From 7cdfacca4a989e795bd2019e0825b819cf8b74a7 Mon Sep 17 00:00:00 2001
From: Huy Nguyen <allforone1511@gmail.com>
Date: Sun, 14 Oct 2018 09:16:47 -0700
Subject: [PATCH] Update documentation of ASNetworkImageNodeDelegate #trivial
 (#1163)

`-imageNodeDidStartFetchingData:` and `-imageNodeDidFinishDecoding:` are always called on main thread, and the documentation should reflect that.
---
 Source/ASNetworkImageNode.h  | 20 +++++++++++---------
 Source/ASNetworkImageNode.mm |  2 ++
 2 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/Source/ASNetworkImageNode.h b/Source/ASNetworkImageNode.h
index f77a9a59d1..576cbb94b8 100644
--- a/Source/ASNetworkImageNode.h
+++ b/Source/ASNetworkImageNode.h
@@ -145,6 +145,15 @@ NS_ASSUME_NONNULL_BEGIN
 @protocol ASNetworkImageNodeDelegate <NSObject>
 @optional
 
+/**
+ * Notification that the image node started to load
+ *
+ * @param imageNode The sender.
+ *
+ * @discussion Called on the main thread.
+ */
+- (void)imageNodeDidStartFetchingData:(ASNetworkImageNode *)imageNode;
+
 /**
  * Notification that the image node finished downloading an image, with additional info.
  * If implemented, this method will be called instead of `imageNode:didLoadImage:`.
@@ -167,15 +176,6 @@ NS_ASSUME_NONNULL_BEGIN
  */
 - (void)imageNode:(ASNetworkImageNode *)imageNode didLoadImage:(UIImage *)image;
 
-/**
- * Notification that the image node started to load
- *
- * @param imageNode The sender.
- *
- * @discussion Called on a background queue.
- */
-- (void)imageNodeDidStartFetchingData:(ASNetworkImageNode *)imageNode;
-
 /**
  * Notification that the image node failed to download the image.
  *
@@ -190,6 +190,8 @@ NS_ASSUME_NONNULL_BEGIN
  * Notification that the image node finished decoding an image.
  *
  * @param imageNode The sender.
+ *
+ * @discussion Called on the main thread.
  */
 - (void)imageNodeDidFinishDecoding:(ASNetworkImageNode *)imageNode;
 
diff --git a/Source/ASNetworkImageNode.mm b/Source/ASNetworkImageNode.mm
index ce864647af..ea863c1ee1 100644
--- a/Source/ASNetworkImageNode.mm
+++ b/Source/ASNetworkImageNode.mm
@@ -614,6 +614,8 @@ static std::atomic_bool _useMainThreadDelegateCallbacks(true);
 
 - (void)_lazilyLoadImageIfNecessary
 {
+  ASDisplayNodeAssertMainThread();
+
   [self lock];
     __weak id<ASNetworkImageNodeDelegate> delegate = _delegate;
     BOOL delegateDidStartFetchingData = _delegateFlags.delegateDidStartFetchingData;