//// This code is part of Document Solutions for PDF .NET demos.// Copyright (c) MESCIUS inc. All rights reserved.//using System;using System.IO;using System.Drawing;using System.Linq;using System.Collections.Generic;using GrapeCity.Documents.Pdf;using GrapeCity.Documents.Text;using GrapeCity.Documents.Pdf.TextMap;using GrapeCity.Documents.Pdf.Structure;using GrapeCity.Documents.Pdf.Recognition.Structure;using GCTEXT = GrapeCity.Documents.Text;using GCDRAW = GrapeCity.Documents.Drawing;
namespace DsPdfWeb.Demos{    // Find tables and read their data using structure tags.    public class ReadTagsTableData    {        private TextFormat _tf, _tfHdr, _tfPgHdr;        private float _margin = 72;
        public int CreatePDF(Stream stream)        {            // Set up some text formats:            _tf = new TextFormat()            {                Font = GCTEXT.Font.FromFile(Path.Combine("Resources", "Fonts", "NotoSans-Regular.ttf")),                FontSize = 9,                ForeColor = Color.Black            };            _tfHdr = new TextFormat(_tf)            {                Font = GCTEXT.Font.FromFile(Path.Combine("Resources", "Fonts", "NotoSans-Bold.ttf")),                FontSize = 11,                ForeColor = Color.DarkBlue            };            _tfPgHdr = new TextFormat(_tf)            {                FontSize = 11,                ForeColor = Color.Gray            };
            // The resulting PDF:            var doc = new GcPdfDocument();            using (var s = File.OpenRead(Path.Combine("Resources", "PDFs", "C1Olap-QuickStart.pdf")))            {                var source = new GcPdfDocument();                source.Load(s);                PrintAllTables(doc, source);            }            // Save the PDF:            doc.Save(stream);            return doc.Pages.Count;        }
        private void PrintAllTables(GcPdfDocument doc, GcPdfDocument source)        {            // Get the LogicalStructure and top parent element:            LogicalStructure ls = source.GetLogicalStructure();            if (ls == null || ls.Elements == null || ls.Elements.Count == 0)            {                // No structure tags found:                Common.Util.AddNote("No structure tags were found in the source document.", doc.Pages.Add());                return;            }            // The root element:            Element root = ls.Elements[0];
            // Find and print all tables:            var tables = new List<(TextLayout, Page)>();            root.Children.ToList().FindAll(e_ => e_.StructElement.Type == "Table").ForEach(t_ => tables.Add(PrintTable(t_)));            // Group tables by the page they were found on:            var tablesByPage = tables.GroupBy(t_ => t_.Item2.Index);            // For each page, print all tables found on that page,            // followed by the original page for reference:            foreach (var tbp in tablesByPage)            {                // The page that will contain the extracted table data:                var pgTables = doc.NewPage();                // The page that will contain the source page for reference:                var pgSrc = doc.NewPage();                // Print the original page:                tbp.First().Item2.Draw(pgSrc.Graphics, pgSrc.Bounds);                // Add a page header:                pgSrc.Graphics.DrawString($"Page {tbp.First().Item2.Index + 1} of the source PDF",                    _tfPgHdr, new RectangleF(0, 0, pgSrc.Size.Width, _margin), TextAlignment.Center, ParagraphAlignment.Center, false);                //                float maxHeight = pgTables.Size.Height - _margin * 2;                float y = _margin;                // Print all table data. For simplicity sake we assume that all table data will fit on a single page:                foreach (var t in tbp)                {                    t.Item1.MaxHeight = maxHeight;                    t.Item1.MaxWidth = pgTables.Size.Width - _margin * 2;                    pgTables.Graphics.DrawTextLayout(t.Item1, new PointF(_margin, y));                    maxHeight -= t.Item1.ContentHeight + _margin;                    y += t.Item1.ContentHeight + _margin;                }            }        }
        private (TextLayout, Page) PrintTable(Element e)        {            if (e.Type != "Table")                throw new Exception($"Unexpected: element type must be 'Table' but it is '{e.Type}'.");
            List<List<IList<ITextParagraph>>> table = new List<List<IList<ITextParagraph>>>();            int maxCols = 0;            // Select all child elements with type TR - table rows:            void SelectRows(IReadOnlyList<Element> elements)            {                foreach (Element ec in elements)                {                    if (ec.HasChildren)                    {                        if (ec.StructElement.Type == "TR")                        {                            var cells = ec.Children.ToList().FindAll((e_) => e_.StructElement.Type == "TD").ToArray();                            maxCols = Math.Max(maxCols, cells.Length);                            List<IList<ITextParagraph>> tableCells = new List<IList<ITextParagraph>>();                            foreach (var cell in cells)                                tableCells.Add(cell.GetParagraphs());                            table.Add(tableCells);                        }                        else                            SelectRows(ec.Children);                    }                }            }            SelectRows(e.Children);
            // show table            var sourcePage = FindPage(e.StructElement);            if (sourcePage == null)                throw new Exception("Unexpected: could not find the default page for the table.");
            var tl = new TextLayout(72);
            // Add table data to the text layout:            tl.Append($"\nTable on page {sourcePage.Index + 1} of the source document has {maxCols} column(s) and {table.Count} row(s).\nData by row:", _tfHdr);            tl.AppendParagraphBreak();            int irow = 0;            foreach (var row in table)            {                int icol = 0;                foreach (var cell in row)                {                    foreach (var para in cell)                    {                        tl.Append(para.GetText());                    }                    if (row.IndexOf(cell) <= row.Count)                        tl.Append("\t");                    else                        tl.AppendLine();                    ++icol;                }                ++irow;                tl.AppendLine();            }            return (tl, sourcePage);        }
        private Page FindPage(StructElement se)        {            if (se.DefaultPage != null)                return se.DefaultPage;            if (se.HasChildren)                foreach (var child in se.Children)                {                    var p = FindPage(child);                    if (p != null)                        return p;                }            return null;        }    }}