Re: What function sets up the GNUstep environment?

Just FYI, you still need a display server (whether that's X or Windows or whatever) to start a headless application.  Is this an issue?  If it is, then we would need something like the null backend.

On Tue, Nov 3, 2020 at 8:48 PM Gustavo Tavares <gustavotavares@mac.com> wrote:

Yes Greg, I want to archive / unarchive GUI classes for Attributed String. Colors, Fonts, Attachments, etc.

On Tue, Nov 3, 2020, at 6:38 PM, Gregory Casamento wrote:
Gustavo,

NSCoder and all of its implementations (NSArchiver/NSUnarchiver/NSKeyedArchiver/NSKeyedUnarchiver) are entirely implemented in Foundation/Base. Unless you need to archive (or unarchive) AppKit/GUI classes, then you really don't have any need for AppKit/GUI. What are your requirements? Perhaps we can close in on what you really need.

NSAttributedString is also implemented in Foundation/Base (see here... https://developer.apple.com/documentation/foundation/nsattributedstring?language=objc). So you should be able to use it without loading GUI as well.

GC

On Tue, Nov 3, 2020 at 4:44 PM Gustavo Tavares <gustavotavares@mac.com> wrote:

To be even more specific, most of what I do would have to do with NSCoding and storing NSAttributedString attributes—most of which are part of AppKit, not Foundation.

On Tue, Nov 3, 2020, at 5:39 PM, Gustavo Tavares wrote:
Confirming, I just need headless so that I have access to the AppKit functions I call.

I don’t need any output whatsoever.

On Tue, Nov 3, 2020, at 5:22 PM, Gregory Casamento wrote:

Gustavo,

What is your true aim here? If having a "headless" application is all you really need, so that you have access to AppKit functions then that is pretty easy. You don't need to have a gui model (xib, nib, gorm, etc) attached to the application.

I like the idea of a no-op or null backend as this might allow us some other freedoms with respect to testing.

On Tue, Nov 3, 2020 at 3:53 PM Gustavo Tavares <mucholove@fastmail.com> wrote:

Yes, Fred, Greg,

This is exactly what I need and was looking at doing just that. I did some no-op classes but I have very little experience with there system to do so immediately.

It doesn’t look like a lot of files but I might be wrong. There are a lot of subtle interactions that I have already bumped into.

For example, right now, I’m still working through the call to +[NSProcessInfo initalizeWithArguments:count:environment:] (I think I have the name right but I didn’t look it up on my phone.

Calling this didn’t solve my problem immediately.

As for testing it’s pretty wonderful. I already have some tests running by enclosing them in a framework (Marcel WeiHer does this in MPWTest)

The use case as a server backend is compelling too because you can save and interact with User preferences for Font, Color, Theme, etc on the backend just as you would on a frontend.

On Tue, Nov 3, 2020, at 4:19 PM, Gregory Casamento wrote:
This is a really interesting notion. Would the no-op backend (I think we need a better name) be able to print, or output postscript? Would it be possible to use it for testing GUI in some way?

GC

On Tue, Nov 3, 2020 at 12:06 PM Fred Kiefer <fredkiefer@gmx.de> wrote:
Your problem got me thinking. Would it help you if we offered a „no-op“ backend for GNUstep? That is a backend where both the window and the drawing system would be implemented as no-operations.

We could try to get this done as a special GNUstep back configuration. Most likely we could cheat here by reusing the gsc classes as a real drawing backend, which of course would not draw but raise subclassResponsibility:. That means we only need code for the window/event part and a lot of configuration to switch all the extra libraries off.

Cheers,
Fred

> Am 03.11.2020 um 16:02 schrieb Gustavo Tavares <mucholove@fastmail.com>:
>
> Thank you! This is great.
>
> I think I'm going to make some sort of subclass—NSCommandLineApplication.
>
> I did implement some of the backend classes in a -doNothingMethod { ; } style: GSFontInfo / GSFontEnumerator.
>
> Previously I just tried running X11 and calling it a day—but that didn't work. So goes the rabbit hole...
>
> Looks like it will be fun though. Just gotta love Objective-C :)
>
> Gustabo
>
>
> On Mon, Nov 2, 2020, at 11:20 PM, Ivan Vučica wrote:
>> Based on https://github.com/gnustep/libs-base/blob/3752016/Source/NSProcessInfo.m#L140-L154, this comes from https://github.com/gnustep/libs-base/blob/3752016/Source/NSProcessInfo.m#L919 or https://github.com/gnustep/libs-base/blob/3752016/Source/NSProcessInfo.m#L1021.
>>
>> If these were GUI apps, I’d recommend calling NSApplicationMain which takes argc and argv and sorts this out for you – in fact, that’s ideally exactly what you should do if you’re using any GUI methods. You’re saying you’re using certain GUI classes on the server; if you believe they will actually behave correctly in a server environment without gnustep-back (not a given; hypothetically, NSColor could heavily depend on Opal’s CGColorRef), you may be able to call NSProcessInfo +initializeWithArguments:..., too.
>>
>> Otherwise study https://github.com/gnustep/libs-gui/blob/0ccdb278d4cc8ad60f033892a5105e0532261838/Source/Functions.m#L63 carefully, but don’t be surprised if lack of x11 breaks GUI classes. You break it (into pieces), you get to pick up those pieces and glue them together :)
>>
>> (Yes, I noticed you said you went ahead and removed some backend-dependent code. This sounds like it’ll be a lot of fun…)
>>
>> Ivan Vučica
>>
>> From: Gustavo Tavares
>> Sent: Tuesday 3 November 2020 02:13
>> To: GNUstep Discuss
>> Subject: What function sets up the GNUstep environment?
>>
>>
>> Hi!
>>
>> Was wondering what function sets up a GNUstep environemtnt?
>>
>> Getting this error:
>>
>> GNUSTEP Internal Error:
>> The private GNUstep function to establish the argv and environment
>> variables was not called.
>>
>> Mismatched library versions between GNUstep Foundation (base) and AppKit
>> (gui) is most often the cause of this message. Please be sure you
>> are using known compatible versions and not a mismatched set. Generally,
>> we recommend you use versions of base and gui which were released together.
>>
>> For more detailed assistance, please report the error to bug-gnustep@gnu.org.
>>
>> ---
>>
>> For context—I built a seperate framework that extracts some "GUI" classes with the intention to use them semantically on a server. (Such as NSImage, NSColor, NSFont...)
>> I already went through the business of overriding / deleting some of the backend functions so that the classes would be "initalized" and wouldn't need to be rendered to screen.
>>
>> Stuck here.
>>
>> Where should I look?
>>
>>
>> Thank you,
>> G

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Gregory Casamento
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--
Gregory Casamento
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--
Gregory Casamento
GNUstep Lead Developer / OLC, Principal Consultant
http://www.gnustep.org - http://heronsperch.blogspot.com
https://www.patreon.com/bePatron?u=352392 - Become a Patron
https://gf.me/u/x8m3sx - My GNUstep GoFundMe
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Gregory Casamento
GNUstep Lead Developer / OLC, Principal Consultant
http://www.gnustep.org - http://heronsperch.blogspot.com
https://www.patreon.com/bePatron?u=352392 - Become a Patron

https://gf.me/u/x8m3sx - My GNUstep GoFundMe

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From:	Gustavo Tavares
Subject:	Re: What function sets up the GNUstep environment?
Date:	Wed, 04 Nov 2020 15:19:09 -0400
User-agent:	Cyrus-JMAP/3.3.0-530-g8da6958-fm-20201021.003-g69105b13-v35