Reset UIScrollView to new frame dimensions after orientation change - ios

Question

I have an ImageZoom class that subclasses UIView and is a delgate for the UIScrollView. It's pretty straight forward. The class contains a UIScrollView which contains a UIImageView. When an instance of the class is added to a view controller the image is zoomed so that it is flush with the view. There is a method that zooms in when you double tap and zooms out when repeated. Everything works great except for when I change orientation to landscape. I can't seem to figure out how to get the zoom right so that the image is now flush with the new orientation. Here is a link to file as well:
http://www.2shared.com/file/bowDjzLr/imagescroll.html
ViewController.h
#import <UIKit/UIKit.h>
#import "ImageZoom.h"
#interface ViewController : UIViewController
#end
ViewController.m
#import "ViewController.h"
#interface ViewController ()
#property (nonatomic,strong) ImageZoom *imageZoom;
#property (nonatomic, strong) UIImage *image;
#end
#implementation ViewController
- (void)viewDidLoad
{
[super viewDidLoad];
self.image = [UIImage imageNamed:#"1.png"];
}
-(void)viewDidAppear:(BOOL)animated
{
ImageZoom *imageZoom = [[ImageZoom alloc]initWithImage:self.image andFrame:self.view.bounds];
self.imageZoom = imageZoom;
[self.view addSubview:imageZoom];
}
-(void)willAnimateRotationToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration
{
[self.imageZoom willAnimateToFrame:self.view.bounds];
}
#end
ImageZoom.h
#import <UIKit/UIKit.h>
#interface ImageZoom : UIView <UIScrollViewDelegate>
- (id)initWithImage:(UIImage *)image andFrame:(CGRect)frame;
-(void)willAnimateToFrame:(CGRect)frame;
#end
ImageZoom.m
#import "ImageZoom.h"
#interface ImageZoom ()
#property (nonatomic, strong) UIImage *image;
#property (nonatomic, strong) UIImageView *imageView;
#property (nonatomic, strong) UIScrollView *scrollView;
#property BOOL zoomed;
#end
#implementation ImageZoom
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self)
{
[self loadContent];
}
return self;
}
-(void)loadContent
{
self.scrollView = [[UIScrollView alloc]initWithFrame:CGRectMake(0, 0, self.frame.size.width, self.frame.size.height)];
self.scrollView.delegate = self;
self.scrollView.contentSize = self.image.size;
[self.scrollView addSubview:self.imageView];
[self addSubview:self.scrollView];
CGRect scrollViewFrame = self.scrollView.frame;
CGFloat scaleWidth = scrollViewFrame.size.width / self.scrollView.contentSize.width;
CGFloat scaleHeight = scrollViewFrame.size.height / self.scrollView.contentSize.height;
CGFloat minScale = MIN(scaleWidth, scaleHeight);
self.scrollView.minimumZoomScale = minScale;
self.scrollView.maximumZoomScale = 1;
self.scrollView.zoomScale = minScale;
UITapGestureRecognizer *doubleTapRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(scrollViewDoubleTapped:)];
doubleTapRecognizer.numberOfTapsRequired = 2;
doubleTapRecognizer.numberOfTouchesRequired = 1;
[self.scrollView addGestureRecognizer:doubleTapRecognizer];
}
-(void)willAnimateToFrame:(CGRect)frame
{
