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Issue 55
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Pascal Newsletter #55 - 30-JUNE-2005 Contents 1. A Few Words From the Editors 2. How to Extract Version Information Using the Windows API 3. Convert BMP to *Any Format* (.NET) 4. Tidy Up Your Temporary Files 5. Universal Embedding of Files in Delphi Units 6. Forums / Mailing Lists 7. Delphi on the Net - Components, Libraries and Utilities - Shareware / Commercial - Freeware - Borland Product Updates - Articles, Tips and Tricks - Tutorials and Training - News - Other / Misc Sites ________________________________________________________________________ 1. A Few Words From the Editors I'd like to thank the authors who contributed articles to this issue: Peter Johnson, Eber Irigoyen, John Lavelle and Max Kleiner. And, I'm pleased to award the following prizes: * John Lavelle - 'Tidy Up Your Temporary Files' KnowledgeBase Expedition 4.2 - by Delphinium Software ($49.35) KnowledgeBASE Expedition features a highly searchable and expandable information tree viewed in outline or audited within a built-in wordprocessor. Includes a database for stored references. http://www.download.com/3000-2064_4-10239072.html * Eber Irigoyen - 'Convert BMP to *Any Format* (.NET)' YAPI Professional - by Owen Mooney ($95) Offers the easiest and yet powerful printing from Delphi. It provides: WYSIWYG setup, print preview, Non database, Database, text, Grids, tabs, bitmaps, TCanvas operation, precise positioning or free flow positioning - all using simple "writeln" statements. http://free.hostdepartment.com/o/owenmooney/ Special thanks to Delphinium Software and Owen Mooney for donating the prizes for this and future issues. Issue #56 will be published in August if I get enough articles so if you've got an idea, start writing! Now, on with the code... Regards, Dave Murray pascal-newsletter-owner@yahoogroups.com ________________________________________________________________________ Help & Manual 3.50 by EC Software - Shareware ($ 299) - Help & Manual is a WYSIWYG help authoring tool that will aid you in creating standard WinHelp files (.HLP), Adobe PDF files, HTML pages and the new HTML HELP (.CHM) files introduced in Windows 98, as well as other file formats and printed documentation, everything from a single source. This is a must- have for any software developer. http://www.helpandmanual.com/hmpage.htm ________________________________________________________________________ 2. How to Extract Version Information Using the Windows API By Peter Johnson, Copyright (c) 2005 <delphidabbler at tiscali dot co dot uk> http://www.delphidabbler.com/ Introduction ============ The Windows API provides a method to extract version information from an executable file. The API is rather arcane and some knowledge of how version information is stored in an executable file is helpful. This article starts with a brief overview of how version information is laid out in a file. It then goes on to develop some code that tests whether version information is present and extracts it if so. We then wrap the code up in a class before finally looking at some of the limitations of the approach we have taken. Version Information Overview ============================ Version information is stored in an executable file's resources. The binary format of this data is complex and is not described here. Conceptually though, version information contains a record that provides a machine-readable binary description of a file (fixed file information) and one or more string tables that provide human-readable information. String tables can be localised - so there can be a string table for each supported language or code page. Because of this, version information also contains a table of supported languages / code pages (the translation table) that effectively provides an index into the string tables. Although version information supports multiple languages it is rare to find executables that take advantage of this - version information usually contains only one string table. Unlike most of the code available on the net ours will handle multiple string tables. Reflecting the organisation discussed above, version information is structured in three main parts: * Fixed file information This is a data structure that contains binary information about the executable file. Windows declares this structure as VS_FIXEDFILEINFO and the Delphi equivalent is TVSFixedFileInfo, defined as follows: type tagVS_FIXEDFILEINFO = packed record dwSignature: DWORD; // always $feef04bd dwStrucVersion: DWORD; // version of structure dwFileVersionMS: DWORD; // most significant file version dwFileVersionLS: DWORD; // least significant file version dwProductVersionMS: DWORD; // most significant product version dwProductVersionLS: DWORD; // last significant product version dwFileFlagsMask: DWORD; // masks valid flags in dwFileFlags dwFileFlags: DWORD; // bit mask of attributes of file dwFileOS: DWORD; // flags describing target OS dwFileType: DWORD; // flag describing type of file dwFileSubtype: DWORD; // sub type for file: keyboard driver dwFileDateMS: DWORD; // most significant part of file date dwFileDateLS: DWORD; // least significant part of date end; TVSFixedFileInfo = tagVS_FIXEDFILEINFO; The fields of this record are described in depth in the Windows help file so we won't discuss further here. * Variable file information According to the Windows documentation this section can be user-defined. However, in practise it always contains a table of "translation" information. Each entry in the table is a pair of language and character set identifiers that together provide a key used to specify a string table. We can define an entry in this table with the following record (not defined by Windows): type TTransRec = packed record Lang, // language code CharSet: Word; // character set (code page) end; * String file information This section stores a string table for each "translation" listed in the variable file information section. The entries in string tables are name / value pairs - i.e. the string values are accessed by specifying a string name. Windows defines several standard names: o Comments o CompanyName o FileDescription o FileVersion o InternalName o LegalCopyright o LegalTrademarks o OriginalFilename o PrivateBuild o ProductName o ProductVersion o SpecialBuild The intended purpose and restrictions on use of these names are set out in the Windows API help file under the VERSIONINFO resource topic. User defined names are also permitted. These different sections of the resource are accessed using an addressing system that is similar to a file path. The "paths" are: * "\" - i.e. the "root" path Accesses fixed file information. * "\VarFileInfo\Translation" Accesses the "translation" table. The table is a sequence of TTransRec records. * "\StringFileInfo\<translation-code>\<string-name>" Accesses