From 5c8fb401a4c907089d201ab905366bb2546acb3e Mon Sep 17 00:00:00 2001
From: Zhuinden <zhuinden@gmail.com>
Date: Sat, 23 Jan 2021 15:44:01 +0100
Subject: [PATCH] Fix a bug in AutoClearedValue when viewLifecycleOwner goes
 directly from CREATED -> DESTROYED while Fragment is still not STARTED

---
 .../example/github/util/AutoClearedValue.kt   | 24 ++++++++++++-------
 1 file changed, 16 insertions(+), 8 deletions(-)

diff --git a/GithubBrowserSample/app/src/main/java/com/android/example/github/util/AutoClearedValue.kt b/GithubBrowserSample/app/src/main/java/com/android/example/github/util/AutoClearedValue.kt
index eed7535f..cbb9d54c 100644
--- a/GithubBrowserSample/app/src/main/java/com/android/example/github/util/AutoClearedValue.kt
+++ b/GithubBrowserSample/app/src/main/java/com/android/example/github/util/AutoClearedValue.kt
@@ -19,7 +19,7 @@ package com.android.example.github.util
 import androidx.fragment.app.Fragment
 import androidx.lifecycle.DefaultLifecycleObserver
 import androidx.lifecycle.LifecycleOwner
-import androidx.lifecycle.observe
+import androidx.lifecycle.Observer
 import kotlin.properties.ReadWriteProperty
 import kotlin.reflect.KProperty
 
@@ -32,15 +32,23 @@ class AutoClearedValue<T : Any>(val fragment: Fragment) : ReadWriteProperty<Frag
     private var _value: T? = null
 
     init {
+        val viewLifecycleOwnerLiveDataObserver = Observer<LifecycleOwner?> {
+            val viewLifecycleOwner = it ?: return@Observer
+
+            viewLifecycleOwner.lifecycle.addObserver(object: DefaultLifecycleObserver {
+                override fun onDestroy(owner: LifecycleOwner) {
+                    _value = null
+                }
+            })
+        }
+
         fragment.lifecycle.addObserver(object: DefaultLifecycleObserver {
             override fun onCreate(owner: LifecycleOwner) {
-                fragment.viewLifecycleOwnerLiveData.observe(fragment) { viewLifecycleOwner ->
-                    viewLifecycleOwner?.lifecycle?.addObserver(object: DefaultLifecycleObserver {
-                        override fun onDestroy(owner: LifecycleOwner) {
-                            _value = null
-                        }
-                    })
-                }
+                fragment.viewLifecycleOwnerLiveData.observeForever(viewLifecycleOwnerLiveDataObserver)
+            }
+
+            override fun onDestroy(owner: LifecycleOwner) {
+                fragment.viewLifecycleOwnerLiveData.removeObserver(viewLifecycleOwnerLiveDataObserver)
             }
         })
     }