Merge pull request #676 from steveram/index-path-for-node

Add a indexPathForNode: to ASTableView

AsyncDisplayKit/ASTableView.h

@@ -227,6 +227,15 @@
  */
 - (ASCellNode *)nodeForRowAtIndexPath:(NSIndexPath *)indexPath;
 
+/**
+ * Similar to -indexPathForCell:.
+ *
+ * @param cellNode a cellNode part of the table view
+ *
+ * @returns an indexPath for this cellNode
+ */
+- (NSIndexPath *)indexPathForNode:(ASCellNode *)cellNode;
+
 /**
  * Similar to -visibleCells.
  *

AsyncDisplayKit/ASTableView.mm

@@ -345,6 +345,11 @@ void ASPerformBlockWithoutAnimation(BOOL withoutAnimation, void (^block)()) {
   return [_dataController nodeAtIndexPath:indexPath];
 }
 
+- (NSIndexPath *)indexPathForNode:(ASCellNode *)cellNode
+{
+  return [_dataController indexPathForNode:cellNode];
+}
+
 - (NSArray *)visibleNodes
 {
   NSArray *indexPaths = [self indexPathsForVisibleRows];

AsyncDisplayKit/Details/ASDataController.h

@@ -173,6 +173,8 @@ typedef NSUInteger ASDataControllerAnimationOptions;
 
 - (ASCellNode *)nodeAtIndexPath:(NSIndexPath *)indexPath;
 
+- (NSIndexPath *)indexPathForNode:(ASCellNode *)cellNode;
+
 - (NSArray *)nodesAtIndexPaths:(NSArray *)indexPaths;
 
 - (NSArray *)completedNodes;  // This provides efficient access to the entire _completedNodes multidimensional array.

AsyncDisplayKit/Details/ASDataController.mm

@@ -632,6 +632,22 @@ static void *kASSizingQueueContext = &kASSizingQueueContext;
   return _completedNodes[indexPath.section][indexPath.row];
 }
 
+- (NSIndexPath *)indexPathForNode:(ASCellNode *)cellNode;
+{
+  ASDisplayNodeAssertMainThread();
+
+  // Loop through each section to look for the cellNode
+  for (NSUInteger i = 0; i < [_completedNodes count]; i++) {
+    NSArray *sectionNodes = _completedNodes[i];
+    NSUInteger cellIndex = [sectionNodes indexOfObjectIdenticalTo:cellNode];
+    if (cellIndex != NSNotFound) {
+      return [NSIndexPath indexPathForRow:cellIndex inSection:i];
+    }
+  }
+  
+  return nil;
+}
+
 - (NSArray *)nodesAtIndexPaths:(NSArray *)indexPaths
 {
   ASDisplayNodeAssertMainThread();

AsyncDisplayKitTests/ASTableViewTests.m

@@ -428,4 +428,27 @@
   }];
 }
 
+- (void)testIndexPathForNode
+{
+  CGSize tableViewSize = CGSizeMake(100, 500);
+  ASTestTableView *tableView = [[ASTestTableView alloc] initWithFrame:CGRectMake(0, 0, tableViewSize.width, tableViewSize.height)
+                                                                style:UITableViewStylePlain
+                                                    asyncDataFetching:YES];
+  ASTableViewFilledDataSource *dataSource = [ASTableViewFilledDataSource new];
+  
+  tableView.asyncDelegate = dataSource;
+  tableView.asyncDataSource = dataSource;
+  
+  [tableView reloadDataWithCompletion:^{
+    for (NSUInteger i = 0; i < NumberOfSections; i++) {
+      for (NSUInteger j = 0; j < NumberOfRowsPerSection; j++) {
+        NSIndexPath *indexPath = [NSIndexPath indexPathForRow:j inSection:i];
+        ASCellNode *cellNode = [tableView nodeForRowAtIndexPath:indexPath];
+        NSIndexPath *reportedIndexPath = [tableView indexPathForNode:cellNode];
+        XCTAssertEqual(indexPath.row, reportedIndexPath.row);
+      }
+    }
+  }];
+}
+
 @end