Page and pages#

A page is a simple structure:

type Page struct {
    Dictnum     Objectnumber // The "/Page" object
    Annotations []Annotation
    Faces       []*Face
    Images      []*Imagefile
    Width       float64
    Height      float64
    Dict        Dict // Additional dictionary entries such as "/Trimbox"
}

Pages are split into two parts in the PDF, a dictionary and a content stream. The Dictnum points to the dictionary.

A page is created and added to the PDF with

func (pw *PDF) AddPage(content *Object, dictnum Objectnumber) *Page

You need to register all used Annotations, Faces and Images to the page object in order to get the contents structure correct.

Permuting pages#

After all pages have been collected, you can re-arrange the pages in the PDF file by changing the Pages slice in the Pages object which the main PDF object has a reference to.

type Pages struct {
    Pages []*Page
}

For example you can do something like this:

pw.Pages.Pages[0], pw.Pages.Pages[1] = pw.Pages.Pages[1], pw.Pages.Pages[0]

to swap the first two pages. pw in this example is the main PDF object.

Writing pages to the PDF#

The PDF backend takes care of writing all the Page objects and the Pages object to the PDF. No user action is required.