kicad-developers team mailing list archive

[Brian Sidebotham <brian.sidebotham@xxxxxxxxx>]

On 24 June 2010 21:36, Wayne Stambaugh <stambaughw@xxxxxxxxxxx> wrote:
> On 6/24/2010 3:44 PM, Dick Hollenbeck wrote:
>> On 06/24/2010 02:19 PM, Wayne Stambaugh wrote:
>>> In preparation for the forth coming changes to the component library
>>> file format, I would like to make some changes in the design of the
>>> component library object format and the component library editor behavior.
>>>
>>> The current component library design creates aliases as a stand alone
>>> objects that reference the actual component object.  The component
>>> object also keeps a copy of the alias information (strings) in a
>>> wxStringArray.
>>
>>
>>>  It seems to me that an alias has no meaning without the
>>> associated component and keeping a copy of the alias data in the
>>> component object is redundant.  I propose that the component object
>>> maintain the list of it's alias objects and only components are added to
>>> the library object.
>>
>> The above 2 sentences seem to contradict each other.  Can we assume that
>> last one is what you intended?
>
> Oops!  You are correct it is the last one.

If I understand correctly, what you want to do is move all aliases of
a component into the component object? I think this would make a good
improvement for some future uses of aliases.

At the moment, aliases are not very powerful because of some limitations.

I don't know whether you caught any of the heavy symbol library
discussion a few weeks ago, but a heavy symbol library can be
implemented much easier is aliases are made a bit more powerful.

At the moment for example, I could create an alias which has a
different footprint, but not an alias that has a different value. It
would be another step towards good support for a heavy symbol library
to be able to change the value of aliases. As well as this, aliases
really need to support the template field names. At the moment you
cannot have these fields in an alias. This would allow aliases to be
used as a heavy symbol library, where only one graphic would need to
be created.

Further on from that, aliases would be easily selectable via a pop-up
list box or similar. One of the biggest time wasting parts of a heavy
symbol library (if taken to it's extreme) is that simply changing a
value of a passive component has to be done by replacing the
component. If a hotkey can be used on a component when editing a
schematic in eeschema to bring up a listbox of all of the aliases of
the component, one can quickly be selected to change the value of the
part.

This sort of thing works well when you need to change things like SMT
electrolytics, as you would simply select by voltage and capacitance
and the correct case size footprint would come from the alias. There's
no risk of forgetting to change the footprint because you've altered
the value.

I just wanted to give a possible good future use for aliases in case
any of this is useful whilst you are working in this area.

Best Regards,

Brian.