[M3devel] UI, Trestle, native... Cocoa??

Darko darko at darko.org
Tue Sep 28 11:00:21 CEST 2010 

I've only encountered one changed function call in the Mac OS API in 25 years. It really never changes, with good reason - everything is distributed as binaries so they have no scope to change things unless they are new calls or symbols.

Portability can be achieved at a higher level, which is the approach I take. The point is is to give the user the experience they're looking for, which his very important. It should be integrated as much as possible. For instance you can right click and get a menu in pretty much any text in Cocoa and look up the word in the dictionary. You get that for free and users expect it everywhere.

Several APIs I've done are by hand using several regular expression search and replaces. Automating it is relatively easy because it doesn't have to be completely general, it only has to parse the header files you are targeting, not every C syntactic construct, which would be a very bad trip. When I did the Mac Carbon APIs I had a file of exceptions which handled the "too hard basket" of declarations. Trying to use the more powerful tools just means you have a steep learning curve and you end up with something  messy and unpredictable which you have to hack anyway.

I agree Carbon is dying, the whole API has been "deprecated" by Apple, but it is the only C based API to be had so I'm sort of stuck for now. 64 bit is no big deal I really don't need an address space bigger than 4GB and I can use long integers in 32 bit code. But Cocoa would be nice because all the new pretty elements are being built in it.



On 28/09/2010, at 1:47 AM, Jay K wrote:

