using PDFScroller with a navigationController - iphone

Question

I am trying to use this PDFScroller code http://dl.dropbox.com/u/5391413/PDFScroller.zip (thanks jbm). I would like to display a pdf from a list (a tableview) thanks to a navigationController. I init a PhotoViewControler with a pdf file name and display it correctly. The problem is that after I have loaded a file once, I don't manage to clean the pdfDoc ref and this causes a crash after coming back to the view list and loading another file.
I tried to release the pdfDoc ref, or set to nil in the PhotoViewController dealloc method but it does not work.
One more thing: the viewDidUnload method of the PhotoViewController is not called when popping the viewController out of the navigationcontroller stack... is that normal?
thanks
G.

Answer 1

here is how I launch a PhotoViewController from he root viewController:
PhotoViewController *detailViewController = [[PhotoViewController alloc] initWithNibName:#"PhotoViewController" bundle:nil pdfName:tmpName];
// Pass the selected object to the new view controller.
[self.navigationController pushViewController:detailViewController animated:YES];
[detailViewController release];
tmpName contains the name of the pdf file, I set a property in the PhotoViewController.Here is the PhotoViewController implementation (little different from the original sample code):
- (void)loadView
{
// Step 1: make the outer paging scroll view
CGRect pagingScrollViewFrame = [self frameForPagingScrollView];
pagingScrollView = [[UIScrollView alloc] initWithFrame:pagingScrollViewFrame];
pagingScrollView.pagingEnabled = YES;
pagingScrollView.backgroundColor = [UIColor blackColor];
pagingScrollView.showsVerticalScrollIndicator = NO;
pagingScrollView.showsHorizontalScrollIndicator = NO;
pagingScrollView.contentSize = CGSizeMake(pagingScrollViewFrame.size.width * [self pdfPageCount],
pagingScrollViewFrame.size.height);
pagingScrollView.delegate = self;
self.view = pagingScrollView;
// Step 2: prepare to tile content
recycledPages = [[NSMutableSet alloc] init];
visiblePages = [[NSMutableSet alloc] init];
[self tilePages];
}
- (void)viewDidUnload
{
[super viewDidUnload];
[pdfName release];
pdfName = nil;
[pagingScrollView release];
pagingScrollView = nil;
//CGPDFDocumentRelease(__pdfDoc);
//__pdfDoc = nil;
[recycledPages release];
recycledPages = nil;
[visiblePages release];
visiblePages = nil;
}
- (void)dealloc
{
NSLog(#"dealloc");
[pdfName release];
[pagingScrollView release];
[super dealloc];
}
- (void)tilePages
{
// 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) {
[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];
}
}
}
- (void)configurePage:(ImageScrollView *)page forIndex:(NSUInteger)index
{
page.index = index;
page.frame = [self frameForPageAtIndex:index];
// Use tiled images
[page displayTiledImageNamed: [self pdfPage: index]
size: [self pdfSize: index]];
}
static CGPDFDocumentRef __pdfDoc = nil;
- (CGPDFPageRef) pdfPage: (NSInteger) index {
if( ! __pdfDoc ) {
NSString *pdfPath = [[NSBundle mainBundle] pathForResource: pdfName ofType:nil];
CFURLRef url = CFURLCreateWithFileSystemPath( NULL, (CFStringRef)pdfPath,
kCFURLPOSIXPathStyle, NO );
__pdfDoc = CGPDFDocumentCreateWithURL( url );
}
if( __pdfDoc ) {
size_t pdfPageCount = CGPDFDocumentGetNumberOfPages( __pdfDoc );
index++; // incoming param is zero-based, CGPDF calls are 1-based
if( index < 1 )
index = 1;
if( index > pdfPageCount )
index = pdfPageCount;
CGPDFPageRef page = CGPDFDocumentGetPage( __pdfDoc, index );
return page;
}
return nil;
}
-(IBAction)backToListView{
[self.navigationController popViewControllerAnimated:YES];
}
The problem is: in the - (CGPDFPageRef) pdfPage: (NSInteger) index method, __pdfDoc remains the same even after the PhotoViewController was popped off the navigationController stack, and this causes a crash. I don't where to clean it correctly.
thanks
Guillaume