Merge pull request #2706 from dreampiggy/bugfix_mac_SDAnimatedImage_NSImage

Fix the bug of SDAnimatedImageView, which can not render the normal NSImage (including animated image) at all. Only `SDAnimatedImage` can be rendered

Examples/SDWebImage OSX Demo/ViewController.m

@@ -29,13 +29,16 @@
     
     // For animated GIF rendering, set `animates` to YES or will only show the first frame
     self.imageView2.animates = YES; // `SDAnimatedImageRep` can be used for built-in `NSImageView` to support better GIF & APNG rendering as well. No need `SDAnimatedImageView`
-    self.imageView3.animates = YES;
     self.imageView4.animates = YES;
+    
+    // NSImageView + Static Image
     self.imageView1.sd_imageIndicator = SDWebImageProgressIndicator.defaultIndicator;
     [self.imageView1 sd_setImageWithURL:[NSURL URLWithString:@"https://raw.githubusercontent.com/recurser/exif-orientation-examples/master/Landscape_2.jpg"] placeholderImage:nil options:SDWebImageProgressiveLoad];
+    // NSImageView + Animated Image
     [self.imageView2 sd_setImageWithURL:[NSURL URLWithString:@"https:raw.githubusercontent.com/onevcat/APNGKit/master/TestImages/APNG-cube.apng"]];
-    [self.imageView3 sd_setImageWithURL:[NSURL URLWithString:@"https://raw.githubusercontent.com/liyong03/YLGIFImage/master/YLGIFImageDemo/YLGIFImageDemo/joy.gif"]];
-    self.imageView4.wantsLayer = YES;
+    // SDAnimatedImageView + Static Image
+    [self.imageView3 sd_setImageWithURL:[NSURL URLWithString:@"https://nr-platform.s3.amazonaws.com/uploads/platform/published_extension/branding_icon/275/AmazonS3.png"]];
+    // SDAnimatedImageView + Animated Image
     self.imageView4.sd_imageTransition = SDWebImageTransition.fadeTransition;
     [self.imageView4 sd_setImageWithURL:[NSURL URLWithString:@"http://littlesvr.ca/apng/images/SteamEngine.webp"] placeholderImage:nil options:SDWebImageForceTransition];
     

SDWebImage/SDAnimatedImageView.m

@@ -678,6 +678,17 @@ static NSUInteger SDDeviceFreeMemory() {
         [super updateLayer];
     }
 }
+
+- (BOOL)wantsUpdateLayer {
+    // AppKit is different from UIKit, it need extra check before the layer is updated
+    // When we use the custom animation, the layer.setNeedsDisplay is directly called from display link (See `displayDidRefresh:`). However, for normal image rendering, we must implements and return YES to mark it need display
+    if (_currentFrame) {
+        return NO;
+    } else {
+        return YES;
+    }
+}
+
 #endif
 
 

Tests/Tests/SDAnimatedImageTest.m

@@ -137,6 +137,18 @@ static const NSUInteger kTestGIFFrameCount = 5; // local TestImage.gif loop coun
     expect(imageView.intrinsicContentSize).equal(image.size);
 }
 
+- (void)test12AnimatedImageViewLayerContents {
+    // Test that SDAnimatedImageView with built-in UIImage/NSImage will actually setup the layer for display
+    SDAnimatedImageView *imageView = [SDAnimatedImageView new];
+    UIImage *image = [[UIImage alloc] initWithData:[self testJPEGData]];
+    imageView.image = image;
+#if SD_MAC
+    expect(imageView.wantsUpdateLayer).beTruthy();
+#else
+    expect(imageView.layer.contents).notTo.beNil();
+#endif
+}
+
 - (void)test20AnimatedImageViewRendering {
     XCTestExpectation *expectation = [self expectationWithDescription:@"test SDAnimatedImageView rendering"];
     SDAnimatedImageView *imageView = [[SDAnimatedImageView alloc] init];