Help me with a solution for what could be solutioned by virtual static fields... in FPC

Posted by Gregory Smith on Stack Overflow See other posts from Stack Overflow or by Gregory Smith
Published on 2010-02-28T02:53:52Z Indexed on 2010/04/10 22:33 UTC
Read the original article Hit count: 432

Filed under:

freepascal

|

fpc

|

oop

|

design

|

design-patterns

Hi
I'm doing an event manager in Freepascal
Each event is an object type TEvent (=object), each kind of event must derive from this class.
Events are differentiated by an integer identificator, assigned dynamically.
The problem is that i want to retrieve the event id of an instance, and i can't do it well.

All instances of a class(object) have a unique id => so it should be static field.
All classes have a diferent id => so it should be virtual.
Event ids are assignated in run time, and can change => so it can't be a simple method

In sum, I can't put all this together.
I'm looking for an elegant solution, i don't want to write a hardcoded table, actualizing it in every constructor... etc, i'd prefer something taking advantage of the polymorphism
Can anyone help me with another technical or design solution?
I remark I don't want to use class instead of object construct.(property doesn't work on objects? :(

© Stack Overflow or respective owner

Related posts about freepascal

Exchanging strings (PChar) between a Freepascal compiled DLL and a Delphi compiled EXE

as seen on Stack Overflow - Search for 'Stack Overflow'
After a lot of experimentations, I found a way to exchange PChar from a FreePascal compiled DLL with a Delphi compiled EXE. I'm in charge of both the DLL and EXE source code but one MUST BE in FreePascal and the other one in Delphi. My solution involves the following methods in the DLL: function… >>> More
Using Freepascal\Lazarus JSON Libraries

as seen on Stack Overflow - Search for 'Stack Overflow'
I'm hoping for a bit of a "simpletons" demo\explanation for using Lazarus\Freepascal JSON parsing. I've asked a question here but all the replies are "read this" and none of them are really helping me get a grasp because the examples are bit too in-depth and I'm seeking a very simple example to help… >>> More
Compatible tool for internationalize Delphi & FreePascal program

as seen on Stack Overflow - Search for 'Stack Overflow'
I'm a program made in Delphi & Lazarus/FreePascal at the same time, so I can reach linux & osx customers. I want to know if exist a cross-plataform tool that work in both environments so I can add multiples languages. I find http://dxgettext.po.dk/Home but is broken (not compile in Lazarus/OSX)… >>> More
Cross-platform tool for translating and internationalizing Delphi & FreePascal programs

as seen on Stack Overflow - Search for 'Stack Overflow'
I'm writing a program for both Delphi and Lazarus/FreePascal, so I can also reach customers using Linux or Mac OS X. Is there a cross-platform tool that works in both environments too, so I can add multiple languages? I tried GNU Gettext for Delphi and C++ Builder, but it does not compile in Lazarus… >>> More
Is there a central FreePascal/Lazarus Component repository?

as seen on Stack Overflow - Search for 'Stack Overflow'
I'm looking to find something like Torry but instead of being Delphi centric, it should be Lazarus centric. I'm aware of the Source Forge Project Code and Component Repository but I'm looking for something with more span and a bit more searching features. >>> More

Related posts about fpc

Why is WPO(whole-program optimization) not doing any improvements in my program size? (FPC 2.4.0)

as seen on Stack Overflow - Search for 'Stack Overflow'
I use FPC 2.4.0 for WinXP(binary from the official page), also tryed with same version but compiled from source on my comp. I put something like this: I:\pascal\fpc-2.4.0.source\fpc-2.4.0\compiler\ppc386 -FWserver-1.wpo -OWsymbolliveness -CX -XX -Xs- -al -Os -oServer1.o Server I:\pascal\fpc-2.4… >>> More
Unicode in fpc doesn't work

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi I'm Romanian and I can't write Unicode in Free Pascal Compiler. I try to write ?,î,â,a,? and it doesn't work. I tried with dos windows changed fonts, tried chcp. I even made a batch file which would do chcp 65001 and start the app. By default when I tried to write these letter I got "?" but when… >>> More
Help me with a solution for what could be solutioned by virtual static fields... in FPC

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi I'm doing an event manager in Freepascal Each event is an object type TEvent (=object), each kind of event must derive from this class. Events are differentiated by an integer identificator, assigned dynamically. The problem is that i want to retrieve the event id of an instance, and i can't do… >>> More
Using a indentifier or reserved word in a automation object under FPC

as seen on Stack Overflow - Search for 'Stack Overflow'
Actually i am using OLE automation under Free Pascal , but some objects have properties which uses reserverd words as names, so i cannot compile the code. check this sample MyObj : OleVariant; begin MyObj := CrealeOleObject('AObject'); MyObj .Descriptor := Param1; MyObj .Type … >>> More
Windows CE Programming Serial Port - Getting Garbled Output

as seen on Stack Overflow - Search for 'Stack Overflow'
I am programming a Windows CE 6 device (Motorola MC3100 scanner Terminal). Using Lazarus FPC to compile it. After 3 weeks work I reluctantly post here in the hope someone can suggest why I am getting garbled output from the serial port. The code I am using is posted below. This is the standard code… >>> More