Issue when rotating a UIScrollView
- by leachianus.gecko
I am having issues trying to get the pageControl sample code to work with rotation.   I managed to get it to rotate but it does not visually load correctly until I start to scroll (then it works fine).   Any Idea on how I can fix this problem?  Here is a link to the project if you want to see it in action.
This code is based off the PageControl example apple has provided.
here is the code:
#import "ScrollingViewController.h"
#import "MyViewController.h"
@interface ScrollingViewController (PrivateMethods)
- (void)loadScrollViewWithPage:(int)page;
@end
@implementation ScrollingViewController
@synthesize scrollView;
@synthesize viewControllers;
- (void)viewDidLoad 
{
    amount = 5;
    [super viewDidLoad];
    [self setupPage];   
}
- (void)didReceiveMemoryWarning 
{
    [super didReceiveMemoryWarning];
}
- (void)viewDidUnload 
{
    [scrollView release];
}
- (void)dealloc 
{
    [super dealloc];
}
- (void)setupPage
{
    NSMutableArray *controllers = [[NSMutableArray alloc] init];
    for (unsigned i = 0; i < amount; i++) {
        [controllers addObject:[NSNull null]];
    }
    self.viewControllers = controllers;
    [controllers release];
    // a page is the width of the scroll view
    scrollView.pagingEnabled = YES;
    scrollView.contentSize = CGSizeMake(scrollView.frame.size.width * amount, 200);
    scrollView.showsHorizontalScrollIndicator = NO;
    scrollView.showsVerticalScrollIndicator = NO;
    scrollView.scrollsToTop = NO;
    scrollView.delegate = self;
    [self loadScrollViewWithPage:0];
    [self loadScrollViewWithPage:1];
}
#pragma mark -
#pragma mark UIScrollViewDelegate stuff
- (void)scrollViewDidScroll:(UIScrollView *)_scrollView
{
    if (pageControlIsChangingPage) {
        return;
    }
    /*
     * We switch page at 50% across
     */
    CGFloat pageWidth = _scrollView.frame.size.width;
    int dog = floor((_scrollView.contentOffset.x - pageWidth / 2) / pageWidth) + 1;
    // pageControl.currentPage = page;
    [self loadScrollViewWithPage:dog - 1];
    [self loadScrollViewWithPage:dog];
    [self loadScrollViewWithPage:dog + 1];
}
- (void)loadScrollViewWithPage:(int)page 
{
    if (page < 0) return;
    if (page >= amount) return;
    MyViewController *controller = [viewControllers objectAtIndex:page];
    if ((NSNull *)controller == [NSNull null]) {
        controller = [[MyViewController alloc] initWithPageNumber:page];
        [viewControllers replaceObjectAtIndex:page withObject:controller];
        [controller release];
    }
    if (nil == controller.view.superview) {
        CGRect frame = scrollView.frame;
        frame.origin.x = frame.size.width * page;
        frame.origin.y = 0;
        controller.view.frame = frame;
        [scrollView addSubview:controller.view];
    }
}
- (void)didRotateFromInterfaceOrientation:(UIInterfaceOrientation)fromInterfaceOrientation {
    [self setupPage];
}
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
    // Return YES for supported orientations
    return YES;
}
@end