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 1,860 other subscribers

Archive for the ‘Delphi’ Category

Some Delphi libraries and ideas you should take a look at (link clearance)

Posted by jpluimers on 2013/03/28

There are a couple of very interesting libraries and ideas every Delphi developer should take a look at.

The list is far from complete, but should give you a good overview on what more recent Delphi language additions like attributes, generics, helpers, overloading, are capable of.

–jeroen

Posted in Delphi, Delphi 2009, Delphi 2010, Delphi XE, Delphi XE2, Delphi XE3, Development, Software Development | 3 Comments »

Delphi XE3 inside a Windows 7 VMware Fusion VM at 2560×1600 on a 15 inch Retina MacBook Pro at 2880×1800

Posted by jpluimers on 2013/03/27

I was amazed that this is still usable:

You can even run VMware Fusion 4 full screen at 2880×1800, but I prefer to have the Mac Desktop and Dock to be visible. I didn’t have any of the VMware Fusion 4 issues mentioned here.

So the only thing you need VMware Fusion 5 for is Windows 8 support.

You need SwitchResX to get the Retina MacBook to use 2880×1800 at all (otherwise you get 1920×1200 at 1.5 scale factor, which is also a 16:10 display ratio).

It really runs 5+ hours on one battery charge, which is much longer than my ThinkPad W701.

All in all, I’m very happy with this setup.

--jeroen

PS:

via: Screen Shot 2013-03-27 at 19.55.39 | Flickr – Photo Sharing!.

Click on the image or here for full size image.

Delphi XE3 inside a Windows 7 VMware Fusion VM at 2560x1600 on a 15 inch Retina MacBook Pro at 2880x1800

Posted in Apple, Delphi, Delphi XE3, Development, Mac, Mac OS X / OS X / MacOS, MacBook, MacBook Retina, OS X 10.8 Mountain Lion, Power User, Software Development | 7 Comments »

Delphi: you should avoid the `with` statement as it makes your code less future proof

Posted by jpluimers on 2013/03/27

As I wrote before, I’m with the [WayBack] Delphi with haters camp, and this is why:

Using the [WayBackwith statement in Delphi makes your code less future proof.

Originally, the with statement in Pascal was argumented in part of allowing compiler optimisations:

PASCAL User Manual and Report – Kathleen Jensen, Niklaus Wirth – Google Books

The with clause effectively opens the scope containing field identifiers of the specified record variable, so that the field identifiers may occur as variable identifiers. (Thereby providing an opportunity for the compiler to optimize the qualified statement.)

Screenshots of this 1975 book are below the fold.

The Delphi (actually even before that Turbo Pascal compiler) has no measurable difference between with and non-with code.

The debugger however, still does not support with, and there are other drawbacks of which one is below.

The below code example is just one of many. I show it because I recently bumped into doing some long overdue code porting to Delphi XE3.

Since I’ve been bitten by using with a couple of times before, it didn’t take me long to find the cause.

Example code where FIConData is of type NOTIFYICONDATAW that used to compile fine:

    with FIconData do
    begin
      cbSize := SizeOf(FIconData);
      Wnd := Self.Handle;
      uID := $DEDB;
      uFlags := NIF_MESSAGE or NIF_ICON or NIF_TIP;
      hIcon := Application.Icon.Handle;
      uCallbackMessage := WM_CAS400NTIcon;
      StrCopy(szTip, PChar(Caption));
    end;

Well, as of Compiler Version 20, it doesn’t compile any more. Read the rest of this entry »

Posted in Borland Pascal, Conference Topics, Conferences, Delphi, Delphi 1, Delphi 2005, Delphi 2006, Delphi 2007, Delphi 2009, Delphi 2010, Delphi 3, Delphi 4, Delphi 5, Delphi 6, Delphi 7, Delphi XE, Delphi XE2, Delphi XE3, Development, Event, Pascal, Software Development, Turbo Pascal, With statement | 32 Comments »

WebSphere MQ errors I encountered.

Posted by jpluimers on 2013/03/26

While porting a library from Delphi 2006 to Delphi XE2.

