Trybik's Dive

CA1800:DoNoCastUnnecessarily

21 Dec 2011

CA1800:DoNoCastUnnecessarily - an FxCop warning that's easily fixed (at least most of the time).

The creator of this fault did not specify a Reason.

18 Dec 2011

"The creator of this fault did not specify a Reason." - the one exception we don't have to worry about.

First steps with Rhino Mocks (in VB.NET)

17 Aug 2011

Using Rhino Mocks in your unit tests? And not finding many examples in VB.NET? Here's an examples of testing that a method was called (AssertWasCalled).

Accessing private and protected members - PrivateObject and PrivateType

26 Feb 2011

Need access to private / protected members of an object when doing unit tests? Use PrivateObject and PrivateType.

Saving / restoring window placements in .NET

25 Feb 2011

It seems that saving window positions and sizes (including the application's main window location) should be easy enough. But even now, after so many years of Windows programming, people get it wrong. But we need to remember about changing screen resolutions, switching from multiple to single monitors, connecting to a projector, etc. Saving the current window's location just ain't gonna do the trick...

Get the TreeViewItem for an Item in a WPF TreeView

17 Jan 2011

When unit testing a user control with a tree view, I wanted to simulate mouse clicks on tree view items. But then it turned out that it's not that straightforward to get the control that displays the item (and that I needed to raise the mouse event for)...

Double Clicks in WPF TreeView Controls

17 Jan 2011

It turns out that double click events in WPF TreeViews are reported for the clicked node as well as for all parent nodes!

Output in MSTest Tests (VS 2010)

17 Jan 2011

Can't find output from Console / Debug / Trace .WriteLine statements when running unit tests in VS 2010? Here's a short text showing where everything goes.

Checking Property Change Notifications

26 Oct 2010

Worried about type safety of property change notifications (INotifyPropertyChanged) in your VB.NET apps? Six lines of code will help in making sure that those are, actually, defined correctly.

Checking "Dangling" Event Handlers in Delphi Forms

25 Oct 2010

I like Visual Form Inheritance (VFI) in Delphi, but the tool support could be much better. One things that like to get out of sync. when working on form hierarchies is event handler mappings between events and the respective procedures. Here's a small procedure that will check any discrepancies in that area.

Rhino Mocks's AssertWasCalled in VB.NET

24 Oct 2010

Using Rhino Mocks in your unit tests? And not finding many examples in VB.NET? Here's an examples of testing that a method was called (AssertWasCalled).

Meaningful identifiers

12 Sep 2010

Meaningful identifiers in code - that's the standard mantra you hear for tech leads, no? But what does this actually mean? Here's a real world example where changing just the names of a couple of identifiers makes the code much more readable, and makes comments wholly unnecessary.

Public fields vs. properties

12 Sep 2010

Why define properties that directly access private fields? Does that really make our code better?

VS Pending Tests

6 Sep 2010

Having problems running unit tests in Visual Studio 2008? Tests remain in "pending" mode forever instead of (finally) succeeding / failing? Well, this hotfix just might help you!

Intraweb and MaxConnections

19 May 2010

Having problems with running out of connections in Intraweb? Check out my solution - maybe it will help.

A Case for FreeAndNIL

15 Feb 2010

Always when I tried to upload a Apache module written in Delphi / Intraweb (VCL for the Web), something didn't work quite as expected. Either the service didn't want to start, or Apache couldn't find / run the module, etc. Apart from the required changes to HTTPD2.pas (that depend on the specific version of your Apache installation), you also need to configure access to your module in the httpd.conf file. And this texts should just how to do that.

Intraweb as an Apache DSO module

11 Feb 2010

Ray casting

8 Feb 2010

The ray casting algorithm is described in detail, with scenes containing triangles only.

"Device not supported" in Intraweb

4 Feb 2010

Getting a "Device not supported" exception when running your Intraweb (VCL for the Web) application in a standard web browser? One possible cause is described in this short text.

Automated GUI Testing

17 Jan 2010

Ever head problems with testing GUI applications using an external testing program? Or maybe you just want to test a single window/form without the need of running your whole program? Start unit testing you GUIs - it's as simple as standard unit tests.

