CLI+GUI

Re: CLI+GUI

[email protected] (Michele Simionato) wrote in message news:<2259b0e2. 0308080948.5a95 [email protected] ogle.com>...[color=blue]
> I wonder what is the recommended way of using Tkinter
> together with a command line oriented application.[/color]

Replying to myself ...

I tried to implement what I discussed in my previous mail via the
threading module:

#cmdriven.py

import Tkinter as t
import cmd,threading

root=t.Tk()
s=t.StringVar()
s.set('ciao')
label=t.Label(r oot,textvariabl e=s)
label.pack()

class Cmd(cmd.Cmd):
def do_display(self ,arg):
s.set(arg)
def do_quit(self,ar g):
root.quit()
return 'quit' # anything <> None will do the job

def cmdloop(stringv ar):
try: Cmd().cmdloop()
finally: pass # gracefully exit if sometimes goes wrong

thread=threadin g.Thread(target =cmdloop,args=( s,))
thread.start()
root.mainloop()

It works if I do something like

$ python cmdriven.py
(Cmd) display hello
(Cmd) display It works!
(Cmd) quit

However, I wonder if this is a robust solution and if I should expect
problems in more complicate situations (some time passes ... I have
just discovered that this script hangs under Windows 98!)

BTW, I have another question, why the Cmd class does not have a default quit
method? Looking at the source I see that any method returning something
different from None will stop the command loop, and so I have used this
hack, but I don't like it. Maybe I have missed something in the documentation?
Thanks,

Michele

Re: CLI+GUI

Michele Simionato wrote:[color=blue]
> [email protected] (Michele Simionato) wrote in message news:<2259b0e2. 0308080948.5a95 [email protected] ogle.com>...
>[color=green]
>>I wonder what is the recommended way of using Tkinter
>>together with a command line oriented application.[/color]
>
>
> Replying to myself ...
>
> I tried to implement what I discussed in my previous mail via the
> threading module:
>
> #cmdriven.py
>
> import Tkinter as t
> import cmd,threading
>
> root=t.Tk()
> s=t.StringVar()
> s.set('ciao')
> label=t.Label(r oot,textvariabl e=s)
> label.pack()
>
> class Cmd(cmd.Cmd):
> def do_display(self ,arg):
> s.set(arg)
> def do_quit(self,ar g):
> root.quit()
> return 'quit' # anything <> None will do the job
>
> def cmdloop(stringv ar):
> try: Cmd().cmdloop()
> finally: pass # gracefully exit if sometimes goes wrong
>
> thread=threadin g.Thread(target =cmdloop,args=( s,))
> thread.start()
> root.mainloop()
>
> It works if I do something like
>
> $ python cmdriven.py
> (Cmd) display hello
> (Cmd) display It works!
> (Cmd) quit
>
> However, I wonder if this is a robust solution and if I should expect
> problems in more complicate situations (some time passes ... I have
> just discovered that this script hangs under Windows 98!)[/color]

I don't know if this is the problem, because you didn't say exactly when the
script hangs, but Tkinter apparently has problems when calls to it are made from
a thread different from the one into which it was initialized. I'd use an Event
between Tkinter's thread and Cmd's thread, checking it regularly with Tkinter's
after method.

HTH
--
- Eric Brunel <eric.brunel@pr agmadev.com> -
PragmaDev : Real Time Software Development Tools - http://www.pragmadev.com

Re: CLI+GUI

Eric Brunel <eric.brunel@pr agmadev.com> wrote in message news:<bh7hs3$dt [email protected] .fr>...[color=blue]
> I don't know if this is the problem, because you didn't say exactly when the
> script hangs, but Tkinter apparently has problems when calls to it are made
> from a thread different from the one into which it was initialized. I'd use
> an Event between Tkinter's thread and Cmd's thread, checking it regularly
> with Tkinter's after method.
>
> HTH[/color]

It hangs immediately when I start the script by clicking on its icon.
What do you mean with "I'd use an Event" ? I thought an Event object
is automatically generated when I click on a widget, or press a key,
or something. Are you saying can I can programmaticall y generate an
Event, faking a real mouse/key press? How so? That is something I
always wanted to know ;)


Michele

Re: CLI+GUI

Michele Simionato wrote:
[color=blue]
> Eric Brunel <eric.brunel@pr agmadev.com> wrote in message
> news:<bh7hs3$dt [email protected] .fr>...[color=green]
>> I don't know if this is the problem, because you didn't say exactly when
>> the script hangs, but Tkinter apparently has problems when calls to it
>> are made from a thread different from the one into which it was
>> initialized. I'd use an Event between Tkinter's thread and Cmd's thread,
>> checking it regularly with Tkinter's after method.
>>
>> HTH[/color]
>
> It hangs immediately when I start the script by clicking on its icon.
> What do you mean with "I'd use an Event" ? I thought an Event object
> is automatically generated when I click on a widget, or press a key,
> or something. Are you saying can I can programmaticall y generate an
> Event, faking a real mouse/key press? How so? That is something I
> always wanted to know ;)[/color]

When talking of event objects in a context of synchronizing threads,
it seems likely one is talking about threading.Event in specific. As
the online docs for the threading module say:

Event()
A factory function that returns a new event object. An event manages a flag
that can be set to true with the set() method and reset to false with the
clear() method. The wait() method blocks until the flag is true.

all details are at:




There is no implication whatsoever that such objects are "automatica lly
generated" by any GUI toolkit. The terminology confusions are, alas,
almost inevitable.


