using System;
using System.Collections.Specialized;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
using System.Runtime.InteropServices;
using System.Text;
using System.Windows.Forms;
namespace GenesisChatClient {
#region Public Enums
// Enum for possible RTF colors
public enum RtfColor {
Black, Maroon, Green, Olive, Navy, Purple, Teal, Gray, Silver,
Red, Lime, Yellow, Blue, Fuchsia, Aqua, White
}
#endregion
/// <summary>
/// This class adds the following functionality to RichTextBox:
///
/// 1. Allows plain text to be inserted or appended programmatically to RTF
/// content.
/// 2. Allows the font, text color, and highlight color of plain text to be
/// specified when inserting or appending text as RTF.
/// 3. Allows images to be inserted programmatically, or with interaction from
/// the user.
/// </summary>
/// <remarks>
/// Many solutions to the problem of programmatically inserting images
/// into a RichTextBox use the clipboard or hard code the RTF for
/// the image in the program. This class is an attempt to make the process of
/// inserting images at runtime more flexible without the overhead of maintaining
/// the clipboard or the use of huge, cumbersome strings.
///
/// RTF Specification v1.6 was used and is referred to many times in this document.
/// http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnrtfspec/html/rtfspec.asp
///
/// For information about the RichEdit (Unmanaged RichTextBox) ...
/// http://msdn.microsoft.com/library/default.asp?url=/library/en-us/shellcc/platform/commctls/richedit/richeditcontrols/aboutricheditcontrols.asp
/// </remarks>
public class ExRichTextBox : System.Windows.Forms.RichTextBox {
#region My Enums
// Specifies the flags/options for the unmanaged call to the GDI+ method
// Metafile.EmfToWmfBits().
private enum EmfToWmfBitsFlags {
// Use the default conversion
EmfToWmfBitsFlagsDefault = 0x00000000,
// Embedded the source of the EMF metafiel within the resulting WMF
// metafile
EmfToWmfBitsFlagsEmbedEmf = 0x00000001,
// Place a 22-byte header in the resulting WMF file. The header is
// required for the metafile to be considered placeable.
EmfToWmfBitsFlagsIncludePlaceable = 0x00000002,
// Don't simulate clipping by using the XOR operator.
EmfToWmfBitsFlagsNoXORClip = 0x00000004
};
#endregion
#region My Structs
// Definitions for colors in an RTF document
private struct RtfColorDef {
public const string Black = @"\red0\green0\blue0";
public const string Maroon = @"\red128\green0\blue0";
public const string Green = @"\red0\green128\blue0";
public const string Olive = @"\red128\green128\blue0";
public const string Navy = @"\red0\green0\blue128";
public const string Purple = @"\red128\green0\blue128";
public const string Teal = @"\red0\green128\blue128";
public const string Gray = @"\red128\green128\blue128";
public const string Silver = @"\red192\green192\blue192";
public const string Red = @"\red255\green0\blue0";
public const string Lime = @"\red0\green255\blue0";
public const string Yellow = @"\red255\green255\blue0";
public const string Blue = @"\red0\green0\blue255";
public const string Fuchsia = @"\red255\green0\blue255";
public const string Aqua = @"\red0\green255\blue255";
public const string White = @"\red255\green255\blue255";
}
// Control words for RTF font families
private struct RtfFontFamilyDef {
public const string Unknown = @"\fnil";
public const string Roman = @"\froman";
public const string Swiss = @"\fswiss";
public const string Modern = @"\fmodern";
public const string Script = @"\fscript";
public const string Decor = @"\fdecor";
public const string Technical = @"\ftech";
public const string BiDirect = @"\fbidi";
}
#endregion
#region My Constants
// Not used in this application. Descriptions can be found with documentation
// of Windows GDI function SetMapMode
private const int MM_TEXT = 1;
private const int MM_LOMETRIC = 2;
private const int MM_HIMETRIC = 3;
private const int MM_LOENGLISH = 4;
private const int MM_HIENGLISH = 5;
private const int MM_TWIPS = 6;
// Ensures that the metafile maintains a 1:1 aspect ratio
private const int MM_ISOTROPIC = 7;
// Allows the x-coordinates and y-coordinates of the metafile to be adjusted
// independently
private const int MM_ANISOTROPIC = 8;
// Represents an unknown font family
private const string FF_UNKNOWN = "UNKNOWN";
// The number of hundredths of millimeters (0.01 mm) in an inch
// For more information, see GetImagePrefix() method.
