Changed the way of opening the first screen - make it much simpler

Android-Academy-Global · Dec 28, 2020 · 2e573b4 · 2e573b4
1 parent d6684da
commit 2e573b4
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Showing 2 changed files with 20 additions and 38 deletions.
diff --git a/app/src/main/java/com/aaglobal/jnc_playground/ui/auth/FinishAuthFragment.kt b/app/src/main/java/com/aaglobal/jnc_playground/ui/auth/FinishAuthFragment.kt
@@ -2,23 +2,18 @@ package com.aaglobal.jnc_playground.ui.auth
 
 import android.os.Bundle
 import android.view.View
-import androidx.activity.OnBackPressedCallback
 import androidx.fragment.app.Fragment
 import androidx.fragment.app.viewModels
-import androidx.navigation.Navigation
 import androidx.navigation.fragment.findNavController
 import com.aaglobal.jnc_playground.R
 import kotlinx.android.synthetic.main.fragment_finish_auth.*
 
 
 class FinishAuthFragment : Fragment(R.layout.fragment_finish_auth) {
 
-    companion object {
-        const val AUTH_FLOW_RESULT_KEY = "auth_flow_result"
-    }
-
     private val finishAuthViewModel: FinishAuthViewModel by viewModels()
 
+
     override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
         super.onViewCreated(view, savedInstanceState)
 
@@ -27,13 +22,13 @@ class FinishAuthFragment : Fragment(R.layout.fragment_finish_auth) {
             finishAuthViewModel.setFinishAuthFlag()
 
             // Navigate back from auth flow
-            Navigation.findNavController(
-                requireActivity(),
-                R.id.activity_root__fragment__nav_host
-            ).popBackStack(R.id.auth__nav_graph, true)
-
-            // Send signal about finishing flow
-            findNavController().currentBackStackEntry?.savedStateHandle?.set(AUTH_FLOW_RESULT_KEY, true)
+            val result = findNavController().popBackStack(R.id.auth__nav_graph, true)
+            if (result.not()) {
+                // we can't open new destination with this action
+                // --> we opened Auth flow from splash
+                // --> need to open main graph
+                findNavController().navigate(R.id.MainFragment)
+            }
         }
     }
 

diff --git a/app/src/main/java/com/aaglobal/jnc_playground/ui/splash/SplashFragment.kt b/app/src/main/java/com/aaglobal/jnc_playground/ui/splash/SplashFragment.kt
@@ -5,10 +5,8 @@ import android.view.View
 import androidx.fragment.app.Fragment
 import androidx.fragment.app.viewModels
 import androidx.lifecycle.Observer
-import androidx.navigation.fragment.findNavController
+import androidx.navigation.Navigation
 import com.aaglobal.jnc_playground.R
-import com.aaglobal.jnc_playground.ui.auth.FinishAuthFragment
-import com.aaglobal.jnc_playground.ui.auth.StartAuthFragmentArgs
 
 
 class SplashFragment : Fragment(R.layout.fragment_splash) {
@@ -19,32 +17,21 @@ class SplashFragment : Fragment(R.layout.fragment_splash) {
     override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
         super.onViewCreated(view, savedInstanceState)
 
-        val authResult = findNavController().currentBackStackEntry
-            ?.savedStateHandle
-            ?.remove<Boolean>(FinishAuthFragment.AUTH_FLOW_RESULT_KEY) == true
-
-        if (authResult) {
-            navigateToMainScreen()
-            return
-        }
-
         // Navigate with SingleLiveEvent from Splash screen
         splashViewModel.splashNavCommand.observe(viewLifecycleOwner, Observer { splashNavCommand ->
-            when (splashNavCommand) {
-                SplashNavCommand.NAVIGATE_TO_MAIN -> navigateToMainScreen()
-                SplashNavCommand.NAVIGATE_TO_AUTH -> navigateToAuthFlow()
-                null -> {
-                    // do nothing
-                }
+            val navController = Navigation.findNavController(requireActivity(), R.id.activity_root__fragment__nav_host)
+
+            val mainGraph = navController.navInflater.inflate(R.navigation.app_nav_graph)
+
+            // Way to change first screen at runtime.
+            mainGraph.startDestination = when (splashNavCommand) {
+                SplashNavCommand.NAVIGATE_TO_MAIN -> R.id.MainFragment
+                SplashNavCommand.NAVIGATE_TO_AUTH -> R.id.auth__nav_graph
+                null -> throw IllegalArgumentException("Illegal splash navigation command")
             }
-        })
-    }
 
-    private fun navigateToAuthFlow() {
-        findNavController().navigate(R.id.action__SplashFragment__to__AuthFlow, StartAuthFragmentArgs(isFromSplashScreen = true).toBundle())
+            navController.graph = mainGraph
+        })
     }
 
-    private fun navigateToMainScreen() {
-        findNavController().navigate(R.id.action__SplashFragment__to__MainFragment)
-    }
 }