
 import gq.kirmanak.mealient.R
 import gq.kirmanak.mealient.data.recipes.db.entity.RecipeSummaryEntity
 import gq.kirmanak.mealient.databinding.FragmentRecipesBinding
+import gq.kirmanak.mealient.extensions.refreshesLiveData
 import gq.kirmanak.mealient.ui.auth.AuthenticationState
 import gq.kirmanak.mealient.ui.auth.AuthenticationViewModel
-import gq.kirmanak.mealient.ui.refreshesLiveData
 import kotlinx.coroutines.flow.collect
 import timber.log.Timber
 

app/src/main/java/gq/kirmanak/mealient/ui/splash/SplashFragment.kt

@@ -9,8 +9,8 @@ import androidx.navigation.NavDirections
 import androidx.navigation.fragment.findNavController
 import dagger.hilt.android.AndroidEntryPoint
 import gq.kirmanak.mealient.R
-import gq.kirmanak.mealient.ui.setActionBarVisibility
-import gq.kirmanak.mealient.ui.setSystemUiVisibility
+import gq.kirmanak.mealient.extensions.setActionBarVisibility
+import gq.kirmanak.mealient.extensions.setSystemUiVisibility
 import timber.log.Timber
 
 @AndroidEntryPoint