private const int HMM_PER_INCH = 2540;
// The number of twips in an inch
// For more information, see GetImagePrefix() method.
private const int TWIPS_PER_INCH = 1440;
#endregion
#region My Privates
// The default text color
private RtfColor textColor;
// The default text background color
private RtfColor highlightColor;
// Dictionary that maps color enums to RTF color codes
private HybridDictionary rtfColor;
// Dictionary that mapas Framework font families to RTF font families
private HybridDictionary rtfFontFamily;
// The horizontal resolution at which the control is being displayed
private float xDpi;
// The vertical resolution at which the control is being displayed
private float yDpi;
#endregion
#region Elements required to create an RTF document
/* RTF HEADER
* ----------
*
* \rtf[N] - For text to be considered to be RTF, it must be enclosed in this tag.
* rtf1 is used because the RichTextBox conforms to RTF Specification
* version 1.
* \ansi - The character set.
* \ansicpg[N] - Specifies that unicode characters might be embedded. ansicpg1252
* is the default used by Windows.
* \deff[N] - The default font. \deff0 means the default font is the first font
* found.
* \deflang[N] - The default language. \deflang1033 specifies US English.
* */
private const string RTF_HEADER = @"{\rtf1\ansi\ansicpg1252\deff0\deflang1033";
/* RTF DOCUMENT AREA
* -----------------
*
* \viewkind[N] - The type of view or zoom level. \viewkind4 specifies normal view.
* \uc[N] - The number of bytes corresponding to a Unicode character.
* \pard - Resets to default paragraph properties
* \cf[N] - Foreground color. \cf1 refers to the color at index 1 in
* the color table
* \f[N] - Font number. \f0 refers to the font at index 0 in the font
* table.
* \fs[N] - Font size in half-points.
* */
private const string RTF_DOCUMENT_PRE = @"\viewkind4\uc1\pard\cf1\f0\fs20";
private const string RTF_DOCUMENT_POST = @"\cf0\fs17}";
private string RTF_IMAGE_POST = @"}";
#endregion
#region Accessors
// TODO: This can be ommitted along with RemoveBadCharacters
// Overrides the default implementation of RTF. This is done because the control
// was originally developed to run in an instant messenger that uses the
// Jabber XML-based protocol. The framework would throw an exception when the
// XML contained the null character, so I filtered out.
public new string Rtf {
get {return RemoveBadChars(base.Rtf);}
set {base.Rtf = value;}
}
// The color of the text
public RtfColor TextColor {
get {return textColor;}
set {textColor = value;}
}
// The color of the highlight
public RtfColor HiglightColor {
get {return highlightColor;}
set {highlightColor = value;}
}
#endregion
#region Constructors
/// <summary>
/// Initializes the text colors, creates dictionaries for RTF colors and
/// font families, and stores the horizontal and vertical resolution of
/// the RichTextBox's graphics context.
