PhoneContentController.m

/*
     File: PhoneContentController.m 
 Abstract: Content controller used to manage the iPhone user interface for this app. 
  Version: 1.4 
  
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 */

#import "PhoneContentController.h"
//#import "AppDelegate.h"
#import "MyViewController.h"

// static NSUInteger kNumberOfPages = 5;  // TEMP: FIXME, should get info from DLC

//static NSString *NameKey = @"nameKey";
//static NSString *ImageKey = @"imageKey";


@interface ContentController (PrivateMethods)
- (void)loadScrollViewWithPage:(int)page;
- (void)scrollViewDidScroll:(UIScrollView *)sender;
@end


@implementation PhoneContentController

@synthesize scrollView, pageControl, viewControllers;

- (void)awakeFromNib
{
	// load our data from a plist file inside our app bundle
    NSString *path = [[NSBundle mainBundle] pathForResource:@"content_iPhone" ofType:@"plist"];
    self.contentList = [NSArray arrayWithContentsOfFile:path];
    
    // view controllers are created lazily
    // in the meantime, load the array with placeholders which will be replaced on demand
	
	NSMutableArray *allmaterials = [[BookShelfManager sharedInstance ] allMaterials ] ;
	int totalBookCovers = [allmaterials count];
	NSLog(@"totalBookCovers   %d ", totalBookCovers);
	int numberOfShelf = 0;
	if (totalBookCovers < 1) {
		// add at least shelf
		numberOfShelf = 1 ;
	}else {
		// create corresponding number of shlef
		numberOfShelf =   ceil( totalBookCovers * 1.0 / [BookShelfManager sharedInstance ].bookNumberOnEachColumn )   ;
	}
	
    NSMutableArray *controllers = [[NSMutableArray alloc] init];
    for (unsigned i = 0; i < numberOfShelf; 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 * numberOfShelf, scrollView.frame.size.height);
    scrollView.showsHorizontalScrollIndicator = NO;
    scrollView.showsVerticalScrollIndicator = NO;
    scrollView.scrollsToTop = NO;
    scrollView.delegate = self;
    
    pageControl.numberOfPages = numberOfShelf ; //kNumberOfPages;
    pageControl.currentPage = 0;
    
    // pages are created on demand
    // load the visible page
    // load the page on either side to avoid flashes when the user starts scrolling
    //
	
	
	// 2011.10.27   do not preload all
	for ( NSUInteger i = 0; i < numberOfShelf ; i++) {
		[self loadScrollViewWithPage:i];
	}
	
//	[self loadScrollViewWithPage:0];



//    [self loadScrollViewWithPage:0];
//	if ( totalBookCovers >= 2 ) {
//		[self loadScrollViewWithPage:1];
//	}
    
}

- (void)dealloc
{
    [viewControllers release];
    [scrollView release];
    [pageControl release];
    
    [super dealloc];
}

- (UIView *)view
{
    return self.scrollView;
}

- (void)loadScrollViewWithPage:(int)page
{
	
	NSLog(@"PhoneContentController # loadScrollViewWithPage   called, page [ %d ]  ", page);
	
	if (page < 0)
        return;
	
	NSMutableArray *materials = [[BookShelfManager sharedInstance ] allMaterials ] ;
	
    if (page >= ceil( [materials count] * 1.0 / [BookShelfManager sharedInstance ].bookNumberOnEachColumn ) )    //kNumberOfPages
        return;
	
	// RAEXP:  the new controller are a subclass of AQGridViewController 
	BookShelfColumnGridViewController *controller = [viewControllers objectAtIndex:page];
    if ((NSNull *)controller == [NSNull null])
    {
        controller = [[BookShelfColumnGridViewController alloc] initWithPageNumber:page];
				
        [viewControllers replaceObjectAtIndex:page withObject:controller];
        [controller release];
    }
	
	    
    // add the controller's view to the scroll view
    if (controller.view.superview == nil)
    {
        CGRect frame = scrollView.frame;
        frame.origin.x = frame.size.width * page;
        frame.origin.y = 0;
        controller.view.frame = frame;
        [scrollView addSubview:controller.view];
        
        //NSDictionary *numberItem = [self.contentList objectAtIndex:page];
        //controller.numberImage.image = [UIImage imageNamed:[numberItem valueForKey:ImageKey]];
        //controller.numberTitle.text = [numberItem valueForKey:NameKey];
    }
}

- (void)scrollViewDidScroll:(UIScrollView *)sender
{
    // We don't want a "feedback loop" between the UIPageControl and the scroll delegate in
    // which a scroll event generated from the user hitting the page control triggers updates from
    // the delegate method. We use a boolean to disable the delegate logic when the page control is used.
    if (pageControlUsed)
    {
        // do nothing - the scroll was initiated from the page control, not the user dragging
        return;
    }
	
    // Switch the indicator when more than 50% of the previous/next page is visible
    CGFloat pageWidth = scrollView.frame.size.width;
    int page = floor((scrollView.contentOffset.x - pageWidth / 2) / pageWidth) + 1;
    pageControl.currentPage = page;

	
    // load the visible page and the page on either side of it (to avoid flashes when the user starts scrolling)
    [self loadScrollViewWithPage:page - 1];
    [self loadScrollViewWithPage:page];
    [self loadScrollViewWithPage:page + 1];
    
    // A possible optimization would be to unload the views+controllers which are no longer visible
}

// At the begin of scroll dragging, reset the boolean used when scrolls originate from the UIPageControl
- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView
{
    pageControlUsed = NO;
}

// At the end of scroll animation, reset the boolean used when scrolls originate from the UIPageControl
- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView
{
    pageControlUsed = NO;
}

- (IBAction)changePage:(id)sender
{
    int page = pageControl.currentPage;
	
    // load the visible page and the page on either side of it (to avoid flashes when the user starts scrolling)
    [self loadScrollViewWithPage:page - 1];
    [self loadScrollViewWithPage:page];
    [self loadScrollViewWithPage:page + 1];
    
	// update the scroll view to the appropriate page
    CGRect frame = scrollView.frame;
    frame.origin.x = frame.size.width * page;
    frame.origin.y = 0;
    [scrollView scrollRectToVisible:frame animated:YES];
    
	// Set the boolean used when scrolls originate from the UIPageControl. See scrollViewDidScroll: above.
    pageControlUsed = YES;
}

@end