Question

My UIScrollView on the iPhone is 480×230 and the content is 972×230 when first displayed. I need to provide functionality where when the user double taps the UIScrollView the contents zoom to fit with the 480×230 UIScrollView proportionally. When the double tap it again it should zoom back out to it’s original size.

What is the best way to do this? I have been fumbling for several hours with this and thought that this would work…

[bodyClockScrollView zoomToRect:bodyClockScrollView.frame animated:YES];

But nothing seems to happen.

Thanks, any help pointing me in the right direction would be appreciated.

Answer 1

Using CGAffineTransform I figured out a way to do what I want…

    //bodyCleckScrollView contains a UIView name bodyClock
    //get the scale factor required to fit bodyClock inside the iPhone window and resize it...
    CGFloat scale = 480/bodyClockScrollView.contentSize.width;  
    bodyClock.transform = CGAffineTransformScale(bodyClock.transform, scale, scale);
    //move bodyClock to the bottom of bodyScrollView.
    bodyClock.transform = CGAffineTransformTranslate(bodyClock.transform, 0.0,bodyClockScrollView.frame.size.height-bodyClock.frame.size.height);
    //scoll bodyScrollView so that bodyClock is centered in the window 
    CGPoint offsetPoint = CGPointMake(bodyClock.frame.origin.x, 0.0);
    [bodyClockScrollView setContentOffset:offsetPoint animated:YES];   

This works great and when I want to zoom it back out to the default size and position you simply call…

    bodyClock.transform = CGAffineTransformIdentity;