Re: Running several drivers with pictogram support

On 09.11.2011 04:15, Stefan Herdler wrote:
> Hi,
> Am 08.11.2011 20:53, Markus Dolze wrote:
>> On 03.11.2011 02:38, Stefan Herdler wrote:
>>   
>>> Hi,
>>> Am 30.10.2011 13:10, Markus Dolze wrote:
>>>     
>>>> * What if two drivers define a different type for the same word? Like
>>>> one driver defining WLAN as a boolean type and another driver as
>>>> numeric type (level bar)?
>>>>
>>>>        
>>> Nothing will happen.
>>> The client has to verify the availability of an icon before using it.
>>> The test has to include the icontype.
>>>
>>> A client searching for a WLAN-bartype-icon wont find one on a Display
>>> with a WLAN-booltype-icon.
>>> So nothing will happen and the icon stays dark.
>>>
>>> A driver with fancy icon names which are not supported by the clients
>>> is pointless.
>>> Thant circumstance will force the drivers programmer to use the
>>> recommended names for his icons.
>>>      
>> Hi,
>>
>> I want to stress that topic even more.
>>
>> We need to keep in mind that it *is* possible and valid to load and run
>> several different drivers at the same time.
> Really? I haven't found anything in the documentation about that.
>
> Are all Displays showing the same content or are they grouped to one
> big display like it is possible with the hd44780?
> And what happens if the Displays doesn't have different sizes?
> Well, I guess, I try it out in the next days.
>
> .... now I know what purpose the loops in the drivers file have.


You are right. This feature is not well documented, but all throughout
LCDd core is is supported. It is also the reason why you see
drvthis->name" in many drivers, because this is the name of the
LCDd.conf section.

You can even load the same driver multiple times with different
settings! (But that doesn't matter for our discussion).


>>   In this case two drivers
>> that assign a different type to the same pictogram name are a problem as
>> LCDd core won't know which syntax shall be treated as correct.
>>    
> I guess in my implementation (see next mail) the core would use the
> syntax of the last driver.
>> We need to state if
>>
>> a) Loading multiple drivers that support pictograms shall be allowed (I
>> say: yes) or
>> b) it should be prevented.
>>
>> If a) then core should accept either
>>
>> c)  all pictograms supported by all loaded drivers (superset) and ignore
>> errors from those that don't support one of these or
>> d)  the common subset of pictograms supports by all loaded drivers (I
>> say: yes). In this case clients can make alternate decisions for those
>> pictograms not supported.
>>    
> A client would switch all Icons on all displays at the same time.
> Is that intended that way?
>
>

If we define it to be, yes.

Regards
Markus