{ ##
@FILE URTFUtils.pas
@COMMENTS Utility functions used when processing RTF.
@PROJECT_NAME CodeSnip
@PROJECT_DESC Offline viewer for routines from the online
DelphiDabbler CodeSnip database.
@DEPENDENCIES None
@HISTORY(
@REVISION(
@VERSION 0.1
@DATE 17/03/2005
@COMMENTS Original version.
)
@REVISION(
@VERSION 1.0
@DATE 24/05/2006
@COMMENTS + Improved and corrected comments.
+ Removed unused unit references.
)
@REVISION(
@VERSION 1.1
@DATE 29/10/2006
@COMMENTS Fixed bug in RTFLoadFromString where long documents
were not displaying correctly. Set max length of RTF
control to length of loaded document.
)
@REVISION(
@VERSION 1.2
@DATE 07/11/2006
@COMMENTS + Added various routines to create RTF controls.
+ Renamed MakeSafeRTFText() as RTFMakeSafeText().
)
@REVISION(
@VERSION 1.3
@DATE 11/11/2006
@COMMENTS Added new IsValidRTFCode() routine.
)
@REVISION(
@VERSION 1.4
@DATE 02/07/2007
@COMMENTS Added support for new \info and \title control
words.
)
@REVISION(
@VERSION 1.5
@DATE 05/09/2007
@COMMENTS + Added new RTFInsertString routine and supporting
private routines.
+ Added new RTFSaveToStream routine.
+ Added new RTFLoadFromStream routine.
+ Added support for new \sa and \sb RTF control
words.
)
)
}
{
* ***** BEGIN LICENSE BLOCK *****
*
* Version: MPL 1.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License for
* the specific language governing rights and limitations under the License.
*
* The Original Code is URTFUtils.pas
*
* The Initial Developer of the Original Code is Peter Johnson
* (http://www.delphidabbler.com/).
*
* Portions created by the Initial Developer are Copyright (C) 2005-2007 Peter
* Johnson. All Rights Reserved.
*
* Contributor(s): None
*
* ***** END LICENSE BLOCK *****
}
unit URTFUtils;
{$WARN UNSAFE_TYPE OFF}
{$WARN UNSAFE_CAST OFF}
{$WARN UNSAFE_CODE OFF}
interface
uses
// Delphi
Classes, ComCtrls;
const
// Constants relating to RTF
cRTFVersion = 1; // RTF version
cDefCodePage = 1252; // default code paeg
cDefLanguage = 1033; // default language
type
{
TRTFControl:
Identifiers for each RTF control word supported by the program.
}
TRTFControl = (
rcRTF, // RTF version
rcAnsi, // use ANSI character set
rcAnsiCodePage, // specifies ANSI code page
rcDefFontNum, // default font number
rcDefLanguage, // default language
rcFontTable, // introduces font table
rcFontPitch, // font pitch
rcFontCharset, // font character set
rcFontFamilyNil, // unknown font family
rcFontFamilyRoman, // serif, proportional fonts
rcFontFamilySwiss, // sans-serif, proportional fonts
rcFontFamilyModern, // fixed pitch serif and sans-serif fonts
rcFontFamilyScript, // script fonts
rcFontFamilyDecor, // decorative fonts
rcFontFamilyTech, // technical, symbol and maths fonts
rcColorTable, // introduces colour table
rcRed, // defines red colour component
rcGreen, // defines gree colour component
rcBlue, // defines blue colour component
rcInfo, // introduces information group
rcTitle, // sets document title
rcPard, // resets to default paragraph format
rcPar, // begins new paragraph
rcPlain, // reset font (character) formatting properties
rcFontNum, // font number (index to font table)
rcForeColorNum, // foreground colour number (index to colour table)
rcBold, // sets or toggles bold style
rcItalic, // sets or toggles italic style
rcUnderline, // sets or toggles underline style
rcFontSize, // font size in 1/2 points
rcSpaceBefore, // space before paragraphs in twips
rcSpaceAfter // space after paragraph in twips
);
function IsValidRTFCode(const Content: string): Boolean;
{Checks if document content is valid rich text code.
@param Content [in] Document content to be checked.
@return True if valid rich text.
}
function RTFControl(const Ctrl: TRTFControl): string; overload;
{Creates a parameterless RTF control word.