/// </summary>
public ExRichTextBox() : base() {
// Initialize default text and background colors
textColor = RtfColor.Black;
highlightColor = RtfColor.White;
// Initialize the dictionary mapping color codes to definitions
rtfColor = new HybridDictionary();
rtfColor.Add(RtfColor.Aqua, RtfColorDef.Aqua);
rtfColor.Add(RtfColor.Black, RtfColorDef.Black);
rtfColor.Add(RtfColor.Blue, RtfColorDef.Blue);
rtfColor.Add(RtfColor.Fuchsia, RtfColorDef.Fuchsia);
rtfColor.Add(RtfColor.Gray, RtfColorDef.Gray);
rtfColor.Add(RtfColor.Green, RtfColorDef.Green);
rtfColor.Add(RtfColor.Lime, RtfColorDef.Lime);
rtfColor.Add(RtfColor.Maroon, RtfColorDef.Maroon);
rtfColor.Add(RtfColor.Navy, RtfColorDef.Navy);
rtfColor.Add(RtfColor.Olive, RtfColorDef.Olive);
rtfColor.Add(RtfColor.Purple, RtfColorDef.Purple);
rtfColor.Add(RtfColor.Red, RtfColorDef.Red);
rtfColor.Add(RtfColor.Silver, RtfColorDef.Silver);
rtfColor.Add(RtfColor.Teal, RtfColorDef.Teal);
rtfColor.Add(RtfColor.White, RtfColorDef.White);
rtfColor.Add(RtfColor.Yellow, RtfColorDef.Yellow);
// Initialize the dictionary mapping default Framework font families to
// RTF font families
rtfFontFamily = new HybridDictionary();
rtfFontFamily.Add(FontFamily.GenericMonospace.Name, RtfFontFamilyDef.Modern);
rtfFontFamily.Add(FontFamily.GenericSansSerif, RtfFontFamilyDef.Swiss);
rtfFontFamily.Add(FontFamily.GenericSerif, RtfFontFamilyDef.Roman);
rtfFontFamily.Add(FF_UNKNOWN, RtfFontFamilyDef.Unknown);
// Get the horizontal and vertical resolutions at which the object is
// being displayed
using(Graphics _graphics = this.CreateGraphics()) {
xDpi = _graphics.DpiX;
yDpi = _graphics.DpiY;
}
}
/// <summary>
/// Calls the default constructor then sets the text color.
/// </summary>
/// <param name="_textColor"></param>
public ExRichTextBox(RtfColor _textColor) : this() {
textColor = _textColor;
}
/// <summary>
/// Calls the default constructor then sets te text and highlight colors.
/// </summary>
/// <param name="_textColor"></param>
/// <param name="_highlightColor"></param>
public ExRichTextBox(RtfColor _textColor, RtfColor _highlightColor) : this() {
textColor = _textColor;
highlightColor = _highlightColor;
}
#endregion
#region Append RTF or Text to RichTextBox Contents
/// <summary>
/// Assumes the string passed as a paramter is valid RTF text and attempts
/// to append it as RTF to the content of the control.
/// </summary>
/// <param name="_rtf"></param>
public void AppendRtf(string _rtf) {
// Move caret to the end of the text
this.Select(this.TextLength, 0);
// Since SelectedRtf is null, this will append the string to the
// end of the existing RTF
this.SelectedRtf = _rtf;
}
/// <summary>
/// Assumes that the string passed as a parameter is valid RTF text and
/// attempts to insert it as RTF into the content of the control.
/// </summary>
/// <remarks>
/// NOTE: The text is inserted wherever the caret is at the time of the call,
/// and if any text is selected, that text is replaced.
/// </remarks>
/// <param name="_rtf"></param>
public void InsertRtf(string _rtf) {
this.SelectedRtf = _rtf;
}
/// <summary>
/// Appends the text using the current font, text, and highlight colors.
/// </summary>
/// <param name="_text"></param>
public void AppendTextAsRtf(string _text) {
AppendTextAsRtf(_text, this.Font);
}
/// <summary>
/// Appends the text using the given font, and current text and highlight
/// colors.
/// </summary>
/// <param name="_text"></param>
/// <param name="_font"></param>
public void AppendTextAsRtf(string _text, Font _font) {
AppendTextAsRtf(_text, _font, textColor);
}
/// <summary>
/// Appends the text using the given font and text color, and the current
/// highlight color.
/// </summary>
/// <param name="_text"></param>
/// <param name="_font"></param>
/// <param name="_color"></param>
public void AppendTextAsRtf(string _text, Font _font, RtfColor _textColor) {
AppendTextAsRtf(_text, _font, _textColor, highlightColor);
}
/// <summary>
/// Appends the text using the given font, text, and highlight colors. Simply
/// moves the caret to the end of the RichTextBox's text and makes a call to
/// insert.
/// </summary>
/// <param name="_text"></param>
/// <param name="_font"></param>
/// <param name="_textColor"></param>
/// <param name="_backColor"></param>
public void AppendTextAsRtf(string _text, Font _font, RtfColor _textColor, RtfColor _backColor) {
// Move carret to the end of the text
this.Select(this.TextLength, 0);
InsertTextAsRtf(_text, _font, _textColor, _backColor);
}
#endregion
#region Insert Plain Text
/// <summary>
/// Inserts the text using the current font, text, and highlight colors.