a named entry in a given string table. <translation-code> is made up of the hexadecimal representation of the translation's language code and character set code. Unsurprisngly <string-name> is the name of the desired string value. For example to access the "ProductName" string in the string table associated with translation "040904E4" the "path" is "\StringFileInfo\040904E4\ProductName". This all looks rather horrendous - and if you write code to access the raw version information binary it is. However the Windows API provides three functions that assist in extracting the code. In the next section we'll review the API calls and write some Delphi wrappers to make them easier to use before finally developing our version information class. Writing The Code ================ Windows API Functions --------------------- Windows provides the following functions to use to access version information. * GetFileVersionInfoSize function GetFileVersionInfoSize(lptstrFilename: PChar; var lpdwHandle: DWORD): DWORD; stdcall; This function returns the size of the given executable file's version information. It returns 0 if there is no version information present. We have to pass a dummy variable as lpdwHandle - the function just sets it to 0! * GetFileVersionInfo function GetFileVersionInfo(lptstrFilename: PChar; dwHandle, dwLen: DWORD; lpData: Pointer): BOOL; stdcall; Once we know the size of the version information we have to create a buffer the same size and then call this function to copy the version information from the executable file into the buffer. We pass the name of the file, a dummy 0 value to dwHandle, followed by the size of the buffer and the buffer pointer itself. The function returns true on success and false on failure. * VerQueryValue function VerQueryValue(pBlock: Pointer; lpSubBlock: PChar; var lplpBuffer: Pointer; var puLen: UINT): BOOL; stdcall; This function is used to read data from the version information buffer we filled using GetFileVersionInfo. We pass the buffer as the first parameter. The next parameter takes a pointer to the "path" that specifies the information we need (as described above). The function sets the pointer variable passed as lplpBuffer to point to the requested data. puLen is set to the length of the data. The function returns true on success and false on failure. If the function fails lplpBuffer has an indeterminate value and can cause a GPF if read. A full description of these functions can be read in the Windows API help. As can be seen the calls we need to make are complex and require a lot of pointer manipulation. In the next section we hide some of this complexity in wrapper routines. Delphi Wrapper Routines ----------------------- Let us now define some wrapper functions that (a) hide the API routines and (b) give easy access to the fixed file information, string values and translation table. We will create five routines: 1. GetVerInfoSize - a thin wrapper round the GetFileVersionInfoSize API function 2. GetVerInfo - a thin wrapper round the GetFileVersionInfo API function 3. GetFFI - gets the fixed file information from the version information buffer using VerQueryValue 4. GetTransTable - uses VerQueryValue to get and return the translation table as a dynamic array of TTransRec records 5. GetVerInfoStr - returns the value of a string table entry using VerQueryValue Here is a description of the five routines: * GetVerInfoSize function GetVerInfoSize(const FileName: string): Integer; var Dummy: DWORD; // Dummy handle parameter begin Result := GetFileVersionInfoSize(PChar(FileName), Dummy); end; This function is a thin wrapper round the GetFileVersionInfoSize API routine - it simply prevents us from having to provide the dummy parameter that routine requires. * GetVerInfo procedure GetVerInfo(const FileName: string; const Size: Integer; const Buffer: Pointer); begin if not GetFileVersionInfo(PChar(FileName), 0, Size, Buffer) then raise Exception.Create('Can''t load version information'); end; This is a thin wrapper that calls the GetFileVersionInfo API function and raises an exception if the call fails. * GetFFI function GetFFI(const Buffer: Pointer): TVSFixedFileInfo; var Size: DWORD; // Size of fixed file info read Ptr: Pointer; // Pointer to FFI data begin // Read the fixed file info if not VerQueryValue(Buffer, '\', Ptr, Size) then raise Exception.Create('Can''t read fixed file information'); // Check that data read is correct size if Size <> SizeOf(TVSFixedFileInfo) then raise Exception.Create('Fixed file information record wrong size'); Result := PVSFixedFileInfo(Ptr)^; end; GetFFI gets fixed file information from the version information data. We call VerQueryValue with a "path" of "\". and then check if the call succeeds and that the returned data is the correct size. * GetTransTable type TTransRec = packed record Lang, // language code CharSet: Word; // character set (code page) end; PTransRec = ^TTransRec; // pointer to TTransRec TTransRecArray = array of TTransRec; // translation table function GetTransTable(const Buffer: Pointer): TTransRecArray; var TransRec: PTransRec; // pointer to a translation record Size: DWORD; // size of data read RecCount: Integer; // number of translation records Idx: Integer; // loops thru translation records begin // Read translation data VerQueryValue( Buffer, '\VarFileInfo\Translation', Pointer(TransRec), Size ); // Get record count and set length of array RecCount := Size div SizeOf(TTransRec); SetLength(Result, RecCount); // Loop thru table storing records in array for Idx := 0 to Pred(RecCount) do begin Result[Idx] := TransRec^; Inc(TransRec); end; end; This routine fetches the translation table from the version information. It gets the raw data using VarFileInfo then calculates the number of translation records by dividing the size of the raw data by the size of a translation record. We then size the dynamic array appropriately and copy each record into the array. We also need to define the TTransRec, PTransRec and TTransRecArray types required by the routine. * GetVerInfoStr function GetVerInfoStr(const Buffer: Pointer; const Trans, StrName: string): string; var Value: PChar; // the string value data Dummy: DWORD; // size of value data (unused) Path: string; // "path" to string value begin // Build "path" from translation and string name Path := '\StringFileInfo\' + Trans + '\' + StrName; // Read the string: return '' if string doesn't exist if VerQueryValue(Buffer, PChar(Path), Pointer(Data), Dummy) then Result := Data else Result := ''; end; This function returns the value of given string from the string table associated with a given translation. We build the "path" needed to access the string value and use VerQueryValue to get the string value. If the string exists we return the data, cast to a string. Otherwise we return the empty string. The demo program accompanying this article