PageLabels

1//
2// Copyright (c) 2001-2020 by PDFTron Systems Inc. All Rights Reserved.
3//
4
5using System;
6using System.IO;
7using System.Threading.Tasks;
8using Windows.Foundation;
9
10using pdftron.PDF;
11using pdftron.SDF;
12
13using PDFNetUniversalSamples.ViewModels;
14
15namespace PDFNetSamples
16{
17    public sealed class PageLabelsTest : Sample
18    {
19        public PageLabelsTest() :
20            base("PageLabels", "This example illustrates how to work with PDF page labels. PDF page labels can be used to describe a page. This is used to allow for non-sequential page numbering or the addition of arbitrary labels for a page (such as the inclusion of Roman numerals at the beginning of a book).")
21        {
22        }
23
24        public override IAsyncAction RunAsync()
25        {
26            return Task.Run(new System.Action(async () => {
27                WriteLine("--------------------------------");
28                WriteLine("Starting Annotation Test...");
29                WriteLine("--------------------------------\n");
30			    try
31			    {
32				    //-----------------------------------------------------------
33				    // Example 1: Add page labels to an existing or newly created PDF
34				    // document.
35				    //-----------------------------------------------------------
36                    {
37                        string input_file_path = Path.Combine(InputPath, "newsletter.pdf");
38                        WriteLine("Opening input file " + input_file_path);
39                        PDFDoc doc = new PDFDoc(input_file_path);
40					    doc.InitSecurityHandler();
41
42					    // Create a page labeling scheme that starts with the first page in 
43					    // the document (page 1) and is using uppercase roman numbering 
44					    // style. 
45					    doc.SetPageLabel(1, PageLabel.Create(doc.GetSDFDoc(), PageLabelStyle.e_roman_uppercase, "My Prefix ", 1));
46
47					    // Create a page labeling scheme that starts with the fourth page in 
48					    // the document and is using decimal arabic numbering style. 
49					    // Also the numeric portion of the first label should start with number 
50					    // 4 (otherwise the first label would be "My Prefix 1"). 
51					    PageLabel L2 = PageLabel.Create(doc.GetSDFDoc(), PageLabelStyle.e_decimal, "My Prefix ", 4);
52					    doc.SetPageLabel(4, L2);
53
54					    // Create a page labeling scheme that starts with the seventh page in 
55					    // the document and is using alphabetic numbering style. The numeric 
56					    // portion of the first label should start with number 1. 
57					    PageLabel L3 = PageLabel.Create(doc.GetSDFDoc(), PageLabelStyle.e_alphabetic_uppercase, "My Prefix ", 1);
58					    doc.SetPageLabel(7, L3);
59
60                        String output_file_path = Path.Combine(OutputPath, "newsletter_with_pagelabels.pdf");
61                        await doc.SaveAsync(output_file_path, SDFDocSaveOptions.e_linearized);
62                        WriteLine("Done. Results saved in " + output_file_path);
63                        await AddFileToOutputList(output_file_path).ConfigureAwait(false);
64					    doc.Destroy();
65				    }
66
67				    //-----------------------------------------------------------
68				    // Example 2: Read page labels from an existing PDF document.
69				    //-----------------------------------------------------------
70                    {
71                        string input_file_path = Path.Combine(OutputPath, "newsletter_with_pagelabels.pdf");
72                        WriteLine("Opening file " + input_file_path);
73                        PDFDoc doc = new PDFDoc(input_file_path);
74					    doc.InitSecurityHandler();
75
76					    PageLabel label;
77					    int page_num = doc.GetPageCount();
78					    for (int i=1; i<=page_num; ++i) 
79					    {
80						    WriteLine(string.Format("Page number: {0}", i));
81						    label = doc.GetPageLabel(i);
82						    if (label.IsValid()) {
83							    WriteLine(string.Format(" Label: {0}", label.GetLabelTitle(i)));
84						    }
85						    else {
86							    WriteLine(" No Label."); 
87						    }
88					    }
89					    doc.Destroy();
90				    }
91
92				    //-----------------------------------------------------------
93				    // Example 3: Modify page labels from an existing PDF document.
94				    //-----------------------------------------------------------
95                    {
96                        string input_file_path = Path.Combine(OutputPath, "newsletter_with_pagelabels.pdf");
97                        WriteLine("Opening file " + input_file_path);
98                        PDFDoc doc = new PDFDoc(input_file_path);
99					    doc.InitSecurityHandler();
100
101					    // Remove the alphabetic labels from example 1.
102					    doc.RemovePageLabel(7); 
103
104					    // Replace the Prefix in the decimal lables (from example 1).
105					    PageLabel label = doc.GetPageLabel(4);
106					    if (label.IsValid()) {
107						    label.SetPrefix("A");
108						    label.SetStart(1);
109					    }
110
111					    // Add a new label
112					    PageLabel new_label = PageLabel.Create(doc.GetSDFDoc(), PageLabelStyle.e_decimal, "B", 1);
113					    doc.SetPageLabel(10, new_label);  // starting from page 10.
114
115                        String output_file_path = Path.Combine(OutputPath, "newsletter_with_pagelabels_modified.pdf");
116                        await doc.SaveAsync(output_file_path, SDFDocSaveOptions.e_linearized);
117                        WriteLine("Done. Results saved in " + output_file_path);
118                        await AddFileToOutputList(output_file_path).ConfigureAwait(false);
119
120					    int page_num = doc.GetPageCount();
121					    for (int i=1; i<=page_num; ++i) 
122					    {
123						    WriteLine(string.Format("Page number: {0}", i));
124						    label = doc.GetPageLabel(i);
125						    if (label.IsValid()) {
126                                WriteLine(string.Format(" Label: {0}", label.GetLabelTitle(i)));
127						    }
128						    else {
129							    WriteLine(" No Label."); 
130						    }
131					    }
132					    doc.Destroy();
133				    }
134
135				    //-----------------------------------------------------------
136				    // Example 4: Delete all page labels in an existing PDF document.
137				    //-----------------------------------------------------------
138				    {
139					    PDFDoc doc = new PDFDoc(Path.Combine(OutputPath, "newsletter_with_pagelabels.pdf"));
140					    //doc.GetRoot().Erase("PageLabels");
141					    // ...
142					    doc.Destroy();
143				    }
144			    }
145			    catch (Exception e)
146			    {
147				    WriteLine(GetExceptionMessage(e));
148                }
149
150                WriteLine("\n--------------------------------");
151                WriteLine("Done PageLabels Test.");
152                WriteLine("--------------------------------\n");
153            })).AsAsyncAction();
154		}
155	}
156}