@param Ctrl [in] Id of required control word.
@return RTF control.
}
function RTFControl(const Ctrl: TRTFControl; const Param: Integer): string;
overload;
{Creates an RTF control word with parameter.
@param Ctrl [in] Id of required control word.
@param Param [in] Required parameter.
@return RTF control.
}
function RTFEscape(const Ch: AnsiChar): string;
{Creates RTF escape sequence for a character.
@param Ch [in] Character to escape.
@return Escape sequence.
}
function RTFHexEscape(const Ch: AnsiChar): string;
{Creates RTF hexadecimal escape sequence for a character.
@param Ch [in] Character to escape.
@return Escape sequence.
}
function RTFMakeSafeText(const TheText: string): string;
{Encodes text so that any RTF-incompatible characters are replaced with
suitable control words.
@param TheText [in] Text to be encoded.
@return Encoded text.
}
procedure RTFInsertString(const RE: TRichEdit; const RTF: string);
{Inserts rich text code to current selection position in a rich edit control.
If text is selected in the control the selection is first deleted.
@param RE [in] Rich edit control in which RTF code is to be inserted.
@param RTF [in] String containing valid rich text code to be inserted.
}
procedure RTFLoadFromStream(const RE: TRichEdit; const Stream: TStream);
{Loads RTF code into an RTF control, replacing all the control's current
content.
@param RE [in] Rich edit control to receive RTF code.
@param RTF [in] Stream containing valid rich text code.
}
procedure RTFLoadFromString(const RE: TRichEdit; const RTF: string);
{Loads RTF code into an RTF control, replacing all the control's current
content.
@param RE [in] Rich edit control to receive RTF code.
@param RTF [in] String containing valid rich text code.
}
procedure RTFSaveToStream(const RE: TRichEdit; const Stream: TStream);
{Saves RTF code from rich edit control into a stream.
@param RE [in] Rich edit control whose content is to be saved.
@param Stream [in] Stream that receives rich text code.
}
implementation
uses
// Delphi
SysUtils, StrUtils, Windows, RichEdit,
// Project
UExceptions;
const
// Map of RTF control ids to control word
cControls: array[TRTFControl] of string = (
'rtf', 'ansi', 'ansicpg', 'deff', 'deflang', 'fonttbl', 'fprq', 'fcharset',
'fnil', 'froman', 'fswiss', 'fmodern', 'fscript', 'fdecor', 'ftech',
'colortbl', 'red', 'green', 'blue', 'info', 'title', 'pard', 'par', 'plain',
'f', 'cf', 'b', 'i', 'ul', 'fs', 'sb', 'sa'
);
function IsValidRTFCode(const Content: string): Boolean;
{Checks if document content is valid rich text code.
@param Content [in] Document content to be checked.
@return True if valid rich text.
}
begin
Result := AnsiStartsText('{' + RTFControl(rcRTF, 1), Content);
end;
function RTFControl(const Ctrl: TRTFControl): string;
{Creates a parameterless RTF control word.
@param Ctrl [in] Id of required control word.
@return RTF control.
}
begin
Result := '\' + cControls[Ctrl];
end;
function RTFControl(const Ctrl: TRTFControl; const Param: Integer): string;
{Creates an RTF control word with parameter.
@param Ctrl [in] Id of required control word.
@param Param [in] Required parameter.
@return RTF control.
}
begin
Result := RTFControl(Ctrl) + IntToStr(Param);
end;
function RTFEscape(const Ch: AnsiChar): string;
{Creates RTF escape sequence for a character.
@param Ch [in] Character to escape.
@return Escape sequence.
}
begin
Result := '\' + Ch;
end;
function RTFHexEscape(const Ch: AnsiChar): string;
{Creates RTF hexadecimal escape sequence for a character.
@param Ch [in] Character to escape.
@return Escape sequence.
}
begin
Result := '\''' + IntToHex(Ord(Ch), 2);
end;
function RTFMakeSafeText(const TheText: string): string;
{Encodes text so that any RTF-incompatible characters are replaced with
suitable control words.
@param TheText [in] Text to be encoded.
@return Encoded text.