shows how to use these routines. The next step is to encapsulate the whole process in a class. Object Oriented Solution ======================== The class we will develop is rather simple but has all the needed functionality. It can detect whether a file contains version information and can extract fixed file information, the translation table and strings from one or more string table. Here's the class declaration: type TVerInfo = class(TObject) private fFixedFileInfo: TVSFixedFileInfo;// fixed file info record fTransTable: TTransRecArray; // translation table fHasVerInfo: Boolean; // whether file contains ver info fVerInfo: Pointer; // buffer storing ver info function GetString(const Trans, Name: string): string; function GetTranslation(Idx: Integer): string; function GetTranslationCount: Integer; public constructor Create(const FileName: string); destructor Destroy; override; property HasVerInfo: Boolean read fHasVerInfo; property FixedFileInfo: TVSFixedFileInfo read fFixedFileInfo; property Translations[Idx: Integer]: string read GetTranslation; property TranslationCount: Integer read GetTranslationCount; property Strings[const Trans,Name: string]: string read GetString; end; The constructor receives the name of the file to be examined. The HasVerInfo property is true if the file contains version information. The FixedFileInfo property contains a copy of the fixed file info record. TranslationCount records the number of translations in the file while Translations is a zero based array of string values corresponding to the translations. These values are used to specify which string table the Strings property uses to get a specified string value. Internally we store the translation table in a dynamic array of TTransRec records. Both the translation and the fixed file information are recorded when the class is created. String file information is read from version information as values are requested from the Strings property. Most of the work is done in the constructor - and we use the routines developed above to simplify the code. So, let us start by looking at the constructor: constructor TVerInfo.Create(const FileName: string); var BufSize: Integer; // size of ver info buffer begin inherited Create; // Get size of buffer: no ver info if size = 0 BufSize := GetVerInfoSize(FileName); fHasVerInfo := BufSize > 0; if fHasVerInfo then begin // Read ver info into buffer GetMem(fVerInfo, BufSize); GetVerInfo(FileName, BufSize, fVerInfo); // Read fixed file info and translation table fFixedFileInfo := GetFFI(fVerInfo); fTransTable := GetTransTable(fVerInfo); end; end; We first use GetVerInfoSize to find the size of the version information data. We set the HasVerInfo property to record if there is version information (by checking the size of the data), and if there is none, we skip the rest of the code. If we do have version information we allocate a buffer to hold it then load the version information from the file using the GetVerInfo routine. We next use the GetFFI and GetTransTable routines to store the fixed file information and translation table in fields. The destructor is very simple: we just free the version info buffer: destructor TVerInfo.Destroy; begin // Free ver info buffer FreeMem(fVerInfo); inherited; end; We'll look at the GetTranslation method next. This simple method returns a string representation of the translation at a given index in the table. The string representation is simply the concatenation of the translation's language code and character set / code page code in hexadecimal: function TVerInfo.GetTranslation(Idx: Integer): string; begin Assert(fHasVerInfo); Assert((Idx >= 0) and (Idx < fTranslationCount)); // Return string representation of translation at given index Result := Format( '%4.4x%4.4x', [fTransTable[Idx].Lang, fTransTable[Idx].CharSet] ); end; The GetTranslationCount method simply returns the size of the dynamic array that stores the translation table: function TVerInfo.GetTranslationCount: Integer; begin Result := Length(fTransTable); end; This leaves just the GetString method. Most of the work is done by the GetVerInfoStr routine. We simply check we have version information and then return the result of calling GetVerInfoStr. function TVerInfo.GetString(const Trans, Name: string): string; begin Assert(fHasVerInfo); Result := GetVerInfoStr(fVerInfo, Trans, Name); end; That's the class completed. Again this can be tested using the demo code. Demo Code ========= Some demo code is included in the newsletter's source code archive. It includes the class, types and routines presented here, along with a test program that exercises them. The demo program can load version information from one of four supplied executables. One of these is the demo program itself while the others are do-nothing console programs whose sole purpose is to have their version information checked by the demo. The example programs contain various different configurations of version information as follows: * the demo program has a single translation / string table * one console program has two translations / string tables * another has no translations (just fixed file information) * the last has no version information at all For a more comprehensive solution to the problem of extracting version information see my Version Information Component available from http://www.delphidabbler.com/software.php?id=verinfo Limitations =========== While the solution presented here works well in the majority of cases, it is by no means perfect. There are two major shortcomings: 1. While standard and non-standard string information can be accessed, the user must know in advance what non-standard string names are present in the version information. The code cannot enumerate the string names. This can't be done using the official API and much more advanced methods are required. My Version Information Spy program can enumerate the strings in a string table. If you need to do this please examine this program's source code, available from: http://www.delphidabbler.com/software.php?id=vis 2. Several programs contain version information that does not follow the Microsoft guidelines - i.e. the structure of the binary version information is non-standard. The API functions can fail on some of these programs. Again the source to Version Information Spy illustrates how to get round this problem by partially ignoring the API and parsing the binary data directly. Summary ======= In this article we have reviewed how Windows handles version information and makes it accessible to programmers via the API. We noted that the API is rather cumbersome and so went on to develop wrapper routines to hide some of the complexity. We then wrote a class that encapsulates the version information and provides a simpler interface for the developer. A demo program was provided that implements and tests the code. Finally we reviewed some of the