From ffc583d0e5cc762b718efb0336aac870ff425629 Mon Sep 17 00:00:00 2001
From: Mohamed Metwalli <mohamed.metwalli@sap.com>
Date: Thu, 10 Jun 2021 19:26:58 +0200
Subject: [PATCH] Reset viewBing when new view is created (#3409)
Co-authored-by: harambasicluka <64483219+harambasicluka@users.noreply.github.com>
---
.../util/ui/ViewBindingExtensions.kt | 30 +++++++++++++++++--
1 file changed, 27 insertions(+), 3 deletions(-)
diff --git a/Corona-Warn-App/src/main/java/de/rki/coronawarnapp/util/ui/ViewBindingExtensions.kt b/Corona-Warn-App/src/main/java/de/rki/coronawarnapp/util/ui/ViewBindingExtensions.kt
index 21b663e70..279dc35a4 100644
--- a/Corona-Warn-App/src/main/java/de/rki/coronawarnapp/util/ui/ViewBindingExtensions.kt
+++ b/Corona-Warn-App/src/main/java/de/rki/coronawarnapp/util/ui/ViewBindingExtensions.kt
@@ -12,6 +12,7 @@ import androidx.viewbinding.ViewBinding
import timber.log.Timber
import kotlin.properties.ReadOnlyProperty
import kotlin.reflect.KProperty
+import com.google.android.material.bottomnavigation.BottomNavigationView
inline fun <reified BindingT : ViewBinding> Fragment.viewBinding() =
viewBinding(
@@ -44,12 +45,13 @@ class ViewBindingProperty<ComponentT : LifecycleOwner, BindingT : ViewBinding>(
private val onDestroyObserver = object : DefaultLifecycleObserver {
// Called right before Fragment.onDestroyView
override fun onDestroy(owner: LifecycleOwner) {
+ Timber.tag(TAG).v("onDestroy(%s)", owner)
localRef?.lifecycle?.removeObserver(this) ?: return
localRef = null
uiHandler.post {
- Timber.v("Resetting viewBinding")
+ Timber.tag(TAG).v("Resetting viewBinding owner=%s", owner)
viewBinding = null
}
}
@@ -58,15 +60,34 @@ class ViewBindingProperty<ComponentT : LifecycleOwner, BindingT : ViewBinding>(
@MainThread
override fun getValue(thisRef: ComponentT, property: KProperty<*>): BindingT {
if (localRef == null && viewBinding != null) {
- Timber.w("Fragment.onDestroyView() was called, but the handler didn't execute our delayed reset.")
+ Timber.tag(TAG).w(
+ "Fragment.onDestroyView(%s) was called, but the handler didn't execute our delayed reset.",
+ thisRef
+ )
/**
- * There is a fragment racecondition if you navigate to another fragment and quickly popBackStack().
+ * There is a fragment race condition if you navigate to another fragment and quickly popBackStack().
* Our uiHandler.post { } will not have executed for some reason.
* In that case we manually null the old viewBinding, to allow for clean recreation.
*/
viewBinding = null
}
+ /**
+ * This is a fix for an edge case where the fragment is created but was never visible to the user
+ * [DefaultLifecycleObserver.onDestroy] was never called despite that the [Fragment.onDestroyView] was called,
+ * therefore the ViewBinding will not be set to `null` and will hold the old view ,while Fragment will
+ * inflate a new [View] when navigating back to it. As result of that the screen ends being blank.
+ *
+ * This is very specific case when navigating by deeplink to one of the [BottomNavigationView] destinations,
+ * that is not the "home destination" of the graph.
+ */
+ (localRef as? Fragment)?.view?.let {
+ if (it != viewBinding?.root && localRef === thisRef) {
+ Timber.tag(TAG).w("Different view for the same fragment, resetting old viewBinding")
+ viewBinding = null
+ }
+ }
+
viewBinding?.let {
// Only accessible from within the same component
require(localRef === thisRef)
@@ -76,9 +97,12 @@ class ViewBindingProperty<ComponentT : LifecycleOwner, BindingT : ViewBinding>(
val lifecycle = lifecycleOwnerProvider(thisRef).lifecycle
return bindingProvider(thisRef).also {
+ Timber.tag(TAG).d("bindingProvider(%s)", thisRef)
viewBinding = it
localRef = thisRef
lifecycle.addObserver(onDestroyObserver)
}
}
}
+
+private const val TAG = "ViewBindingExtension"
--
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