Alex

Re: CLI+GUI

Michele Simionato wrote:[color=blue]
> Eric Brunel <eric.brunel@pr agmadev.com> wrote in message news:<bh7hs3$dt [email protected] .fr>...
>[color=green]
>>I don't know if this is the problem, because you didn't say exactly when the
>>script hangs, but Tkinter apparently has problems when calls to it are made
>>from a thread different from the one into which it was initialized. I'd use
>>an Event between Tkinter's thread and Cmd's thread, checking it regularly
>>with Tkinter's after method.
>>
>>HTH[/color]
>
>
> It hangs immediately when I start the script by clicking on its icon.
> What do you mean with "I'd use an Event" ? I thought an Event object
> is automatically generated when I click on a widget, or press a key,
> or something.[/color]

I wasn't thinking about this Event class. I thought about the one described here:


It allows very basic communications between threads.
[color=blue]
> Are you saying can I can programmaticall y generate an
> Event, faking a real mouse/key press? How so? That is something I
> always wanted to know ;)[/color]

Generating a *Tk* event is quite easy: just use the event_generate method that
exists on all widgets. I used it to generate simple events, often user-defined
one. The syntax is simple:

myWidget.event_ generate("<<MyE vent>>")

If you have a binding for "<<MyEvent> >" for myWidget, you can trigger it this way.

I never tried to pass event detail, though.

HTH
--
- Eric Brunel <eric.brunel@pr agmadev.com> -
PragmaDev : Real Time Software Development Tools - http://www.pragmadev.com

Re: CLI+GUI

| It hangs immediately when I start the script
| by clicking on its icon.

Michele ....

I experience hangs with SIMPLE Python/Tk scripts
regularly using Windows 98 and this has been
a source of much frustration, almost to the point
of giving up on Tk ....

Your tk_cli script works for me, displaying the Tk window,
accepting display whatEver commands, and displaying the
results back in the Tk window ....

However, it will hang _sometimes_ at the (Cmd) prompt
on the second pass through after displaying the first
time as expected ....

--
Cousin Stanley
Human Being
Phoenix, Arizona

Re: CLI+GUI

Cousin Stanley wrote:[color=blue]
> Michele ....
>
> I experience hangs with SIMPLE Python/Tk scripts
> regularly using Windows 98 and this has been
> a source of much frustration, almost to the point
> of giving up on Tk ....[/color]

Same problem, different solution: it made me give up on Windows 98... ;-)

FYI, and just to make this post a bit more useful, it seems to be a problem in
Windows 95/98, since no problem ever occured with the same scripts/distros on
Win2k or WinXP, not to mention Unices...
--
- Eric Brunel <eric.brunel@pr agmadev.com> -
PragmaDev : Real Time Software Development Tools - http://www.pragmadev.com

Re: CLI+GUI

Eric Brunel wrote:
[color=blue]
> Same problem, different solution: it made me give up on Windows 98... ;-)[/color]

quoting microsoft's lifecycle page:

"Mainstream support for Windows 98/98 SE ended on June 30th 2002,
and no-charge incident support and extended hotfix support ends on
June 30th 2003."
[color=blue]
> FYI, and just to make this post a bit more useful, it seems to be a problem in
> Windows 95/98, since no problem ever occured with the same scripts/distros on
> Win2k or WinXP, not to mention Unices...[/color]

iirc, the problem is that (some versions of the) Tk DLL locks up during the cleanup
phase (probably due to a race problem), and Win2k/XP is smart enough to kill the
process when that happens.

the sourceforge bug tracker has more details.

</F>

Re: CLI+GUI

| Same problem, different solution:
| it made me give up on Windows 98 ...

Eric ...

I do plan on eventually moving to a Linux distribution
in the near future, but have to deal with what I have
at the moment ...

The limited experimentation that I've done using Knoppix,
proved to me that Tk under Win98 was the problem
as the same scripts that hang intermittently under Win98
ran under Knoppix without any problems ...

It's also good to hear that the Tk problems
under later versions of Windows are alleviated ...

Thanks for the info ...

--
Cousin Stanley
Human Being
Phoenix, Arizona

Re: CLI+GUI

Eric Brunel <eric.brunel@pr agmadev.com> wrote in message news:<bh8da1$ti [email protected] .fr>...[color=blue]
> Cousin Stanley wrote:[color=green]
> > Michele ....
> >
> > I experience hangs with SIMPLE Python/Tk scripts
> > regularly using Windows 98 and this has been
> > a source of much frustration, almost to the point
> > of giving up on Tk ....[/color]
>
> Same problem, different solution: it made me give up on Windows 98... ;-)
>
> FYI, and just to make this post a bit more useful, it seems to be a problem in
> Windows 95/98, since no problem ever occured with the same scripts/distros on
> Win2k or WinXP, not to mention Unices...[/color]

These are very good news to me, since it means that the fault is not
mine
and that the approach I came out is not unreasonable (I hope). No bad,
for my first program using thread ;) For the record, I NEVER use
Windows for development(act ually I use it only for watching DVDs),
nevertheless I
wanted to try the script to check about portability issues.


