Question

I am using a UIImageView to display both still and animated images. So sometimes, I’m using .image and sometimes I’m using .animationImages. This is fine.

Whether it’s static or animated, I store the UIImages‘s in item.frames (see below)

The problem is that I’d like to display a UIActivityIndicatorView in the center of the view when the animation frames are loading. I would like this to happen with no images or frames in there. The line that isn’t doing what it’s supposed to is:

[self.imageView removeFromSuperview];

As a matter of fact, setting it to another image at this point doesn’t do anything either. It seems like none of the UI stuff is happening in here. BTW,

NSLog(@"%@", [NSThread isMainThread]?@"IS MAIN":@"IS NOT");

prints IS MAIN.

The image that is in there will stick around until the new animation frames are all in there (1-2 seconds) and they start animating

This is all being run from a subclass of UIView with the UIImageView as a subview.

- (void)loadItem:(StructuresItem *)item{

    self.imageView.animationImages = nil;
    self.imageView.image = nil;   

    [self.spinner startAnimating];

    self.item = item;

    if (item.frameCount.intValue ==1){
        self.imageView.image = [item.frames objectAtIndex:0];
        self.imageView.animationImages = nil;
    }else {
        [self.imageView removeFromSuperview];

        self.imageView =[[UIImageView alloc] initWithFrame:self.bounds];
        [self addSubview:self.imageView ];
        if( self.imageView.isAnimating){
            [self.imageView stopAnimating];
        }
        self.imageView.animationImages = item.frames;
        self.imageView.animationDuration = self.imageView.animationImages.count/12.0f;

        //if the image doesn't loop, freeze it at the end
        if (!item.loop){
            self.imageView.image = [self.imageView.animationImages lastObject];
            self.imageView.animationRepeatCount = 1;
        }
        [self.imageView startAnimating];
    }

    [self.spinner stopAnimating];

}

My ignorant assessment is that something isn’t being redrawn once that image is set to nil. Would love a hand.

Answer 1

What I have found is not an answer to the question, but rather a much better approach to the problem. Simply, use NSTimer instead of animationImages. It loads much faster, doesn’t exhaust memory and is simpler code. yay!

Do this:

-(void)stepFrame{
    self.currentFrameIndex =   (self.currentFrameIndex + 1) % self.item.frames.count;
    self.imageView.image = [self.item.frames objectAtIndex:self.currentFrameIndex];
}

and this

-(void)run{
    if (self.item.frameCount.intValue>1){
        self.imageView.image = [self.item.frames objectAtIndex:self.currentFrameIndex];
        self.timer = [NSTimer scheduledTimerWithTimeInterval:1/24.0f target:self selector:@selector(stepFrame) userInfo:nil repeats:YES];
    }else{
        self.imageView.image = [self.item.frames objectAtIndex:0];
    }
}