Fix for Highslide HTML Slides

15 Jan 2010

A fix for a small defect in the Highslide library in the displaying of HTML slides.

Random()'s Determinism

12 Jan 2010

The determinism of (pseudo)random number generators is usually described in pejorative terms. :-)
In this text we describe an application of random number generators, where their determinism plays a key role.

Rounding and precision on the 8087 FPU

2 Jan 2010

After moving my testing to a virtual machine it turned out that newly generated results of statistical calculations differ from reference results (calculated and saved earlier). Although the differences appear on the least significant digits of floating-point values, the root cause of the problem was unknown to me, thus to serious to be ignored. It turns out that results of calculations may depend on the Intel's numerical coprocessor's control word. The issue is discussed in more detailed in the text.

Eddie::MSE vs. Mizar-MSE

30 Dec 2009

Mizar-MSE as used in Eddie::MSE differs in some points from the classic Mizar-MSE language. These differences, as well as motivations leading to their introduction, are here described.

Clicking on links in JavaScript

24 Aug 2009

Simulating clicking on links in JavaScript that works in IE, Firefox, and Opera.

PHP's mail()

13 Aug 2009

Having problems with character encoding when using PHP's mail() function?
Maybe this text will help you some.

File | Save Atavism

22 Jul 2009

Sometimes it is really worth going back to basics and solutions not discussed in a long while... to find out that they're really needed. In a new version of one of my applications I thought about dropping Save from the File menu. The option wasn't really needed since the program did automatic saves often enough. No way - users, including myself, don't trust their programs / computers enough yet!

SessionTimeout in Intraweb

7 Jul 2009

A solution to better handling of Intraweb's session timeouts and automatic destruction of inactive user sessions.

Using TChart with Intraweb

1 Jul 2009

A method for displaying TChart charts in Delphi applications based on the Intraweb (VCL for the Web) framework.

DBXMySql

29 Jun 2009

Getting an "Unknown driver: MySQL" message in your Delphi application?
Just add DBXMySql to the uses clause!

Automated GUI Testing in VMs

26 Jun 2009

GUI testing, when being run on the development machine, blocks work because you can't use the keyboard or the mouse during the tests. Well, use a virtual machine for your tests while continuing work on the host.

TIdMessage's CharSet

25 Jun 2009

Wanted to encode a TIdMessage in Delphi using some ISO character set, like, for instance, ISO-8859-2? And had problems with that? This text should help at least some of you (I hope).

Eddie, version 0.34

23 Jun 2009

Various small enhancements and fixes.

Product Peer Reviews - Introduction

27 May 2009

A short introductory text on product peer reviews.

Software Guarantees

22 May 2009

If you are a customer of software applications, if these don't work as advertised, and you can't get bug fixes for free and in a timely manner - dump them! Software developers aren't so special not to be responsible for their work. Software guarantees will not annihilate IT! So, go ahead and vote with your wallet!

Automated Testing of Window Forms

21 May 2009

Tired of continuously verifying tab orders and accelerators in your window forms? How many times have you shipped a program that duplicates shortcuts, doesn't have FocusControl assigned in labels, doesn't have default buttons in dialog windows, etc.? Well, this text describes an approach for automatic testing of window forms (and other controls, for that matter). An approach that, at least for me, saves hours of testing time each week.

TChart - Missing Labels in Axes

22 Apr 2009

Description of the problem and the solution of missing labels in TChart axes when different numbers of values are added to the chart's data series.

Calculating Positions of HTML Elements

20 Apr 2009

Description of the problem and the solution of calculating positions of HTML elements in Internet Explorer.

Memory Leaks and Connection Explosions in DBExpress

17 Apr 2009

Delphi 2009 fixes both problems when accessing MySQL via DBExpress. However, if you're still on Delphi 2007 and are experiencing one of these problems, you may want to try the fix in D2007 that was added to DBExpress in D2009.

