Tkinter programming problem

[Andrew Gregory]

Could someone help me out with these few lines of code: I would like
to know why the Quit button in this application removes the buttons
and causes "Quitting" to be printed, but does not close the outer
frame.

Andrew.


# Demonstration TK interface Windows application
# Runs ok from within IDLE
#
from Tkinter import *

class CommonStuff: # to get common access to variables and functions
def __init__(cself, frame):
cself.frame = frame

def say_hi(cself):
print "Hello all"


class MyWidgets(Frame, CommonStuff):
def __init__(wself, CS):
Frame.__init__(wself, CS.frame)
wself.quitbutton = Button(wself)
wself.quitbutton["text"] = "Quit"
wself.quitbutton["fg"] = "red"
wself.quitbutton["command"] = wself.destroy

wself.quitbutton.pack({"side": "left"})

wself.hi_there = Button(wself)
wself.hi_there["text"] = "Hello",
wself.hi_there["command"] = CS.say_hi

wself.hi_there.pack({"side": "left"})


class Application:
def __init__(self, master):
self.frame=Frame(master)
CS = CommonStuff(self.frame)

displayedwidget=MyWidgets(CS)
displayedwidget.grid(row=0, column=0)
self.frame.grid(row=0, column=0)
self.frame.columnconfigure(0)
displayedwidget.bind("<Destroy>", self.quit)
self.frame.update()

def quit(self, event):
print"Quitting..."
self.frame.destroy # Destroy frame and all children


root = Tk()
mainWin = Application(root)
root.wait_window(mainWin.frame)

 

[Eric Brunel]

Could someone help me out with these few lines of code: I would like
to know why the Quit button in this application removes the buttons
and causes "Quitting" to be printed, but does not close the outer
frame.

Andrew.


# Demonstration TK interface Windows application
# Runs ok from within IDLE
#
from Tkinter import *

class CommonStuff: # to get common access to variables and functions
def __init__(cself, frame):
cself.frame = frame

It is a Bad Idea to give the first parameter of a method any other name than
"self"... Checking tools like PyChecker will complain if you do that, and your
programs will be harder to read for anyone else doing Python...

def say_hi(cself):
print "Hello all"


class MyWidgets(Frame, CommonStuff):
def __init__(wself, CS):
Frame.__init__(wself, CS.frame)

Where have you found this type of Tkinter object initialization? Apparently,
there are weird style guides lying around somewhere... You can rewrite all of this:

wself.quitbutton = Button(wself)
wself.quitbutton["text"] = "Quit"
wself.quitbutton["fg"] = "red"
wself.quitbutton["command"] = wself.destroy

wself.quitbutton.pack({"side": "left"})

like that:

wself.quitbutton = Button(wself, text='Quit', fg='red', command=wself.destroy)
wself.quitbutton.pack(side=LEFT)

This is the most common way to do things. BTW, since you never do anything to
the buttons themselves ouside this method, there's no need at all to store them
in attributes. So you can just do:

quitbutton = Button(wself, text='Quit', fg='red', command=wself.destroy)
quitbutton.pack(side=LEFT)

or even:

Button(wself, text='Quit', fg='red', command=wself.destroy).pack(side=LEFT)

wself.hi_there = Button(wself)
wself.hi_there["text"] = "Hello",
wself.hi_there["command"] = CS.say_hi

wself.hi_there.pack({"side": "left"})

Same here:

wself.hi_there = Button(wself, text="Hello", command=CS.say_hi)
wself.hi_there.pack(side=LEFT)

or:

hi_there = Button(wself, text="Hello", command=CS.say_hi)
hi_there.pack(side=LEFT)

or even:

Button(wself, text="Hello", command=CS.say_hi).pack(side=LEFT)

class Application:
def __init__(self, master):
self.frame=Frame(master)
CS = CommonStuff(self.frame)

displayedwidget=MyWidgets(CS)
displayedwidget.grid(row=0, column=0)
self.frame.grid(row=0, column=0)
self.frame.columnconfigure(0)

This statement is a no-op: you say you'll configure the column n#0 of
self.frame, but you do not give any features for the column. What are you trying
to do?

displayedwidget.bind("<Destroy>", self.quit)
self.frame.update()

def quit(self, event):
print"Quitting..."
self.frame.destroy # Destroy frame and all children

Compare this line to the last in the __init__ method just above. To call the
update method on self.frame, you did self.frame.update(). So to call the destroy
method on self.frame, you must do self.frame.destroy(). self.frame.destroy
merely returns the destroy method of the self.frame object, but doesn't do
anything with it.

root = Tk()
mainWin = Application(root)
root.wait_window(mainWin.frame)

I don't know if this works, but I know it's not the usual way to run a Tkinter
application. You'd better replace the last line by:

root.mainloop()

HTH

 

[Andrew Gregory]

Many thanks for such a comprehensive answer.

