Merge pull request #620 from nguyenhuy/617_relayout_loading_nodes

Fix new constrained size is not applied to loading nodes

AsyncDisplayKit/Details/ASDataController.mm

@@ -564,13 +564,30 @@ static void *kASSizingQueueContext = &kASSizingQueueContext;
     LOG(@"Edit Command - relayoutRows");
     [_editingTransactionQueue waitUntilAllOperationsAreFinished];
     
-    [_completedNodes enumerateObjectsUsingBlock:^(NSMutableArray *section, NSUInteger sectionIndex, BOOL *stop) {
-      [section enumerateObjectsUsingBlock:^(ASCellNode *node, NSUInteger rowIndex, BOOL *stop) {
-        ASSizeRange constrainedSize = [_dataSource dataController:self
-                                constrainedSizeForNodeAtIndexPath:[NSIndexPath indexPathForRow:rowIndex inSection:sectionIndex]];
-        [node measureWithSizeRange:constrainedSize];
-        node.frame = CGRectMake(0.0f, 0.0f, node.calculatedSize.width, node.calculatedSize.height);
+    void (^relayoutNodesBlock)(NSMutableArray *) = ^void(NSMutableArray *nodes) {
+      if (!nodes.count) {
+        return;
+      }
+      
+      [self accessDataSourceWithBlock:^{
+        [nodes enumerateObjectsUsingBlock:^(NSMutableArray *section, NSUInteger sectionIndex, BOOL *stop) {
+          [section enumerateObjectsUsingBlock:^(ASCellNode *node, NSUInteger rowIndex, BOOL *stop) {
+            NSIndexPath *indexPath = [NSIndexPath indexPathForRow:rowIndex inSection:sectionIndex];
+            ASSizeRange constrainedSize = [_dataSource dataController:self constrainedSizeForNodeAtIndexPath:indexPath];
+            [node measureWithSizeRange:constrainedSize];
+            node.frame = CGRectMake(0.0f, 0.0f, node.calculatedSize.width, node.calculatedSize.height);
+          }];
+        }];
       }];
+    };
+
+    // Can't relayout right away because _completedNodes may not be up-to-date,
+    // i.e there might be some nodes that were measured using the old constrained size but haven't been added to _completedNodes
+    // (see _layoutNodes:atIndexPaths:withAnimationOptions:).
+    [_editingTransactionQueue addOperationWithBlock:^{
+      ASDisplayNodePerformBlockOnMainThread(^{
+        relayoutNodesBlock(_completedNodes);
+      });
     }];
   }];
 }

AsyncDisplayKitTests/ASTableViewTests.m

@@ -202,4 +202,44 @@
   }
 }
 
+- (void)testRelayoutAllRows
+{
+  // Initial width of the table view is 0 and all nodes are measured with this size.
+  ASTestTableView *tableView = [[ASTestTableView alloc] initWithFrame:CGRectMake(0, 0, 0, 500)
+                                                                style:UITableViewStylePlain
+                                                    asyncDataFetching:YES];
+  CGSize tableViewFinalSize = CGSizeMake(100, 500);
+  
+  ASTableViewFilledDataSource *dataSource = [ASTableViewFilledDataSource new];
+
+  tableView.asyncDelegate = dataSource;
+  tableView.asyncDataSource = dataSource;
+  
+  [tableView reloadData];
+  
+  [tableView beginUpdates];
+  
+  tableView.frame = CGRectMake(0, 0, tableViewFinalSize.width, tableViewFinalSize.height);
+  [tableView layoutIfNeeded];
+  
+  XCTestExpectation *nodesMeasuredUsingNewConstrainedSizeExpectation = [self expectationWithDescription:@"nodesMeasuredUsingNewConstrainedSize"];
+
+  [tableView endUpdatesAnimated:NO completion:^(BOOL completed) {
+    for (int section = 0; section < NumberOfSections; section++) {
+      for (int row = 0; row < NumberOfRowsPerSection; row++) {
+        NSIndexPath *indexPath = [NSIndexPath indexPathForRow:row inSection:section];
+        ASCellNode *node = [tableView nodeForRowAtIndexPath:indexPath];
+        XCTAssertEqual(node.constrainedSizeForCalculatedLayout.max.width, tableViewFinalSize.width);
+      }
+    }
+    [nodesMeasuredUsingNewConstrainedSizeExpectation fulfill];
+  }];
+  
+  [self waitForExpectationsWithTimeout:5 handler:^(NSError *error) {
+    if (error) {
+      XCTFail(@"Expectation failed: %@", error);
+    }
+  }];
+}
+
 @end