PDF zooming & quality

Question

I have a problem, I'm not a programmer but I try to do some app for fun.
I try to create a pdf viewer, I create a UIView class like this:
[CODE]   - (id)initWithFrame:(CGRect)frame {
        self = [super initWithFrame:(CGRect)frame];
        if (self) {
            self.backgroundColor = [UIColor clearColor];
            NSString *pathToPdfDoc = [[NSBundle mainBundle] pathForResource:@"myPDF" ofType:@"pdf"];
            NSURL *pdfUrl = [NSURL fileURLWithPath:pathToPdfDoc];
            document = CGPDFDocumentCreateWithURL((CFURLRef)pdfUrl);
            currentPage = 1;
        return self;
    -(void)drawRect:(CGRect)inRect{                
        if(document) {
            CGPDFPageRef page = CGPDFDocumentGetPage(document, currentPage);
            CGContextRef ctx = UIGraphicsGetCurrentContext();
            CGContextSaveGState(ctx);
            CGContextTranslateCTM(ctx, 0.0, [self bounds].size.height);
            CGContextScaleCTM(ctx, 1.0, -1.0);
            CGContextConcatCTM(ctx, CGPDFPageGetDrawingTransform(page, kCGPDFCropBox, [self bounds], 0, true));
            CGContextDrawPDFPage(ctx, page);   
            CGContextRestoreGState(ctx);
    -(void)increasePageNumber {
        size_t pageCount = CGPDFDocumentGetNumberOfPages(document);
        if (currentPage == pageCount) {
            // do nothing
        else {
            currentPage++;
            [self setNeedsDisplay];
    -(void)decreasePageNumber {
        if (currentPage == 1) {
            // do nothing
        else {
            currentPage--;
            [self setNeedsDisplay];
[/CODE]
now I try to add zoom but without luck, fro zoom I create a layer:
[CODE]
    -(void)viewDidLoad {
        CGRect frame;
        if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad) {
            frame = CGRectMake(0, 0, 960, 1024);
        else{
            frame = CGRectMake(0, 0, 320, 460);
        tiledLayer = [CATiledLayer layer];
        tiledLayer.delegate = self;
        tiledLayer.tileSize = CGSizeMake(1024, 1024);
        tiledLayer.levelsOfDetail = 200;
        tiledLayer.levelsOfDetailBias = 200;
        tiledLayer.frame = frame;
        myPDFView = [[viewPDF alloc] initWithFrame:frame];  
        //[self.view addSubview:myPDFView]; 
        [myPDFView.layer addSublayer:tiledLayer];
        CGRect viewFrame = self.view.frame;
        viewFrame.origin = CGPointZero;
        scrollView = [[UIScrollView alloc] initWithFrame:viewFrame];
        scrollView.delegate = self;
        scrollView.contentSize = frame.size;
        scrollView.maximumZoomScale = 5;
        [scrollView addSubview:myPDFView];
        [self.view addSubview:scrollView];
    - (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView
        return myPDFView;
    }[/CODE]
but when I zooming i lost quality...how can I adjust it?

Answer 1

Open the PDF file in Preview, located in the Applications folder.  Drag the thumbnail onto the Keynote slide. If thumbnails are not showing, click the side panel options button directly underneath the red close button top right in Preview.