Question

The implementation of pinch zoom is been done by using UIScrollView and putting ‘UIImageView` inside it, through following code:

-(void)viewDidLoad{
    slideShowImageViewScrollView.maximumZoomScale = 4.0;
    slideShowImageViewScrollView.minimumZoomScale = 1.0;
    slideShowImageViewScrollView.clipsToBounds = YES;
    slideShowImageViewScrollView.delegate = self;
    slideShowImageViewScrollView.scrollEnabled = NO;
}

Then after checking zoomScale scrolling is been enabled as:

- (void)scrollViewDidZoom:(UIScrollView *)scrollView 
{
if (scrollView.zoomScale!=1.0) 
{
    slideShowImageViewScrollView.scrollEnabled = YES;
}
else 
{
    slideShowImageViewScrollView.scrollEnabled = NO;
}
}

And here is the view that is for zooming in, in scroll view

- (UIView *) viewForZoomingInScrollView:(UIScrollView *)scrollView
{
return slideShowImageView;
}

Now using timer the image of UIImageView is been changed after a time period, by following code:

- (void) changeImageSlide
{
    if (imageCounter>=totalNoOfImages-1) 
    {
        imageCounter=0;
    }
    NSString *str = [NSString stringWithFormat:@"%@.jpg",[copyOf_myGlobleArrayOfImageIds objectAtIndex:imageCounter]];
    mainSlideShowImageView setImage:[UIImage imageNamed:str]];
    [mainSlideShowImageView setTag:[[copyOf_myGlobleArrayOfImageIds objectAtIndex:imageCounter] intValue]];     
    imageCounter++;
}

Only thing problamatic here is when the next image is loaded that is also, ‘zoomed in’, we want image in normal mode.
Can we achieve it(by coding it for zoom out in our changeImageSlide method or any where)?
If yes, then how?
If no, then is there any alternative?

Thank You.

Answer 1

You can set the zoom scale on the scrollview to reset it to 1.0. You could even store zoom levels against images so that it preserves the individual zoom setting per image.