CSS for Scrollbars in Pages and in Frames

15 Apr 2009

Do you have problems with centered pages in HTML that are shifted left or right depending on the length of the page, thus visibility of scrollbars? Or maybe you would like to show or hide scrollbars in frames / iframes? If so, maybe you'll find the solution in this post.

Controlling Conditional Defines and Compilation Switches

10 Apr 2009

An idea on how to augment software build / release processes by automatically checking compilation settings and combinations of conditional defines during compilation.

Turning Browser Caching off when Displaying Images Using PHP

9 Apr 2009

Many examples can be found on the Internet showing how one can display images using PHP (either from a file or from a DB). But usually nothing is said about caching those images by internet browsers. However, when updating a picture on my profile, for example, I would like to view the new version, and not the previous one... :-)

Equivalence of Deterministic and Epsilon Nondeterministic Automata

13 Jan 2009

Based on concepts introduced in REWRITE3, semiautomata and left-languages, automata and right-languages, and languages accepted by automata are defined. The powerset construction is defined for transition systems, semiautomata and automata. Finally, the equivalence of deterministic and epsilon nondeterministic automata is shown.

Labelled State Transition Systems

13 Jan 2009

This article introduces labelled state transition systems, where transitions may be labelled by words from a given alphabet. Reduction relations from REWRITE1 are used to define transitions between states, acceptance of words, and reachable states. Deterministic transition systems are also defined.

Detecting Memory Leaks with DUnit

23 Dec 2008

It's much better do detect memory leaks during the (automated) unit testing phase than during later phases of the development cycle. For Delphi, DUnit is the way to go, with its leaked memory checking per test case (and, for other languages, similar unit testing frameworks can be used). However, there are certain caveats to deal with here, and one of these is discussed in the article.

last_insert_id() and DBExpress

19 Dec 2008

MySQL's last_insert_id() function gets the last automatically generated value for a given table. That's pretty helpful, for instance, when you're inserting records and want to retrieve their newly generated IDs. I spent some time on solving this in Delphi's DBExpress framework, and this text documents the issue.

YAC Data Language

16 Dec 2008

Description of a language that is used in YAC applications, often in place of XML, for defining various elements, such as questions, responses, 3D objects, DB entries, etc.

Registering Extensions

11 Dec 2008

Delphi code for registering application-specific file extensions in Windows.

DBExpress and Thread Safety

8 Dec 2008

Description of the problem and the workaround of intermittent Access Violation errors on WideStrings.TWideStrings.GetValue and System.TObject.Free when using DBExpress components for communication with MySQL databases (under heavy load).

Forms as Frames

16 Nov 2008

Placing standard forms (TForm) as frames on other forms.

Checking Dangling Pointers vs the New Memory Manager

13 Nov 2008

Description of the problem and the solution of intermittent Access Violation errors when using DBExpress components for communication with MySQL databases.

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22 Sep 2008

Description of the problem and the solution when using nested layout managers (TIWLayoutMgrHTML) do generate pages under Opera.

Eddie, version 0.33

3 Mar 2008

Various small enhancements and fixes.

Accessing Protected Members

19 Feb 2008

The text describes a simple trick for accessing protected members of instantiated classes without instantiating descendants of those classes - descendants that would make these protected members public.

Eddie, version 0.30

24 Jun 2007

Various small enhancements and fixes.

Regular Expression Quantifiers - at least m Occurrences

3 Jun 2007

Formal languages are introduced as subsets of the set of all 0-based finite sequences over a given set (the alphabet). Concatenation, the n-th power and closure (Kleene closure / star closure) are defined and their properties are shown. Finally, it is shown that the closure of the alphabet (understood here as the language of words of length 1) equals to the set of all words over that alphabet, and that the alphabet is the minimal set with this property.

Ray tracing - rotary figures

11 Mar 2007

Handling of 3D rotary objects in our ray tracing program.

Eddie::MSE, version 0.20

26 Feb 2007

Mizar-MSE is supported in the second edition of the editor.

Eddie::MIZ - version 0.10 released

5 Jan 2007

First edition of an editor dedicated for writers of Mizar articles.