From 557ef9dc38aef5ae5a1d16d9f40e83a784760915 Mon Sep 17 00:00:00 2001
From: gongdao123 <gongdao123@gmail.com>
Date: Mon, 22 Apr 2019 10:43:21 +0800
Subject: [PATCH] pre-render image to improve loading performance

---
 ios/RCTImageSequence/RCTImageSequenceView.m | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/ios/RCTImageSequence/RCTImageSequenceView.m b/ios/RCTImageSequence/RCTImageSequenceView.m
index 9038f5f..a1a3617 100644
--- a/ios/RCTImageSequence/RCTImageSequenceView.m
+++ b/ios/RCTImageSequence/RCTImageSequenceView.m
@@ -30,9 +30,16 @@ - (void)setImages:(NSArray *)images {
         #endif
 
         dispatch_async(dispatch_queue_create("dk.mads-lee.ImageSequence.Downloader", NULL), ^{
-            UIImage *image = [UIImage imageWithData:[NSData dataWithContentsOfURL:[NSURL URLWithString:url]]];
+            UIImage *frameImage = [UIImage imageWithData:[NSData dataWithContentsOfURL:[NSURL URLWithString:url]]];
+            // here is the code to pre-render the image
+            UIGraphicsBeginImageContext(frameImage.size);
+            CGRect rect = CGRectMake(0, 0, frameImage.size.width, frameImage.size.height);
+            [frameImage drawInRect:rect];
+            UIImage *renderedImage = UIGraphicsGetImageFromCurrentImageContext();
+            UIGraphicsEndImageContext();
+            
             dispatch_async(dispatch_get_main_queue(), ^{
-              [weakSelf onImageLoadTaskAtIndex:index image:image];
+                [weakSelf onImageLoadTaskAtIndex:index image:renderedImage];
             });
         });