Write page content to PDF on iOS

To write page content to a new document.

PTPDFDoc *doc = [[PTPDFDoc alloc] init];

// ElementBuilder is used to build new Element objects
PTElementBuilder *builder = [[PTElementBuilder alloc] init];

// ElementWriter is used to write Elements to the page
PTElementWriter *writer = [[PTElementWriter alloc] init];	

// Start a new page
PTPage *page = [doc PageCreate: [[PTPDFRect alloc] initWithX1: 0 y1: 0 x2: 612 y2: 794]];

// begin writing to the page
[writer WriterBeginWithPage: page placement: e_ptoverlay page_coord_sys: YES compress: YES];	

// Create an Image that can be reused multiple times in the document or multiple on the same page.		
PTImage *img = [PTImage Create: [doc GetSDFDoc] filename: imagename];
PTElement *element = [builder CreateImageWithMatrix:img mtx: [[PTMatrix2D alloc] initWithA: 200 b: -145 c: 20 d: 300 h: 200 v: 150]];
[writer WritePlacedElement: element];

// use the same image (just change its matrix)
PTGState *gstate = [element GetGState];	
[gstate SetTransform: 200 b: 0 c: 0 d: 300 h: 50 v: 450];
[writer WritePlacedElement: element];

// use the same image again (just change its matrix).
[writer WritePlacedElement: [builder CreateImageWithCornerAndScale: img x: 300 y: 600 hscale: 200 vscale: -150]];

// save changes to the current page
[writer End];  

// Add the new page to the document sequence
[doc PagePushBack: page];

Build, Write, Embed Elements in PDF Pages
Full code sample which illustrates how to use PDFNet page writing API, how to embed fonts and images and how to copy graphical elements from one page to another.

New page content can be added to an existing page or a blank new page using ElementBuilder and ElementWriter. ElementBuilder is used to instantiate one or more Elements that can be written to one or more pages using ElementWriter:

Note that once the Element is instantiated using ElementBuilder, you have full control over its properties and graphics state.

Page content can also come from existing pages. For example, you can use ElementReader to read paths, text, and images from existing pages and copy them to the current page. Note that, along the way, you can fully modify an Element's properties or its graphics state. This is how to perform page content editing. For example, the following copies all Elements from an existing page and changes text color to blue:

PTPDFDoc *doc = [[PTPDFDoc alloc] initWithFilepath: filename];
PTPage *first_page = [doc GetPage:1];

PTElementWriter *writer = [[PTElementWriter alloc] init];
PTElementReader *reader = [[PTElementReader alloc] init];
[reader Begin: page];
[writer Begin: page placement: e_ptreplacement page_coord_sys: NO];

PTElement *element;	
while ((element = [reader Next])) 	// Read page contents
{
  switch ([element GetType])
  {		
    case e_pttext_obj:
      {
        // Set all text to blue color.
        PTGState *gs = [element GetGState];
        [gs SetFillColorSpace: [PTColorSpace CreateDeviceRGB]];
        PTColorPt *cp = [[PTColorPt alloc] initWithX: 0 y: 0 z: 1 w: 0];
        [gs SetFillColorWithColorPt: cp];
        [writer WriteElement: element];
        break;
      }
    default:
        [writer WriteElement: element];
  }
}

[writer End];
[reader End];

PDF Editor (Programmatic)
Full code sample which strips all images from the page and changes text color to blue.