Pascal Newsletter #30
The full source code examples of this issue are available for download.
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Pascal Newsletter #30 - 20-DEC-2001 INDEX 1. A FEW WORDS FROM THE EDITOR 2. DESIGN PATTERNS IN DELPHI 3. FORUMS 4. TIPS & TRICKS - Downloading Files - Printing a TStringGrid - Ellipsis - Displaying a long text in a short space - Running an application as an NT Service - Searching for files recursing into subdirectories 5. DELPHI ON THE NET - Components, Libraries and Utilities . Shareware/Commercial . Freeware - Articles, Tips and Tricks - Tutorials - Other Links ________________________________________________________________________ 1. A FEW WORDS FROM THE EDITOR In the tip "Using a login form in our application" published in the last issue, I used "exit" to terminate the program, but that doesn't destroy the login form correctly. Thanks Steven for the notice. There are many ways to correct this, like freeing the login form to terminate the application instead of using "exit": if frmLogin.ShowModal <> mrOK then frmLogin.Free; // Login failed ==> Terminate program In this issue I'm glad to thank Bradley Baumann for contributing two articles for this publication. By the way, if you solved a particular problem, I'd like to invite you to share your code in this newsletter. If you feel this newsletter is useful, please give us a hand to help us reach 10,000 subscribers in the next months. One way you can help us is by sending this link to your friends: http://www.latiumsoftware.com/en/pascal/delphi-newsletter.php Another way you can help us is by voting for us in any or some of these rankings to help give more visibility to our web site and thus increase the number of subscriptions to this newsletter: http://www.sandbrooksoftware.com/cgi-bin/TopSite2/rankem.cgi?id=latium http://news.optimax.com/topdelphi/links.exe/click?id=70C517ECAE6E http://www.top219.org/cgi-bin/vote.cgi?delphi&83 http://top100borland.com/in.php?who=20 http://top200.jazarsoft.com/delphi/rank.php3?id=latium Please vote. It's just a few seconds that REALLY make the difference. Regards, Ernesto De Spirito eds2004 @ latiumsoftware.com ________________________________________________________________________ JfControls Library. Multi-language. Multi-appearance. Skins. Privileges. More than 40 integrated and customizable components. Impressive GUI. Centralized resources administration. Multiple programming problems solved. For Delphi 3-7 and C++ Builder 3-6. http://www.jfactivesoft.com/ ________________________________________________________________________ 2. DESIGN PATTERNS IN DELPHI Design patterns are said to be the future of OOP. If you are interested in design patterns in Delphi, here are some links to get you started: * What are Design Patterns? http://www.burn-rubber.demon.co.uk/patterns.htm * Introduction to Design Patterns - by Ader Gonzalez http://www.delphi-jedi.org/Jedi:VOYPATTERNS * Introduction to Design Patterns in Delphi - by James Heyworth, 1996 http://www.obsof.com/delphi_tips/pattern.html * PatternExplorer http://www.geocities.com/beckmi/patterns0.htm * Wrapper Design Pattern http://www.castle-cadenza.demon.co.uk/wrapper.htm * Creating a real singleton class in Delphi 5 - by Lasse V. Karlsen http://community.borland.com/article/0,1410,22576,00.html These examples (singleton, observer, explorer, etc.) seem nice for the classroom, but they are too "low level" for my taste. A "higher level" example that comes to my mind is a treeview/listview pattern, which can be materialized in a VCL component encapsulating the relationship between a treeview (any TCustomTreeview descendant) and a listview (any TCustomListview descendant), like for example drag-and-drop to copy or move elements. I hope in the future we get to see more of this stuff to make our lives as programmers easier. ________________________________________________________________________ IBAdmin 3.2 - Complete Interbase SQL tool - A powerful DBA/Development tool for managing Interbase servers and databases. IBAdmin provides many capabilities to help with your DB design and management. You can use the Database Designer to visually design the database structure, the Grant Manager to manage users, or the SQL Debugger which can be used to debug stored procedures and