Re: GtkAda question

[DrPi <314@drpi.fr>]

Le 14/04/2021 à 08:11, Dmitry A. Kazakov a écrit :
> On 2021-04-13 23:36, DrPi wrote:
>> Le 13/04/2021 à 13:55, Dmitry A. Kazakov a écrit :
>>> On 2021-04-13 13:07, DrPi wrote:
>>>
>>>> That's what I've written (and use).
>>>> However, I think the use of Error is incorrect in all Key_File 
>>>> functions.
>>>> I will investigate further.
>>>
>>> Handling GError is tricky. You must call Error_Free on it if returned 
>>> not null.
>>>
>> Yes, I've read this in the Gtk documentation.
>>
>> Is there a good GtkAda documentation (with examples) somewhere ?
> 
> No that I know. BTW, that would not be documentation, rather tutorial, 
> book etc. GtkAda is only bindings. You would not expect it to cover Gtk 
> topics.
> 
>> I've found a french tutorial. Very instructive but incomplete and a 
>> little bit outdated.
>> I also read Test code in GtkAda repository. Again, useful but very 
>> incomplete.
> 
> Use Gtk tutorials and then translate that knowledge back to GtkAda, it 
> is more or less straightforward.
> 
That's what I do. But there are things specific to GtkAda that are not 
always easy to find. For example, GtkAda makes use of Gint data types. 
You have to use Glib.To_Gint() function to do the conversion. You also 
have to use Glib.Convert.Locale_To_UTF8() function to be able to use 
Strings with non ASCII characters. It is almost impossible to find this 
by yourself.

>>> Why on Earth you even use Key_File? It is much simpler to parse 
>>> manually in Ada.
>> When I need a functionality I start to look at what already exists.
>> Key_File is what I need. Why rewrite it myself ?
> 
> I doubt anybody needs g_key_file. For start, it loads all file into the 
> memory. Surely you do not want that if there are lots of parameters and 
> settings. Or, put it this way, if you can load/store your parameters 
> object, then there are better means than *.ini files.
> 
> If you cannot then you need some cashing infrastructure to avoid massive 
> I/O (and potential data loss). A typical solution for the latter would 
> be a persistent storage, maybe, backed by a DB, like SQLite or a custom 
> written storage. Or things like GtkRecentManager [*] and Windows registry.
> 
I only need to store and retrieve few data like window position and 
size. Key_File is made for this.

>> And I currently don't have the knowledge to write it myself.
> 
> You do not know Ada text I/O or Ada stream attributes?
Not yet (except Put_Line() of course).

> 
>> I'm learning Ada at home, on my spare time. And lazy I am. For sure ;)
> 
> Even more reasons to write it yourself all in Ada [**].
> 
This could be a good exercise.

> ----
> * Note that GtkRecentManager suffers the potential problems I mentioned. 
> You may experience corruption of *.xbel files (the equivalent to *.ini, 
> but in XML) because it is poorly designed.
> 
> ** I see in another response that it is already done in Ada. Though I 
> never used it, I am certain it is better designed and written than 
> g_key_file.
>