PreviewPrintController.cs source code in C# .NET

Source code for the .NET framework in C#

                        
Code:

                         / DotNET / DotNET / 8.0 / untmp / whidbey / REDBITS / ndp / fx / src / CommonUI / System / Drawing / Printing / PreviewPrintController.cs / 1 / PreviewPrintController.cs
                        

                        
                            //------------------------------------------------------------------------------ 
// 
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// 
//----------------------------------------------------------------------------- 

namespace System.Drawing.Printing { 
 
    using Microsoft.Win32;
    using System; 
    using System.Collections;
    using System.ComponentModel;
    using System.Diagnostics;
    using System.Drawing; 
    using System.Drawing.Internal;
    using System.Drawing.Drawing2D; 
    using System.Drawing.Imaging; 
    using System.Drawing.Text;
    using System.Runtime.InteropServices; 

    using CodeAccessPermission = System.Security.CodeAccessPermission;

    ///  
    /// 
    ///     A PrintController which "prints" to a series of images. 
    ///  
    public class PreviewPrintController : PrintController {
        private IList list = new ArrayList(); // list of PreviewPageInfo 
        private System.Drawing.Graphics graphics;
        private DeviceContext dc;
        private bool antiAlias;
 
        private void CheckSecurity() {
            IntSecurity.SafePrinting.Demand(); 
        } 

        ///  
        /// 
        ///    
        ///       This is new public property which notifies if this controller is used for PrintPreview.
        ///     
        /// 
        public override bool IsPreview { 
            get { 
                return true;
            } 
        }

        /// 
        ///  
        ///    
        ///       Implements StartPrint for generating print preview information. 
        ///     
        /// 
        public override void OnStartPrint(PrintDocument document, PrintEventArgs e) { 
            Debug.Assert(dc == null && graphics == null, "PrintController methods called in the wrong order?");

            // For security purposes, don't assume our public methods methods are called in any particular order
            CheckSecurity(); 

            base.OnStartPrint(document, e); 
 

            try { 

                if (!document.PrinterSettings.IsValid)
                throw new InvalidPrinterException(document.PrinterSettings);
 
                IntSecurity.AllPrintingAndUnmanagedCode.Assert();
 
                // We need a DC as a reference; we don't actually draw on it. 
                // We make sure to reuse the same one to improve performance.
                dc = document.PrinterSettings.CreateInformationContext(modeHandle); 
            }
            finally {
                CodeAccessPermission.RevertAssert();
            } 

        } 
 
        /// 
        ///  
        ///    
        ///       Implements StartEnd for generating print preview information.
        ///    
        ///  
        public override Graphics OnStartPage(PrintDocument document, PrintPageEventArgs e) {
            Debug.Assert(dc != null && graphics == null, "PrintController methods called in the wrong order?"); 
 
            // For security purposes, don't assume our public methods methods are called in any particular order
            CheckSecurity(); 

            base.OnStartPage(document, e);

 
            try {
                IntSecurity.AllPrintingAndUnmanagedCode.Assert(); 
                e.PageSettings.CopyToHdevmode(modeHandle); 
                Size size = e.PageBounds.Size;
 
                // Metafile framing rectangles apparently use hundredths of mm as their unit of measurement,
                // instead of the GDI+ standard hundredth of an inch.
                Size metafileSize = PrinterUnitConvert.Convert(size, PrinterUnit.Display, PrinterUnit.HundredthsOfAMillimeter);
 
                // Create a Metafile which accepts only GDI+ commands since we are the ones creating
                // and using this ... 
                // Framework creates a dual-mode EMF for each page in the preview. 
                // When these images are displayed in preview,
                // they are added to the dual-mode EMF. However, 
                // GDI+ breaks during this process if the image
                // is sufficiently large and has more than 254 colors.
                // This code path can easily be avoided by requesting
                // an EmfPlusOnly EMF.. 
                Metafile metafile = new Metafile(dc.Hdc, new Rectangle(0,0, metafileSize.Width, metafileSize.Height), MetafileFrameUnit.GdiCompatible, EmfType.EmfPlusOnly);
 
                PreviewPageInfo info = new PreviewPageInfo(metafile, size); 
                list.Add(info);
                PrintPreviewGraphics printGraphics = new PrintPreviewGraphics(document, e); 
                graphics = Graphics.FromImage(metafile);

                if (graphics != null && document.OriginAtMargins) {
 
                    // Adjust the origin of the graphics object to be at the
                    // user-specified margin location 
                    // 
                    int dpiX = UnsafeNativeMethods.GetDeviceCaps(new HandleRef(dc, dc.Hdc), SafeNativeMethods.LOGPIXELSX);
                    int dpiY = UnsafeNativeMethods.GetDeviceCaps(new HandleRef(dc, dc.Hdc), SafeNativeMethods.LOGPIXELSY); 
                    int hardMarginX_DU = UnsafeNativeMethods.GetDeviceCaps(new HandleRef(dc, dc.Hdc), SafeNativeMethods.PHYSICALOFFSETX);
                    int hardMarginY_DU = UnsafeNativeMethods.GetDeviceCaps(new HandleRef(dc, dc.Hdc), SafeNativeMethods.PHYSICALOFFSETY);
                    float hardMarginX = hardMarginX_DU * 100 / dpiX;
                    float hardMarginY = hardMarginY_DU * 100 / dpiY; 

                    graphics.TranslateTransform(-hardMarginX, -hardMarginY); 
                    graphics.TranslateTransform(document.DefaultPageSettings.Margins.Left, document.DefaultPageSettings.Margins.Top); 
                }
 

                graphics.PrintingHelper = printGraphics;

 
                if (antiAlias) {
                    graphics.TextRenderingHint = TextRenderingHint.AntiAlias; 
                    graphics.SmoothingMode = SmoothingMode.AntiAlias; 
                }
            } 
            finally {
                CodeAccessPermission.RevertAssert();
            }
            return graphics; 
        }
 
        ///  
        /// 
        ///     
        ///       Implements EndPage for generating print preview information.
        ///    
        /// 
        public override void OnEndPage(PrintDocument document, PrintPageEventArgs e) { 
            Debug.Assert(dc != null && graphics != null, "PrintController methods called in the wrong order?");
 
            // For security purposes, don't assume our public methods methods are called in any particular order 
            CheckSecurity();
 
            graphics.Dispose();
            graphics = null;

            base.OnEndPage(document, e); 
        }
 
        ///  
        /// 
        ///     
        ///       Implements EndPrint for generating print preview information.
        ///    
        /// 
        public override void OnEndPrint(PrintDocument document, PrintEventArgs e) { 
            Debug.Assert(dc != null && graphics == null, "PrintController methods called in the wrong order?");
 
            // For security purposes, don't assume our public methods are called in any particular order 
            CheckSecurity();
 
            dc.Dispose();
            dc = null;

            base.OnEndPrint(document, e); 
        }
 
        ///  
        /// 
        ///     
        ///       The "printout".
        ///    
        /// 
        public PreviewPageInfo[] GetPreviewPageInfo() { 
            // For security purposes, don't assume our public methods methods are called in any particular order
            CheckSecurity(); 
 
            PreviewPageInfo[] temp = new PreviewPageInfo[list.Count];
            list.CopyTo(temp, 0); 
            return temp;
        }

        ///  
        public virtual bool UseAntiAlias {
            get { 
                return antiAlias; 
            }
            set { 
                antiAlias = value;
            }
        }
    } 
}
 
 
// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.

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