> 
>> but Mac OS APIs almost never change
> 
> 
> Mostly agreed.
> But there can be silent breaks when only linking gets checked.
> At least libc across various systems has a bad track record.
> 
> 
> I think therefore we're talking about generating wrapper libraries, more or less idiomatic.
> 
> 
>> or on Windows the user can change the look whenever they want.
> 
> This is actually allowed for to some extent.
> It is the point of GetSysColor.
> 
> 
> "Native" would be good imho because it just generally looks so much better.
> However it leads to loss of portability.
> I would really rather see KDE or wxWidgets or somesuch.
> They do look close to native and do things themselves to varying degrees.
> 
> 
> Look at our WinBase.i3 for a feel for what people have done in the past.
> That is seemingly a direct hand written translation.
> Do that for a few functions/structs?
> And then automate it somehow?
> There is "gccxml" that parses headers and spits out xml, you can then use xml-dom or xsl etc.
> There might also be enough runtime type information in Macintosh binaries, to save you from parsing declarations.
> 
> 
> Realize Carbon is dying to some degree -- stuff not being ported to 64bit.
> 
> 
> 
> - Jay
> 
> 
> ----------------------------------------
>> From: darko at darko.org
>> Date: Tue, 28 Sep 2010 01:39:40 -0700
>> To: jay.krell at cornell.edu
>> CC: m3devel at elegosoft.com
>> Subject: Re: [M3devel] UI, Trestle, native... Cocoa??
>> 
>> I think the point is that GUI support for Cocoa and Windows is useful to myself and possibly other people, I'm not really counting how many platforms it will work on - I need those two platforms and I need them native. Actually I need Carbon and Windows right now but Cocoa would be very nice.
>> 
>> Implementing Trestle to look like Cocoa would be non-trivial, and pointless. The idea is that you want your GUI to change when the underlying OS changes, which it does very regularly, or on Windows the user can change the look whenever they want.
>> 
>> As far as static breaks go, there would be links to library calls so when they change the linking would break, but Mac OS APIs almost never change, they just get updated with new calls so it wouldn't really be a problem. I don't know if there is any subtle issues wrt Obj-C but I doubt it.
>> 
>> 
>> On 28/09/2010, at 1:26 AM, Jay K wrote:
>> 
>>> 
>>> I think you have a few unrelated choices:
>>> 
>>> 
>>> Make Trestle look like Macintosh when on Macintosh.
>>> This is altering some low level drawing code, mouse logic. Doable.
>>> It has little/nothing to do with Objective C or Cocoa.
>>> 
>>> 
>>> Wrap other GUI libraries.
>>> There are many to chose from.
>>> With more or less idiomatic wrappers.
>>> If you are going to do this, please do something that runs on more than one system.
>>> KDE, wxWidgets, FLTK, GTk+, etc.
>>> But GTk+ doesn't seem well supported on Windows.
>>> KDE would be my choice. It looks good, it seems to be fairly nice, complete, and evolving fairly rapidly, it has money behind it.
>>> An idiomatic wrapper for Cocoa is just one GUI library you could wrap, and it'd have the least value since it only runs on one system. Granted, a slowly growing in popularity system, and iPhone.
>>> 
>>> 
>>> If you get the hang of things, sure, go all out, wrap several. Please.
>>> 
>>> 
>>> SWIG might be useful here.
>>> 
>>> 
>>> Please whatever it is, make sure it gets static checking.
>>> Assume the C/C++ headers underneath you will change, and you want a compilation break when that happens. Instead of silent memory corruption.
>>> 
>>> 
>>> I don't think Trestle implemented on top of Cocoa makes much sense.
>>> It does make some. Using CoreGraphics instead of X Windows. Using Carbon or Cocoa event manager instead of X Windows.
>>> But given that Trestle draws things itself, "porting" analogous to where the Win32 layer varies from the X layer, wouldn't give you something that looks like Macintosh.
>>> 
>>> 
>>> 
>>> - Jay
>>> 
>>> ----------------------------------------
>>>> From: darko at darko.org
>>>> Date: Mon, 27 Sep 2010 23:47:06 -0700
>>>> To: jay.krell at cornell.edu
>>>> CC: m3devel at elegosoft.com
>>>> Subject: Re: [M3devel] UI, Trestle, native... Cocoa??
>>>> 
>>>> I think that's the problem with implementing Trestle on another GUI, it's too idiosyncratic in its structure. Generated Obj-C interfaces using OBJECT are definitely the way to go. It mostly involves a thin layer but all field access is done using functions from what I understand so it won't be completely natural without some syntax extensions to M3. The question is if it matters.
>>>> 
>>>> 
>>>> On 27/09/2010, at 11:38 PM, Jay K wrote:
>>>> 
>>>>> 
>>>>> I think what is a bit unusual about Trestle is how much it implements itself.
>>>>> 
>>>>> 