Michele

Re: CLI+GUI

Hello Michele,
[color=blue]
> I wonder what is the recommended way of using Tkinter
> together with a command line oriented application.[/color]
I know it's not Tkinter but what about wxPython with wxCrust?

HTH.
Miki

Re: CLI+GUI

Late to this thread, but --

in a similar situation, I just put:

_tkinter.doonee vent(_tkinter.D ONT_WAIT)

in my main logic loop (cmd interpreter in your case), instead of
calling Frame.mainloop( ). I believe Frame.update() does something
similar but for some reason this worked better.

ISTM this would be cleaner (and safer) than using threads. You can do
all your draw operations from your command line routines, and they
will get displayed as soon as the routine returns to your main loop to
wait for more input.

Am I missing something?

-dbm

[email protected] (Michele Simionato) wrote in message news:<2259b0e2. 0308080948.5a95 [email protected] ogle.com>...[color=blue]
> I wonder what is the recommended way of using Tkinter
> together with a command line oriented application.
> I have in mind something like that:
>
> import cmd,sys
>
> class CMD(cmd.Cmd):
> def do_this(self,*a rgs):
> draw_a_diagram( )
> def do_that(self,*a rgs):
> draw_another_di agram()
> def do_exit(self,*a rgs):
> sys.exit(0)
>
> c=CMD()
> c.cmdloop()
>
> Here the methods ``draw_a_diagra m`` and ``draw_another_ diagram``
> should do what you expect. Notice that I don't want to use
> different windows, the graphs should be displayed on the same
> window one over the other. BTW, I am not really displaying
> diagrams, this is only the simplest example I can figure out
> of graphics program driven by a command line interpreter.
> I want to stay with the CLI interface, which I like a lot
> thanks to the readline and completion support, the easy
> of use and the easy of implementation.
>
> I have no idea of how to do that, except via contorsions
> such as saving (a representation of) the diagrams in a file
> and having a separated Tkinter process that periodically look at the
> file, changing the display if the file has been updated. I
> guess there is a better way, since this is a quite common issue.
> Any suggestion?
>
> TIA,
>
> Michele[/color]

Re: CLI+GUI

danbmil99@yahoo .com (dan) wrote in message news:<fbf8d8f2. 0308120814.75e8 [email protected] gle.com>...[color=blue]
> Late to this thread, but --
>
> in a similar situation, I just put:
>
> _tkinter.doonee vent(_tkinter.D ONT_WAIT)
>
> in my main logic loop (cmd interpreter in your case), instead of
> calling Frame.mainloop( ). I believe Frame.update() does something
> similar but for some reason this worked better.
>
> ISTM this would be cleaner (and safer) than using threads. You can do
> all your draw operations from your command line routines, and they
> will get displayed as soon as the routine returns to your main loop to
> wait for more input.
>
> Am I missing something?
>
> -dbm[/color]

I like quite a lot you suggestion! "dooneevent " was the method I was
looking for! Actually, I would rather prefer to avoid threads for such a
simple program. Thanks to the power of Python I wrote down a working
script in less than five minutes, even if probably I will need more
than five minutes to understand what I wrote ;)
Here it is:

import Tkinter as t
import cmd

root=t.Tk()
s=t.StringVar()
s.set('ciao')
label=t.Label(r oot,textvariabl e=s)
label.pack()

class Cmd(cmd.Cmd):
def do_display(self ,arg):
s.set(arg)
root.tk.dooneev ent(0)
def do_quit(self,ar g):
root.quit()
return 'quit' # anything != None will do

Cmd().cmdloop()


I will later try it on Windows 98. Dunno exactly what "dooneevent " is doing,
I searched my python directories for "dooneevent " and found only one
usage of "doonevent" and copied it ;) Unfortunately "dooneevent "
has no docstring, however few experiments show that "dooneevent ()"
is the same that "dooneevent (0)" whereas "dooneevent (1)" hangs up
(it is waiting for what??)

Thanks for your help,


Michele

Re: CLI+GUI

davesum99@yahoo .com (smarter_than_y ou) wrote in message
[color=blue]
> Also note that there are at least three ways to get this behavior:
>
> _tkinter.doonee vent(TCL_DONT_W AIT)
> Frame.update()
> Tkinter.dooneev ent(0) #this is new to me! You found a third way to
> call it
>[/color]
that would be:

root.tk.dooneev ent()

but anyway --

in my experiments, this last way (Michelle's way) has very bad timing,
if you care about that sort of thing. Both the _tkinter call and
update() seem to be more reactive.