I am printing a pdf from iPhone to Airprint compatible printer using Apple print document example. But I am not getting full page print from iPhone, please see the picture of what I am getting, I need the pdf to be printed on full paper lenght,width.

The code I am using for print function is given below, its the same code as in Apple print sample app,
    UIPrintInteractionController *controller = [UIPrintInteractionController sharedPrintController];
    if(!controller){
        NSLog(@"Couldn't get shared UIPrintInteractionController!");
        return;
    }
    UIPrintInteractionCompletionHandler completionHandler =
    ^(UIPrintInteractionController *printController, BOOL completed, NSError *error) {
        if(!completed && error){
            NSLog(@"FAILED! due to error in domain %@ with error code %u", error.domain, error.code);
        }
    };
    controller.delegate = self;
    // Obtain a printInfo so that we can set our printing defaults.
    UIPrintInfo *printInfo = [UIPrintInfo printInfo];
    // This application produces General content that contains color.
    printInfo.outputType = UIPrintInfoOutputGeneral;
    // We'll use the URL as the job name.
    printInfo.jobName = [_filePath lastPathComponent];
    // Set duplex so that it is available if the printer supports it. We are
    // performing portrait printing so we want to duplex along the long edge.
    printInfo.duplex = UIPrintInfoDuplexLongEdge;
    // Use this printInfo for this print job.
    controller.printInfo = printInfo;
    controller.printingItem = myData;
    // Be sure the page range controls are present for documents of > 1 page.
    controller.showsPageRange = YES;
    // This code uses a custom UIPrintPageRenderer so that it can draw a header and footer.
    APLPrintPageRenderer *myRenderer = [[APLPrintPageRenderer alloc] init];
//  UIPrintPageRenderer *myRenderer = [[UIPrintPageRenderer alloc] init];
    // The APLPrintPageRenderer class provides a jobtitle that it will label each page with.
//    myRenderer.jobTitle = printInfo.jobName;
    // To draw the content of each page, a UIViewPrintFormatter is used.
    UIViewPrintFormatter *viewFormatter = [docWebView viewPrintFormatter];
#if SIMPLE_LAYOUT
    UIFont *font = [UIFont fontWithName:@"Helvetica" size:HEADER_FOOTER_TEXT_HEIGHT];
    CGSize titleSize = [myRenderer.jobTitle sizeWithFont:font];
    myRenderer.headerHeight = myRenderer.footerHeight = titleSize.height + HEADER_FOOTER_MARGIN_PADDING;
#endif
    [myRenderer addPrintFormatter:viewFormatter startingAtPageAtIndex:0];
    // Set our custom renderer as the printPageRenderer for the print job.
    controller.printPageRenderer = myRenderer;
    if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad)
    {
        [controller presentFromBarButtonItem:sender animated:YES completionHandler:completionHandler];  // iPad
    }
    else
    {
        docWebView.hidden = YES;
        [controller presentAnimated:YES completionHandler:completionHandler];  // iPhone
    }