Support Fragments which are not hosted by Activities.

A Fragment host can be of any type; if it is not an Activity, then calling
#getActivity will always return null. Use #getContext instead, which works
similarly but is non-null while the Fragment is attached.

PiperOrigin-RevId: 259059132

Author: daniel-google

library/src/main/java/com/bumptech/glide/Glide.java

@@ -769,7 +769,7 @@ public static RequestManager with(@NonNull FragmentActivity activity) {
    */
   @NonNull
   public static RequestManager with(@NonNull Fragment fragment) {
-    return getRetriever(fragment.getActivity()).get(fragment);
+    return getRetriever(fragment.getContext()).get(fragment);
   }
 
   /**

library/src/main/java/com/bumptech/glide/manager/RequestManagerRetriever.java

@@ -134,13 +134,13 @@ public RequestManager get(@NonNull FragmentActivity activity) {
   @NonNull
   public RequestManager get(@NonNull Fragment fragment) {
     Preconditions.checkNotNull(
-        fragment.getActivity(),
+        fragment.getContext(),
         "You cannot start a load on a fragment before it is attached or after it is destroyed");
     if (Util.isOnBackgroundThread()) {
-      return get(fragment.getActivity().getApplicationContext());
+      return get(fragment.getContext().getApplicationContext());
     } else {
       FragmentManager fm = fragment.getChildFragmentManager();
-      return supportFragmentGet(fragment.getActivity(), fm, fragment, fragment.isVisible());
+      return supportFragmentGet(fragment.getContext(), fm, fragment, fragment.isVisible());
     }
   }
 
@@ -301,7 +301,7 @@ private void findAllFragmentsWithViewsPreO(
   }
 
   @Nullable
-  private Activity findActivity(@NonNull Context context) {
+  private static Activity findActivity(@NonNull Context context) {
     if (context instanceof Activity) {
       return (Activity) context;
     } else if (context instanceof ContextWrapper) {
@@ -388,15 +388,17 @@ private RequestManager fragmentGet(
   }
 
   @NonNull
-  SupportRequestManagerFragment getSupportRequestManagerFragment(FragmentActivity activity) {
+  SupportRequestManagerFragment getSupportRequestManagerFragment(
+      Context context, FragmentManager fragmentManager) {
     return getSupportRequestManagerFragment(
-        activity.getSupportFragmentManager(), /*parentHint=*/ null, isActivityVisible(activity));
+        fragmentManager, /*parentHint=*/ null, isActivityVisible(context));
   }
 
-  private static boolean isActivityVisible(Activity activity) {
+  private static boolean isActivityVisible(Context context) {
     // This is a poor heuristic, but it's about all we have. We'd rather err on the side of visible
     // and start requests than on the side of invisible and ignore valid requests.
-    return !activity.isFinishing();
+    Activity activity = findActivity(context);
+    return activity == null || !activity.isFinishing();
   }
 
   @NonNull

library/src/main/java/com/bumptech/glide/manager/SupportRequestManagerFragment.java

@@ -7,7 +7,7 @@
 import androidx.annotation.Nullable;
 import androidx.annotation.VisibleForTesting;
 import androidx.fragment.app.Fragment;
-import androidx.fragment.app.FragmentActivity;
+import androidx.fragment.app.FragmentManager;
 import com.bumptech.glide.Glide;
 import com.bumptech.glide.RequestManager;
 import com.bumptech.glide.util.Synthetic;
@@ -111,9 +111,22 @@ Set<SupportRequestManagerFragment> getDescendantRequestManagerFragments() {
    */
   void setParentFragmentHint(@Nullable Fragment parentFragmentHint) {
     this.parentFragmentHint = parentFragmentHint;
-    if (parentFragmentHint != null && parentFragmentHint.getActivity() != null) {
-      registerFragmentWithRoot(parentFragmentHint.getActivity());
+    if (parentFragmentHint == null || parentFragmentHint.getContext() == null) {
+      return;
     }
+    FragmentManager rootFragmentManager = getRootFragmentManager(parentFragmentHint);
+    if (rootFragmentManager == null) {
+      return;
+    }
+    registerFragmentWithRoot(parentFragmentHint.getContext(), rootFragmentManager);
+  }
+
+  @Nullable
+  private static FragmentManager getRootFragmentManager(@NonNull Fragment fragment) {
+    while (fragment.getParentFragment() != null) {
+      fragment = fragment.getParentFragment();
+    }
+    return fragment.getFragmentManager();
   }
 
   @Nullable
@@ -135,10 +148,13 @@ private boolean isDescendant(@NonNull Fragment fragment) {
     return false;
   }
 