triggers. Comfortable SQL code editing with Code- Insight and Code Completion. >>>>>>>>> http://www.sqlly.com/ibadmin2.htm ________________________________________________________________________ 3. FORUMS Delphi ====== If you know much of Delphi but you are still far from being a guru this forum is for you. This is the only forum for intermediate-level Delphi programmers on the Web (Delphi hackers are also welcome :-)). The forum now has more than 420 members, while it maintains its low traffic: http://groups.yahoo.com/group/delphi-en If you want to join the group, the best way is to subscribe from the web since you can access the special features available at the web site (a Yahoo! ID is required and you can get yours free by registering as a Yahoo! user), but if you don't want to register or if you don't have full Internet access you also can subscribe by email: http://groups.yahoo.com/group/delphi-en/join delphi-en-subscribe@yahoogroups.com Components ========== This is a forum for searching/recommending software components (VCL and CLX components, ActiveX objects, DLL libraries, shared objects, etc.), as well as utilities, tutorials, information, etc. The forum is rather new and currently has a bit more than 50 members and almost no messages: http://groups.yahoo.com/group/components I hope you join the forum to form a larger group. You can subscribe from the web or --more easily-- by email: http://groups.yahoo.com/group/components/join components-subscribe@yahoogroups.com ________________________________________________________________________ 4. TIPS & TRICKS Downloading Files ================= By Bradley Baumann http://www.scrapcode.com bradley@bestweb.net / _@scrapcode.com Seems as if not too many people know about the great URLMon (included with Delphi)... Here's a quick example that will download index.html from "www.scrapcode.com", to "c:\": unit Unit1; interface uses Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, Dialogs, StdCtrls, URLMon; type TForm1 = class(TForm) Button1: TButton; procedure Button1Click(Sender: TObject); private { Private declarations } public { Public declarations } end; var Form1: TForm1; implementation {$R *.dfm} procedure TForm1.Button1Click(Sender: TObject); begin URLDownloadToFile(nil, 'http://www.scrapcode.com/index.html', 'c:\index.html', 0, nil); end; end. Printing a TStringGrid ====================== By Bradley Baumann http://www.scrapcode.com bradley@bestweb.net / _@scrapcode.com Here is a component that I wrote to print out the selected lines (to the printer) of a TStringGrid, it's called TPrintGrid. I hope enjoy it, if you have any questions, comments, suggestions - please don't hesitate to ask me. ------------------ Editor's note: The code of this component is included in the archive that accompanies this newsletter. I included a little demo application. Ellipsis - Displaying a long text in a short space ================================================== Probably you saw in many places that when when the text is too long for the space assigned to it (for example in the case of long items in a narrow ListBox), the text is then displayed with ellipsis ('...') at the end. This is done with the API DrawText or DrawTextEx, using the constants DT_END_ELLIPSIS or DT_WORD_ELLIPSIS in the format parameter. For example: procedure TForm1.PaintBox1Paint(Sender: TObject); var DTParams: DrawTextParams; Rect : TRect; begin with DTParams do begin cbSize := SizeOf(DrawTextParams); iTabLength := 6; iLeftMargin := 2; iRightMargin := 2; end; Rect := Paintbox1.ClientRect; Paintbox1.Canvas.Rectangle(Rect); DrawTextEx(Paintbox1.Canvas.Handle, PChar(Paintbox1.Hint), -1, Rect, DT_CENTER + DT_VCENTER + DT_SINGLELINE + DT_END_ELLIPSIS, @DTParams); end; Probably you also saw the use of ellipsis to abbreviate file paths. This is done with the DT_PATH_ELLIPSIS constant: DrawTextEx(Paintbox1.Canvas.Handle, PChar(Application.ExeName), -1, Rect, DT_CENTER + DT_VCENTER + DT_SINGLELINE + DT_PATH_ELLIPSIS, @DTParams); Running an application as an NT Service ======================================= In Windows NT/2000, one option is executing your application with SRVANY.EXE so it runs as a service, but the application won't benefit from all the features the OS makes available for services. SRVANY.EXE is basically for Win 9x