From 3150297590e128bdb2d4493af1fbcebdf0382130 Mon Sep 17 00:00:00 2001
From: Sergey Vlasenko <sergey.vlasenko@touchin.ru>
Date: Mon, 8 Apr 2024 12:19:28 +0300
Subject: [PATCH] fix crash when ViewControllerFragment is used in ViewPager

---
 .../fragments/ViewControllerFragment.kt       | 26 ++++++++++++-------
 1 file changed, 16 insertions(+), 10 deletions(-)

diff --git a/navigation-viewcontroller/src/main/java/ru/touchin/roboswag/navigation_viewcontroller/fragments/ViewControllerFragment.kt b/navigation-viewcontroller/src/main/java/ru/touchin/roboswag/navigation_viewcontroller/fragments/ViewControllerFragment.kt
index 053f9a9..496dda0 100644
--- a/navigation-viewcontroller/src/main/java/ru/touchin/roboswag/navigation_viewcontroller/fragments/ViewControllerFragment.kt
+++ b/navigation-viewcontroller/src/main/java/ru/touchin/roboswag/navigation_viewcontroller/fragments/ViewControllerFragment.kt
@@ -35,6 +35,7 @@ import android.view.animation.Animation
 import androidx.fragment.app.Fragment
 import androidx.fragment.app.FragmentActivity
 import androidx.lifecycle.Lifecycle
+import ru.touchin.roboswag.core.utils.ShouldNotHappenException
 import ru.touchin.roboswag.navigation_viewcontroller.BuildConfig
 import ru.touchin.roboswag.navigation_viewcontroller.viewcontrollers.ViewController
 
@@ -80,7 +81,8 @@ open class ViewControllerFragment<TActivity : FragmentActivity, TState : Parcela
 
     lateinit var state: TState private set
 
-    lateinit var viewControllerClass: Class<ViewController<TActivity, TState>> private set
+    var viewControllerClass: Class<ViewController<TActivity, TState>>? = null
+        private set
 
     private var viewController: ViewController<out TActivity, out TState>? = null
 
@@ -241,15 +243,19 @@ open class ViewControllerFragment<TActivity : FragmentActivity, TState : Parcela
             creationContext: ViewController.CreationContext,
             savedInstanceState: Bundle?
     ): ViewController<out TActivity, out TState> {
-        if (viewControllerClass.constructors.size != 1) {
-            throw IllegalStateException("There should be single constructor for $viewControllerClass")
-        }
-        val constructor = viewControllerClass.constructors[0]
-        return when (constructor.parameterTypes.size) {
-            1 -> constructor.newInstance(creationContext)
-            2 -> constructor.newInstance(creationContext, savedInstanceState)
-            else -> throw IllegalArgumentException("Wrong constructor parameters count: ${constructor.parameterTypes.size}")
-        } as ViewController<out TActivity, out TState>
+        viewControllerClass
+                ?.let { mViewControllerClass ->
+                    if (mViewControllerClass.constructors.size != 1) {
+                        throw IllegalStateException("There should be single constructor for $viewControllerClass")
+                    }
+                    val constructor = mViewControllerClass.constructors[0]
+                    return when (constructor.parameterTypes.size) {
+                        1 -> constructor.newInstance(creationContext)
+                        2 -> constructor.newInstance(creationContext, savedInstanceState)
+                        else -> throw IllegalArgumentException("Wrong constructor parameters count: ${constructor.parameterTypes.size}")
+                    } as ViewController<out TActivity, out TState>
+                }
+                ?: throw ShouldNotHappenException("viewControllerClass is null")
     }
 
     override fun toString(): String = "${super.toString()} ViewController: $viewControllerClass"