Re: gEDA-user: wishful UI

[John Doty <jpd@xxxxxxxxx>]

On Aug 6, 2010, at 6:42 PM, Andrew Poelstra wrote:

> On Sat, Aug 07, 2010 at 12:51:34AM +0200, Stefan Salewski wrote:
>> 
>> The current status of my mind:
>> 
>> Having net classes in gschem would make all much easier.

Nothing new needs to be added to gschem: you can attach arbitrary attributes to net segments already.

The place where you need a new capability is gnetlist: a gnetlist back end cannot currently query a net segment for its attributes.

>> We can start drawing schematics as now. Then we define a set (or load
>> existing) of net classes, each class can define parameters like trace
>> width, clearance, maximum length, maybe impedance...
>> 
> 
> Sounds good so far.
> 
>> First we select all nets and assign a default class.
>> Then we select a other class and click on all nets which should be a
>> member of this class (power3.3V, power5.0V, gnd, fast signals, slow
>> signals, sensitive analog signals, traces with maximum total
>> length, ...). The classes of nets can be marked by colors, we go on
>> until all nets have the correct class.  
>> 
> 
> Do we want each net to have one class? Or would it be useful for nets
> to be "tagged" with multiple classes? Probably not, but it's something
> to think about.

Classification is opposed to modular, orthogonal design. Don't classify, describe. Impedance, current handling capability, maximum length, etc. are independent properties. gEDA's attribute-oriented design makes this quite natural.

Do not start from GUI and torque the design around according to that. Find a well-factored, orthogonal description of the problem space and then worry about capturing it graphically if necessary. Be hard-nosed about the "if necessary".

John Doty              Noqsi Aerospace, Ltd.
http://www.noqsi.com/
jpd@xxxxxxxxx




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