service applications that you want to run as services in NT. If you want your application to truly be an NT service, you should design it as such (File menu / New... / New / Service Application). Here you can find some examples: http://www.aldyn.ru/demos/ http://delphi.icm.edu.pl/ftp/d50free/svcxmpl.zip http://delphi.icm.edu.pl/ftp/d40free/servicew.zip Searching for files recursing into subdirectories ================================================= The following function will search the directory passed as parameter, as well as all its subdirectories, searching for files matching the file specification (like '*.htm?') also passed as parameter. The files found will be added to a string list passed as the third parameter: procedure SearchDir(Folder: string; FileSpec: string; List: TStrings); procedure rSearchDir(Folder: string); var SearchRec: TSearchRec; begin if FindFirst(Folder + FileSpec, faReadOnly Or faHidden Or faSysFile Or faArchive, SearchRec) = 0 then try repeat List.Add(Folder + SearchRec.Name); until FindNext(SearchRec) <> 0; finally FindClose(SearchRec); end; if FindFirst(folder + '*', faReadOnly Or faHidden Or faSysFile Or faArchive Or faDirectory, SearchRec) = 0 then try repeat if ((SearchRec.Attr and faDirectory) <> 0) and (SearchRec.Name <> '.') and (SearchRec.Name <> '..') then rSearchDir(Folder + SearchRec.Name + '\'); until FindNext(SearchRec) <> 0; finally FindClose(SearchRec); end; end; begin rSearchDir(IncludeTrailingBackslash(Folder)); end; Sample call: SearchDir('C:\Windows', '*.EXE', Listbox1.Items); ________________________________________________________________________ 5. DELPHI ON THE NET By Dave Murray Components, Libraries and Utilities =================================== Shareware/Commercial -------------------- * CoolHints2k version 1.01a With CoolHints2k you can create Office2000-like dialogs and hint system. The package contains all necessary controls and can be used to build ordinal dialogs and other purpose windows. Use Delphi's designer to build the forms and combine controls from the CoolHints2k package with any other VCL you have. For Delphi 3-6 and BCB 3-5. http://www.cooldev.com/coolhints2k.html * HtmlTools version 1.03b Package to deal with the HTML code. Currenty contains an HTML parser that allows to parse HTML code and various HTML tags and an HTML stripper to work with the HTML document. Native Delphi code. For Delphi 2-6 and BCB 3-5. http://www.cooldev.com/htmltools.html Considering registering the package? The license of Tips System includes the HtmlTools package as well and it uses advantages of HtmlTools: http://www.cooldev.com/tipssystem.html * PsQRFilters v 2.0 - by Pragnaan Software. Shareware ($79) WYSIWYG Export Filters for QuickReport! Export to PDF, HTML, RTF, Excel, Text, JPEG, GIF, BMP and more. An ideal solution for creating copies of reports for distribution. All report elements are exported and there are plenty of options to play with! http://www.pragnaan.com * PsFRExportFilters v 1.1 - by Pragnaan Software. Shareware ($79) WYSIWYG Export Filters for FastReport! Export to PDF, HTML, RTF, JPEG, GIF, BMP and more. An ideal solution for creating copies of reports for distribution. All report elements are exported and output can be easily customized even by the end-user! http://www.pragnaan.com Freeware -------- * UniRed 1.10 An Unicode plain text editor that supports many charsets including 16-bit Unicode (little and big endian), UTF-8, Windows ANSI, DOS OEM, Latin-1, Latin-2, etc. and Cyrillic charsets. Syntax highlighting can emphasize elements by colors and/or text styles. Supports many languages including HTML, C/C++, Delphi, Java, etc. Search and replace by regular expressions. Can co-operate with ISpell, allowing spell check in any language. Can call external compilers and more. http://www.esperanto.mv.ru/UniRed/ENG/index.html * CursorDance - by Neil J. Rubenking Create 16-color and 256-color cursors and animated cursors with this easy-to-use utility. Delphi 5 source code included. http://www.pcmag.com/article/0,2997,s%253D1478%2526a%253D9354,00.asp * A Component that plots graphs - by Vimil Saju A TGraph Component. http://www.delphi3000.com/articles/article_2790.asp * EldoS Sounds v.1.12 - by Eugene Mayevski The component for different sound decoders and players. Currently includes