//// 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;using GCTEXT = GrapeCity.Documents.Text;using GCDRAW = GrapeCity.Documents.Drawing;
namespace DsPdfWeb.Demos.Basics{    // Fallback fonts are fonts used to draw glyphs that are not present    // in a font specified by the application.    // DsPdf provides a default list of fallback font families    // that is automatically initialized, and includes large fonts    // that are usually suitable to be used as fallbacks for many    // languages for which some common fonts do not have the glyphs.    // These automatically added fallback font families are available    // via methods on the FontCollection.SystemFonts static collection.    // You can customize the default (and system-dependent) behavior    // by providing your own fallback fonts, and by adding them either    // to fallbacks managed by the global FontCollection.SystemFonts,    // by adding them to your own instance of the FontCollection,    // or to specific fonts that you are using.    // In this way the fallback font behavior can be finely tuned    // and be completely system-independent.    //    // This sample demonstrates the basic fallback behavior -    // clearing system fallbacks and re-adding them again.    // Additionally, it prints the list of fallback fonts    // found on the current system.    public class FontFallbacks    {        public int CreatePDF(Stream stream)        {            // Set up GcPdfDocument:            var doc = new GcPdfDocument();            var g = doc.NewPage().Graphics;
            // Set up some helper vars for rendering lines of text:            const float margin = 36;            // Insertion point (DsPdf's default resolution is 72dpi, use 1/2" margins all around):            var ip = new PointF(margin, margin);            // Init a text format with one of the standard fonts. Standard fonts are minimal            // and contain very few glyphs for non-Latin characters.            var tf = new TextFormat() { Font = StandardFonts.Courier, FontSize = 14 };
            // Get the list of fallback font families:            string[] fallbacks = FontCollection.SystemFonts.GetFallbackFontFamilies();
            // Clear global fallbacks list:            FontCollection.SystemFonts.ClearFallbackFontFamilies();            FontCollection.SystemFonts.ClearFallbackFonts();
            // Now there are no global fallback fonts, so Japanese text rendered using            // a standard font will produce 'blank boxes' instead of real Japanese characters:            g.DrawString("A Japanese text that won't render: あなたは日本語を話せますか？", tf, ip);            ip.Y += 36;
            // Re-add the original list of fallback font families to global SystemFonts:            FontCollection.SystemFonts.AppendFallbackFontFamilies(fallbacks);            // On some systems, default system fallbacks might not provide Japanese glyphs,            // so we add our own fallback just in case:            var arialuni = GCTEXT.Font.FromFile(Path.Combine("Resources", "Fonts", "NotoSansJP-Regular.ttf"));            FontCollection.SystemFonts.AppendFallbackFonts(arialuni);
            // Now that fallback fonts are available again, the same Japanese text will render            // correctly as an appropriate fallback will have been found:            g.DrawString("Same text with fallbacks available: あなたは日本語を話せますか？", tf, ip);            ip.Y += 36;
            // Finally, we list all fallbacks and print a test line using each:            Action<string> drawTestLine = (fnt_) =>            {                var tf1 = new TextFormat() { FontName = fnt_ };                var tstr = $"{fnt_}: The quick brown fox jumps over the lazy dog.";                var s = g.MeasureString(tstr, tf1, doc.PageSize.Width - margin * 2);                g.DrawString(tstr, tf1, new RectangleF(ip, s));                ip.Y += s.Height * 1.5f;                if (ip.Y > doc.Pages.Last.Size.Height - margin * 2)                {                    g = doc.NewPage().Graphics;                    ip.Y = 36;                }            };            foreach (var fnt in fallbacks)                drawTestLine(fnt);
            // Done:            doc.Save(stream);            return doc.Pages.Count;        }    }}