>>>>> It does *not* appear to be a thin wrapper around a native event or control or window management interface. It appears to handle event routing itself, clipping itself, some aspects of drawing itself. I think it might only depend on the ability to draw dots, and to get some form of keyboard/mouse events.
>>>>> 
>>>>> 
>>>>> *and* it is multithreaded.
>>>>> Unusual for GUI libraries (e.g. Java swing).
>>>>> 
>>>>> 
>>>>> Whenever I read about it, I get lost once they start talking about the locking protocol.
>>>>> 
>>>>> 
>>>>> The "split" layout mechanism seems maybe nice.
>>>>> It bugs me how Windows encouraged pixel count layout and how much fixed size gui there is.
>>>>> 
>>>>> 
>>>>> I suspect the authors knew or discovered far more than any of us here.
>>>>> 
>>>>> 
>>>>> You probably can make a decent binding to Cocoa.
>>>>> But I don't know.
>>>>> 
>>>>> 
>>>>> Runtime and compiler support, often allow for nicer syntax, but I really don't know if a mere wrapper library will be nice/graceful or not. I would suggest looking into if you have enough "generation" ability to, e.g. spit the headers back out, or generate a nicer C++ library. And then you can probably without much difficulty make either a "straightforward" wrapper library or maybe even something a bit more idiomatic ... e.g. do you use OBJECT or not?
>>>>> 
>>>>> 
>>>>>> Trestle under X did not took my breath
>>>>> 
>>>>> 
>>>>> I find Trestle GUI pretty difficult to interact with.
>>>>> Using scrollbars for example.
>>>>> I have trouble with most X GUI actually.
>>>>> 
>>>>> 
>>>>> The Win32 changes are a bit encouraging though. With only a little bit of change the GUI is a slightly less little bit better. We still don't have the dpi problem fixed properly. I don't have a high dpi system.
>>>>> 
>>>>> 
>>>>> Qt looks very nice...
>>>>> 
>>>>> 
>>>>> - Jay
>>>>> 
>>>>> ----------------------------------------
>>>>>> From: dragisha at m3w.org
>>>>>> To: darko at darko.org
>>>>>> Date: Tue, 28 Sep 2010 08:23:04 +0200
>>>>>> CC: m3devel at elegosoft.com
>>>>>> Subject: Re: [M3devel] UI, Trestle, native... Cocoa??
>>>>>> 
>>>>>> I am about to do a port of some simple (in its GUI aspect) application
>>>>>> to Mac.
>>>>>> 
>>>>>> I am also discouraged (at least tried to) to near death :) by a guy from
>>>>>> another community, he is 1000% sure Modula-3 cannot be made to support
>>>>>> Cocoa not a "g" of gracefully.
>>>>>> 
>>>>>> Trestle under X did not took my breath. After peeking and pooking around
>>>>>> sources a bit, I think it was very nice project in its time, and
>>>>>> reasonable one to use 12-15yrs ago, but things moved on. In other words
>>>>>> - I cannot think an explanation to my customer why a GUI appliction of
>>>>>> mine is not more.... GUIsh...
>>>>>> 
>>>>>> I did a lot of Gtk+ in Modula-3, under Linux (and colleague did his
>>>>>> testing on Windows while he was working with me on it) and from that
>>>>>> experience I know it's not impossible to make native GUI work.
>>>>>> 
>>>>>> In other words - count on me for low level binding/interfacing once I
>>>>>> start doing my work on Mac - in few weeks time.
>>>>>> 
>>>>>> On Mon, 2010-09-27 at 13:12 -0700, Darko wrote:
>>>>>>> I can't say I'm interested in Trestle, and getting compatibility with Cocoa objects might be a hassle, but I am interested in Cocoa support in M3. The things that need to be done to make this happen are:
>>>>>>> 
>>>>>>> - run time support for Objective-C objects, basically the ability to call Obj-C methods and reference Obj-C fields in objects
>>>>>>> - conversion of Cocoa interfaces to M3. This can probably be automated to some degree, I've already gone through the process with Carbon API (admittedly from Pascal interfaces).
>>>>>>> 
>>>>>>> If anyone wants to take on the first task I'd be happy to take on the second. Apple has Obj-C internals doco on the web.
>>>>>>> 
>>>>>>> 
>>>>>>> On 25/09/2010, at 1:42 PM, Dragiša Durić wrote:
>>>>>>> 
>>>>>>>> Is it feasible to make it mora native to Mac? Interesting?
>>>>>>>> 
>>>>>>>> On Sat, 2010-09-25 at 12:31 +0000, Jay K wrote:
>>>>>>>>> It draws all the controls itself.
>>>>>>>>> The Mac version is the X Windows version.
>>>>>>>>> 
>>>>>>>>> - Jay
>>>>>>>>> 
>>>>>>>>> ----------------------------------------
>>>>>>>>>> From: dragisha at m3w.org
>>>>>>>>>> To: m3devel at elegosoft.com
>>>>>>>>>> Date: Sat, 25 Sep 2010 13:41:19 +0200
>>>>>>>>>> Subject: [M3devel] UI, Trestle, native... Cocoa??
>>>>>>>>>> 
>>>>>>>>>> Anybody working UI's with Trestle? It is mapped no native widgets on
>>>>>>>>>> Windows? What about Mac?
>>>>>>>>>> --
>>>>>>>>>> Dragiša Durić
>>>>>>>>>> 
>>>>>>>>> 
>>>>>>>> 
>>>>>>>> --
>>>>>>>> Dragiša Durić
>>>>>>>> 
>>>>>>> 
>>>>>> 
>>>>>> --
>>>>>> Dragiša Durić
>>>>>> 
>>>> 
>>

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