limitations of the code. I hope the article has been useful. If you have any comments or suggestions please contact me via my website at: http://www.delphidabbler.com/ __________________ Peter Johnson is a hobbyist programmer living in West Wales (UK) who maintains the DelphiDabbler website (http://www.delphidabbler.com/) where his articles and freeware Delphi applications & components are published. The code for this article is also available at: http://www.delphidabbler.com/download.php?file=article-20-demo.zip ________________________________________________________________________ Vote for the Pascal Newsletter in The Borland Top 100! http://top100borland.com/in.php?who=20 ________________________________________________________________________ 3. Convert BMP to *Any Format* (.NET) By Eber Irigoyen Originally published on delphi3000.com as article 4219: http://www.delphi3000.com/articles/article_4219.asp Question / Problem / Abstract: ============================== When working in Delphi.NET you pretty much have to re-learn the VCL, (FCL) to accomplish every single task. There is tons of code for Win32 to convert images to / from other formats, here I show you how to convert an Image from BMP to any format (JPG, PNG, GIF, etc) in .NET. Answer: ======= The FCL provides methods to do many image manipulation tricks, you just have to know where to find them. This function will do the job for you: procedure TWinForm3.Bmp2AnyFormat(theBmp:Bitmap; const FileName:string; const ImgFormat:ImageFormat); var fs:FileStream; begin fs:=FileStream.Create(FileName, FileMode.CreateNew); try try theBmp.Save(fs, ImgFormat); except on E:Exception do raise Exception.Create('Error converting image: '+E.Message); end finally fs.Close end end; The Bitmap class comes from: System.Drawing.Imaging The FileStream comes from: System.IO So you'll need those namespaces in your uses clause. Now an example of use. Say you have a PictureBox with a .BMP in it on your form, and you wanted to save that as a jpeg... You need some code to load a bmp at runtime: procedure TWinForm3.TWinForm3_Load(sender: System.Object; e: System.EventArgs); begin PictureBox1.Image:=Image.FromFile('c:\SomeFile.bmp'); end; Then a button to convert the image (to JPEG) using the function: procedure TWinForm3.Button1_Click(sender: System.Object; e: System.EventArgs); begin Bmp2AnyFormat(Bitmap(PictureBox1.Image),'f:\new.jpg',ImageFormat.Jpeg) end; To get any image format you want, you can use ImageFormat.Tiff ImageFormat.Gif ImageFormat.Png ImageFormat.Jpeg etc... That's it, as you can see, is really easy. The hard part is to find which class does what. ________________________________________________________________________ InstallAWARE 2005 - by InstallAWARE Software Corporation ($69-$899) What sets InstallAWARE apart from the competition is how it goes about building an MSI. The graphical choices such as adding files and registry entries are provided as most tools offer. However, when you switch to the "script view" you do not see a list of sequences and actions, but an easy to read (and manipulate) script that spells out each action to be taken by the MSI and under what condition. When everything is just as you wish, InstallAWARE builds a fully compliant Windows Installer setup requiring no scripting runtimes or distributable. Special limited offer: 33% off all editions, Studio only $559.95! Order any cross-grade edition for a 33% discount on purchase price. >>>> http://www.installaware.com/buy.asp <<<< ________________________________________________________________________ 4. Tidy up your Temporary Files By John Lavelle <john at jql dot co dot uk> http://www.jql.co.uk/ Originally published on delphi3000.com as article 4315: http://www.delphi3000.com/articles/article_4315.asp Question / Problem / Abstract: ============================== Don't you just hate it when programs leave Temporary Files all over the place and don't clean up after themselves? Here's a class that will create unique Temporary Files in your temporary directory and clean up after itself. Answer: ======= Introduction ------------ Every so often there is a requirement to store information in Temporary Files either because there is an automatic backup feature in your program or because of some processing on the file. In virtually all cases you want your program to delete the temporary file when it closes and/or offer the user the chance to save their work. If some other program crashes the computer, you also need to be able to offer the user a chance to recover their work. With all this in mind I wrote a small class to look after my Temporary Files. The class needed to do the following: - Find the user's temporary directory - Create a unique temporary file - Store the name of the temporary file in case of a system crash - Delete the temporary file either when the program had finished with it or when the program terminated A Little History ---------------- From the early days of DOS, environment variables have been available and one of the most common ones was the TMP, or TEMP, environment variable. Until Windows 95 came along, this variable had to be set in DOS usually in the AUTOEXEC.BAT file but it could also be changed on the command line using the SET command (SET TEMP=C:\TEMP). If the TEMP variable was not set then it usually defaulted to C:\. With the advent of Windows 98, Microsoft changed the default value of the TEMP and TMP environment variable to C:\WINDOWS\TEMP, but you are still able to alter the location of the TEMP directory. If you are using profiles, then the location of the TEMP directory could be in your profile directory or, on rare occasions, on a network drive. Thankfully, when Microsoft produced Windows 3.x, they also included an API call to create unique Temporary Files, but it wasn't until Windows 95 came along that Microsoft included an API call to easily locate the user's TEMP directory. Class Structure --------------- You need two private string variables, FTempDir and FTempFileName, to hold the Temporary directory path and the Temporary File Name respectively. The full class declaration is as follows: type TTempFile = class private FTempDir: String; FTempFileName: String; procedure SetTempDir; procedure SetTempFileName; procedure SetINI(const INIValue: string); public constructor Create; destructor Destroy; override; function TempFileName: string; function TempDir: string; procedure DelTempFile; end; SetTempDir and SetTempFileName call the Windows API functions GetTempPath and GetTempFileName. These two functions do most of the work. I'll deal with these two functions one at a time. The Two Windows API Functions ----------------------------- GetTempDir - The full Windows API declaration for this function is: DWORD GetTempPath( DWORD nBufferLength, LPTSTR lpBuffer); nBufferLength specifies the size, in characters, of the string buffer identified