ubuntu-phone team mailing list archive

[Riccardo Ferrazzo <f.riccardo87@xxxxxxxxx>]

I've removed realtime calculations from the calculator application, now to get 
the result you have to press the equal button, and to start a new calculation you 
have to press C button.


Replies in line


On 11 Mar 2013, at 18:33, Dalius wrote:


Automatic calculations reevaluates the whole equation when new operation is 
added - therefore 1 + 2 x 4 will be 9 as it should be. Simple question: do you 
have device or possibility to test current implementation? Trying live thing might 
get better feeling how it works.


Wouldn't that be more confusing though, as then you'd *think* you were 
multiplying 3 by 4, not 2, because it would be a 3 that you see on the screen?


Another idea: we could do testing with users who have not seen previously 
calculator and see how they react because we are guessing now. Preferably we 
should do that with non-technical users.




Sure, I'll let you know. However most users will have seen a basic calculator in 
physical form! ;-)


Thanks Dalius, this has made such great progress! 


Regards,
Dalius


On Mon, Mar 11, 2013 at 4:33 PM, Calum K Pringle 
<calum.pringle@xxxxxxxxxxxxx[1]> wrote:


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>[2]
*To:*
ubuntu-touch-coreapps@xxxxxxxxxxxxxxxxxxx[3]


Hi,


Here is what design team proposes for simple calculator:
http://design.canonical.com/wp-content/uploads/numpad.png[4]


Here is our current implementation:
http://i.imgur.com/F2DqWdL.png[5]



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[1]








-- 
Riccardo Ferrazzo <f.riccardo87@xxxxxxxxx>

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