/// </summary>
/// <param name="_text"></param>
public void InsertTextAsRtf(string _text) {
InsertTextAsRtf(_text, this.Font);
}
/// <summary>
/// Inserts the text using the given font, and current text and highlight
/// colors.
/// </summary>
/// <param name="_text"></param>
/// <param name="_font"></param>
public void InsertTextAsRtf(string _text, Font _font) {
InsertTextAsRtf(_text, _font, textColor);
}
/// <summary>
/// Inserts the text using the given font and text color, and the current
/// highlight color.
/// </summary>
/// <param name="_text"></param>
/// <param name="_font"></param>
/// <param name="_color"></param>
public void InsertTextAsRtf(string _text, Font _font, RtfColor _textColor) {
InsertTextAsRtf(_text, _font, _textColor, highlightColor);
}
/// <summary>
/// Inserts the text using the given font, text, and highlight colors. The
/// text is wrapped in RTF codes so that the specified formatting is kept.
/// You can only assign valid RTF to the RichTextBox.Rtf property, else
/// an exception is thrown. The RTF string should follow this format ...
///
/// {\rtf1\ansi\ansicpg1252\deff0\deflang1033{\fonttbl{[FONTS]}{\colortbl ;[COLORS]}}
/// \viewkind4\uc1\pard\cf1\f0\fs20 [DOCUMENT AREA] }
///
/// </summary>
/// <remarks>
/// NOTE: The text is inserted wherever the caret is at the time of the call,
/// and if any text is selected, that text is replaced.
/// </remarks>
/// <param name="_text"></param>
/// <param name="_font"></param>
/// <param name="_color"></param>
/// <param name="_color"></param>
public void InsertTextAsRtf(string _text, Font _font, RtfColor _textColor, RtfColor _backColor) {
StringBuilder _rtf = new StringBuilder();
// Append the RTF header
_rtf.Append(RTF_HEADER);
// Create the font table from the font passed in and append it to the
// RTF string
_rtf.Append(GetFontTable(_font));
// Create the color table from the colors passed in and append it to the
// RTF string
_rtf.Append(GetColorTable(_textColor, _backColor));
// Create the document area from the text to be added as RTF and append
// it to the RTF string.
_rtf.Append(GetDocumentArea(_text, _font));
this.SelectedRtf = _rtf.ToString();
}
/// <summary>
/// Creates the Document Area of the RTF being inserted. The document area
/// (in this case) consists of the text being added as RTF and all the
/// formatting specified in the Font object passed in. This should have the
/// form ...
///
/// \viewkind4\uc1\pard\cf1\f0\fs20 [DOCUMENT AREA] }
///
/// </summary>
/// <param name="_text"></param>
/// <param name="_font"></param>
/// <returns>
/// The document area as a string.
/// </returns>
private string GetDocumentArea(string _text, Font _font) {
StringBuilder _doc = new StringBuilder();
// Append the standard RTF document area control string
_doc.Append(RTF_DOCUMENT_PRE);
// Set the highlight color (the color behind the text) to the
// third color in the color table. See GetColorTable for more details.
_doc.Append(@"\highlight2");
// If the font is bold, attach corresponding tag
if (_font.Bold)
_doc.Append(@"\b");
// If the font is italic, attach corresponding tag
if (_font.Italic)
_doc.Append(@"\i");
// If the font is strikeout, attach corresponding tag
if (_font.Strikeout)
_doc.Append(@"\strike");
// If the font is underlined, attach corresponding tag
if (_font.Underline)
_doc.Append(@"\ul");
// Set the font to the first font in the font table.
// See GetFontTable for more details.
_doc.Append(@"\f0");
// Set the size of the font. In RTF, font size is measured in
// half-points, so the font size is twice the value obtained from
// Font.SizeInPoints
_doc.Append(@"\fs");
_doc.Append((int)Math.Round((2 * _font.SizeInPoints)));
// Apppend a space before starting actual text (for clarity)
_doc.Append(@" ");
// Append actual text, however, replace newlines with RTF \par.