}
var
I: Integer; // loops thru characters in string
Ch: AnsiChar; // character being processed
begin
Result := '';
for I := 1 to Length(TheText) do
begin
Ch := TheText[I];
case Ch of
#0..#$19, #$80..#$FF:
// Replace these chars by hex control word
Result := Result + RTFHexEscape(Ch);
'{', '\', '}':
// Escape these reserved chars
Result := Result + RTFEscape(Ch);
else
// Pass remaining chars thru unchanged
Result := Result + Ch;
end;
end;
end;
function EditStreamReader(Stream: TStream; pBuff: Pointer;
cb: LongInt; pcb: PLongInt): DWORD; stdcall;
{Callback routine used to read data from stream that is being inserted into a
rich edit control. This routine is called by rich edit control when processing
EM_STREAMIN message.
@param Stream [in] Reference to TStream being read. (Actual param is
supposed to be DWORD, but we cast to TStream).
@param pBuff [in] Pointer to buffer to receive data read from stream.
@param cb [in] Number of bytes requested to be read.
@param pcb [in] Pointer to variable to receive number of bytes actually
read from stream.
@return Success / error code. 0 indicates succcess. None-zero indicates an
error condition.
}
begin
// Assume no error
Result := $0000;
try
// Read required data from stream, recording bytes actually read
pcb^ := Stream.Read(pBuff^, cb);
except
// Indicates error to calling routine
Result := $FFFF;
end;
end;
procedure RTFInsertStream(const RE: TRichEdit; const Stream: TStream);
{Inserts a stream of rich text code to current selection position in a rich
edit control. If text is selected in the control the selection is first
deleted.
@param RE [in] Rich edit control in which RTF code is to be inserted.
@param Stream [in] Stream containing valid rich text code to be inserted.
}
const
// Flags used in EM_STREAMIN message call
cFlags = SFF_SELECTION or SF_RTF or SFF_PLAINRTF;
// Bug error message ** do not localise
cStreamErrMsg = 'RTFInsertStream: Error inserting stream';
var
EditStream: TEditStream; // defines callback used to read inserted RTF
begin
RE.Lines.BeginUpdate;
try
// Make sure rich edit control size is large enough to take inserted code
RE.MaxLength := RE.MaxLength + Stream.Size;
// Stream in the RTF via EM_STREAMIN message
EditStream.dwCookie := DWORD(Stream);
EditStream.dwError := $0000;
EditStream.pfnCallback := @EditStreamReader;
RE.Perform(EM_STREAMIN, cFlags, LPARAM(@EditStream));
// Report any errors as a bug
if EditStream.dwError <> $0000 then
raise EBug.Create(cStreamErrMsg);
finally
RE.Lines.EndUpdate;
end;
end;
procedure RTFInsertString(const RE: TRichEdit; const RTF: string);
{Inserts rich text code to current selection position in a rich edit control.
If text is selected in the control the selection is first deleted.
@param RE [in] Rich edit control in which RTF code is to be inserted.
@param RTF [in] String containing valid rich text code to be inserted.
}
var
Stm: TStringStream; // stream onto RTF code string
begin
Stm := TStringStream.Create(RTF);
try
RTFInsertStream(RE, Stm);
finally
Stm.Free;
end;
end;
procedure RTFLoadFromStream(const RE: TRichEdit; const Stream: TStream);
{Loads RTF code into an RTF control, replacing all the control's current
content.
@param RE [in] Rich edit control to receive RTF code.
@param RTF [in] Stream containing valid rich text code.
}
begin
RE.PlainText := False;
RE.MaxLength := Stream.Size; // long docs may not display if MaxLength not set
RE.Lines.LoadFromStream(Stream);
end;
procedure RTFLoadFromString(const RE: TRichEdit; const RTF: string);
{Loads RTF code into an RTF control, replacing all the control's current
content.
@param RE [in] Rich edit control to receive RTF code.
@param RTF [in] String containing valid rich text code.
}
var
Stm: TStringStream; // stream onto RTF code
begin
// Load stream containing RTF code into control
Stm := TStringStream.Create(RTF);
try
RTFLoadFromStream(RE, Stm);
finally
Stm.Free;
end;
end;
procedure RTFSaveToStream(const RE: TRichEdit; const Stream: TStream);
{Saves RTF code from rich edit control into a stream.
@param RE [in] Rich edit control whose content is to be saved.
@param Stream [in] Stream that receives rich text code.
}
begin
RE.Lines.SaveToStream(Stream);
end;
end.