Altered root.wait_window(mainWin.frame) to root.mainloop()
and found that it runs and closes ok within IDLE. I seem to remember
having crashes on closing within IDLE before.

I did try self.frame.destroy as the function
self.frame.destroy(), but the Quit button still didn't work. The
application can be closed via the window corner X, but I'm still
puzzled as to why it does not respond to Quit.

Any more suggestions?


Updated code below, Andrew.



# Demonstration TK interface Windows application
# Runs ok from within IDLE
#
from Tkinter import *

class CommonStuff: # to get common access to variables and functions
def __init__(self, frame):
self.frame = frame

def say_hi(self):
print "Hello all"


class MyWidgets(Frame, CommonStuff):
def __init__(self, CS):
Frame.__init__(self, CS.frame)
self.quitbutton = Button(self, text='Quit', fg='red',
command=self.destroy)
self.quitbutton.pack(side=LEFT)
self.hi_there = Button(self, text='Hello', command=CS.say_hi)
self.hi_there.pack(side=LEFT)


class Application:
def __init__(self, master):
self.frame=Frame(master)
CS = CommonStuff(self.frame)

displayedwidget=MyWidgets(CS)
displayedwidget.grid(row=0, column=0)
self.frame.grid(row=0, column=0)
displayedwidget.bind("<Destroy>", self.quit)
self.frame.update()

def quit(self, event):
print"Quitting..."
self.frame.destroy() # Destroy frame and all children


root = Tk()
mainWin = Application(root)
root.mainloop()

 

[klappnase]

# Demonstration TK interface Windows application
# Runs ok from within IDLE
#
from Tkinter import *

class CommonStuff: # to get common access to variables and functions
def __init__(self, frame):
self.frame = frame

def say_hi(self):
print "Hello all"


class MyWidgets(Frame, CommonStuff):
def __init__(self, CS):
Frame.__init__(self, CS.frame)
self.quitbutton = Button(self, text='Quit', fg='red',
command=self.destroy)
self.quitbutton.pack(side=LEFT)
self.hi_there = Button(self, text='Hello', command=CS.say_hi)
self.hi_there.pack(side=LEFT)


class Application:
def __init__(self, master):
self.frame=Frame(master)
CS = CommonStuff(self.frame)

displayedwidget=MyWidgets(CS)
displayedwidget.grid(row=0, column=0)
self.frame.grid(row=0, column=0)
displayedwidget.bind("<Destroy>", self.quit)
self.frame.update()

def quit(self, event):
print"Quitting..."
self.frame.destroy() # Destroy frame and all children


root = Tk()
mainWin = Application(root)
root.mainloop()

I think you could have it easier, if you just want to exit you
application with the quit button:

class MyWidgets(Frame, CommonStuff):
def __init__(self, CS):
Frame.__init__(self, CS.frame)
self.quitbutton = Button(self, text='Quit', fg='red',
command=self.quit)
self.quitbutton.pack(side=LEFT)
self.hi_there = Button(self, text='Hello', command=CS.say_hi)
self.hi_there.pack(side=LEFT)

def quit(self):
print "Quitting..."
sys.exit(0)

If you want to run it from within the interpreter (I am not sure if it
is that what you are trying) the following might work too:

class Application:
def __init__(self, master):
self.frame=Frame(master)
CS = CommonStuff(self.frame)

displayedwidget=MyWidgets(CS)
displayedwidget.grid(row=0, column=0)
self.frame.grid(row=0, column=0)
displayedwidget.bind("<Destroy>", self.quit)
self.frame.update()

self.master = master

def quit(self, event):
print"Quitting..."
self.master.destroy() # Destroy root window

However I would recommend to store the code in a file and then run the
file.
I am sorry that I cannot give you more detailed advice, but I am still
a beginner, too. I hope this helped anyway.

Good luck!

Michael

 

[klappnase]

This may also work, but the most common way is the one I describe above. If you
want to do it here, you can do:

def quit(self, event):
print "Quitting..."
self.master.quit()

AFAIK, all Tkinter widgets have a quit method that will quit the Tk mainloop.

HTH

I think Tkinter's quit() method will not work while running from
within the interpreter, because there is no mainloop. I think you will
have to destroy() there.

Best regards

Michael

 

[Eric Brunel]

why don't use 'sys.exit(0)' as command?
Ex:
quitButton = Button(root,text="Quit",command=sys.exit(0))

Don't do that!! Written like above, sys.exit(0) will be called when the button
is *created*, not when it is pressed! If you want to do that, write:

quitButton = Button(root, text='Quit', command=lambda: sys.exit(0))