// Any other special text should be handled here (e.g.) tabs, etc.
_doc.Append(_text.Replace("\n", @"\par "));
// RTF isn't strict when it comes to closing control words, but what the
// heck ...
// Remove the highlight
_doc.Append(@"\highlight0");
// If font is bold, close tag
if (_font.Bold)
_doc.Append(@"\b0");
// If font is italic, close tag
if (_font.Italic)
_doc.Append(@"\i0");
// If font is strikeout, close tag
if (_font.Strikeout)
_doc.Append(@"\strike0");
// If font is underlined, cloes tag
if (_font.Underline)
_doc.Append(@"\ulnone");
// Revert back to default font and size
_doc.Append(@"\f0");
_doc.Append(@"\fs20");
// Close the document area control string
_doc.Append(RTF_DOCUMENT_POST);
return _doc.ToString();
}
#endregion
#region Insert Image
/// <summary>
/// Inserts an image into the RichTextBox. The image is wrapped in a Windows
/// Format Metafile, because although Microsoft discourages the use of a WMF,
/// the RichTextBox (and even MS Word), wraps an image in a WMF before inserting
/// the image into a document. The WMF is attached in HEX format (a string of
/// HEX numbers).
///
/// The RTF Specification v1.6 says that you should be able to insert bitmaps,
/// .jpegs, .gifs, .pngs, and Enhanced Metafiles (.emf) directly into an RTF
/// document without the WMF wrapper. This works fine with MS Word,
/// however, when you don't wrap images in a WMF, WordPad and
/// RichTextBoxes simply ignore them. Both use the riched20.dll or msfted.dll.
/// </summary>
/// <remarks>
/// NOTE: The image is inserted wherever the caret is at the time of the call,
/// and if any text is selected, that text is replaced.
/// </remarks>
/// <param name="_image"></param>
public void InsertImage(Image _image) {
StringBuilder _rtf = new StringBuilder();
// Append the RTF header
_rtf.Append(RTF_HEADER);
// Create the font table using the RichTextBox's current font and append
// it to the RTF string
_rtf.Append(GetFontTable(this.Font));
// Create the image control string and append it to the RTF string
_rtf.Append(GetImagePrefix(_image));
// Create the Windows Metafile and append its bytes in HEX format
_rtf.Append(GetRtfImage(_image));
// Close the RTF image control string
_rtf.Append(RTF_IMAGE_POST);
this.SelectedRtf = _rtf.ToString();
}
/// <summary>
/// Creates the RTF control string that describes the image being inserted.
/// This description (in this case) specifies that the image is an
/// MM_ANISOTROPIC metafile, meaning that both X and Y axes can be scaled
/// independently. The control string also gives the images current dimensions,
/// and its target dimensions, so if you want to control the size of the
/// image being inserted, this would be the place to do it. The prefix should
/// have the form ...
///
/// {\pict\wmetafile8\picw[A]\pich[B]\picwgoal[C]\pichgoal[D]
///
/// where ...
///
/// A = current width of the metafile in hundredths of millimeters (0.01mm)
/// = Image Width in Inches * Number of (0.01mm) per inch
/// = (Image Width in Pixels / Graphics Context's Horizontal Resolution) * 2540
/// = (Image Width in Pixels / Graphics.DpiX) * 2540
///
/// B = current height of the metafile in hundredths of millimeters (0.01mm)
/// = Image Height in Inches * Number of (0.01mm) per inch
/// = (Image Height in Pixels / Graphics Context's Vertical Resolution) * 2540
/// = (Image Height in Pixels / Graphics.DpiX) * 2540
///
/// C = target width of the metafile in twips
/// = Image Width in Inches * Number of twips per inch
/// = (Image Width in Pixels / Graphics Context's Horizontal Resolution) * 1440
/// = (Image Width in Pixels / Graphics.DpiX) * 1440
///
/// D = target height of the metafile in twips
/// = Image Height in Inches * Number of twips per inch
/// = (Image Height in Pixels / Graphics Context's Horizontal Resolution) * 1440
/// = (Image Height in Pixels / Graphics.DpiX) * 1440
///
/// </summary>
/// <remarks>
/// The Graphics Context's resolution is simply the current resolution at which
/// windows is being displayed. Normally it's 96 dpi, but instead of assuming
/// I just added the code.