-  private void registerFragmentWithRoot(@NonNull FragmentActivity activity) {
+  private void registerFragmentWithRoot(
+      @NonNull Context context, @NonNull FragmentManager fragmentManager) {
     unregisterFragmentWithRoot();
     rootRequestManagerFragment =
-        Glide.get(activity).getRequestManagerRetriever().getSupportRequestManagerFragment(activity);
+        Glide.get(context)
+            .getRequestManagerRetriever()
+            .getSupportRequestManagerFragment(context, fragmentManager);
     if (!equals(rootRequestManagerFragment)) {
       rootRequestManagerFragment.addChildRequestManagerFragment(this);
     }
@@ -154,8 +170,18 @@ private void unregisterFragmentWithRoot() {
   @Override
   public void onAttach(Context context) {
     super.onAttach(context);
+
+    FragmentManager rootFragmentManager = getRootFragmentManager(this);
+    if (rootFragmentManager == null) {
+      if (Log.isLoggable(TAG, Log.WARN)) {
+        // Not expected to occur; ancestor fragments should be attached before descendants.
+        Log.w(TAG, "Unable to register fragment with root, ancestor detached");
+      }
+      return;
+    }
+
     try {
-      registerFragmentWithRoot(getActivity());
+      registerFragmentWithRoot(getContext(), rootFragmentManager);
     } catch (IllegalStateException e) {
       // OnAttach can be called after the activity is destroyed, see #497.
       if (Log.isLoggable(TAG, Log.WARN)) {

library/test/src/test/java/com/bumptech/glide/manager/RequestManagerRetrieverTest.java

@@ -13,10 +13,15 @@
 import android.content.Context;
 import android.content.ContextWrapper;
 import android.os.Build;
+import android.os.Handler;
 import android.os.Looper;
+import android.view.LayoutInflater;
+import androidx.annotation.Nullable;
 import androidx.annotation.RequiresApi;
 import androidx.fragment.app.Fragment;
 import androidx.fragment.app.FragmentActivity;
+import androidx.fragment.app.FragmentController;
+import androidx.fragment.app.FragmentHostCallback;
 import androidx.test.core.app.ApplicationProvider;
 import com.bumptech.glide.RequestManager;
 import com.bumptech.glide.tests.BackgroundUtil.BackgroundTester;
@@ -50,7 +55,7 @@ public class RequestManagerRetrieverTest {
   public void setUp() {
     appContext = ApplicationProvider.getApplicationContext();
 
-    retriever = new RequestManagerRetriever(null /*factory*/);
+    retriever = new RequestManagerRetriever(/*factory=*/ null);
 
     harnesses =
         new RetrieverHarness[] {new DefaultRetrieverHarness(), new SupportRetrieverHarness()};
@@ -161,6 +166,23 @@ public void testSupportCanGetRequestManagerFromFragment() {
     assertEquals(manager, retriever.get(fragment));
   }
 
+  @Test
+  public void testSupportCanGetRequestManagerFromFragment_nonActivityController() {
+    FragmentController controller =
+        FragmentController.createController(new NonActivityHostCallback(appContext));
+    controller.attachHost(/*fragment=*/ null);
+    controller.dispatchCreate();
+    controller.dispatchStart();
+    controller.dispatchResume();
+
+    Fragment fragment = new Fragment();
+    controller.getSupportFragmentManager().beginTransaction().add(fragment, PARENT_TAG).commit();
+    controller.getSupportFragmentManager().executePendingTransactions();
+
+    RequestManager manager = retriever.get(fragment);
+    assertEquals(manager, retriever.get(fragment));
+  }
+
   @Test
   public void testCanGetRequestManagerFromDetachedFragment() {
     helpTestCanGetRequestManagerFromDetachedFragment();
@@ -488,4 +510,27 @@ public void addFragmentWithTag(String tag, RequestManager manager) {
       controller.get().getSupportFragmentManager().executePendingTransactions();
     }
   }
+
+  /** Simple callback for creating an Activity-less Fragment host. */
+  private final class NonActivityHostCallback
+      extends FragmentHostCallback<RequestManagerRetrieverTest> {
+
+    private final Context context;
+
+    NonActivityHostCallback(Context context) {
+      super(context, new Handler(Looper.getMainLooper()), /*windowAnimations=*/ 0);
+      this.context = context;
+    }
+
+    @Override
+    public LayoutInflater onGetLayoutInflater() {
+      return LayoutInflater.from(context).cloneInContext(context);
+    }
+
+    @Nullable
+    @Override
+    public RequestManagerRetrieverTest onGetHost() {
+      return RequestManagerRetrieverTest.this;
+    }
+  }
 }