The Wiert Corner – irregular stream of stuff

Jeroen W. Pluimers on .NET, C#, Delphi, databases, and personal interests

  • My badges

  • Twitter Updates

  • My Flickr Stream

  • Pages

  • All categories

  • Enter your email address to subscribe to this blog and receive notifications of new posts by email.

    Join 1,854 other subscribers

Archive for the ‘Event’ Category

Delphi: using IInterface to restore cursor at end of mehod (prelude to a memento that executes any code at end of method).

Posted by jpluimers on 2014/08/06

A long while ago, I wrote about a (then overdue post) on .NET/C#: Using IDisposable to restore temporary settrings example: TemporaryCursor class.

I had been using a similar technique in Delphi since before I found out about the [WayBack] TRecall class and thought: I think my TTemporaryCursor is smarter, as it is based on interfaces.

TRecall (and the [WayBack] Vcl.Graphics descendants [WayBack] TBrushRecall, [WayBack] TFontRecall, and [WayBack] TPenRecall) store [WayBack] TPersistent properties using the Assign method. They were introduced in Delphi 6.

Too bad there are only [WayBackvery few people using TRecall as lots of TPersistent things warrant sasaving and restoring.

My [WayBack] TTemporaryCursor (now [WayBack] at bitbucket) class only stores an integer, so it cannot derive from TRecall. Besides it is based on IInterface which got introduced in Delphi 6, but was present as IUnknown since Delphi 3 (see [WayBack] Interface It! A quick guide to the ins and outs of interfaces in Delphi. By Jimmy Tharpe).

This means that TRecall could have been based on IInterface, so I wonder why it was not.

Note I’m not the first to publish about such a class (Malcolm Grooves wrote [WayBack] TCursorSnapshot, SwissDelphiCenter has [WayBack] TMyCursor, Nick Hodges published about [WayBack] TAutoCursor), it’s just that it has been in my tool box for so long, and written memento classes that you will see 2 articles on it this week.

In the mean time (this works with Delphi 2009 and up), I also wrote a small class that does similar things for any  [WayBackanonymous method. More on that tomorrow.

Back to TRecall: it is an example of [WayBack] the memento pattern in Delphi. The [WayBack] memento pattern allows you to restore state.

SourceMaking.com a.k.a. [WayBack] Design Patterns and Refactoring is a great site about [WayBack] Design Patterns, [WayBack] UML, [WayBack] AntiPatterns and [WayBack] Refactoring.

Most pattern example code is available in all of the C#, C++, Delphi, Java and PHP languages.

Great stuff!

One of the constructs for restoring state is a [WayBack] try … finally … end construct: it allows you to always execute something in the finally block, for instance restoring the state to right before the try block. Read the rest of this entry »

Posted in Conference Topics, Conferences, Delphi, Delphi 2005, Delphi 2006, Delphi 2007, Delphi 2009, Delphi 2010, Delphi 3, Delphi 4, Delphi 5, Delphi 6, Delphi 7, Delphi x64, Delphi XE, Delphi XE2, Delphi XE3, Delphi XE4, Design Patterns, Development, Diagram, Event, Software Development, UML | 14 Comments »

FastMM4 FullDebugMode quick tip: don’t forget to give your EXE access to the correct FullDebugMode.dll

Posted by jpluimers on 2014/03/06

If you run FastMM4 in FullDebugMode, then here are two tips that new (and sometimes existing users) often overlook:

  1. If you set the FullDebugMode directive in the IDE, build your project.
  2. Don’t forget to give your EXE access to FastMM_FullDebugMode.dll (x86), or FastMM_FullDebugMode64.dll (x64) which are stored in the FastMM4 download and in the precompiled directory of the source code.
    Either put that DLL in your path, or copy it to your EXE directory.
  3. Make sure your EXE can write in the directory of the EXE.

The first makes sure all units are compiled with FullDebugMode (Delphi does not always do that automagically).

The second makes sure your EXE can access the DLL that writes out your *MemoryManager_EventLog.txt file containing memory leaks and other issues FastMM4 detected.

–jeroen

Posted in Conference Topics, Conferences, Delphi, Delphi 2007, Delphi 2009, Delphi 2010, Delphi XE, Delphi XE2, Delphi XE3, Delphi XE4, Delphi XE5, Development, Event, FastMM, Software Development | 2 Comments »

Pre-build trick does not work to circumvent [BRCC32 Error] xxx.vrc(1): error creating xxx.res (via: Embarcadero Discussion Forums & StackOverflow)

Posted by jpluimers on 2014/01/10

Ever since around Delphi 2007, it started to use temporary .VRC files to re-build the project .RES file.

It confuses people, and with reason as the only public information about it on the dockwiki seems to be in the Version Info page (though there is more on the other embarcadero sites).

The reason is that parts of the .RES file are no more leading in the process of getting them from your project options to the final binary (EXE/DLL/BPL/…) of your project.

Delphi XE3 for instance can have these resource structures in the .VRC file:

Except for type 24, Delphi XE2 seems to have the same kinds of resource types.

All in all, most if not all of the .RES files are being auto-generated for at least a couple of years now so there is less and less need to put it under version control.

