| several quick questions [message #13203] |
Fri, 23 October 1998 00:00 |
philip aldis
Messages: 13
Registered: October 1998
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Junior Member |
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I'll apologise in advance if these questions are very simple but I've only been
doing computer programming for a couple of months.
-Is the best way to find out the number of lines in a file without actually reading
the file to spawn a unix command, if so what command? Or is there a way of doing it
from within IDL. I'd prefer not to read the file because some of the files are very
large. ( I've already got a copy of DDRead, and the nlines program is fine but if
the file is very long then it takes time)
-I'm writing a visualisation program for displaying some ray tracing data. A C
program that has already been written translates ray path histories for an engine
duct and translates them onto a flattened version of the duct, so a 2-d appreciation
of where the rays are in real-time can be obtained. I have to animate these images.
I could build my widget program using the cw_animate widgets but they direct output
to their own window. The problem is that I want to display the animation inside a
frame of the duct with some drawings, and a second animation of the end plate of the
duct and a drawing of the duct. So, can you direct output from cw_animate into
specific parts of draw widgets. Or would it be best just to do the pixmaps myself?
- If I am building a widget application, but wish to do all my actual processes
using objects - which contain data and methods - then is it best to program the
widgets as normal - functionally - then create my objects in the widget program and
use the methods on the objects.
-I am still not sure about how much functionality one can put into event handlers. I
realise that if I put too much then the program will not be spending enough time in
the event loop then the users will be clicking buttons thinking the programs crashed
which will then send xmanager haywire. But, if we take the example of loading in
data - is it best to get all the data parameters then call an object method which
loads data into self. However while all this is going on, the user could be clicking
buttons and causing problems. Again, if I was doing an object method to load the
data into pixmaps ready for an animation, this is also going to take a little bit of
time, and the user could cause problems. If I have to stop the user from mucking
around what are some good ways of telling the user that a process is going on.
- Finally, I was on a course with David Fanning and he mentioned something about
distracting the user while you did something to make it look as if you'd done the
process faster. How would you go about this?
Thanks very much, in advance for any replies - sorry again if these are silly
questions.
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