Idle thread (Polling) python GUI and saving program state

[Rolando]

I have a GUI with a bunch of cells which is my "View" in the MVC design. The user enters some information in the view and I pass this on to the model so that using the information entered by the user it(model) can do some processing.

I have coded up my model as a state machine. Wherein, once a function is complete it switches to the next state and so on.

I want to know how do I save the program state between restarts. Basically, I'm trying to handle a scenario wherein if someone closes the program. The next time someone starts it up, it should start from where it left off (both the view and model)

Also, I want to setup a poll method where once in a while I can poll each cell to know the state it is in. How do I do this? I don't want my GUI to hang when I'm doing anything. It will be great if someone could help. Thanks!

 

[MRAB]

I have a GUI with a bunch of cells which is my "View" in the MVC
design. The user enters some information in the view and I pass this
on to the model so that using the information entered by the user
it(model) can do some processing.

I have coded up my model as a state machine. Wherein, once a function
is complete it switches to the next state and so on.

I want to know how do I save the program state between restarts.
Basically, I'm trying to handle a scenario wherein if someone closes
the program. The next time someone starts it up, it should start from
where it left off (both the view and model)

When the user closes the window (you don't say what you're using for
the GUI, but there should be a way of detecting when window closes),
save the necessary info to a file using, say, the 'json' module. You
can then reload the info from the file when the program is restarted.

Also, I want to setup a poll method where once in a while I can poll
each cell to know the state it is in. How do I do this? I don't want
my GUI to hang when I'm doing anything. It will be great if someone
could help. Thanks!

Can the model run continuously? If so, you should run it in its own
(background) thread and the GUI in the main thread and communicate
with the model's thread via, say, a queue (for that use the 'queue'
module).

 

[Rolando]

When the user closes the window (you don't say what you're using for

the GUI, but there should be a way of detecting when window closes),

save the necessary info to a file using, say, the 'json' module. You

can then reload the info from the file when the program is restarted.








Can the model run continuously? If so, you should run it in its own

(background) thread and the GUI in the main thread and communicate

with the model's thread via, say, a queue (for that use the 'queue'

module).

I'm using wxPython for my GUI. I have tried running the model thread in thebackground. But how will I save the state if the whole model is running ona thread? When the program is restarted I want the program to continue from the same state where it left off for each cell. I was thinking of having an idle thread that calls a poll method which polls all the cells and checks what each one is doing. But, I don't know how to do that. I'm confused.

 

[MRAB]

On 2014-03-04 02:41, Rolando wrote:> On Monday, March 3, 2014 6:06:22 PM

I'm using wxPython for my GUI. I have tried running the model thread

in the background. But how will I save the state if the whole model is
running on a thread? When the program is restarted I want the program to
continue from the same state where it left off for each cell. I was
thinking of having an idle thread that calls a poll method which polls
all the cells and checks what each one is doing. But, I don't know how
to do that. I'm confused.Please read this:

https://wiki.python.org/moin/GoogleGroupsPython

because Gmail is formatting your email badly, making it harder to read.


When the front-end wants to quit, it tells the back-end and then waits
for it to terminate before itself quitting.

When the back-end receives the message that it should quit, it saves
its state and terminates.

When the front-end starts up again, it starts the back-end.

When the back-end starts, it load the state and runs.