///
/// According to Ken Howe at pbdr.com, "Twips are screen-independent units
/// used to ensure that the placement and proportion of screen elements in
/// your screen application are the same on all display systems."
///
/// Units Used
/// ----------
/// 1 Twip = 1/20 Point
/// 1 Point = 1/72 Inch
/// 1 Twip = 1/1440 Inch
///
/// 1 Inch = 2.54 cm
/// 1 Inch = 25.4 mm
/// 1 Inch = 2540 (0.01)mm
/// </remarks>
/// <param name="_image"></param>
/// <returns></returns>
private string GetImagePrefix(Image _image) {
StringBuilder _rtf = new StringBuilder();
// Calculate the current width of the image in (0.01)mm
int picw = (int)Math.Round((_image.Width / xDpi) * HMM_PER_INCH);
// Calculate the current height of the image in (0.01)mm
int pich = (int)Math.Round((_image.Height / yDpi) * HMM_PER_INCH);
// Calculate the target width of the image in twips
int picwgoal = (int)Math.Round((_image.Width / xDpi) * TWIPS_PER_INCH);
// Calculate the target height of the image in twips
int pichgoal = (int)Math.Round((_image.Height / yDpi) * TWIPS_PER_INCH);
// Append values to RTF string
_rtf.Append(@"{\pict\wmetafile8");
_rtf.Append(@"\picw");
_rtf.Append(picw);
_rtf.Append(@"\pich");
_rtf.Append(pich);
_rtf.Append(@"\picwgoal");
_rtf.Append(picwgoal);
_rtf.Append(@"\pichgoal");
_rtf.Append(pichgoal);
_rtf.Append(" ");
return _rtf.ToString();
}
/// <summary>
/// Use the EmfToWmfBits function in the GDI+ specification to convert a
/// Enhanced Metafile to a Windows Metafile
/// </summary>
/// <param name="_hEmf">
/// A handle to the Enhanced Metafile to be converted
/// </param>
/// <param name="_bufferSize">
/// The size of the buffer used to store the Windows Metafile bits returned
/// </param>
/// <param name="_buffer">
/// An array of bytes used to hold the Windows Metafile bits returned
/// </param>
/// <param name="_mappingMode">
/// The mapping mode of the image. This control uses MM_ANISOTROPIC.
/// </param>
/// <param name="_flags">
/// Flags used to specify the format of the Windows Metafile returned
/// </param>
[DllImportAttribute("gdiplus.dll")]
private static extern uint GdipEmfToWmfBits (IntPtr _hEmf, uint _bufferSize,
byte[] _buffer, int _mappingMode, EmfToWmfBitsFlags _flags);
/// <summary>
/// Wraps the image in an Enhanced Metafile by drawing the image onto the
/// graphics context, then converts the Enhanced Metafile to a Windows
/// Metafile, and finally appends the bits of the Windows Metafile in HEX
/// to a string and returns the string.
/// </summary>
/// <param name="_image"></param>
/// <returns>
/// A string containing the bits of a Windows Metafile in HEX
/// </returns>
private string GetRtfImage(Image _image) {
StringBuilder _rtf = null;
// Used to store the enhanced metafile
MemoryStream _stream = null;
// Used to create the metafile and draw the image
Graphics _graphics = null;
// The enhanced metafile
Metafile _metaFile = null;
// Handle to the device context used to create the metafile
IntPtr _hdc;
try {
_rtf = new StringBuilder();
_stream = new MemoryStream();
// Get a graphics context from the RichTextBox
using(_graphics = this.CreateGraphics()) {
// Get the device context from the graphics context
_hdc = _graphics.GetHdc();
// Create a new Enhanced Metafile from the device context
_metaFile = new Metafile(_stream, _hdc);
// Release the device context
_graphics.ReleaseHdc(_hdc);
}
// Get a graphics context from the Enhanced Metafile
using(_graphics = Graphics.FromImage(_metaFile)) {
// Draw the image on the Enhanced Metafile
_graphics.DrawImage(_image, new Rectangle(0, 0, _image.Width, _image.Height));
}
// Get the handle of the Enhanced Metafile
IntPtr _hEmf = _metaFile.GetHenhmetafile();
// A call to EmfToWmfBits with a null buffer return the size of the
// buffer need to store the WMF bits. Use this to get the buffer
// size.
