ios newsfeed blur 1.m

self.text = self.event.text;
__weak id wself = self;
NSString *imageUrl = self.event.imageUrl;

self.image = nil;
self.overlay.image = nil;

dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
    UIImage *image = [[wself downloadImage:imageUrl] scaleWithWidth:cellWidth];
    UIImage *blurredImage = [image blurRect:overlayRect];

    dispatch_async(dispatch_get_main_queue(), ^{
        // skip if the cell’s event has changed
        if (![imageUrl isEqualToString:wself.event.imageUrl]) {
            return;
        }

        wself.overlay.image = blurredImage;
        wself.image = image;
    });
});