by lpBuffer. You set lpBuffer to MAX_PATH in length and nBufferLength to MAX_PATH. lpBuffer points to a string buffer that receives the null-terminated string specifying the temporary file path - in our case the private string variable FTempDir. Because GetTempPath returns the length (excluding the null-terminator) of the string copied to FTempDir it can be used to size itself. This makes the SetTempDir procedure, to all intents and purposes, just two lines of code (note the typecasting of FTempDir as a PChar). procedure TTempFile.SetTempDir; begin { Set the length of FTempDir to the maximum Path length } SetLength(FTempDir, MAX_PATH); { Get the TEMP directory and resize FTempDir to the length of the path returned} SetLength(FTempDir, GetTempPath(MAX_PATH, PChar(FTempDir))); end; Now that you have the location of the TEMP directory you can create a unique Temporary File in it. This is done with GetTempFileName, which is declared in the Windows API as follows: UINT GetTempFileName( LPCTSTR lpPathName, LPCTSTR lpPrefixString, UINT uUnique, LPTSTR lpTempFileName); As you can see this function is a little more complex, so I'll run through each of the parameters: lpPathName points to a null-terminated string that specifies the directory path for the filename. Use the result of the GetTempPath function for this parameter. If this parameter is NULL, the function fails. lpPrefixString points to a null-terminated prefix string. The function uses the first three characters of this string as the prefix of the filename. I used to use my initials JQL but users could identify the file as coming from my programs and were opening them, or deleting them while they were still in use causing one or two "unforeseen problems". Therefore, I now use TMP as the prefix and the users tend to leave the files alone. Note the file extension is always .TMP. uUnique specifies an unsigned integer that the function converts to a hexadecimal string for use in creating the temporary filename. If uUnique is zero, which in our case it is, the function uses a hexadecimal string derived from the current system time. The function uses different values until it finds a unique filename, and then it creates the file in the lpPathName directory. If uUnique is not zero, the function adds the hexadecimal string to lpPrefixString to form the temporary filename. In this case, the function does not create the specified file, and does not test whether the filename is unique. lpTempFileName points to the buffer that receives the temporary filename. This buffer should be at least the length, in bytes, specified by MAX_PATH to accommodate the path. GetTempFileName returns the unique numeric value used in the temporary filename, or zero if it fails, therefore we need to manually trim FTempFileName to the correct length, which we do by searching for the null-terminator (#0). The full SetTempFileName procedure is as follows: procedure TTempFile.SetTempFileName; begin { Set the length of FTempFileName to the maximum Path length } SetLength(FTempFileName, MAX_PATH); if GetTempFileName(PChar(TempDir), PChar('TMP'), 0, PChar(FTempFileName)) <> 0 then SetLength(FTempFileName, Pos(#0, FTempFileName)-1) else FTempFileName := ''; SetINI(FTempFileName); end; Notice that you passed the function TempDir as the directory path. Also note that if the GetTempFileName function fails FTempFileName contains a zero length string, which, if necessary, you can test for in your code. Public Functions ================ Now that you have the TEMP directory path and a unique TempFileName you need to make them available to the rest of your program, which you do by using the two public functions TempDir and TempFileName. Because it is vaguely possible the user could change the TEMP directory "on the fly" it's a good idea to check that it hasn't been altered. The TempDir function is shown below: function TTempFile.TempDir: string; begin // The value of TEMP could change so check it SetTempDir; Result := FTempDir; end; The TempFileName function checks to see if a TempFileName has been created. If it has, it returns the filename. If it hasn't, it creates one then returns it: function TTempFile.TempFileName: string; begin // If it doesn't exist - create it if FTempFileName = '' then SetTempFileName; Result := FTempFileName; end; Having created a TempFileName you also need to delete it when necessary. That is accomplished in the aptly named DelTempFile procedure. This public procedure checks to see if there is a Temporary File before trying to delete it. procedure TTempFile.DelTempFile; begin { Do we have a temporary file? } if Length(FTempFileName) > 0 then If FileExists(FTempFileName) then DeleteFile(FTempFileName); FTempFileName := ''; SetINI(FTempFileName); end; Bear in mind that when the class is Freed, it calls DelTempFile to tidy up after itself. Therefore you must only free the class when you no longer need the Temporary file. destructor TTempFile.Destroy; begin // Delete the Temporary file if it still exists DelTempFile; inherited Destroy; end; Persistence ----------- It won't have escaped your notice that SetTempFileName and DelTempFile both call the private procedure SetINI. SetINI is used in case of a catastrophic system crash to hold the TempFileName, if there is one. Your program can, on start up, test to see if a TempFileName entry exists in the INI file and, if it does, offer to recover the information. I use an INI file rather than the Registry because my Registry has reached gargantuan proportions and it is easier for the user to manually delete an INI file if necessary. The SetINI procedure creates an INI file in the application directory, with the same name as your application but with the extension '.INI'. SetINI then checks the value passed to it. If the value is an empty string it deletes the TempFileName key from the INI file otherwise it writes the TempFileName to the TempFileName key as shown below. procedure TTempFile.SetINI(const INIValue: string); var TheINIFile: TINIFile; begin TheINIFile := TINIFile.Create(ChangeFileExt(Application.ExeName, '.INI')); try with TheINIFile do begin if INIValue = '' then DeleteKey('TempFiles', 'TempFileName') else WriteString('TempFiles', 'TempFileName', INIValue); end; finally TheINIFile.Free; end; end; Remember to add INIFiles to the uses clause in interface not in implementation. In Action --------- To show the use of the TTempFile class I have incorporated it into Borland's RichEdit Demo (without the "internationalisation") to add rudimentary Auto Backup facilities to the program. In the edit menu add an item named 'miAutoBackup'. Set its caption to '&Auto Backup' and its checked property to 'True'. Add a Timer to the form and change its name from 'Timer1' to 'Timer' and set it's enabled property to 'True'. Listing 1 shows the code for the miAutoBackup OnClick event, the Timer's OnTimer event and the TMainForm.FormDestroy