Merge pull request #7149 from TacoTheDank/updateFragWorkaround

Update pager workaround code to Fragment 1.3.6

Author: litetex

app/src/main/java/androidx/fragment/app/FragmentStatePagerAdapterMenuWorkaround.java

@@ -51,8 +51,12 @@
  *     <li>{@link #saveState()}</li>
  *     <li>{@link #restoreState(Parcelable, ClassLoader)}</li>
  * </ul>
+ *
+ * @deprecated Switch to {@link androidx.viewpager2.widget.ViewPager2} and use
+ * {@link androidx.viewpager2.adapter.FragmentStateAdapter} instead.
  */
 @SuppressWarnings("deprecation")
+@Deprecated
 public abstract class FragmentStatePagerAdapterMenuWorkaround extends PagerAdapter {
     private static final String TAG = "FragmentStatePagerAdapt";
     private static final boolean DEBUG = false;
@@ -86,9 +90,10 @@ public abstract class FragmentStatePagerAdapterMenuWorkaround extends PagerAdapt
     private final int mBehavior;
     private FragmentTransaction mCurTransaction = null;
 
-    private final ArrayList<Fragment.SavedState> mSavedState = new ArrayList<Fragment.SavedState>();
-    private final ArrayList<Fragment> mFragments = new ArrayList<Fragment>();
+    private final ArrayList<Fragment.SavedState> mSavedState = new ArrayList<>();
+    private final ArrayList<Fragment> mFragments = new ArrayList<>();
     private Fragment mCurrentPrimaryItem = null;
+    private boolean mExecutingFinishUpdate;
 
     /**
      * Constructor for {@link FragmentStatePagerAdapterMenuWorkaround}
@@ -208,7 +213,7 @@ public void destroyItem(@NonNull final ViewGroup container, final int position,
         mFragments.set(position, null);
 
         mCurTransaction.remove(fragment);
-        if (fragment == mCurrentPrimaryItem) {
+        if (fragment.equals(mCurrentPrimaryItem)) {
             mCurrentPrimaryItem = null;
         }
     }
@@ -247,7 +252,19 @@ public void setPrimaryItem(@NonNull final ViewGroup container, final int positio
     @Override
     public void finishUpdate(@NonNull final ViewGroup container) {
         if (mCurTransaction != null) {
-            mCurTransaction.commitNowAllowingStateLoss();
+            // We drop any transactions that attempt to be committed
+            // from a re-entrant call to finishUpdate(). We need to
+            // do this as a workaround for Robolectric running measure/layout
+            // calls inline rather than allowing them to be posted
+            // as they would on a real device.
+            if (!mExecutingFinishUpdate) {
+                try {
+                    mExecutingFinishUpdate = true;
+                    mCurTransaction.commitNowAllowingStateLoss();
+                } finally {
+                    mExecutingFinishUpdate = false;
+                }
+            }
             mCurTransaction = null;
         }
     }