//// 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 GrapeCity.Documents.Pdf;using GrapeCity.Documents.Text;
namespace DsPdfWeb.Demos.Basics{    // Creates a multi-column text layout with balanced columns.    // The heart of this sample is the TextLayout.SplitAndBalance() method    // which allows splitting a text between multiple columns,    // AND balance those columns so that their heights are similar,    // thus allowing to produce magazine- and newspaper-like text layouts.    public class BalancedColumns    {        public int CreatePDF(Stream stream)        {            var doc = new GcPdfDocument();            var font = StandardFonts.Times;            var fontSize = 12;            // 1/2" margins all around (72 dpi is the default resolution used by DsPdf):            var margin = 72 / 2;            var pageWidth = doc.PageSize.Width;            var pageHeight = doc.PageSize.Height;            var cW = pageWidth - margin * 2;            // Text format for the chapter titles:            var tlCaption = new TextLayout(72);            tlCaption.DefaultFormat.Font = font;            tlCaption.DefaultFormat.FontSize = fontSize + 4;            tlCaption.DefaultFormat.Underline = true;            tlCaption.MaxWidth = pageWidth;            tlCaption.MaxHeight = pageHeight;            tlCaption.MarginLeft = tlCaption.MarginTop = tlCaption.MarginRight = tlCaption.MarginBottom = margin;            tlCaption.TextAlignment = TextAlignment.Center;            // Height of chapter caption (use a const for simplicity):            const float captionH = 24;            // Text layout for main document body (default DsPdf resolution is 72dpi):            var tl = new TextLayout(72);            tl.DefaultFormat.Font = font;            tl.DefaultFormat.FontSize = fontSize;            tl.FirstLineIndent = 72 / 2;            tl.MaxWidth = pageWidth;            tl.MaxHeight = pageHeight;            tl.MarginLeft = tl.MarginRight = tl.MarginBottom = margin;            tl.MarginTop = margin + captionH;            tl.ColumnWidth = cW * 0.3f;            tl.TextAlignment = TextAlignment.Justified;            // Array of PageSplitArea's which control additional columns (1st column is controlled by            // the 'main' TextLayout, for each additional one a PageSplitArea must be provided -             // it will create and return a TextLayout that can then be used to render the column):            var psas = new PageSplitArea[]            {                new PageSplitArea(tl) { MarginLeft = tl.MarginLeft + (cW * 0.35f) },                new PageSplitArea(tl) { ColumnWidth = -cW * 0.3f }            };            // Split options to control splitting text between pages:            var tso = new TextSplitOptions(tl)            {                RestMarginTop = margin,                MinLinesInFirstParagraph = 2,                MinLinesInLastParagraph = 2            };            // Generate a number of "chapters", provide outline entry for each:            const int NChapters = 20;            doc.Pages.Add();            for (int i = 0; i < NChapters; ++i)            {                // Print chapter header across all columns:                string chapter = $"Chapter {i + 1}";                tlCaption.Clear();                tlCaption.Append(chapter);                tlCaption.PerformLayout(true);                doc.Pages.Last.Graphics.DrawTextLayout(tlCaption, PointF.Empty);                // Add outline node for the chapter:                doc.Outlines.Add(new OutlineNode(chapter, new DestinationFitV(doc.Pages.Last, null)));                //                // Clear last chapter's text and add new chapter:                tl.FirstLineIsStartOfParagraph = true;                tl.LastLineIsEndOfParagraph = true;                tl.Clear();                tl.Append(Common.Util.LoremIpsum(5, 7, 9, 15, 25));                tl.PerformLayout(true);                // Variable to hold last chapter end's bottom coord:                float contentBottom = 0f;                // Print the chapter:                var tls = new TextLayoutSplitter(tl);                while (true)                {                    var tlCol0 = tls.SplitAndBalance(psas, tso);                    var g = doc.Pages.Last.Graphics;                    g.DrawTextLayout(tlCol0, PointF.Empty);                    g.DrawTextLayout(psas[0].TextLayout, PointF.Empty);                    g.DrawTextLayout(psas[1].TextLayout, PointF.Empty);                    if (tls.SplitResult != SplitResult.Split)                    {                        // End of chapter, find out how much height left on page for next chapter:                        contentBottom = tl.ContentY + tl.ContentHeight;                        contentBottom = Math.Max(contentBottom, psas[0].TextLayout.ContentRectangle.Bottom);                        contentBottom = Math.Max(contentBottom, psas[1].TextLayout.ContentRectangle.Bottom);                        // Done printing chapter:                        break;                    }                    // Continue printing chapter on new page:                    psas[0].MarginTop = psas[1].MarginTop = margin;                    doc.Pages.Add();                }                // Next chapter - find out if we have enough space left on current page to start new chapter:                if (contentBottom + captionH < pageHeight * 0.8f)                {                    // Start new chapter on current page:                    contentBottom += pageHeight * 0.05f;                    tlCaption.MarginTop = contentBottom;                    tl.MarginTop = psas[0].MarginTop = psas[1].MarginTop = contentBottom + captionH;                }                else if (i < NChapters - 1)                {                    // Start new chapter on new page:                    tlCaption.MarginTop = margin;                    tl.MarginTop = psas[0].MarginTop = psas[1].MarginTop = margin + captionH;                    doc.Pages.Add();                }            }            // Done:            doc.Save(stream);            return doc.Pages.Count;        }    }}