event. In the TMainForm.OnCreate event add the following two lines: TempFile := TTempFile.Create; Timer.Interval := 300000; // 5 minutes Change the TMainForm.FileSave procedure to include a test to see if we are backing up or saving as follows: procedure TMainForm.FileSave(Sender: TObject); begin if FFileName = sUntitled then FileSaveAs(Sender) else begin Editor.Lines.SaveToFile(FFileName); // if not backing up change the modified settings if FFileName <> TempFile.TempFileName then begin Editor.Modified := False; SetModified(False); end; end; end; Add TempFilesUnit to the uses clause in interface and TempFile: TTempFile; to the var clause. There you have it. A simple word processor with Auto Backup facilities. The source code for the TTempFile class and a demo application are included in the newsletter's archive or can be downloaded from my website. Conclusion ---------- Delphi makes it easy to use the Windows API by the easy typecasting of strings to PChars and, although Borland have translated a great deal of the Windows API functions for use in Delphi, there are still some left that are useful. The WIN32SDK.HLP file which is in the ..\PROGRAM FILES\COMMON FILES\BORLAND SHARED\MSHELP directory (or click the Windows SDK menu item) has more information on the Windows API functions. The TTempFile class, when first conceived, did not need to know how to read and write to the temporary file or how to recover data after a system crash, and I will leave it to you to decide whether you want extend the class with that functionality. __________________ John Lavelle lives on the edge of the beautiful English Lake District. John has been programming since 1981 and has been using Delphi since version 1. When he isn't programming, he is a consultant to some of the local companies, builds computers, installs networks, teaches computer skills and makes the tea ;-) ________________________________________________________________________ Vote for the Pascal Newsletter in The Delphi Top 200! http://top200.jazarsoft.com/delphi/rank.php3?id=latium ________________________________________________________________________ 5. Universal Embedding of Files in Delphi Units By Max Kleiner max@kleiner.com Kleiner Kommunikation Reference: http://max.kleiner.com/ Component Download: http://www.softwareschule.ch/download/hexer2.zip This article attempts to explain how to include files inside a Delphi unit / application as different kinds of binaries and how to manage them without using the resource technology. The app is called the Hexer works on VCL and CLX. //Update 1, 2005-05-29: Migration to Linux in one pas file //Update 2, 2005-06-05: Call the bytearray from a dll (export) You can put your files into your delphi project at design time and then just compile it to get all into one or more units. First you have to convert the file in a delphi unit by the Hexer. Then you call it from your own app which embeds the unit. You can even store waves or pictures and play it without the need to create a file, play it from memory. if not PlaySound(@UtopiaWinstarten_wav, 0, SND_MEMORY + SND_SYNC) It is possible to embed any kind of file (also executables) in an executable using the Hexer. First example is a picture: procedure TForm1.btnPicloadClick(Sender: TObject); var mybitmap: TBitmap; bitStream: TStream; begin //mybitmap.LoadFromFile('dws_logo.bmp'); for the mortals mybitmap:= TBitmap.Create; bitStream:= TMemoryStream.Create; try bitStream.Writebuffer(dws_logo_bmp, sizeof(dws_logo_bmp)); bitStream.Position:= 0; mybitmap.LoadFromStream(bitStream); if assigned(mybitmap) then begin image1.Picture.assign(mybitmap); image1.update; end; finally bitStream.Free; mybitmap.Free; end; end; Second example is an executable: procedure TForm1.btnApploadClick(Sender: TObject); var mybitmap: TBitmap; bitStream: TMemoryStream; begin mybitmap:= TBitmap.Create; bitStream:= TMemoryStream.Create; try bitStream.Writebuffer(viergewinnt_exe, sizeof(viergewinnt_exe)); bitStream.Position:= 0; bitstream.LoadFromStream(bitstream); bitstream.SaveToFile('vierg.exe'); WinExec(pchar('vierg.exe'){ + ' ' + ParamStr},SW_NORMAL); finally bitStream.Free; mybitmap.Free; end; end; How Does Hexer Work? -------------------- MainForm2.TForm1.btnConvertClick (97i) MainForm2.TForm1.ConvertToUnit (103i) MainForm2.WriteString (108i) MainForm2.EmbedFile (117i) MainForm2.WriteString (108i) We open with createFile() the unit for write down the file in the unit. The CreateFile function creates or opens objects and returns a handle that can be used to access the object. f_hndoutput:= CreateFile(PChar(ChangeFileExt(edtUnitToCreate.Text, '.pas')), GENERIC_WRITE, 0, NIL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, 0); Then we call EmbedFile which opens the file to be write down in the unit. The WriteFile function writes data to a file and is designed for both synchronous and asynchronous operation. The function starts writing data to the file at the position indicated by the file pointer. BOOL WriteFile( HANDLE hFile, // handle to file to write to LPCVOID lpBuffer, // pointer to data to write to file DWORD nNumberOfBytesToWrite, // number of bytes to write LPDWORD lpNumberOfBytesWritten, // pointer to bytes written LPOVERLAPPED lpOverlapped ); After the write operation has been completed, the file pointer is adjusted by the number of bytes actually written. f_hndopen:= CreateFile(PChar(filename), GENERIC_WRITE + GENERIC_READ, 0, NIL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0); Each time the file pointer is adjusted we write a block of abuf: array[0..19] of byte; Result:= ReadFile(f_hndopen, abuf, sizeof(abuf), BytesRead, NIL); if bytesRead > 0 then begin At least our generated unit looks like Unit dws_logo2; interface const dws_logo_bmp: array[0..21717] of byte = ( $42,$4D,$D6,$54,$00,$00,$00,$00,$00,$00,$76,$00,$00,$00,$28,$00,$00,$00, $F0,$00, $00,$00,$B4,$00,$00,$00,$01,$00,$04,$00,$00,$00,$00,$00,$60, $54,$00,$00,$C4,$0E,$00,$00,$C4,$0E,$00,$00,$00,$00,$00,$00,$00,$00,$00, $00,$00,$00,$00,$00,$00,$00, .............. Conclusion ---------- You have three possibilities to embed files: 1. Delphi3000.com articles 2606 or 4217 show the way with resources 2. Delphi3000.com article 2321 is based on TComponent and TStream with read and write 3. This article is more generic, the advantage is transparency at design time and protection at runtime of the embedded files, you can even use binaries which you control with an inline assembler format. The project Hexer and loader / player is not included in the attached source code archive due to its size. It can be downloaded from the URL at the start of this article. Update 1 - Some pointers for CLX -------------------------------- Despite the low level stuff of the WinAPI no great obstacles were found during the migration. QForms, QDialogs, QStdCtrls, QControls, QExtCtrls, Classes; A few functions had to be