Clears Fragment reference in FragmentContextWrapper after Fragment#on…

…Destroy() This CL uses the fragment Lifecycle to clear the fragment instance from the FragmentContextWrapper after onDestroy. Fixes: #2070 See #2070 RELNOTES=Fixes #2070: clears Fragment reference in FragmentContextWrapper after Fragment#onDestroy() PiperOrigin-RevId: 352579115
google · Jan 19, 2021 · 1822650 · 1822650
1 parent 8c45caf
commit 1822650
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Showing 5 changed files with 30 additions and 5 deletions.
diff --git a/WORKSPACE b/WORKSPACE
@@ -106,6 +106,7 @@ maven_install(
         "androidx.appcompat:appcompat:1.2.0",
         "androidx.activity:activity:1.2.0-rc01",
         "androidx.fragment:fragment:1.3.0-rc01",
+        "androidx.lifecycle:lifecycle-common:2.3.0-rc01",
         "androidx.lifecycle:lifecycle-viewmodel:2.3.0-rc01",
         "androidx.lifecycle:lifecycle-viewmodel-savedstate:2.3.0-rc01",
         "androidx.multidex:multidex:2.0.1",

diff --git a/java/dagger/hilt/android/BUILD b/java/dagger/hilt/android/BUILD
@@ -157,6 +157,7 @@ gen_maven_artifact(
         "androidx.activity:activity",
         "androidx.annotation:annotation",
         "androidx.fragment:fragment",
+        "androidx.lifecycle:lifecycle-common",
         "androidx.lifecycle:lifecycle-viewmodel",
         "androidx.lifecycle:lifecycle-viewmodel-savedstate",
         "androidx.savedstate:savedstate",

diff --git a/java/dagger/hilt/android/internal/managers/BUILD b/java/dagger/hilt/android/internal/managers/BUILD
@@ -50,6 +50,7 @@ android_library(
         "@maven//:androidx_activity_activity",
         "@maven//:androidx_annotation_annotation",
         "@maven//:androidx_fragment_fragment",
+        "@maven//:androidx_lifecycle_lifecycle_common",
         "@maven//:androidx_lifecycle_lifecycle_viewmodel",
     ],
 )

diff --git a/java/dagger/hilt/android/internal/managers/ViewComponentManager.java b/java/dagger/hilt/android/internal/managers/ViewComponentManager.java
@@ -16,6 +16,9 @@
 
 package dagger.hilt.android.internal.managers;
 
+import androidx.lifecycle.Lifecycle;
+import androidx.lifecycle.LifecycleEventObserver;
+import androidx.lifecycle.LifecycleOwner;
 import android.content.Context;
 import android.content.ContextWrapper;
 import androidx.fragment.app.Fragment;
@@ -104,7 +107,7 @@ private GeneratedComponentManager<?> getParentComponentManager(boolean allowMiss
       if (context instanceof FragmentContextWrapper) {
 
         FragmentContextWrapper fragmentContextWrapper = (FragmentContextWrapper) context;
-        return (GeneratedComponentManager<?>) fragmentContextWrapper.fragment;
+        return (GeneratedComponentManager<?>) fragmentContextWrapper.getFragment();
       } else if (allowMissing) {
         // We didn't find anything, so return null if we're not supposed to fail.
         // The rest of the logic is just about getting a good error message.
@@ -167,20 +170,38 @@ private static Context unwrap(Context context, Class<?> target) {
    */
   // This is only non-final for the account override
   public static final class FragmentContextWrapper extends ContextWrapper {
+    private Fragment fragment;
     private LayoutInflater baseInflater;
     private LayoutInflater inflater;
-    public final Fragment fragment;
-
-    public FragmentContextWrapper(Context base, Fragment fragment) {
+    private final LifecycleEventObserver fragmentLifecycleObserver =
+        new LifecycleEventObserver() {
+          @Override
+          public void onStateChanged(LifecycleOwner source, Lifecycle.Event event) {
+            if (event == Lifecycle.Event.ON_DESTROY) {
+              // Prevent the fragment from leaking if the view outlives the fragment.
+              // See https://github.com/google/dagger/issues/2070
+              FragmentContextWrapper.this.fragment = null;
+            }
+          }
+        };
+
+    FragmentContextWrapper(Context base, Fragment fragment) {
       super(Preconditions.checkNotNull(base));
       this.baseInflater = null;
       this.fragment = Preconditions.checkNotNull(fragment);
+      this.fragment.getLifecycle().addObserver(fragmentLifecycleObserver);
     }
 
-    public FragmentContextWrapper(LayoutInflater baseInflater, Fragment fragment) {
+    FragmentContextWrapper(LayoutInflater baseInflater, Fragment fragment) {
       super(Preconditions.checkNotNull(Preconditions.checkNotNull(baseInflater).getContext()));
       this.baseInflater = baseInflater;
       this.fragment = Preconditions.checkNotNull(fragment);
+      this.fragment.getLifecycle().addObserver(fragmentLifecycleObserver);
+    }
+
+    Fragment getFragment() {
+      Preconditions.checkNotNull(fragment, "The fragment has already been destroyed.");
+      return fragment;
     }
 
     @Override

diff --git a/java/dagger/hilt/android/testing/BUILD b/java/dagger/hilt/android/testing/BUILD
@@ -202,6 +202,7 @@ gen_maven_artifact(
         "androidx.activity:activity",
         "androidx.annotation:annotation",
         "androidx.fragment:fragment",
+        "androidx.lifecycle:lifecycle-common",
         "androidx.lifecycle:lifecycle-viewmodel",
         "androidx.lifecycle:lifecycle-viewmodel-savedstate",
         "androidx.multidex:multidex",