I have carefully reviewed answers to Interactively validating Entry widget content in tkinter, but my script fails to restore previous value if the validate command returns False. I captured %P and %s and print them out...They both show the same value.
import tkinter as tk
class Controller :
def __init__(self) :
i=10
j=20
# list comprehension
self.entry_widgets = [[None for col in range(j)] for row in range(i)]
#print(self.entry_widgets)
self.values = [["string"+str(row) + str(col) for col in range(10)] for row in range(20)]
#print(self.values)
class EnterBox(tk.Entry):
def __init__(self,*args,**kwargs):
#print (args)
self._modified = False
self._save = 0
self._raise = 1
self._lower = 2
frame, i,j, *newargs = args
self._content = tk.StringVar()
# tk.Entry.__init__(self,frame,*newargs,
# validate = 'focusout',
# validatecommand = vcmd,
# **kwargs)
tk.Entry.__init__(self,frame,*newargs,**kwargs)
vcmd = (self.register(self._revert), '%P', '%s')
ct.entry_widgets[i][j] = self
self.config(textvariable=self._content)
self.config(validate = "focusout")
self.config(validatecommand = vcmd )
x=(ct.values[i][j])
self.insert(0,x)
#self._content.set(x)
self.bind("<Return>",lambda event, x=self._save : self._action(event,x) )
self.bind("<Button-2>",lambda event, x=self._save : self._action(event,x) )
self.bind("<FocusIn>", lambda event, x=self._raise : self._action(event,x))
self.bind("<FocusOut>", lambda event, x=self._lower : self._action(event,x))
self.bind('<Button-3>', lambda event, x=self._lower : self._action(event,x))
self.grid(column=i+1,row=j+2)
def _revert(self,P,s):
print ("Hi There")
print(P)
print(s)
return False
def _action(self,event,action):
print(str(action)+' ' + str(event))
if action == self._save :
ct.values[i][j] = self._content.get()
self.config(bg='lightskyblue2')
self._modified = True
elif action == self._raise :
self.config(bg = 'light pink')
elif action == self._lower :
self.config(bg = 'gray80')
self._modified = False
else :
print('action value is bad action =>' + str(action))
if "__main__" == __name__ :
root = tk.Tk()
frame = tk.Frame()
i=j=0
ct = Controller()
root.grid()
frame.grid()
check = EnterBox(frame,i,j,width = 24)
check2 = EnterBox(frame,i+1,j,width = 24)
root.mainloop()
I have tried removing all other bindings, to no avail. Interestingly, but a separate issue, If I use StringVar. set instead of self.insert, (see commented out line) the validate command runs once, and never again despite several focus changes. Using Python 3.8