The problem is that if for one reason or the other, your project .RES file becomes readonly, and you get errors like mentioned in Why does a projects res file need to ….

[BRCC32 Error] xxx.vrc(1): error creating xxx.res

.RES in VCS or not?

Read the rest of this entry »

Posted in Conference Topics, Conferences, Delphi, Delphi XE, Delphi XE2, Delphi XE3, Delphi XE4, Delphi XE5, Development, Event, QC, Resource Files and Scripts (.res/.rc), Software Development | Leave a Comment »

Delphi SOAP: some reminders to Self

Posted by jpluimers on 2014/01/04

Hadn’t been doing SOAP in Delphi for a while, and needed to send some Delphi data structures over the write where both Client and Server were going to be Delphi.

These links helped me:

If both client and server are Delphi, you can share the interface units and registration.

Note: since native Delphi SOAP support uses old-skool RTTI, so any property you want to go over the wire needs to be published, not public.

If you want to go beyond that, or use other protocols than SOAP, use libraries for Delphi like RemObjects SDK.

–jeroen

Posted in Conference Topics, Conferences, Delphi, Delphi XE3, Delphi XE4, Delphi XE5, Development, Event, Software Development | Leave a Comment »

I’m Speaking at EKON 17; early bird ends on Friday October 4th 2013: save EUR 100 and get a free Android tablet.

Posted by jpluimers on 2013/10/03

Early bird ends October 4th: get an Android tablet for free and save EUR 100!

Early bird ends October 4th: get an Android tablet for free and save EUR 100!

EKON17 (from November 4-6 in Cologne, Germany) will be a fun event this year: lots of nice sessions and workshops, a lovely city (not just the Dom Cathedral), and a great group of speakers.

Since there are so many speakers that are able to speak English, it is interesting for non-German attendees as too, especially the post-conference workshop from Nick Hodges.

I’ll be speaking too (more on that below) and will be there all 3 days (plus the evening before and morning after to aid people with their Delphi related questions).

Among the speakers, these will do their sessions in English:

Posted in Conferences, Delphi, Delphi XE5, Development, EKON, Event, Software Development | Tagged: , , | Leave a Comment »

On Windows: Do not install the Android SDK ADT bundle in a path with spaces

Posted by jpluimers on 2013/08/28

Some 20 years after someone thought it was a nice idea to allow spaces in path names on Windows, it still is a bad idea to rely that just “works” for everything.

Today I tried to see if it still applied what I mentioned 2 years ago during the German BASTA! Fall conference in the Rheingoldhalle when talking about cross platform .NET development using MonoDroid/MonoTouch/Visual Studio:

Android SDK
– http://developer.android.com/sdk/index.html
– Windows:
- http://dl.google.com/android/installer_r13-windows.exe
- http://dl.google.com/android/android-sdk_r13-windows.zip
Do not install in a directory with spaces (not C:\Program Files, but C:\android-sdk)

And it does still apply: though not mentioned in the Android SDK/ADT documentation, most of the batch files in the Android SDK ADT bundle are not compatible being stored in a path that has spaces.

Unquoted referrals to paths like this are used in most SDK batch files:

cd /d %~dp0

The only way to run these batch files is with the current directory being the directory of the batch file itself, or referring to them in their fully quoted form.

Another correct way would be to use short names, but that’s only done in find_java.bat:

%~dps0

Summary of the batch files and how they are affected:


+ …\adt-bundle-windows-x86-20130522\sdk\build-tools\android-4.2.2\dx.bat
+ …\adt-bundle-windows-x86-20130522\sdk\tools\android.bat
+ …\adt-bundle-windows-x86-20130522\sdk\tools\ddms.bat
+ …\adt-bundle-windows-x86-20130522\sdk\tools\draw9patch.bat
+ …\adt-bundle-windows-x86-20130522\sdk\tools\hierarchyviewer.bat
+ …\adt-bundle-windows-x86-20130522\sdk\tools\jobb.bat
+ …\adt-bundle-windows-x86-20130522\sdk\tools\lint.bat
+ …\adt-bundle-windows-x86-20130522\sdk\tools\monitor.bat
+ …\adt-bundle-windows-x86-20130522\sdk\tools\monkeyrunner.bat
+ …\adt-bundle-windows-x86-20130522\sdk\tools\traceview.bat
+ …\adt-bundle-windows-x86-20130522\sdk\tools\uiautomatorviewer.bat
– …\adt-bundle-windows-x86-20130522\sdk\tools\lib\find_java.bat
+ …\adt-bundle-windows-x86-20130522\sdk\tools\lib\post_tools_install.bat
* …\adt-bundle-windows-x86-20130522\sdk\tools\proguard\bin\proguard.bat
* …\adt-bundle-windows-x86-20130522\sdk\tools\proguard\bin\proguardgui.bat
* …\adt-bundle-windows-x86-20130522\sdk\tools\proguard\bin\retrace.bat
– …\adt-bundle-windows-x86-20130522\sdk\tools\templates\gradle\wrapper\gradlew.bat
– compatible with spaces in path
+ incompatible with spaces in path
* won't run at all when current directory is different from directory of batch file

view raw

gistfile1.txt

hosted with ❤ by GitHub

(Side note: most incompatible batch files correctly do `for %%i in (“%cd%”) do set prog_dir=%%~fsi`)

So: make sure “…”  is a path not containing spaces.

