fix bug where some reloads wouldn't be performed

Change-Id: I4482996ea218f6c9b2054cf00e4a3f8757da19ba

Author: morganchen12

FirebaseFirestoreUI/FUIBatchedArray.m

@@ -128,7 +128,7 @@ - (BOOL)isEqual:(FIRDocumentSnapshot *)object {
  return NO;
  }
 
- return [object.documentID isEqual:self.documentID] && [object.data isEqual:self.data];
+ return [object.documentID isEqual:self.documentID];
 }
 
 - (instancetype)copyWithZone:(NSZone *)zone {

FirebaseFirestoreUI/FUICollectionViewDataSource.h

@@ -28,7 +28,7 @@ NS_ASSUME_NONNULL_BEGIN
  * FUICollectionViewDataSource provides a class that conforms to the
  * UICollectionViewDataSource protocol which allows UICollectionViews to
  * adopt FUICollectionViewDataSource in order to provide a UICollectionView
- * synchronized to a Firebase reference or query.
+ * synchronized to a Firestore reference or query.
  */
 @interface FUICollectionViewDataSource : NSObject <UICollectionViewDataSource>
 
@@ -74,7 +74,7 @@ NS_ASSUME_NONNULL_BEGIN
  * Initialize an instance of FUICollectionViewDataSource that populates
  * UICollectionViewCells with FIRDataSnapshots.
  * @param collection A FUICollection that the data source uses to pull snapshots
- * from Firebase Database.
+ * from Cloud Firestore.
  * @param populateCell A closure used by the data source to create the cells that
  * are displayed in the collection view. This closure is retained by the data
  * source, so if you capture self in the closure and also claim ownership of the
@@ -90,7 +90,7 @@ NS_ASSUME_NONNULL_BEGIN
 /**
  * Initialize an unsorted instance of FUICollectionViewDataSource that populates
  * UICollectionViewCells with FIRDataSnapshots.
- * @param query A Firebase query to bind the data source to.
+ * @param query A Firestore query to bind the data source to.
  * @param populateCell A closure used by the data source to create the cells that 
  * are displayed in the collection view. This closure is retained by the data
  * source, so if you capture self in the closure and also claim ownership of the
@@ -125,14 +125,14 @@ NS_ASSUME_NONNULL_BEGIN
  * Creates a data source, attaches it to the collection view, and returns it.
  * The returned data source is not retained by the collection view and must be
  * retained or it will be deallocated while still in use by the collection view.
- * @param query A Firebase database query to bind the collection view to.
+ * @param query A Cloud Firestore query to bind the collection view to.
  * @param populateCell A closure used by the data source to create the cells
  * displayed in the collection view. The closure is retained by the returned
  * data source.
  * @return The created data source. This value must be retained while the collection
  * view is in use.
  */
-- (FUICollectionViewDataSource *)bindToQuery:(FIRDocumentSnapshot *)query
+- (FUICollectionViewDataSource *)bindToQuery:(FIRQuery *)query
  populateCell:(UICollectionViewCell *(^)(UICollectionView *collectionView,
  NSIndexPath *indexPath,
  FIRDocumentSnapshot *object))populateCell __attribute__((warn_unused_result));

FirebaseFirestoreUI/FUICollectionViewDataSource.m

@@ -110,7 +110,10 @@ - (void)batchedArray:(FUIBatchedArray *)array
  NSIndexPath *changed = [NSIndexPath indexPathForItem:changedIndex.integerValue inSection:0];
  [changedIndexPaths addObject:changed];
  }
- [self.collectionView reloadItemsAtIndexPaths:changedIndexPaths];
+ // Use a delete and insert instead of a reload. See
+ // https://stackoverflow.com/questions/42147822/uicollectionview-batchupdate-edge-case-fails
+ [self.collectionView deleteItemsAtIndexPaths:changedIndexPaths];
+ [self.collectionView insertItemsAtIndexPaths:changedIndexPaths];
 
  for (NSInteger i = 0; i < diff.movedInitialIndexes.count; i++) {
  NSInteger initialIndex = diff.movedInitialIndexes[i].integerValue;

