PDF First Page doesn't show in iOS - ios

Question

I have to show PDF First Page in UITableViewCell's ImageView.
My PDF Documents are located in document directory of app.
Here is my code in CellForRowAtIndexPath
NSURL* url =[self.arrayOfBooks objectAtIndex:indexPath.row];
UIImage *cellImage = [self buildThumbnailImage:MyGetPDFDocumentRef(url.absoluteString)];
cell.imageView.image = cellImage;
And Here is buildThumbnailImage Method.
- (UIImage *)buildThumbnailImage:(CGPDFDocumentRef)pdfDocument
{
BOOL hasRetinaDisplay = FALSE; // by default
CGFloat pixelsPerPoint = 1.0; // by default (pixelsPerPoint is just the "scale" property of the screen)
if ([UIScreen instancesRespondToSelector:#selector(scale)]) // the "scale" property is only present in iOS 4.0 and later
{
// we are running iOS 4.0 or later, so we may be on a Retina display; we need to check further...
if ((pixelsPerPoint = [[UIScreen mainScreen] scale]) == 1.0)
hasRetinaDisplay = FALSE;
else
hasRetinaDisplay = TRUE;
}
else
{
// we are NOT running iOS 4.0 or later, so we can be sure that we are NOT on a Retina display
pixelsPerPoint = 1.0;
hasRetinaDisplay = FALSE;
}
size_t imageWidth = 320; // width of thumbnail in points
size_t imageHeight = 460; // height of thumbnail in points
if (hasRetinaDisplay)
{
imageWidth *= pixelsPerPoint;
imageHeight *= pixelsPerPoint;
}
size_t bytesPerPixel = 4; // RGBA
size_t bitsPerComponent = 8;
size_t bytesPerRow = bytesPerPixel * imageWidth;
void *bitmapData = malloc(imageWidth * imageHeight * bytesPerPixel);
// in the event that we were unable to mallocate the heap memory for the bitmap,
// we just abort and preemptively return nil:
if (bitmapData == NULL)
return nil;
// remember to zero the buffer before handing it off to the bitmap context:
bzero(bitmapData, imageWidth * imageHeight * bytesPerPixel);
CGContextRef theContext = CGBitmapContextCreate(bitmapData, imageWidth, imageHeight, bitsPerComponent, bytesPerRow,
CGColorSpaceCreateDeviceRGB(), kCGImageAlphaPremultipliedLast);
//CGPDFDocumentRef pdfDocument = MyGetPDFDocumentRef(); // NOTE: you will need to modify this line to supply the CGPDFDocumentRef for your file here...
CGPDFPageRef pdfPage = CGPDFDocumentGetPage(pdfDocument, 1); // get the first page for your thumbnail
CGAffineTransform shrinkingTransform =
CGPDFPageGetDrawingTransform(pdfPage, kCGPDFMediaBox, CGRectMake(0, 0, imageWidth, imageHeight), 0, YES);
CGContextConcatCTM(theContext, shrinkingTransform);
CGContextDrawPDFPage(theContext, pdfPage); // draw the pdfPage into the bitmap context
CGPDFDocumentRelease(pdfDocument);
//
// create the CGImageRef (and thence the UIImage) from the context (with its bitmap of the pdf page):
//
CGImageRef theCGImageRef = CGBitmapContextCreateImage(theContext);
free(CGBitmapContextGetData(theContext)); // this frees the bitmapData we malloc'ed earlier
CGContextRelease(theContext);
UIImage *theUIImage;
// CAUTION: the method imageWithCGImage:scale:orientation: only exists on iOS 4.0 or later!!!
if ([UIImage respondsToSelector:#selector(imageWithCGImage:scale:orientation:)])
{
theUIImage = [UIImage imageWithCGImage:theCGImageRef scale:pixelsPerPoint orientation:UIImageOrientationUp];
}
else
{
theUIImage = [UIImage imageWithCGImage:theCGImageRef];
}
CFRelease(theCGImageRef);
return theUIImage;
}
CGPDFDocumentRef MyGetPDFDocumentRef(NSString *inputPDFFile)
{
//NSString *inputPDFFile = [[[NSBundle mainBundle] bundlePath] stringByAppendingPathComponent:#"test.pdf"];
const char *inputPDFFileAsCString = [inputPDFFile cStringUsingEncoding:NSASCIIStringEncoding];
//NSLog(#"expecting pdf file to exist at this pathname: \"%s\"", inputPDFFileAsCString);
CFStringRef path = CFStringCreateWithCString(NULL, inputPDFFileAsCString, kCFStringEncodingUTF8);
CFURLRef url = CFURLCreateWithFileSystemPath(NULL, path, kCFURLPOSIXPathStyle, 0);
CFRelease (path);
CGPDFDocumentRef document = CGPDFDocumentCreateWithURL(url);
CFRelease(url);
if (CGPDFDocumentGetNumberOfPages(document) == 0)
{
printf("Warning: No pages in pdf file \"%s\" or pdf file does not exist at this path\n", inputPDFFileAsCString);
return NULL;
}
return document;
}
And Here is how i load pdf file list from document directory.
- (NSMutableArray *)loadBookFromDocumentDirectory
{
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [NSString stringWithFormat:#"%#",[paths objectAtIndex:0]];
NSFileManager *manager = [NSFileManager defaultManager];
NSError *error;
NSArray *files = [manager contentsOfDirectoryAtURL:[NSURL fileURLWithPath:documentsDirectory]
includingPropertiesForKeys:[NSArray arrayWithObject:NSURLContentModificationDateKey]
options:NSDirectoryEnumerationSkipsHiddenFiles
error:&error];
NSArray* sortArray = [files sortedArrayUsingComparator:
^(NSURL *file1, NSURL *file2)
{
NSDate *file1Date;
[file1 getResourceValue:&file1Date forKey:NSURLContentModificationDateKey error:nil];
NSDate *file2Date;
[file2 getResourceValue:&file2Date forKey:NSURLContentModificationDateKey error:nil];
// Ascending:
//return [file1Date compare: file2Date];
// Descending:
return [file2Date compare: file1Date];
}];
NSMutableArray *sortedContents = [[NSMutableArray alloc] initWithArray:sortArray];
return sortedContents;
}
When i run my app , it doesn't show anything at Cell ImageView and showing this message.
file:///Users/MacUser/Library/Application%20Support/iPhone%20Simulator/7.1-64/Applications/08BE9071-6251-44ED-A8E0-55CD478380FC/Documents/CGPDFDocument.pdf" or pdf file does not exist at this path
I am sure i have that pdf and even showing PDF Name in TableView.
Where am i wroning?

Answer 1

Okay. I think I understand what's going on here.
You've "added your PDF files via iTunes". I have NO idea how that is supposed to actually work.
But it's clear to me that the PDF files in your simulator folder are zero bytes in size.
The code you have right now should work, you just need to get valid PDF files into there to start with.
In Terminal, you can open that folder using the command
open ~/Library/Application\ Support/iPhone\ Simulator/7.1-64/Applications/08BE9071-6251-44ED-A8E0-55CD478380FC/Documents
And when it opens in the Macintosh Finder, you'll see that all the PDF files in there are zero bytes in size. Manually copy in your correct PDF files and your app should begin to magically work in the simulator.
Now, for production code, you need to write code to REALLY copy the PDF files into the documents folder. Where do the PDF files come from originally? Do you download them or are they built into the app somewhere?