GtkSharp/sample/GtkDemo/DemoPrinting.cs

/* Printing
 *
 * GtkPrintOperation offers a simple API to support printing in a cross-platform way.
 */

using System;
using System.IO;
using System.Reflection;
using Gtk;
using Cairo;

namespace GtkDemo
{
	[Demo ("Printing", "DemoPrinting.cs")]
        public class DemoPrinting
        {
		private static double headerHeight = (10*72/25.4);
		private static double headerGap = (3*72/25.4);
		private static int pangoScale = 1024;

		private PrintOperation print;

		private string fileName = "DemoPrinting.cs";
		private double fontSize = 12.0;
		private int linesPerPage;
		private string[] lines;
		private int numLines;
		private int numPages;

                public DemoPrinting ()
                {
			print = new PrintOperation ();
			
			print.BeginPrint += new BeginPrintHandler (OnBeginPrint);
			print.DrawPage += new DrawPageHandler (OnDrawPage);
			print.EndPrint += new EndPrintHandler (OnEndPrint);

			print.Run (PrintOperationAction.PrintDialog, null);
		}

		private void OnBeginPrint (object obj, Gtk.BeginPrintArgs args)
		{
			string contents;
			double height;

			PrintContext context = args.Context;
			height = context.Height;
		
			linesPerPage = (int)Math.Floor(height / fontSize);
			contents = LoadFile("DemoPrinting.cs");

			lines = contents.Split('\n');
			
			numLines = lines.Length;
			numPages = (numLines - 1) / linesPerPage + 1;
			
			print.NPages = numPages;			
		}

		private string LoadFile (string filename)
		{
			Stream file = Assembly.GetExecutingAssembly ().GetManifestResourceStream 
(filename);
                        if (file == null && File.Exists (filename)) {
                                file = File.OpenRead (filename);
                        }
			if (file == null) {
				return "File not found";
			}

			StreamReader sr = new StreamReader (file);
			return sr.ReadToEnd ();
		}

		private void OnDrawPage (object obj, Gtk.DrawPageArgs args)
		{
			PrintContext context = args.Context;

			Cairo.Context cr = context.CairoContext;
			double width = context.Width;

			cr.Rectangle (0, 0, width, headerHeight);
			cr.SetSourceRGB (0.8, 0.8, 0.8);
			cr.FillPreserve ();

			cr.SetSourceRGB (0, 0, 0);
			cr.LineWidth = 1;
			cr.Stroke();

			Pango.Layout layout = context.CreatePangoLayout ();
			
			Pango.FontDescription desc = Pango.FontDescription.FromString ("sans 14");
			layout.FontDescription = desc;
			
			layout.SetText (fileName);
			layout.Width = (int)width;
			layout.Alignment = Pango.Alignment.Center;

			int layoutWidth, layoutHeight;
			layout.GetSize (out layoutWidth, out layoutHeight);
			double textHeight = (double)layoutHeight / (double)pangoScale;

			cr.MoveTo (width/2, (headerHeight - textHeight) / 2);
			Pango.CairoHelper.ShowLayout (cr, layout);

			string pageStr = String.Format ("{0}/{1}", args.PageNr + 1, numPages);
			layout.SetText (pageStr);
			layout.Alignment = Pango.Alignment.Right;

			cr.MoveTo (width - 2, (headerHeight - textHeight) / 2);
			Pango.CairoHelper.ShowLayout (cr, layout);

			layout = null;
			layout = context.CreatePangoLayout ();

			desc = Pango.FontDescription.FromString ("mono");
			desc.Size = (int)(fontSize * pangoScale);
			layout.FontDescription = desc;
			
			cr.MoveTo (0, headerHeight + headerGap);
			int line = args.PageNr * linesPerPage;
			for (int i=0; i < linesPerPage && line < numLines; i++)
			{
				layout.SetText (lines[line]);
				Pango.CairoHelper.ShowLayout (cr, layout);
				cr.RelMoveTo (0, fontSize);
				line++;
			}
			(cr as IDisposable).Dispose ();
			layout = null;
		}

		private void OnEndPrint (object obj, Gtk.EndPrintArgs args)
		{
		}
	}
}