The really cool thing is that the Windows Event Log contains details of what I did wrong (:

  • 2277 (08E5) (RC2277): MQRC_CD_ERROR
    Oops, typo on the header file.The MQCD structure supplied was not valid.The value of the ‘CLWLChannelWeight’ field has the value ‘0’. This value is invalid for the operation requested.Change the parameter and retry the operation.
  • 2538 (09EA) (RC2538): MQRC_HOST_NOT_AVAILABLE
    Oops, typo in the host name (:Remote host ‘Host.Domain’ not available, retry later.The attempt to allocate a conversation using TCP/IP to host ‘Host.Domain’ for channel WebSphereMQChannelName was not successful. However the error may be a transitory one and it may be possible to successfully allocate a TCP/IP conversation later. &P In some cases the remote host cannot be determined and so is shown as ‘????’.Try the connection again later. If the failure persists, record the error values and contact your systems administrator. The return code from TCP/IP is 11001 (X’0′). The reason for the failure may be that this host cannot reach the destination host. It may also be possible that the listening program at host ‘Host.Domain’ was not running. If this is the case, perform the relevant operations to start the TCP/IP listening program, and try again.
  • 2009 (07D9) (RC2009): MQRC_CONNECTION_BROKENTwo causes:- The service job on the AS/400 restarted; need to make the client more robust so it gracefully handles this.
    – WebSphere MQ 7.x needs different initialization than WebSphere MQ 5.x, I didn’t get some of the extra fields initialized correctly.
    Connection to host ‘Host (dot.ted.ip.addr)(TCPPort)’ for channel ‘WebSphereMQChannelName’ closed.An error occurred receiving data from ‘Host (dot.ted.ip.addr)(TCPPort)’ over TCP/IP. The connection to the remote host has unexpectedly terminated. &P The channel name is ‘WebSphereMQChannelName’; in some cases it cannot be determined and so is shown as ‘????’.

    Tell the systems administrator.

–jeroen

Posted in Delphi, Delphi XE2, Development, MQ Message Queueing/Queuing, Software Development, WebSphere MQ | Leave a Comment »

Porting to Delphi XE2: Delphi XE2 Unit scope names not always right

Posted by jpluimers on 2013/03/21

Sometimes, Delphi XE2 gets confused after converting an old Delphi project because the Unit scope names are not correct. When creating a new Delphi XE2 application, the Unit scope names are as follows:

  • System;Xml;Data;Datasnap;Web;Soap;Vcl;Vcl.Imaging;Vcl.Touch;Vcl.Samples;Vcl.Shell

This means that if you don’t prepend a unit with a Unit scope prefix, Delphi will automatically try the list above. The thing is: when importing a Delphi project from an old Delphi version, the Unit scope names are somehow “guessed”, and not always complete:

  • System;Xml;Data;Datasnap;Web;Soap;Winapi

This means it cannot resolve the right name for the VCL units like Controls or Forms, and you get a nice compiler error: But with the default, it cannot resolve the Windows and other units in the Winapi scope. So the list I normally use is one of these:

  • System;Xml;Data;Datasnap;Web;Soap;Vcl;Vcl.Imaging;Vcl.Touch;Vcl.Samples;Vcl.Shell;Winapi;System.Win
  • System;Xml;Data;Datasnap;Web;Soap;Vcl;Vcl.Imaging;Vcl.Touch;Vcl.Samples;Vcl.Shell;Winapi;System.Win;Bde

(Yes, some apps still store Paradox data locally and use the BDE)

–jeroen

Posted in Delphi, Delphi XE2, Delphi XE3, Development, Software Development | 2 Comments »

Confusing Delphi message: [DCC Error] E2201 Need imported data reference ($G) to access ‘VarCopyProc’ from unit ‘XXX’

Posted by jpluimers on 2013/03/20

I recently had an error like this when building with packages:

[DCC Error] E2201 Need imported data reference ($G) to access 'VarCopyProc' from unit 'SynCommons'

It was a bit hard to find good information about this error, mainly because of two reasons:

  1. the documentation on E2201 Need imported data reference ($G) to access ‘%s’ from unit ‘%s’ isn’t very well written
  2. [dcc error] e2201 need imported data reference ($g) to access ‘varcopyproc’ from unit – Google Search doesn’t yield very good answers

Finally, it was the FastMM and D2007 – Delphi Language BASM – BorlandTalk.com thread pointing me to Hallvard’s Blog: Hack#13: Access globals faster ($ImportedData).

That explained the error was caused by:

  • VarCopyProc being a variable in one package
  • VarCopyProc access being needed from the package that failed to compile
  • Not having {$G+} or {$IMPORTEDDATA ON} in the failing package would prevent that access

Somehow that does not work for all cases. Apparently, the VarCopyProc isn’t exported from the Delphi RTL as that package is compiled in the $G- state.

So I had to add the USEPACKAGES define to the conditional defines list, which forces the SynCommons to use the standard version of the RecordCopy method in stead of a highly optimized one that calls VarCopyProc.

