[kde-edu]: KmPlot - New Features

[Jason Harris]

Hi,

Looks very good.  I have a couple of ideas:

+ when I click on a function, it enters a "trace mode", in which the mouse 
cursor is constrained to lie on the function.  This is really nice.  However, 
the cursor lines turn red to indicate that this mode is active, but currently 
they only turn red once the mouse is moved.  They should turn red as soon as 
the user clicks on the function.  Same thing for clicking to leave "trace 
mode".  I tried to path the code to do this by adding "update()" to 
appropriate places in mousePressEvent(), but it didn't work correctly.

+ I think it would be nice if I could click and drag in the background to 
translate around the plotting area, and zoom in and out easily (perhaps very 
similar to what we do in kstars :).  AFAICT, the only way to adjust the plot 
limits now is to open the configuration dialog and adjust the numerical 
values of the limits.  That's pretty cumbersome.

+ The error message when entering an invalid function could be more helpful.  
If I enter "y=x*x", I get a messagebox with "Parser error at position 1: Void 
function variable".  Hmm, so I read the handbook, and see that it expects 
something like "f(x)=x*x" instead.  It would be great if the error message 
would suggest a valid function form.

+ Also, you should strip out whitespace characters when parsing the function 
string; the user should be able to enter something like "f(x) = x * x".  
Actually, I just noticed that spaces after the "=" are OK, it's only the one 
before "=" that it chokes on.

It's looking very good, nice work!

Jason

-- 
KStars: A KDE Planetarium
http://edu.kde.org/kstars