uint _bufferSize = GdipEmfToWmfBits(_hEmf, 0, null, MM_ANISOTROPIC,
EmfToWmfBitsFlags.EmfToWmfBitsFlagsDefault);
// Create an array to hold the bits
byte[] _buffer = new byte[_bufferSize];
// A call to EmfToWmfBits with a valid buffer copies the bits into the
// buffer an returns the number of bits in the WMF.
uint _convertedSize = GdipEmfToWmfBits(_hEmf, _bufferSize, _buffer, MM_ANISOTROPIC,
EmfToWmfBitsFlags.EmfToWmfBitsFlagsDefault);
// Append the bits to the RTF string
for(int i = 0; i < _buffer.Length; ++i) {
_rtf.Append(String.Format("{0:X2}", _buffer[i]));
}
return _rtf.ToString();
}
finally {
if(_graphics != null)
_graphics.Dispose();
if(_metaFile != null)
_metaFile.Dispose();
if(_stream != null)
_stream.Close();
}
}
#endregion
#region RTF Helpers
/// <summary>
/// Creates a font table from a font object. When an Insert or Append
/// operation is performed a font is either specified or the default font
/// is used. In any case, on any Insert or Append, only one font is used,
/// thus the font table will always contain a single font. The font table
/// should have the form ...
///
/// {\fonttbl{\f0\[FAMILY]\fcharset0 [FONT_NAME];}
/// </summary>
/// <param name="_font"></param>
/// <returns></returns>
private string GetFontTable(Font _font) {
StringBuilder _fontTable = new StringBuilder();
// Append table control string
_fontTable.Append(@"{\fonttbl{\f0");
_fontTable.Append(@"\");
// If the font's family corresponds to an RTF family, append the
// RTF family name, else, append the RTF for unknown font family.
if (rtfFontFamily.Contains(_font.FontFamily.Name))
_fontTable.Append(rtfFontFamily[_font.FontFamily.Name]);
else
_fontTable.Append(rtfFontFamily[FF_UNKNOWN]);
// \fcharset specifies the character set of a font in the font table.
// 0 is for ANSI.
_fontTable.Append(@"\fcharset0 ");
// Append the name of the font
_fontTable.Append(_font.Name);
// Close control string
_fontTable.Append(@";}}");
return _fontTable.ToString();
}
/// <summary>
/// Creates a font table from the RtfColor structure. When an Insert or Append
/// operation is performed, _textColor and _backColor are either specified
/// or the default is used. In any case, on any Insert or Append, only three
/// colors are used. The default color of the RichTextBox (signified by a
/// semicolon (;) without a definition), is always the first color (index 0) in
/// the color table. The second color is always the text color, and the third
/// is always the highlight color (color behind the text). The color table
/// should have the form ...
///
/// {\colortbl ;[TEXT_COLOR];[HIGHLIGHT_COLOR];}
///
/// </summary>
/// <param name="_textColor"></param>
/// <param name="_backColor"></param>
/// <returns></returns>
private string GetColorTable(RtfColor _textColor, RtfColor _backColor) {
StringBuilder _colorTable = new StringBuilder();
// Append color table control string and default font (;)
_colorTable.Append(@"{\colortbl ;");
// Append the text color
_colorTable.Append(rtfColor[_textColor]);
_colorTable.Append(@";");
// Append the highlight color
_colorTable.Append(rtfColor[_backColor]);
_colorTable.Append(@";}\n");
return _colorTable.ToString();
}
/// <summary>
/// Called by overrided RichTextBox.Rtf accessor.
/// Removes the null character from the RTF. This is residue from developing
/// the control for a specific instant messaging protocol and can be ommitted.
/// </summary>
/// <param name="_originalRtf"></param>
/// <returns>RTF without null character</returns>
private string RemoveBadChars(string _originalRtf) {
return _originalRtf.Replace("\0", "");
}
#endregion
}
}
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