–jeroen

Posted in Delphi, Delphi XE2, Delphi XE3, Development, Software Development | 2 Comments »

Porting Delphi 2006 to XE2, fields versus properties: tightened compiler error E2197

Posted by jpluimers on 2013/03/19

When porting some communications code that used records as properties from Delphi 2006 to Delphi XE2, I came across a tightened compiler error “E2197 Constant object cannot be passed as var parameter“.

Let me first explain the good old occurrence of E2197 with some code that uses my last Variant Records example:

Just look at TPacket.InitializePacket and TPacketBase.InitializeFPacket: Basically even though the Packet property has storage specifiers indicating it directly reads from a field and directly writes to a field, you cannot pass it as a var parameter in the FillChar method.

Of course you can with a field, you can pass it to FillChar without trouble as TPacketBase.InitializeFPacket shows. Read the rest of this entry »

Posted in Delphi, Delphi 2006, Delphi XE2, Delphi XE3, Development, Software Development | 3 Comments »

Delphi “Variant Records”, a few notes

Posted by jpluimers on 2013/03/14

Variant Records are a feature that has been in the Pascal language since Standard Pascal.

A cool page for historic perspective is R3R: Pascal Features in Popular Compilers, hopefully someone will update it to more modern versions of the mentioned compilers.

There is not much official documentation on the Delphi side on this, so below some parts of a case I used for a project that started in 1997 and is still in use to day. Read the rest of this entry »

Posted in APPC, AS/400 / iSeries / System i, ASCII, COBOL, Communications Development, Conference Topics, Conferences, CPI-C, Delphi, Delphi 1, Delphi 2005, Delphi 2006, Delphi 2007, Delphi 2009, Delphi 2010, Delphi 3, Delphi 4, Delphi 5, Delphi 6, Delphi 7, Delphi 8, Delphi XE, Delphi XE2, Delphi XE3, Development, Encoding, Event, HIS Host Integration Services, Internet protocol suite, MQ Message Queueing/Queuing, SNA, Software Development, TCP, Unicode, UTF-8, WebSphere MQ | 9 Comments »

When you automatically check “Automatically close on successful compile” and the compiler progress disappears…

Posted by jpluimers on 2013/03/13

Every once in a while I manage to check “Automatically close on successful compile” during compilation, the compiler progress disappears, and I loose my clue if compilation ended or not.

This is how to fix it:

  • find the registry portion of your Delphi version, under either of these
    – HKEY_CURRENT_USER\Software\Borland\BDS\#.0
    – HKEY_CURRENT_USER\Software\CodeGear\BDS\#.0
    – HKEY_CURRENT_USER\Software\Embarcadero\BDS\#.0
    Where #.0 is your version number from this Delphi Release Dates page.
  • Under the key “Compiling”, find the string value named “Auto Close Progress Dialog”  and change it from “True” to “False”

–jeroen

via: Embarcadero Newsgroup Archive :: embarcadero.public.delphi.ide :: Re: D2006 compiler progress.

Posted in Delphi, Delphi 2006, Delphi 2007, Delphi 2009, Delphi 2010, Delphi x64, Delphi XE, Delphi XE2, Delphi XE3, Development, Software Development | 7 Comments »

Delphi “type types”: similar types but not the same type identity, some examples.

Posted by jpluimers on 2013/03/12

Few people know about a Delphi language feature that has been present since Delphi 1: prepending the type definition with a type keyword to make the type getting a new identity.

Each time I use it, I have to do some browsing for the consequences, and this time I wrote down some notes and created a small example program (source is also below).

This time I needed it when writing class wrappers on top of the Delphi bindings for WebSphere MQ.

WebSphere MQ has Queues where you can put and get messages. It also has Queue Managers to which you connect, and that provide queuing services and manages queues.

Both Queues and Queue Managers have names that can be up to 48 (single byte) characters long.
Those names mean totally different things, so though the have similar data types, they have a different identity.

The same holds for 20 byte character arrays (they can be used as names for ChannelNameShortConnectionName and MCAName). The 264 byte character array is so far used for ConnectionName only.

Distinguishing those types: That’s what “type types” in Delphi are all about. Read the rest of this entry »

Posted in CP437/OEM 437/PC-8, Delphi, Delphi 1, Delphi 2005, Delphi 2006, Delphi 2007, Delphi 2009, Delphi 2010, Delphi 3, Delphi 4, Delphi 5, Delphi 6, Delphi 7, Delphi 8, Delphi x64, Delphi XE, Delphi XE2, Delphi XE3, Development, Encoding, Shift JIS, Software Development, Unicode, UTF-8, UTF8 | 1 Comment »