FirebaseFirestoreUI/FUISnapshotArrayDiff.m

@@ -416,11 +416,20 @@ - (void)buildDiffsFromDocumentChanges:(NSArray<FIRDocumentChange *> *)documentCh
  }
  continue;
  case FIRDocumentChangeTypeModified:
- // Don't try to reload changes that were later deleted.
- if (newIndex == nil) { continue; }
- if (newIndex != oldIndex) { continue; /* Not a change */ }
- [changedIndexes addObject:newIndex];
- [changedObjects addObject:snapshot];
+ // Don't try to reload changes that weren't in the initial and result arrays.
+ if (newIndex == nil || oldIndex == nil) { continue; }
+ // This should be counted as a move.
+ if (![newIndex isEqualToNumber:oldIndex]) {
+ [movedInitialIndexes addObject:oldIndex];
+ [movedResultIndexes addObject:newIndex];
+ [movedObjects addObject:snapshot];
+
+ // Keep track of which insertions we should ignore later.
+ [movedSnapshots addObject:snapshot];
+ } else {
+ [changedIndexes addObject:oldIndex];
+ [changedObjects addObject:snapshot];
+ }
  continue;
  case FIRDocumentChangeTypeAdded:
  // Ignore insertions that were later removed.
@@ -429,10 +438,9 @@ - (void)buildDiffsFromDocumentChanges:(NSArray<FIRDocumentChange *> *)documentCh
  // counted as moves.
  if (oldIndex != nil) { continue; }
  // Ignore insertions that we consider moves.
- if (![movedSnapshots containsObject:snapshot]) {
- [insertedIndexes addObject:newIndex];
- [insertedObjects addObject:snapshot];
- }
+ if ([movedSnapshots containsObject:snapshot]) { continue; }
+ [insertedIndexes addObject:newIndex];
+ [insertedObjects addObject:snapshot];
  continue;
  }
  }

FirebaseFirestoreUI/FUITableViewDataSource.h

@@ -24,13 +24,11 @@
 
 NS_ASSUME_NONNULL_BEGIN
 
-@class FIRDatabaseReference;
-
 /**
  * FUITableViewDataSource provides a class that conforms to the
  * UITableViewDataSource protocol which allows UITableViews to implement
  * FUITableViewDataSource in order to provide a UITableView synchronized
- * to a Firebase reference or query. 
+ * to a Firestore reference or query.
  */
 @interface FUITableViewDataSource : NSObject <UITableViewDataSource>
 
@@ -80,7 +78,7 @@ NS_ASSUME_NONNULL_BEGIN
 /**
  * Initialize an instance of FUITableViewDataSource.
  * @param collection An FUICollection used by the data source to pull data
- * from Firebase Database.
+ * from Cloud Firestore.
  * @param populateCell A closure used by the data source to create/reuse
  * table view cells and populate their content. This closure is retained
  * by the data source, so if you capture self in the closure and also claim ownership
@@ -96,7 +94,7 @@ NS_ASSUME_NONNULL_BEGIN
 /**
  * Initialize an instance of FUITableViewDataSource with contents ordered
  * by the query.
- * @param query A Firebase query to bind the data source to.
+ * @param query A Firestore query to bind the data source to.
  * @param populateCell A closure used by the data source to create/reuse
  * table view cells and populate their content. This closure is retained
  * by the data source, so if you capture self in the closure and also claim ownership
@@ -130,7 +128,7 @@ NS_ASSUME_NONNULL_BEGIN
  * Creates a data source, attaches it to the table view, and returns it.
  * The returned data source is not retained by the table view and must be
  * retained or it will be deallocated while still in use by the table view.
- * @param query A Firebase database query to bind the table view to.
+ * @param query A Cloud Firestore query to bind the table view to.
  * @param populateCell A closure used by the data source to create the cells
  * displayed in the table view. The closure is retained by the returned
  * data source.