Zitat von Graeme Geldenhuys <[email protected]>:
[...]
Here is the difference....
Kylix 3 type signature:
THelpEvent = function(HelpType: THelpType; HelpContext: THelpContext;
const HelpKeyword: String; const HelpFile: String;
var Handled: Boolean): Boolean of object;
Free Pascal & Delphi type signature:
THelpEvent = function (Command: Word; Data: Longint;
var CallHelp: Boolean): Boolean of object;
Lazarus type signature:
THelpEvent = function(Command: Word; Data: PtrInt;
var CallHelp: Boolean): Boolean of object;
Where Data is PHelpInfo. It is used by the widgetsets.
[...]
The Kylix 3 signature seems more useful to me as a cross-platform
developer, as it clearly defines the parameters (no ambiguous
parameters) and sends all information needed to the OnHelp event
handler. My proposal is that the THelpEvent definition in FPC be changed
to the Kylix 3 signature.
I miss a "Sender: TObject".
Why - you ask?
* The K3 THelpEvent parameters are more related to newer help systems.
Not tied to the deprecated WinHelp from Microsoft.
* The parameters used in that even is what is already defined and
used elsewhere:
- HelpType (TComponent)
- HelpContext (TComponent)
- HelpKeyword (TComponent)
- HelpFile (TApplication)
So yes, this will break backward compatibility in Lazarus, but Lazarus
is not the only GUI toolkit and development tools using FPC and it's
classes. Also FPC and Lazarus have already implemented things that break
compatibility with Delphi - simply because FPC and Lazarus are not so
closely tied to Windows; it may be a better design and for the greater
good (better cross-platform support).
I see no gain in Kylix compatibility.
Lazarus has already a help system, which is quite different from Delphi's.
Mattias
--
_______________________________________________
Lazarus mailing list
[email protected]
http://lists.lazarus.freepascal.org/mailman/listinfo/lazarus