self.scrollView.frame = CGRectMake(0, 0, frame.size.width, frame.size.height);
CGRect scrollViewFrame = self.scrollView.frame;
CGFloat scaleWidth = scrollViewFrame.size.width / self.scrollView.contentSize.width;
CGFloat scaleHeight = scrollViewFrame.size.height / self.scrollView.contentSize.height;
CGFloat minScale = MIN(scaleWidth, scaleHeight);
self.scrollView.minimumZoomScale = minScale;
self.scrollView.maximumZoomScale = 1;
self.scrollView.zoomScale = minScale;
CGPoint centerPoint = CGPointMake(CGRectGetMidX(self.scrollView.frame), CGRectGetMidY(self.scrollView.frame));
[self view:self.imageView setCenter:centerPoint];
}
- (void)view:(UIView*)view setCenter:(CGPoint)centerPoint
{
CGRect viewFrame = view.frame;
CGPoint scrollViewContentOffset = self.scrollView.contentOffset;
CGFloat x = centerPoint.x - viewFrame.size.width / 2.0;
CGFloat y = centerPoint.y - viewFrame.size.height / 2.0;
if(x < 0)
{
scrollViewContentOffset.x = -x;
viewFrame.origin.x = 0.0;
}
else
{
viewFrame.origin.x = x;
}
if(y < 0)
{
scrollViewContentOffset.y = -y;
viewFrame.origin.y = 0.0;
}
else
{
viewFrame.origin.y = y;
}
view.frame = viewFrame;
self.scrollView.contentOffset = scrollViewContentOffset;
self.zoomed = NO;
}
- (id)initWithImageView:(UIImageView *)imageView andFrame:(CGRect)frame
{
self.image = imageView.image;
self.imageView = imageView;
return [self initWithFrame:frame];
}
- (id)initWithImage:(UIImage *)image andFrame:(CGRect)frame
{
self.image = image;
self.imageView = [[UIImageView alloc] initWithImage:self.image];
return [self initWithFrame:frame];
}
- (UIView*)viewForZoomingInScrollView:(UIScrollView *)scrollView
{
return self.imageView;
}
- (void)scrollViewDidZoom:(UIScrollView *)sv
{
UIView* zoomView = [sv.delegate viewForZoomingInScrollView:sv];
CGRect zoomViewFrame = zoomView.frame;
if(zoomViewFrame.size.width < sv.bounds.size.width)
{
zoomViewFrame.origin.x = (sv.bounds.size.width - zoomViewFrame.size.width) / 2.0;
}
else
{
zoomViewFrame.origin.x = 0.0;
}
if(zoomViewFrame.size.height < sv.bounds.size.height)
{
zoomViewFrame.origin.y = (sv.bounds.size.height - zoomViewFrame.size.height) / 2.0;
}
else
{
zoomViewFrame.origin.y = 0.0;
}
zoomView.frame = zoomViewFrame;
}
- (void)scrollViewDoubleTapped:(UITapGestureRecognizer*)recognizer
{
if(self.zoomed==NO)
{
CGPoint pointInView = [recognizer locationInView:self.imageView];
CGSize scrollViewSize = self.scrollView.bounds.size;
CGFloat w = scrollViewSize.width / self.scrollView.maximumZoomScale;
CGFloat h = scrollViewSize.height / self.scrollView.maximumZoomScale;
CGFloat x = pointInView.x - (w / 2.0);
CGFloat y = pointInView.y - (h / 2.0);
CGRect rectToZoomTo = CGRectMake(x, y, w, h);
[self.scrollView zoomToRect:rectToZoomTo animated:YES];
self.zoomed = YES;
}
else if(self.zoomed == YES)
{
CGRect rectToZoomTo = CGRectMake(0, 0, self.scrollView.contentSize.width, self.scrollView.contentSize.height);
[self.scrollView zoomToRect:rectToZoomTo animated:YES];
self.zoomed = NO;
}
}
#end
It has something to do with the willAnimateToFrame method that is called when the viewController changes orientation. Any help would be greatly appreciated.