MP3 decoder and player. http://www.eldos.org/elsounds/elsounds.html * Regular Expression Library v.2.1.1 - by Edward Diener A library of components and classes to do search and replace of data using Regular Expressions. There is full support for using the library in non-VCL modules as well as VCL components. http://www.tropicsoft.com/Components/RegularExpression/ * Decosp Components Library v.2.5 - by Decosp A set of 20+ multipurpose components for Delphi, that allow you to make your application more attractive and GUI more convenient. Components include: Enhanced mask edit, Date edit, Tree edit, Enhanced combo box edit, Tree grid, InterDev style Page controls, Outbar control and Syntax Memo edit (with Delphi and T-SQL syntax). http://www.decosp.ru/tools/ * MPEG Tools Freeware library of classes for Mpeg player functions. http://www.dv.co.yu/mpgscript/mpgtools.htm * PGP Components for Delphi Directly interface with PGP's SDK libraries versions 6.5.X and 7.X.X. Functions include: Encode & decode; Create & verify file detached signatures; Import, export, revoke, delete keys; Key management functions; Key generation (DH/DSS, RSA); Keyserver functions; etc. http://home.t-online.de/home/idw.doc/PGPcomp.htm * JabberCOM 2.4.2.1 COM component which allows developers quick and easy implementation of a Jabber (XML Instant Messaging) client. JabberCOM encapsulates all of the socket and XML handling into a single DLL. http://jabbercom.sourceforge.net/ * ReSource Compression Component v.2.61 - by Victor Kasenda. BWT (Block Sorting) Compressor, includes Archiver Demo with add/ extract/ delete. Uses Sadakane's Suffix Sort, Structured Arithmetic Encoder and CRC32. Compression levels similar to PPM, with speeds closer to LZ. Source included. http://homex.coolconnect.com/member3/gruvrs/resource/ * Aravil CAB Components v.1.03 - by Ravil Batyrshin. Consists of 2 native VCL components TSTCabReader & TSTCabWriter. Easily create CAB archives and then extract files from archives. The components are wrappers over Microsoft Cabinet.dll, they simplify your work with archives and add useful capabilities. Source included. http://aravilsoft.tripod.com/cabd103.zip * XP Menu v.1.506 - by Khaled Shagrouni. XP Menu is non-visual component that changes the visual aspects of menus & toolbars to the look and feel of Office XP. No code required, you do not have to reconstruct menus or toolbars using components other than those shipped with Delphi. Source included. http://www.shagrouni.com/english/software/xpmenu.html Articles, Tips and Tricks ========================= * Delphi Database Programming Course - by Zarko Gajic Free online database programming course for beginner Delphi developers focused on ADO techniques. http://delphi.about.com/library/weekly/aa010101a.htm A new chapter has been added in the last two weeks: Chapter 21 "Using ADO in Delphi 3 and 4 (before AdoExpress)" explains how to import Active Data Objects (ADO) type-libraries in Delphi 3 and 4 to create a wrapper around components that encapsulate the functionality of ADO objects, properties and methods. http://delphi.about.com/library/weekly/aa112701a.htm * Extending WebSnap: Changing grid layout - by Gabriel Corneanu Web components designed to combine the power of DataSetAdapter and AdapterGrid with the layout generated by AdapterFieldGroup and LayoutGroup. http://community.borland.com/article/0,1410,28105,00.html * Exceptional exceptions - by Marcelo Lopez Ruiz Learn about structured exceptions and some unusual ways to use them. http://community.borland.com/article/0,1410,27185,00.html * Checking if an application (window) is not responding? - by T Stutz http://www.swissdelphicenter.ch/torry/showcode.php?id=910 * How to convert a Bitmap to an Icon? - by Thomas Stutz http://www.swissdelphicenter.ch/torry/showcode.php?id=913 * Yahoo Instant Messenger protocol - by César Nicolás Peña Núñez Implementing Yahoo Instant Messenger protocol in Delphi. This article covers how to login to the server, get buddy list, ignore list and whether the user has mail. Requires Indy Internet Library or an HTTP component that you know how to use. http://www.howtodothings.com/showarticle.asp?article=361 * Header file format of Interbase/Firebird files - by Peter Morris This simple class will allow you to specify an Interbase / Firebird database and it will retrive information about the database including secondary files, page sizes & number of pages for each file and disk structure number. http://www.howtodothings.com/showarticle.asp?article=369 * Julian Date - by Peter Morris How many days since the start of the year. http://www.howtodothings.com/showarticle.asp?article=374 * Copy files with windows progress - by Peter Morris How to copy multiple / large files & show the windows progress form. http://www.howtodothings.com/showarticle.asp?article=383 * Easy XML - by Boris Yankov How to use TXMLDocument in Delphi 6. http://www.delphi3000.com/articles/article_2902.asp * A simple Internet Explorer like autosuggest - by Masoud Kalali A simple Internet Explorer like autosuggest listbox. http://www.delphi3000.com/articles/article_2905.asp * How to Reboot, Shut Down and Log Off Windows - by David Cardeiro http://www.delphi3000.com/articles/article_2910.asp * Changing the default printer - by May Dexter How do I change the default Windows printer? http://www.delphi3000.com/articles/article_2911.asp * Undocumented: Delphi VCL Access License - by Erwin Molendijk The SysUtils.pas unit contains some very interesting routines that are used by the VCL to check if the correct version of Delphi is being used to compile the code (eg. Enterprise or Pro). http://www.delphi3000.com/articles/article_2912.asp * TICQ OCX Component, Full Source Code - by Ruslan Abu Zant Full component source code you can use to connect to ICQ servers. http://www.delphi3000.com/articles/article_2913.asp * Finding Printers on the network - by Cleverson Gallego Find the printers for a specific server on the network. http://www.delphi3000.com/articles/article_2915.asp * Streaming COM objects as XML - Alessandro Federici Quick and dirty example of how to read Type Library information and generate XML files out of a COM object. http://www.delphi3000.com/articles/article_2916.asp * How to get the default printer name - by Philippe Randour You want to access the default printer but you don't know how to get its name from the system. This article will show you how. http://community.borland.com/article/0,1410,28000,00.html * Top 10 list: using XL to speed Delphi development - by Patrick Foley This article shows creative ways to use Excel to speed coding and database development. http://community.borland.com/article/0,1410,28076,00.html * Domain authentication with WebSnap - by Gokhan Ergul Network domain authentication component for WebSnap. http://community.borland.com/article/0,1410,28036,00.html * WebServices Made Simple in Delphi 6(Part 2) - by Magesh Puvananthiran Continuation of a previous article that showed how to write a Web Services Client using a WSDL file. This article shows how to write a Web Services Server itself in Delphi 6. http://www.delphi3000.com/articles/article_2884.asp * Auxiliary TQuery used with run-time queries - by Fernando Martins Reducing code replication when using auxiliary TQuery objects. http://www.delphi3000.com/articles/article_2887.asp * Garbage Collector for Delphi Applications - by Frederico Pissarra How to implement a garbage collector in Delphi? http://www.delphi3000.com/articles/article_2888.asp * Create + Manage dynamic Forms using Class References - by M Hoffmann How to dynamicaly create and manage different Forms at runtime in a global manner? http://www.delphi3000.com/articles/article_2893.asp * Priority of an applications main thread - by Simon Grossenbacher How to change the priority of an applications main thread. http://www.swissdelphicenter.ch/torry/showcode.php?id=904 * How to get the power status? - by Simon Grossenbacher http://www.swissdelphicenter.ch/torry/showcode.php?id=903 * How to Drag & Drop multiple items within a TListView? - by Peter Kooi http://www.swissdelphicenter.ch/torry/showcode.php?id=902 * How to change Screen.Cursor without need to restore? - by KK Gian http://www.swissdelphicenter.ch/torry/showcode.php?id=895 * "The Big Brother" Delphi code toolkit - by Zarko Gajic Going undercover: hiding from the task list, disabling task-switch, removing from the TaskBar, disabling shut down... http://delphi.about.com/library/weekly/aa022701a.htm * Using ADO in Delphi 3 and 4 (before AdoExpress) - by Zarko Gajic Chapter 21 of the free Delphi ADO DB Couse for