iphone: error and pdf pages question

Question

I am building a pdf viewer app. my skills are at medium LOL voodoo level now... I've got real far on my own with this app but I'm pretty stuck ether on my theory or on my code. My app has a paging scroll view that makes its self the length of the entire pdf document, then it shows the current page in another scrollview (ImageScrollView) which is its own class. ImageScrollView makes a UIView which does the CATiledLayer usual stuff and it all work fine! :)

My ImageScrollView shows the on-screen page (when you scroll to the next page ImageScrollView loads again CATiledLayer on-screen and you can see the tiles). I've been researching about how to get the pages left and right of the current page to preload (as I don't think having a pdf load as tiles on-screen is good for the user experience) but Im not to sure if I'm thinking about it correctly.

Maybe I should be making a left and right UIView that sit next to the onscreen UIView in ImageScrollView?

or maybe it has to do with recycling no-longer-visible pages as seen below (but I think I would still need views to the left/right and even still wont I need to recycle the views also??)

- (void)tilePages {
// Calculate which pages are visible
CGRect visibleBounds = pagingScrollView.bounds;//CGRect visibleBounds =     CGRectMake(0.0f, 0.0f, 320.0f * [self pdfPageCount], 435.0f);
int firstNeededPageIndex = floorf(CGRectGetMinX(visibleBounds) / CGRectGetWidth(visibleBounds));
int lastNeededPageIndex  = floorf((CGRectGetMaxX(visibleBounds)-1) / CGRectGetWidth(visibleBounds));


firstNeededPageIndex = MAX(firstNeededPageIndex, 0);
lastNeededPageIndex  = MIN(lastNeededPageIndex, [self pdfPageCount] - 1);

// Recycle no-longer-visible pages 
for (ImageScrollView *page in visiblePages) {

    if (page.index < firstNeededPageIndex || page.index > lastNeededPageIndex) {
        [recycledPages addObject:page];
        [page removeFromSuperview];}}
[visiblePages minusSet:recycledPages];

// add missing pages
for (int index = firstNeededPageIndex; index <= lastNeededPageIndex; index++) {
    if (![self isDisplayingPageForIndex:index]) {
        ImageScrollView *page = [self dequeueRecycledPage];
        if (page == nil) {
            page = [[[ImageScrollView alloc] init] autorelease];}
        [self configurePage:page forIndex:index];
        [pagingScrollView addSubview:page];
        [visiblePages addObject:page];}}}

I changed the code to see what happened below (not sure) also I get error: initialization makes pointer from integer without a cast

- (void)tilePages:(NSUInteger) index {                
// Calculate which pages are visible
CGRect visibleBounds = pagingScrollView.bounds;
int firstNeededPageIndex = floorf(CGRectGetMinX(visibleBounds) / CGRectGetWidth(visibleBounds));
int lastNeededPageIndex  = floorf((CGRectGetMaxX(visibleBounds)-1) / CGRectGetWidth(visibleBounds));
firstNeededPageIndex = MAX(firstNeededPageIndex, 0);
lastNeededPageIndex  = MIN(lastNeededPageIndex, [self pdfPageCount] - 1);
// Recycle no-longer-visible pages 
for (ImageScrollView *page in visiblePages) {
    if (page.index < firstNeededPageIndex || page.index > lastNeededPageIndex) {
// visible N/Ppages *start*
if (index == 1) {
ImageScrollView *Npage = Npage.index +1;
Npage = [[[ImageScrollView alloc] init] autorelease];
[self configurePage:Npage forIndex:index +1];
[pagingScrollView addSubview:Npage];
[visiblePages addObject:Npage];}
if (index < 2 || index > [self pdfPageCount] -2) {
ImageScrollView *Ppage = Ppage.index -1;
ImageScrollView *Npage = Npage.index +1;
Ppage = [[[ImageScrollView alloc] init] autorelease];
[self configurePage:Ppage forIndex:index -1];
[pagingScrollView addSubview:Ppage];
[visiblePages addObject:Ppage];
Npage = [[[ImageScrollView alloc] init] autorelease];
[self configurePage:Npage forIndex:index +1];
[pagingScrollView addSubview:Npage];
[visiblePages addObject:Npage];}
if (index == [self pdfPageCount] -1) {
ImageScrollView *Ppage = Ppage.index -1;
Ppage = [[[ImageScrollView alloc] init] autorelease];
[self configurePage:Ppage forIndex:index -1];
[pagingScrollView addSubview:Ppage];
[visiblePages addObject:Ppage];}
// visible N/Ppages *end*
        [recycledPages addObject:page];
        [page removeFromSuperview];}}
[visiblePages minusSet:recycledPages];
// add missing pages
for (int index = firstNeededPageIndex; index <= lastNeededPageIndex; index++) {
// recycled N/Ppages *start*
if (index == firstNeededPageIndex +1) {
ImageScrollView *Npage = Npage.index +1;
[recycledPages addObject:Npage];
[Npage removeFromSuperview];}
if (index < firstNeededPageIndex +2 || index > lastNeededPageIndex -2) {
ImageScrollView *Ppage = Ppage.index -1;
ImageScrollView *Npage = Npage.index +1;
[recycledPages addObject:Ppage];
[Ppage removeFromSuperview];
[recycledPages addObject:Npage];
[Npage removeFromSuperview];}
if (index == lastNeededPageIndex -1) {
ImageScrollView *Ppage = Ppage.index -1;
[recycledPages addObject:Ppage];
[Ppage removeFromSuperview];}
// recycled N/Ppages *end*
    if (![self isDisplayingPageForIndex:index]) {
        ImageScrollView *page = [self dequeueRecycledPage];
        if (page == nil) {
            page = [[[ImageScrollView alloc] init] autorelease];}
        [self configurePage:page forIndex:index];
        [pagingScrollView addSubview:page];
        [visiblePages addObject:page];}}}

Could I store 3 pdf pages in an NSIndex? eg: previousPageToRecycle, previousPage, currentPage, nextPage, nextPageToRecycle

I'm unsure of how to do this.