–jeroen

Posted in Android, BASTA!, Conferences, Development, Event, Mobile Development, Software Development | Tagged: , , , , , , , | Leave a Comment »

Dutch stop of the RAD Studio in Action LIVE! event: September 7th, Leiden (close to Amsterdam) with extra conference track.

Posted by jpluimers on 2013/08/27

The Dutch stop of the RAD Studio In Action LIVE! tour is on September 7th.

The venue location is via Holiday Inn Leiden Hotels: Haagse Schouwweg 10, 2332 KG  Leiden, The Netherlands.

It is close to the advertised “Amsterdam Netherlands” (about half an hour drive), close to the A44 highway and close enough to public transport. And it is indeed on Saturday September 7, 2013

Full day event: RAD Studio In Action LIVE! + conference track Read the rest of this entry »

Posted in Android, Android Devices, CodePlex, Conferences, Delphi, Delphi XE4, Delphi XE5, Development, DVCS - Distributed Version Control, Event, FreePascal, git, iOS Development, Lazarus, Mercurial/Hg, Mobile Development, Power User, Software Development, Source Code Management, SourceForge, Subversion/SVN, TFS (Team Foundation System) | Leave a Comment »

.NET/C#: UnitPrefixes class that facilitates distinguishing decimal and binary file/drive/memory size (mega versus mibi, etc)

Posted by jpluimers on 2013/08/14

Everyone knows there is a size difference between a gigabyte of memory, and a gigabyte of disk space.

The former is 102410241024, the latter is 100010001000.

To facilitate this, I’ve created a C# class UnitPrefixes containing quite a few constants and readonly values.

The class is below, but a few interesting facts first:

  • Most values are const, but a few are readonly static variables because they cannot calculated at compile time (the C# compiler by design does very limited calculations at compile time; it is complex enough as it already is).
    As Jon Skeet explains, there are some other differences between const and readonly static, which is why I favour const.
  • Though all consts are positive, I could have used UInt32 and UInt64, but the .NET framework favours signed Int32 and Int64 types for parameters, so to avoid casting, I used the signed ones.
  • There is no Int128 or UInt128, but there is System.Numerics.BigInteger which I use for values too large for 64-bit integers.
    Note that BigInteger is relatively new, so this code will only work in C# 4 or higher, and requires .NET 4 or higher.
    This is also the place where I use the public readonly static fields, as I need to call the BigInteger constructor to initialize it.
  • I used the Decimal type, as the mantissa holds up to 28 digits of accuracy.

I used the Wikipedia pages Binary Prefix and Metric Prefix (I could also have used File Size) for the unit names and abbreviations.

Note that BitsPerByte is a const I needed too, and I will probably add constants for 512 and 4096, as you see those often in computing as well.

The below sample code is also available as a changeset on BeSharp.CodePlex.com. Read the rest of this entry »

Posted in .NET, .NET 4.0, .NET 4.5, C#, C# 4.0, C# 5.0, Conference Topics, Conferences, Development, Event, Jon Skeet, Software Development | Tagged: , | Leave a Comment »

Reminiscence of the past: Delphi I/O error 131

Posted by jpluimers on 2013/08/06

I was called by a client that didn’t want to do maintenance on an old Delphi application, but wanted to get dir of an I/O Error 131:

I/O Error 131: ERROR_NEGATIVE_SEEK

MessageText: An attempt was made to move the file pointer before the beginning of the file.

Tough luck: psychic powers told me someone is using an unsigned 32-bit integer to access a file using traditional style Assign/Reset/Seek/Read/Close patterns that Delphi kept as intrinsic routines for Turbo Pascal backward compatibility, and that file has grown over 2 gigabyte in size.

I quickly found an import file had grown over the 2 gigabyte, so this was indeed the case.

The original developers didn’t do the file access using the 64-bit Seek/Position of the TStream descendant TFileStream.

Too bad, as now someone has to dig through the mothballs to find the sources (if they survived 3 different version control system switches), create a working development environment, and fix the bug.

Another instance where technical debt in IT raises its ugly head and the compound interest is really expensive.

–jeroen

via: erikmartin.com – IO Errors in Delphi.

Posted in Conference Topics, Conferences, Delphi, Delphi 5, Development, Event, Software Development, Technical Debt | 14 Comments »

A few notes on Delphi, WSDL and SOAP: passing nil values, Document/Literal versus RPC Encoded

Posted by jpluimers on 2013/05/14

I had some notes on Delphi WSDL and SOAP peculiarities somewhere, but I misplaced them.

Luckily, I found some links that explain most of my notes well:

–jeroen

Posted in Conference Topics, Conferences, Delphi, Delphi 2007, Delphi 2009, Delphi 2010, Delphi XE, Delphi XE2, Delphi XE3, Development, Event, SOAP/WebServices, Software Development | Leave a Comment »