Answer 1

Got it working in case anyone is interested. I had to make some changes to my ImageZoom.m file:
#import "ImageZoom.h"
#interface ImageZoom ()
#property (nonatomic, strong) UIImage *image;
#property (nonatomic, strong) UIImageView *imageView;
#property (nonatomic, strong) UIScrollView *scrollView;
#property BOOL zoomed;
#end
#implementation ImageZoom
- (id)initWithFrame:(CGRect)frame
{
self = [super initWithFrame:frame];
if (self)
{
[self loadContentWithFrame:frame];
}
return self;
}
-(void)loadContentWithFrame:(CGRect)frame
{
self.scrollView = [[UIScrollView alloc]initWithFrame:CGRectMake(self.frame.origin.x, self.frame.origin.y, frame.size.width, frame.size.height)];
self.scrollView.delegate = self;
self.scrollView.contentSize = self.image.size;
self.backgroundColor = [UIColor redColor];
[self.scrollView addSubview:self.imageView];
[self addSubview:self.scrollView];
CGRect scrollViewFrame = self.scrollView.frame;
CGFloat scaleWidth = scrollViewFrame.size.width / self.scrollView.contentSize.width;
CGFloat scaleHeight = scrollViewFrame.size.height / self.scrollView.contentSize.height;
CGFloat minScale = MIN(scaleWidth, scaleHeight);
self.scrollView.minimumZoomScale = minScale;
self.scrollView.maximumZoomScale = 1;
self.scrollView.zoomScale = minScale;
UITapGestureRecognizer *doubleTapRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:#selector(scrollViewDoubleTapped:)];
doubleTapRecognizer.numberOfTapsRequired = 2;
doubleTapRecognizer.numberOfTouchesRequired = 1;
[self.scrollView addGestureRecognizer:doubleTapRecognizer];
self.zoomed = NO;
}
-(void)willAnimateToFrame:(CGRect)frame
{
self.frame = frame;
[self loadContentWithFrame:frame];
}
- (id)initWithImageView:(UIImageView *)imageView andFrame:(CGRect)frame
{
self.image = imageView.image;
self.imageView = imageView;
return [self initWithFrame:frame];
}
- (id)initWithImage:(UIImage *)image andFrame:(CGRect)frame
{
self.image = image;
self.imageView = [[UIImageView alloc] initWithImage:self.image];
return [self initWithFrame:frame];
}
- (UIView*)viewForZoomingInScrollView:(UIScrollView *)scrollView
{
return self.imageView;
}
- (void)scrollViewDidZoom:(UIScrollView *)sv
{
UIView* zoomView = [sv.delegate viewForZoomingInScrollView:sv];
CGRect zoomViewFrame = zoomView.frame;
if(zoomViewFrame.size.width < sv.bounds.size.width)
{
zoomViewFrame.origin.x = (sv.bounds.size.width - zoomViewFrame.size.width) / 2.0;
}
else
{
zoomViewFrame.origin.x = 0.0;
}
if(zoomViewFrame.size.height < sv.bounds.size.height)
{
zoomViewFrame.origin.y = (sv.bounds.size.height - zoomViewFrame.size.height) / 2.0;
}
else
{
zoomViewFrame.origin.y = 0.0;
}
zoomView.frame = zoomViewFrame;
}
- (void)scrollViewDoubleTapped:(UITapGestureRecognizer*)recognizer
{
if(self.zoomed==NO)
{
CGPoint pointInView = [recognizer locationInView:self.imageView];
CGSize scrollViewSize = self.scrollView.bounds.size;
CGFloat w = scrollViewSize.width / self.scrollView.maximumZoomScale;
CGFloat h = scrollViewSize.height / self.scrollView.maximumZoomScale;
CGFloat x = pointInView.x - (w / 2.0);
CGFloat y = pointInView.y - (h / 2.0);
CGRect rectToZoomTo = CGRectMake(x, y, w, h);
[self.scrollView zoomToRect:rectToZoomTo animated:YES];
self.zoomed = YES;
}
else if(self.zoomed == YES)
{
CGRect rectToZoomTo = CGRectMake(0, 0, self.scrollView.contentSize.width, self.scrollView.contentSize.height);
[self.scrollView zoomToRect:rectToZoomTo animated:YES];
self.zoomed = NO;
}
}
#end