[Lazarus] WriteLn back to the GUI
listmember at letterboxes.org
Wed Oct 23 21:14:15 CEST 2013
On 2013-10-23 21:46, Sven Barth wrote:
> "Writeln" is a complex functionality. So you should better trust us
> (hint: I'm a compiler developer) when we say this is more difficult
> than you imagine.
I know you're a compiler developer; and, I have no intention of
challenging you on that front --actually, I don't want to challenge
anyone on any front at all, I have enough challenges as it is.
And, I am not trying to replace all of WriteLn functionality with my own
I am guessing, just guessing, FPC uses WriteLn to communicate with other
modules (perhaps Lazarus too), but I also need its output directly in my
How about this:
Instead of redirecting all of its output through the callback, I only
use callback to redirect a copy of its output --leaving the rest of its
>>> As I wrote in my post: See the CRT unit.
>>> It does exactly that. You need maybe 20 lines of code to do as you
>> Will do, thanks.
>> But, let me ask this:
>> If I used the CRT unit, would I need to add it to every single unit in
>> the project that uses WriteLn?
> Michael did not say that you should use the CRT unit, but that the
> unit implements something similar and that you should take a look at
> it to implement your own variant of it.
> And then you need to include your own unit only once (e.g. either you
> put the "hooking" into the initialization section or you do it at the
> start of your program)
I took a look at crt.pas and AFAIC it is not significantly less complex
than finding the place of WriteLn in compiler code and altering it to
use a callback ;)
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