//// This code is part of Document Solutions for PDF .NET demos.// Copyright (c) MESCIUS inc. All rights reserved.//using System.IO;using System.Drawing;using System.Linq;using System.Collections.Generic;using GrapeCity.Documents.Pdf;using GrapeCity.Documents.Pdf.Articles;using GrapeCity.Documents.Drawing;using DsPdfWeb.Demos.Common;
namespace DsPdfWeb.Demos{    // This sample shows how to create article threads in a PDF document.    // An article thread is a sequence of related pages or page areas that can be    // navigated sequentially (forward or back) in a supporting PDF viewer.    // In this sample we load a number of photos from a folder and render them    // one per page in a random order.    // Some photos are associated (via known file names) with a specific subject    // (buildings, art, etc.), and we put all images associated with    // each subject into a subject-specific article thread (images that are not    // associated with any known subject are put in the 'Miscellaneous' thread).    // In addition we create 3 threads for different aspect ratios (horizontal,    // vertical and square), and add each image to the appropriate aspect article.    // See section 'Article threads' in Navigating PDF pages    // for details on how to navigate article threads in Acrobat    // (our JavaScript PDF viewer provides a similar UI for this).    public class ImageArticles    {        // Article names:        static class ArticleNames        {            public static string Landscape => "Subject: landscape";            public static string Art => "Subject: art";            public static string Flora => "Subject: flora";            public static string Buildings => "Subject: buildings";            public static string Misc => "Subject: Miscellaneous";            public static string AspectHorz => "Aspect: horizontal";            public static string AspectVert => "Aspect: vertical";            public static string AspectSquare => "Aspect: square";        }
        // Associate known image file names with appropriate subjects:        static readonly Dictionary<string, string> _subjects = new Dictionary<string, string>()        {            {"aurora.jpg", ArticleNames.Landscape },            {"chairs.jpg", ArticleNames.Buildings },            {"clouds.jpg", ArticleNames.Landscape },            {"colosseum.jpg", ArticleNames.Art },            {"deadwood.jpg", ArticleNames.Flora },            {"door.jpg", ArticleNames.Buildings },            {"ferns.jpg", ArticleNames.Flora },            {"fiord.jpg", ArticleNames.Landscape },            {"firth.jpg", ArticleNames.Landscape },            {"lady.jpg", ArticleNames.Art },            {"lavender.jpg", ArticleNames.Flora },            {"maple.jpg", ArticleNames.Buildings },            {"minerva.jpg", ArticleNames.Art },            {"newfoundland.jpg", ArticleNames.Landscape },            {"pines.jpg", ArticleNames.Flora },            {"purples.jpg", ArticleNames.Flora },            {"reds.jpg", ArticleNames.Flora },            {"road.jpg", ArticleNames.Landscape },            {"rome.jpg", ArticleNames.Art },            {"roofs.jpg", ArticleNames.Buildings },            {"sea.jpg", ArticleNames.Landscape },            {"skye.jpg", ArticleNames.Landscape },            {"tudor.jpg", ArticleNames.Buildings },            {"windswept.jpg", ArticleNames.Flora },            // Images not in this list are 'misc'.        };
        // Class to hold image info:        private class ImageInfo        {            public string Name;            public IImage Image;            public string Subject;            public string Aspect;        }
        public int CreatePDF(Stream stream)        {            // Load images and their associated infos:            var imageInfos = new List<ImageInfo>();            foreach (var fname in Directory.GetFiles(Path.Combine("Resources", "Images"), "*", SearchOption.AllDirectories))            {                var image = Util.ImageFromFile(fname);                var aspect = image.Width > image.Height ? ArticleNames.AspectHorz :                    (image.Width < image.Height ? ArticleNames.AspectVert : ArticleNames.AspectSquare);                var name = Path.GetFileName(fname);                _subjects.TryGetValue(name, out string subject);                if (string.IsNullOrEmpty(subject))                    subject = ArticleNames.Misc;                imageInfos.Add(new ImageInfo()                {                    Name = name,                    Image = image,                    Subject = subject,                    Aspect = aspect                });            }            // Randomize the order of images in the PDF:            imageInfos.Shuffle();
            // Keys are article thread names (from ArticleNames),            // values are ArticleThread objects to be added to the PDF:            var articles = new Dictionary<string, ArticleThread>();            foreach (var subject in _subjects.Values.Distinct())                articles.Add(subject,                    new ArticleThread()                    {                        Info = new DocumentInfo() { Title = subject }                    });            articles.Add(ArticleNames.Misc,                new ArticleThread()                {                    Info = new DocumentInfo() { Title = ArticleNames.Misc }                });            var horizontals = new ArticleThread()            {                Info = new DocumentInfo() { Title = ArticleNames.AspectHorz }            };            var verticals = new ArticleThread()            {                Info = new DocumentInfo() { Title = ArticleNames.AspectVert }            };            var squares = new ArticleThread()            {                Info = new DocumentInfo() { Title = ArticleNames.AspectSquare }            };
            // Create the document:            var doc = new GcPdfDocument();
            // Add images (one per page) to the PDF and article threads:            var ia = new ImageAlign(ImageAlignHorz.Center, ImageAlignVert.Top, true, true, true, false, false);            for (int i = 0; i < imageInfos.Count; ++i)            {                var page = doc.NewPage();                var ii = imageInfos[i];                var rc = new RectangleF(72, 72, doc.PageSize.Width - 144, doc.PageSize.Height - 144);                // Note that we get the actual image bounds to precisely specify the page area in the thread:                page.Graphics.DrawImage(ii.Image, rc, null, ia, out RectangleF[] imageBounds);                var bounds = imageBounds[0];                // Add the image to proper subject and aspect threads:                articles[ii.Subject].Beads.Add(new ArticleBead() { Page = page, Bounds = bounds });                if (ii.Aspect == ArticleNames.AspectHorz)                    horizontals.Beads.Add(new ArticleBead() { Page = page, Bounds = bounds });                else if (ii.Aspect == ArticleNames.AspectVert)                    verticals.Beads.Add(new ArticleBead() { Page = page, Bounds = bounds });                else                    squares.Beads.Add(new ArticleBead() { Page = page, Bounds = bounds });            }            // Add subject and aspect article threads to the PDF:            foreach (var article in articles.Select(a_ => a_.Value))                doc.ArticleThreads.Add(article);            doc.ArticleThreads.Add(horizontals);            doc.ArticleThreads.Add(verticals);            doc.ArticleThreads.Add(squares);
            // Done:            doc.Save(stream);            return doc.Pages.Count;        }    }}