Question

I generated a PDF file from my iPhone app and while most of the documents are only one page, I want to be able detect if the text is going to go outside of the “margins” and if so, add it to the next page. I am new to this so not really sure how to do this.

Below is the code. Any suggestions?

- (void) drawBorder
{
    CGContextRef    currentContext = UIGraphicsGetCurrentContext();
    UIColor *borderColor = [UIColor grayColor];

    CGRect rectFrame = CGRectMake(kBorderInset, kBorderInset, pageSize.width-kBorderInset*2, pageSize.height-kBorderInset*2);

    CGContextSetStrokeColorWithColor(currentContext, borderColor.CGColor);
    CGContextSetLineWidth(currentContext, kBorderWidth);
    CGContextStrokeRect(currentContext, rectFrame);
}

- (void)drawPageNumber:(NSInteger)pageNumber
{
    NSString* pageNumberString = [NSString stringWithFormat:@"Page %d", pageNumber];
    UIFont* theFont = [UIFont systemFontOfSize:12];

    CGSize pageNumberStringSize = [pageNumberString sizeWithFont:theFont
                                               constrainedToSize:pageSize
                                                   lineBreakMode:UILineBreakModeWordWrap];

    CGRect stringRenderingRect = CGRectMake(kBorderInset,
                                            pageSize.height - 40.0,
                                            pageSize.width - 2*kBorderInset,
                                            pageNumberStringSize.height);

    [pageNumberString drawInRect:stringRenderingRect withFont:theFont lineBreakMode:UILineBreakModeWordWrap alignment:UITextAlignmentCenter];
}

- (void) drawHeader:(NSString *)header
{
    CGContextRef    currentContext = UIGraphicsGetCurrentContext();
    CGContextSetRGBFillColor(currentContext, 0.0, 0.0, 0.0, 1.0);

    NSString *textToDraw = header;

    UIFont *font = [UIFont systemFontOfSize:24.0];

    CGSize stringSize = [textToDraw sizeWithFont:font constrainedToSize:CGSizeMake(pageSize.width - 2*kBorderInset-2*kMarginInset, pageSize.height - 2*kBorderInset - 2*kMarginInset) lineBreakMode:UILineBreakModeWordWrap];

    CGRect renderingRect = CGRectMake(kBorderInset + kMarginInset, kBorderInset + kMarginInset, pageSize.width - 2*kBorderInset - 2*kMarginInset, stringSize.height);

    [textToDraw drawInRect:renderingRect withFont:font lineBreakMode:UILineBreakModeWordWrap alignment:UITextAlignmentLeft];
}

- (void) drawText:(NSString *)bodyText
{
    CGContextRef    currentContext = UIGraphicsGetCurrentContext();
    CGContextSetRGBFillColor(currentContext, 0.0, 0.0, 0.0, 1.0);

    NSString *textToDraw = bodyText;

    UIFont *font = [UIFont systemFontOfSize:14.0];

    CGSize stringSize = [textToDraw sizeWithFont:font
                               constrainedToSize:CGSizeMake(pageSize.width - 2*kBorderInset-2*kMarginInset, pageSize.height - 2*kBorderInset - 2*kMarginInset) 
                                   lineBreakMode:UILineBreakModeWordWrap];

    CGRect renderingRect = CGRectMake(kBorderInset + kMarginInset, kBorderInset + kMarginInset + 50.0, pageSize.width - 2*kBorderInset - 2*kMarginInset, stringSize.height);

    [textToDraw drawInRect:renderingRect 
                  withFont:font
             lineBreakMode:UILineBreakModeWordWrap
                 alignment:UITextAlignmentLeft];

}

- (void) drawLine
{
    CGContextRef    currentContext = UIGraphicsGetCurrentContext();

    CGContextSetLineWidth(currentContext, kLineWidth);

    CGContextSetStrokeColorWithColor(currentContext, [UIColor blackColor].CGColor);

    CGPoint startPoint = CGPointMake(kMarginInset + kBorderInset, kMarginInset + kBorderInset + 40.0);
    CGPoint endPoint = CGPointMake(pageSize.width - 2*kMarginInset -2*kBorderInset, kMarginInset + kBorderInset + 40.0);

    CGContextBeginPath(currentContext);
    CGContextMoveToPoint(currentContext, startPoint.x, startPoint.y);
    CGContextAddLineToPoint(currentContext, endPoint.x, endPoint.y);

    CGContextClosePath(currentContext);    
    CGContextDrawPath(currentContext, kCGPathFillStroke);
}

- (void) drawImage:(UIImage *)image
{
    //UIImage * demoImage = [UIImage imageNamed:@"demo.png"];
    [image drawInRect:CGRectMake( (pageSize.width - image.size.width/2)/2, 350, image.size.width/2, image.size.height/2)];
}


- (void) generatePdf: (NSString *)thefilePath :(NSString *) theHeader :(NSString *) theText :(UIImage *) theImage
{

    pageSize = CGSizeMake(612, 792);
    UIGraphicsBeginPDFContextToFile(thefilePath, CGRectZero, nil);

    NSInteger currentPage = 0;
    BOOL done = NO;
    do 
    {
        //Start a new page.
        UIGraphicsBeginPDFPageWithInfo(CGRectMake(0, 0, pageSize.width, pageSize.height), nil);

        //Draw a page number at the bottom of each page.
        currentPage++;
        [self drawPageNumber:currentPage];

        //Draw a border for each page.
        [self drawBorder];

        //Draw text fo our header.
        [self drawHeader:theHeader];

        //Draw a line below the header.
        [self drawLine];

        //Draw some text for the page.
        [self drawText:theText];

        //Draw an image
        [self drawImage:theImage];
        done = YES;
    } 
    while (!done);

    // Close the PDF context and write the contents out.
    UIGraphicsEndPDFContext();
}

#pragma mark - View lifecycle

- (void)viewDidLoad
{
    [super viewDidLoad];
}

- (void)viewDidUnload
{
    [super viewDidUnload];
}

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
{
    return (interfaceOrientation == UIInterfaceOrientationPortrait);
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
}

- (IBAction)generatePdfWithFileName:(id)sender
{
    pageSize = CGSizeMake(612, 792);
    NSString *fileName = @"test.pdf";
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString *pdfFileName = [documentsDirectory stringByAppendingPathComponent:fileName];

    NSString *header = @"This is the bad ass header section!";
    NSString *text = @"There is so much to say here I don't know where to begin....";

    [self generatePdf : pdfFileName : header:text:nil];
}

@end

Answer 1

The concept can be seen here

[from http://spitzkoff.com/craig/?p=160%5D

When placing items, get the Height:

CGSize size = [name sizeWithFont:studentNameFont forWidth:maxWidth lineBreakMode:UILineBreakModeWordWrap];
[name drawAtPoint:CGPointMake(kMargin, currentPageY) forWidth:maxWidth withFont:studentNameFont lineBreakMode:UILineBreakModeWordWrap];
currentPageY += size.height;

At appropriate points, check the currentY and decide if you need to move to a new page:

if (size.height + currentPageY > maxHeight) {
// create a new page and reset the current page's Y value
UIGraphicsBeginPDFPageWithInfo(CGRectMake(0, 0, kDefaultPageWidth, kDefaultPageHeight), nil);
currentPageY = kMargin;
}

I hope that helps.