Navigate to prev and next pdf file? - iphone

Question

I got a pdf viewer in a uiwebview, from Daniel Barry http://github.com/danberry/PDF-Viewer and it works really well, it displays a pdf doc that you can scroll up and down.
Now I would like to display just one page at the time and also have a menu underneat the pdf page with a prev and next button. Can anybody help a newbe to figure out how?
Thanks!
#import "PDFViewController.h" // PDF View Controller
#implementation PDFViewController
// Synthesize UI Element properties
#synthesize webView;
// Synthesize Variable properties
#synthesize pdfURL;
#pragma mark -
#pragma mark UIViewController methods
- (void)viewDidLoad {
[super viewDidLoad];
pdfURL = [NSURL fileURLWithPath:[[NSBundle mainBundle] pathForResource:#"stuff pdf" ofType:#"pdf"]];
[webView loadRequest:[NSURLRequest requestWithURL:pdfURL]];
webView.transform = CGAffineTransformScale( webView.transform, 1.00, 1.00 );
}
#pragma mark -
#pragma mark Memory Management
- (void)dealloc {
[webView release];
[pdfURL release];
[super dealloc];
}
#end

Answer 1

I think a webview should show PDFs by using a default request, no need to have a new implementation?
Anyways... There are 2 methods you could check out and link to your prev and next button
- (void)goBack:(id)sender
{
if ([webView canGoBack]) {
[webView goBack];
}
}
- (void)goForward:(id)sender
{
if ([webView canGoForward]) {
[webView goForward];
}
}
Here is the documentation of UIWebView where the methods are explained in detail: http://developer.apple.com/iphone/library/documentation/uikit/reference/UIWebView_Class/Reference/Reference.html
EDIT: Oh I think, I first misunderstood your question...
Just create an Array of the PDF URLs that you want to load. Create a counter variable that will hold the index value of the currently opened PDF.
And finally similar to the methods above create a forward and backward method and link them to the prev and next buttons. In those methods you increment or decrement the counter by 1 and load the appropriate index from the array [array objectAtIndex:counter] so the next or previous PDF is opened.
If you need more help, let me know...

Answer 2

ok im gonna post this as another answer...
In the header file add
NSArray *arrURLs;
NSInteger *currentIndex;
and make the array a property (retain), synthesize it in the .m file, also release it in dealloc.
In - (void)viewDidLoad initalize the array with all the URLs and set the currentIndex to 0.
arrUrls = [[NSArray alloc] initWithObjects:#"url", #"url", ..., nil];
currentIndex = 0;
add two methods that you call something like prevPage and nextPage and link them to your buttons. In those methods you do something like...
// next page
currentIndex += 1;
NSString *str = [arrUrls objectAtIndex:currentIndex];
NSURL *url = [NSURL URLWithString:str];
[webView loadRequest:[NSURLRequest requestWithURL:url]];
I would probably create another method where you set the currentIndex and check if it is in the correct bounds (e.g. should not be smaller than 0 and must be smaller than the length of the array). Than you can change the first line and let the method call handle the in/decrementing of the variable.
hope this helps.