On Fri, 12 Nov 2004 22:32:48 +0100 (CET) [EMAIL PROTECTED] wrote: > > > On Fri, 12 Nov 2004, Mattias Gaertner wrote: > > > > > I don't know, if this is the right list, but the topic is quite fpc > > specific and needs some compiler gurus: > > > > The Lazarus IDE needs to create new classes at runtime. For example when > > loading/creating a descendent of TDataModule named TMyDataModule, > > it needs a unique TMyDataModule = class(TDataModule) complete with vmt, > > method table (empty), field table (empty), typeinfo > > (no properties), and .. ? > > At the moment lazarus only supports TDataModule and TForm, so I was able to > > just define the two and copy. > > But for inheriting I need 'real' custom classes. > > > > Creating the empty method table, field table and new typeinfo seems to be > > easy. But I found some fields, which I don't know: > > In objpash.inc there is > > const > > vmtInstanceSize = 0; > > vmtParent = sizeof(ptrint)*2; > > > > The fields behind vmtParent are easy (at least I think so). But what about > > the 8 bytes (i386) behind vmtInstanceSize and in front of vmtParent? > > They seem to be a negative number and a pointer? What are they are good for? > > > > And: Is this solution portable or will I get into trouble? > > What are you trying to do ?
Well, that's a long story ... > As soon as you have the class, you know everything there is to know or that > you need to know. You don't need to have more than the TMyClass class pointer. Wow. That would be great. > In the case of TMyDatamodule, you have the TMyDataModule class pointer, so > You can create an instance and 'show' that on screen ? Where do I get this TMyDataModule class pointer? I also want TMyDataModule1, TMyOwnDataModule, TAnotherMyDataModule, ... . The classname should be different. And I want a TMyGrandChildDataModule = class(TAnotherMyDataModule) = class(TMyDataModule) = class(TDataModule). I only have a TDataModule class pointer. The rest should be created by the IDE just from class names. But maybe I think too complicated. Fact is, I have class names and I need class pointers. > For forms you must only assume it is a descendant of TCustomForm. > > The Delphi IDE also can only handle things that descend from TCustomForm and > TDatamodule. That's not sufficient. I want at least TComponent. > When registering custom forms or datamodules in the IDE, you > need to supply Delphi with the actual class pointer, and then it knows what > to do... > If you want I can show you code that registers custom forms in the Delphi > IDE, I use it myself at work. Yes, please enlighten me. :) Mattias _______________________________________________ fpc-devel maillist - [EMAIL PROTECTED] http://lists.freepascal.org/mailman/listinfo/fpc-devel