beginners. How to import Active Data Objects (ADO) type-libraries in Delphi 3 and 4 to create a wrapper around components that encapsulate the functionality of ADO objects, properties and methods. http://delphi.about.com/library/weekly/aa121101a.htm Tutorials ========= * Learn your way around XML - by Irina Medvinskaya A simple introduction to XML, when to use it and a glossary of terms. http://www.techrepublic.com/article.jhtml?id=r00820011213med01.htm * Writing And Controlling Automation Servers In Delphi - by Brian Long This tutorial explores how to control Automation servers and how to write them in Delphi. http://www.blong.com/Articles/Automation In Delphi/Automation.htm * More Automation In Delphi, an ICon UK 2000 paper - by Brian Long This follows on Writing And Controlling Automation Servers In Delphi. http://www.blong.com/Conferences/IConUK2000/DelphiMoreAutomation/ More Automation In Delphi.htm * Another crash course in SQL - by TechRepublic Shows you how to run a query that pulls information from two tables that share a common "key" field. http://www.techrepublic.com/article.jhtml?id=r00320011204jed01.htm * A TCP/UDP primer - by Francois Piette Most people don't know which protocol to choose between TCP and UDP when they begin to work with TCP/IP. And when they have chosen, they begin to have some problems because it doesn't work as expected. This primer explains in easy words the pros and cons for each one in the context of the freeware TWSocket component for Delphi and C++Builder. http://users.swing.be/francois.piette/tcpudpuk.htm * A crash course in SQL - by TechRepublic A short introductory to SQL for complete beginners. http://www.techrepublic.com/article.jhtml?id=r00320010717jed01.htm * SQLcourse.com Unique SQL tutorial not only provides easy-to-understand SQL instructions, but allows you to practice what you learn using online SQL interpreter. You will receive immediate results after submitting your SQL commands. You will be able to create your own unique tables as well as perform selects, inserts, updates, deletes, and drops. http://www.sqlcourse.com * Free-Ed.Net Massive site of free courses and tutorials with subjects including Delphi, HTML, Javascript, SQL, TCPIP and Windows. http://www.free-ed.net/catalog/itcat01.htm Other Links =========== * Resources for Software Architects - by Bredemeyer Consulting Software architecture is getting a lot of attention. Is it just the silver bullet du jour? This site organizes a variety of resources to help you deepen & expand your understanding of software architecture and the role of the architect. http://www.bredemeyer.com/index.html * Pascal Gebruikers Groep The only well-known organization of Dutch-speaking Pascal/Delphi/ Kylix users. 2000+ members. Activities, CDs, Blaise newsletter, etc. http://www.hcc-pgg.nl ________________________________________________________________________ If you haven't received the full source code examples for this issue, you can get them from http://www.latiumsoftware.com/download/p0030.zip ________________________________________________________________________ This newsletter is provided "AS IS" without warranty of any kind. Its use implies the acceptance of our licensing terms and disclaimer of warranty you can read at http://www.latiumsoftware.com/en/legal.php where you will also find a note about legal trademarks. Articles are copyright of their respective authors and they are reproduced here with their permission. You can redistribute this newsletter as long as you do it in full (including copyright notices), without changes, and gratis. ________________________________________________________________________ Main page: http://www.latiumsoftware.com/en/pascal/delphi-newsletter.php Group home page: http://groups.yahoo.com/group/pascal-newsletter/ Subscribe/join: pascal-newsletter-subscribe@yahoogroups.com Unsubscribe/leave: pascal-newsletter-unsubscribe@yahoogroups.com Problems with your subscription? eds2004 @ latiumsoftware.com ________________________________________________________________________ Latium Software http://www.latiumsoftware.com/en/index.php Copyright (c) 2001 by Ernesto De Spirito. All rights reserved. ________________________________________________________________________ |
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