re-selected, for example: FileWrite writes Count bytes to the file given by Handle from the buffer specified by Buffer. Handle is a file handle returned by the FileOpen or FileCreate method. Or another approach to define the file size has to be considered: If the file is declared as a file of byte, then the record size defaults to one byte, and FileSize returns the number of bytes in the file. Update 2 - Exporting a great const from a DLL --------------------------------------------- First you declare the type of the const and second you define a wrap function around the type: library hexerdll; type Tviergewinnt_exe = array[0..88598] of byte; const viergewinnt_exe: TViergewinnt_exe = ( $4D,$5A,$00,$01,$01,$00,$00,$00,$08,$00,$10,$00,$FF,$FF,$08,$00,$00, $01,$00,$00, ............. function getArrayofByte: Tviergewinnt_exe; begin result:= viergewinnt_exe; end; exports getArrayofByte; The call of the client has the following structure: The important thing is to declare a local var of the const in our case dllexe: Tviergewinnt_exe; unit playmain; // examples to call the embedded file in the unit or the dll ........ type Tviergewinnt_exe = array[0..88598] of byte; function getArrayofByte: Tviergewinnt_exe; external 'hexerdll'; procedure TForm1.btnApploadClick(Sender: TObject); var bitStream: TMemoryStream; dllexe: Tviergewinnt_exe; begin bitStream:= TMemoryStream.Create; //getArrayofByte dllexe:= getArrayofByte; try // import DLL const bitStream.Writebuffer(dllexe, sizeof(dllexe)); bitStream.Position:= 0; bitstream.LoadFromStream(bitstream); bitstream.SaveToFile('viergewinnt.exe'); case WinExec(PChar('viergewinnt.exe'), SW_SHOWDEFAULT) of 0: ShowMessage('The system is out of memory or resources.'); ERROR_BAD_FORMAT: ShowMessage('The .EXE file is invalid.'); ERROR_FILE_NOT_FOUND: ShowMessage('The specified file was not found.'); ERROR_PATH_NOT_FOUND: ShowMessage('The specified path was not found.'); end; finally bitstream.Free; end; end; ________________________________________________________________________ KnowledgeBase Expedition 4.2 - by Delphinium Software ($49.35) KnowledgeBASE Expedition features a highly searchable and expandable information tree viewed in outline or audited within a built-in wordprocessor. Includes a database for stored references. http://www.download.com/3000-2064_4-10239072.html ________________________________________________________________________ 6. Forums / Mailing Lists To join any of our forums, the best way is to subscribe from the web, since then you'll be able to access the website features (message archive, files section, etc). A Yahoo! ID is required for that, and you can get yours free by registering as a Yahoo! user, but you can also subscribe by email (you'll only have email access). * Delphi-En: A unique forum for intermediate-level Delphi programmers. A large group with a helpful community of members. If you are a beginner please stay as a listener and learn from others' questions and answers. Home Page: http://groups.yahoo.com/group/delphi-en/ Subscription: http://groups.yahoo.com/group/delphi-en/join delphi-en-subscribe@yahoogroups.com * Kylix: Kylix programming. Home Page: http://groups.yahoo.com/group/KylixGroup/ Subscription: http://groups.yahoo.com/group/KylixGroup/join KylixGroup-subscribe@yahoogroups.com * Components: This is a forum for searching / recommending software components (VCL and CLX components, ActiveX objects, DLL libraries, .Net, etc.), as well as utilities, tutorials, information, etc. Home Page: http://groups.yahoo.com/group/components/ Subscription: http://groups.yahoo.com/group/components/join components-subscribe@yahoogroups.com * Software Developers: A place for subjects related to software development and the industry. For developers to share their experiences as an academic, professional or hobbyist. It is not a programming forum, messages here are supposed to be more general or language independent. Home Page: http://groups.yahoo.com/group/software-developers/ Subscription: http://groups.yahoo.com/group/software-developers/join software-developers-subscribe@yahoogroups.com ________________________________________________________________________ Vote for the Pascal Newsletter in The Delphi Resource Center! http://news.optimax.com/delphi/links/links.exe/click?id=70C517ECAE6E ________________________________________________________________________ 7. Delphi on the Net By Dave Murray <irongut at vodafone dot net> Components, Libraries and Utilities =================================== Shareware / Commercial ---------------------- * KnowledgeBase Expedition 4.2 - by Delphinium Software ($49.35) KnowledgeBASE Expedition features a highly searchable and expandable information tree viewed in outline or audited within a built-in wordprocessor. Includes a database for stored references. http://www.download.com/3000-2064_4-10239072.html Freeware -------- * AnyDAC v1.0.5 - by Dmitry Arefiev A multi DBMS, high-speed, flexible data access framework for Delphi with a multi-layered, plugable architecture. DBMS supported natively are: Oracle v8.0.3 and higher; MySQL v3.23 and higher; MSSQL 2000 and higher; MSAccess 2000 and higher; IBM DB2 UDB v8 and higher; Sybase ASA v8 and higher. AnyDAC was optimized for these databases but also supports generic data sources through dbExpress and ODBC drivers. http://www.da-soft.com/ * BackgroundWorker v1.0 - by Mauro Venturini (with source) Windows Forms applications often require some sort of asynchronous invocation option. .NET 2.0 provides the BackgroundWorker component to facilitate easy asynchronous invocation with Windows Forms. This is a Delphi.NET BackgroundWorker component implementation for .NET 1.1. http://www.torry.net/net/system/threads/BackgroundWorker.zip * GDI Plus Controls v1.0 - by Matt Harrison (with source) A set of GDI+ based components for Delphi. Includes: a GDI Plus font selector; HSV/RGB Color selector with Alpha Support with Frame and Dialog implementations; a Color Panel with alpha support; a GDI+ Canvas, like a TPaintBox but GDI+ instead; a TGDIPlusWinControl to descend your own controls from. http://www.lummie.co.uk/content/view/52/42/ * THDDInfo v1.22 - by Artem Parlyuk (with source) Non-visual Delphi component providing low level information about IDE, ATAPI and SCSI (WinNT only) devices. Supports both Win9x and WinNT. Provides drive type; Model sting; Firmware revision; Serial number. For IDE also provides drive geometry (cylinders, heads, sectors); LBA sectors count; drive size (non-formatted); controller buffer size. http://artsoft.nm.ru/works.html * Inno Setup v5.1.4 - by Jordan Russell (with source) A free installer for Windows that rivals commercial installers in features and stability. Key features: All 32-bit Windows versions; Creation of a single EXE; Standard Windows 2000/XP-style interface; Customizable setup types; Complete uninstall capabilities; Integrated "deflate", bzip2, and 7-Zip LZMA file compression; Create shortcuts, registry and .INI entries.; Integrated Pascal scripting engine. http://www.jrsoftware.org/isinfo.php Borland Product Updates ----------------------- * Update 3 for Delphi 2005 Available Now Delphi 2005 Update 3 is now available to download for registered users. It resolves the modeling performance issues that affected Delphi 2005 Update 2. http://community.borland.com/article/0,1410,33069,00.html * CaliberRM Plugin for Delphi 2005 - A Technology Preview Got requirements? Got Delphi? Got CaliberRM? A Technology Preview for CaliberRM Integration in Delphi 2005 is now available from the Delphi 2005 registered users download page. http://community.borland.com/article/0,1410,33077,00.html * Free Download: Bold for Delphi 2005 A Delphi 2005 compatible version of the award winning model-driven framework Bold for Delphi is now available for download from CodeCentral. This edition contains a few bug fixes beyond Delphi 7 Architect Service Pack 2, but has no new features. http://community.borland.com/article/0,1410,33058,00.html Articles, Tips and Tricks ========================= * A New Look For BDN Information to help you make the best use of the new BDN web site. http://bdn.borland.com/article/0,1410,33078,00.html * Wanted: VCL for Win32 to VCL for .NET Migration Stories! Borland normally pay $200 for articles submitted via GetPublished, but for awesome "VCL to VCL for .NET" migration stories they'll pay more. http://community.borland.com/article/0,1410,33070,00.html * New Borland Delphi Survey Your opportunity to provide feedback directly to the Delphi team. http://community.borland.com/article/0,1410,33065,00.html * Borland Delphi 2005 Compiler, Language, and Debugger Enhancements This article provides an overview of several of the new features found in Delphi 2005. http://community.borland.com/article/0,1410,33050,00.html * Placing a TProgressBar into a TListView - by Zarko Gajic How to add a progress bar (or any other Delphi component) to a ListView control. Plus: full source code to the TListViewEx component (TListView descendant) with ColumnResize events! http://delphi.about.com/library/weekly/aa053105a.htm * MDI Development in Delphi - by Zarko Gajic In an MDI application, more than one document or child window can be opened within a single parent window. Learn how to create a powerful "multiple document interface" application using Delphi. http://delphi.about.com/od/beginners/l/aa031103a.htm * Delphi History: From Turbo Pascal to Delphi 2005 - by Zarko Gajic This document provides concise descriptions of Delphi versions and its history, along with a brief list of features and notes. Find out how Delphi evolved from Pascal to a RAD tool that can help you solve complex development problems not only for Windows but also for Linux and the .NET. http://delphi.about.com/cs/azindex/a/dhistory.htm * TDBButton: Data Aware TButton Control - by Zarko Gajic Learn how to create a data-aware TButton Delphi control. http://delphi.about.com/library/weekly/aa050305a.htm Tutorials and Training ====================== * BDNtv: The new Delphi 2005 CaliberRM plug-in Daniel Polistchuck, the developer of the new CaliberRM plug-in for Delphi, provides a quick overview of its functionality. http://community.borland.com/article/0,1410,33086,00.html * BDNtv: Using StarTeam with the Delphi 2005 History View See how productive reviewing code changes can become with StarTeam integration into the Delphi history view. FLASH http://bdn.borland.com/article/0,1410,33082,00.html * BDNtv: Accelerating Development with Enterprise Core Objects (ECO II) With ECO II, the model is the system. This BDNtv episode shows how this powerful architecture can dramatically accelerate the development process and at the same time reduce complexity and the amount of code required. (Flash) http://community.borland.com/article/0,1410,33061,00.html * BDNtv: Maximizing the Business Value of Software Watch the BorCon 2004 keynote presentation by Boz Elloy introducing Software Delivery Optimization. (WMV) http://community.borland.com/article/0,1410,33049,00.html News ==== * Developer spotlight:Danny Thorpe Danny Thorpe is the chief scientist at Borland, and was part of the original team that developed Delphi. Builder magazine caught up with Danny to talk about the move to .NET, Kylix, and the future of Delphi. http://www.builderau.com.au/architect/sdi/0,39024602,39194366,00.htm * Borland Wins Coveted 'Jolt' Awards for Requirements and Modeling Tools CaliberRM 2005 and Together Designer 2005 both recently earned honors at the coveted Software Development Jolt Product Excellence and Productivity Awards. http://home.businesswire.com/portal/site/google/index.jsp?ndmViewId=news_view&newsId=20050506005402&newsLang=en * People's Choice Awards - Your Vote Counts! Vote for Delphi 2005, Together 2005 for Visual Studio, StarTeam 2005 and CaliberRM 2005 at MSD2D's 4rd Annual People's Choice Awards. http://community.borland.com/article/0,1410,33062,00.html * Borland Honoured in SD Times 100 for Third Consecutive Year Borland today announced that it has been chosen as one of the SD Times 100 leaders and innovators for the third consecutive year. http://www.itweb.co.za/sections/business/2005/0505300927.asp * Borland Delivers Resources, Solutions for Software Risk Management Borland today announced the availability of a global seminar series, assessment workshops and other resources designed to help IT teams understand how to both minimise and harness risk to drive growth and competitive advantage. http://www.itweb.co.za/sections/business/2005/0505230846.asp Other / Misc Sites ================== * Take Part in the IDC Worldwide Developer Survey IDC is conducting a worldwide survey of software developers in collaboration with several large IT vendors, including Borland. http://www.idcswdc.com/cgi-bin/survey?id=105dez * BDNradio: Trust in Borland Listen to the replay of the live chat with Dale Fuller discussing "Trust in Borland", and read the chat log. http://community.borland.com/article/0,1410,33056,00.html * Koders Koders is a search engine for open source code in almost any language you can think of (including Delphi). Koders searches over 198,319,800 lines of code and can be added to your website or integrated into the Mozilla and Firefox browsers as a search plugin. http://www.koders.com/ ________________________________________________________________________ Irongut's Delphi Pages Dedicated to programming with Borland Delphi and Kylix. We have articles on programming, Borland and Delphi news, source code and components to use in your applications and more. >> http://www.paranoia.clara.net/ << ________________________________________________________________________ YOU CAN HELP US We need your help to keep this newsletter going and growing. 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