ubuntu-touch-coreapps team mailing list archive

[Riccardo Ferrazzo <f.riccardo87@xxxxxxxxx>]

Hi there,

There was a misundertand between me and Dalius regarding the +/- button, i 
said that the button is unuseful because the - button can be used either as the 
minus operator or to identify a negative number. The engine is smart enough to 
identify the use based on the position of the operator and the preceding sign.
So we don't need that button because just pressing - before a number will give 
the same result. (if we want to use negative inputs).

In data lunedì 11 marzo 2013 14:33:52, Calum K Pringle ha scritto:


Hi everyone hope you’ve had a nice weekend!
Last week was a bit mad because of UDS, but we have honestly been thinking 
about Calculators a lot of the time too! Dalius raised a good point about the 
‘equals’ feature, and as it came up on the blog too, we’ve cc’d the list in our 
reply.
*Why have an equals button?

We don't calculate automatically as it would muddy the order of operations. 1 + 
2 x 4 = 9. However, calculating automatically would result in 1 + 2 = 3 X 4 = 12. 
*
Secondly, when two things happen at the same time on screen - displaying 
typed entry AND answer - it can be confusing.
It is common to find yourself pressing the equals button for confirmation at the 
end of a calculation which also complements the physical metaphor we have 
used for the calculation history. We have also found it to be a common behaviour 
of simple calculators that pressing equals multiple times would repeat the 
previous operation.
*Why do we need +/ - key

>From last weeks discussion (copy below) we realised that it was not expected for 
subtract to be the entry point for making a negative number. For that reason, 
and to fit in the layout, we opted to add this button. *
If we follow our own direction, prioritising things like daily budgeting etc, minus 
might well be very useful! (Stay out of that overdraft!!!)



Calum


-------- Original Message --------
*Subject:*
[Ubuntu-touch-coreapps] [Calculator] Numpad layout design
*Date:*
Sat, 9 Mar 2013 14:57:42 +0200
*From:*
Dalius <dalius@xxxxxxxxxx>[1]
*To:*
ubuntu-touch-coreapps@xxxxxxxxxxxxxxxxxxx[2]


Hi,


Here is what design team proposes for simple calculator:
http://design.canonical.com/wp-content/uploads/numpad.png[3]


Here is our current implementation:
http://i.imgur.com/F2DqWdL.png[4]



Design team's proposal has two unnecessary buttons:


= - as I don't see any reason why calculations can't be automatic


± - it is simple calculator why we need negative numbers at all?




Any other opinions?


Regards,Dalius




Calum Pringle
Interaction Designer

Canonical Design Team

m: 0773 9317055e: calum.pringle@xxxxxxxxxxxxx[5]




-- 
Riccardo Ferrazzo <f.riccardo87@xxxxxxxxx>

--------
[1] mailto:dalius@xxxxxxxxxx
[2] mailto:ubuntu-touch-coreapps@xxxxxxxxxxxxxxxxxxx
[3] http://design.canonical.com/wp-content/uploads/numpad.png
[4] http://i.imgur.com/F2DqWdL.png
[5] mailto:calum.pringle@xxxxxxxxxxxxx