Tkinter - Limit Tab Sequence To The Focused Frame

When repeatedly pressing the TAB key while running the code below you'll note that the focused entry widget cycles through all the entry widgets. I would like to know if there's a simple way to make the tab only cycle through the entry widgets in the "selected frame".

import tkinter as tk
class Frame_Tab:
def __init__(self):
self.root = tk.Tk()
self.root.geometry('300x350')
self.root.title('Frame Tab')
self.dg = '#c0c0c0'
self.bg = '#54ed58'
self.lg = '#c9c9c9'
self.frame1 = tk.LabelFrame(self.root,highlightcolor=self.bg,highlightthickness=3,highlightbackground=self.dg,padx=5,pady=5)
self.frame1.pack()
self.f1heading = tk.Button(self.frame1,text='Frame 1',takefocus=0,bg=self.lg,fg='black',height=1,borderwidth=5,command=lambda:self.f1e1.focus(), relief=tk.RAISED,font=('Arial',12))
self.f1heading.grid(row=0,column=0,columnspan=2,ipadx=10)
self.f1l1 = tk.Label(self.frame1,text='Frame1 Entry1',font=('Arial',12))
self.f1l1.grid(row=1,column=0,pady=5)
self.f1e1 = tk.Entry(self.frame1,width=8,bg='white',fg='black',font=('Arial',12))
self.f1e1.grid(row=1,column=1,pady=5)
self.f1l2 = tk.Label(self.frame1,text='Frame1 Entry2',font=('Arial',12))
self.f1l2.grid(row=2,column=0,pady=5)
self.f1e2 = tk.Entry(self.frame1,width=8,bg='white',fg='black',font=('Arial',12))
self.f1e2.grid(row=2,column=1,pady=5)
self.frame2 = tk.LabelFrame(self.root,highlightcolor=self.bg,highlightthickness=3,highlightbackground=self.dg,padx=5,pady=5)
self.frame2.pack(pady=10)
self.f2heading = tk.Button(self.frame2,text='Frame 2',takefocus=0,bg=self.lg,fg='black',height=1,borderwidth=5,command=lambda:self.f2e1.focus(), relief=tk.RAISED,font=('Arial',12))
self.f2heading.grid(row=0,column=0,columnspan=2,ipadx=10)
self.f2l1 = tk.Label(self.frame2,text='Frame1 Entry1',font=('Arial',12))
self.f2l1.grid(row=1,column=0,pady=5)
self.f2e1 = tk.Entry(self.frame2,width=8,bg='white',fg='black',font=('Arial',12))
self.f2e1.grid(row=1,column=1,pady=5)
self.f2l2 = tk.Label(self.frame2,text='Frame1 Entry2',font=('Arial',12))
self.f2l2.grid(row=2,column=0,pady=5)
self.f2e2 = tk.Entry(self.frame2,width=8,bg='white',fg='black',font=('Arial',12))
self.f2e2.grid(row=2,column=1,pady=5)
self.f2l3 = tk.Label(self.frame2,text='Frame1 Entry3',font=('Arial',12))
self.f2l3.grid(row=3,column=0,pady=5)
self.f2e3 = tk.Entry(self.frame2,width=8,bg='white',fg='black',font=('Arial',12))
self.f2e3.grid(row=3,column=1,pady=5)
self.root.mainloop()
if __name__ == '__main__':
Frame_Tab()

OK, I give up on trying to get this revised code to format correctly! SMH (THANKS for the code format edit)

I have found a solution, but it is somewhat of a hack. The code below is the same as above with the following changes:

1. I create a list of ALL Entry widgets in the applications

   self.allEntry = [self.f1e1,self.f1e2,self.f2e1,self.f2e2,self.f2e3]

2. I then bind each Entry widget to the FocusIn event. The binds call a function applicable to the Frame the Entry widget is in (self.set1 or self.set2)

3. I then define set1, set2, and setTakeFocus - each of these functions can be found near the end of the code below and should be self-explanatory.

Code:

import tkinter as tk
class Frame_Tab:
def __init__(self):
self.root = tk.Tk()
self.root.geometry('300x350')
self.root.title('Frame Tab')
self.dg = '#c0c0c0'
self.bg = '#54ed58'
self.lg = '#c9c9c9'
self.frame1 = tk.LabelFrame(self.root,highlightcolor=self.bg,highlightthickness=3,highlightbackground=self.dg,padx=5,pady=5)
self.frame1.pack()
self.f1heading = tk.Button(self.frame1,text='Frame 1',takefocus=0,bg=self.lg,fg='black',height=1,borderwidth=5,command=lambda:self.f1e1.focus(), relief=tk.RAISED,font=('Arial',12))
self.f1heading.grid(row=0,column=0,columnspan=2,ipadx=10)
self.f1l1 = tk.Label(self.frame1,text='Frame1 Entry1',font=('Arial',12))
self.f1l1.grid(row=1,column=0,pady=5)
self.f1e1 = tk.Entry(self.frame1,width=8,bg='white',fg='black',font=('Arial',12))
self.f1e1.grid(row=1,column=1,pady=5)
self.f1e1.bind('<FocusIn>',self.set1)
self.f1l2 = tk.Label(self.frame1,text='Frame1 Entry2',font=('Arial',12))
self.f1l2.grid(row=2,column=0,pady=5)
self.f1e2 = tk.Entry(self.frame1,width=8,bg='white',fg='black',font=('Arial',12))
self.f1e2.grid(row=2,column=1,pady=5)
self.f1e2.bind('<FocusIn>',self.set1)
self.frame2 = tk.LabelFrame(self.root,highlightcolor=self.bg,highlightthickness=3,highlightbackground=self.dg,padx=5,pady=5)
self.frame2.pack(pady=10)
self.f2heading = tk.Button(self.frame2,text='Frame 2',takefocus=0,bg=self.lg,fg='black',height=1,borderwidth=5,command=lambda:self.f2e1.focus(), relief=tk.RAISED,font=('Arial',12))
self.f2heading.grid(row=0,column=0,columnspan=2,ipadx=10)
self.f2l1 = tk.Label(self.frame2,text='Frame1 Entry1',font=('Arial',12))
self.f2l1.grid(row=1,column=0,pady=5)
self.f2e1 = tk.Entry(self.frame2,width=8,bg='white',fg='black',font=('Arial',12))
self.f2e1.grid(row=1,column=1,pady=5)
self.f2e1.bind('<FocusIn>',self.set2)
self.f2l2 = tk.Label(self.frame2,text='Frame1 Entry2',font=('Arial',12))
self.f2l2.grid(row=2,column=0,pady=5)
self.f2e2 = tk.Entry(self.frame2,width=8,bg='white',fg='black',font=('Arial',12))
self.f2e2.grid(row=2,column=1,pady=5)
self.f2e2.bind('<FocusIn>',self.set2)
self.f2l3 = tk.Label(self.frame2,text='Frame1 Entry3',font=('Arial',12))
self.f2l3.grid(row=3,column=0,pady=5)
self.f2e3 = tk.Entry(self.frame2,width=8,bg='white',fg='black',font=('Arial',12))
self.f2e3.grid(row=3,column=1,pady=5)
self.f2e3.bind('<FocusIn>',self.set2)
self.allEntry = [self.f1e1,self.f1e2,self.f2e1,self.f2e2,self.f2e3]
self.root.mainloop()
def set1(self,e=None):
keep = [self.f1e1,self.f1e2]
self.setTakeFocus(keep)
def set2(self,e=None):
keep = [self.f2e1,self.f2e2,self.f2e3]
self.setTakeFocus(keep)
def setTakeFocus(self,keep):
for e in self.allEntry:
if e in keep:
e.config(takefocus=1)
else:
e.config(takefocus=0)
if __name__ == '__main__':
Frame_Tab()

This will lead to usability problems if your users only use the keyboard, since it will make it impossible to traverse to the next frame unless you provide some way for the user to switch frames.

That being said, the simplest solution might be to simply add a custom binding for the last widget in each group to move the first to the first widget in the group.

For example, the following function will make it so that pressing tab in the second widget that is passed in will move focus to the first, and pressing shift-tab in the first will move focus to the second.

def _set_tab_bindings(self, w1, w2):
w2.bind("<Tab>", lambda event: w1.focus_set() or "break")
w1.bind("<Shift-Tab>", lambda event: w2.focus_set() or "break")

You can then call this in the code that creates each frame.

self._set_tab_bindings(self.f1e1, self.f1e2)
self._set_tab_bindings(self.f2e1, self.f2e3)

This might not be the most elegant solution, but arguably it's the most straight-forward.

(this only works for versions 3.9 and below) I did that by simply binding last entry widgets by "Tab FocusOut". So if tab has been pressed and it focused out, you focus on the first entry widgets. So Just add that two lines:

self.f1e2.bind("<Tab> <FocusOut>", lambda refocus: self.f1e1.focus())
self.f2e3.bind("<Tab> <FocusOut>", lambda refocus: self.f2e1.focus())

Seems to work for me. Full code:

import tkinter as tk 
class Frame_Tab:
def __init__(self):
self.root = tk.Tk()
self.root.geometry('300x350')
self.root.title('Frame Tab')
self.dg = '#c0c0c0'
self.bg = '#54ed58'
self.lg = '#c9c9c9'
self.frame1 = tk.LabelFrame(self.root,highlightcolor=self.bg,highlightthickness=3,highlightbackground=self.dg,padx=5,pady=5)
self.frame1.pack()
self.f1heading = tk.Button(self.frame1,text='Frame 1',takefocus=0,bg=self.lg,fg='black',height=1,borderwidth=5,command=lambda:self.f1e1.focus(), relief=tk.RAISED,font=('Arial',12))
self.f1heading.grid(row=0,column=0,columnspan=2,ipadx=10)
self.f1l1 = tk.Label(self.frame1,text='Frame1 Entry1',font=('Arial',12))
self.f1l1.grid(row=1,column=0,pady=5)
self.f1e1 = tk.Entry(self.frame1,width=8,bg='white',fg='black',font=('Arial',12))
self.f1e1.grid(row=1,column=1,pady=5)
self.f1l2 = tk.Label(self.frame1,text='Frame1 Entry2',font=('Arial',12))
self.f1l2.grid(row=2,column=0,pady=5)
self.f1e2 = tk.Entry(self.frame1,width=8,bg='white',fg='black',font=('Arial',12))
self.f1e2.grid(row=2,column=1,pady=5)
self.f1e2.bind("<Tab> <FocusOut>", lambda refocus: self.f1e1.focus())  # there
self.frame2 = tk.LabelFrame(self.root,highlightcolor=self.bg,highlightthickness=3,highlightbackground=self.dg,padx=5,pady=5)
self.frame2.pack(pady=10)
self.f2heading = tk.Button(self.frame2,text='Frame 2',takefocus=0,bg=self.lg,fg='black',height=1,borderwidth=5,
command=lambda:self.f2e1.focus(), relief=tk.RAISED,font=('Arial',12))
self.f2heading.grid(row=0,column=0,columnspan=2,ipadx=10)
self.f2l1 = tk.Label(self.frame2,text='Frame1 Entry1',font=('Arial',12))
self.f2l1.grid(row=1,column=0,pady=5)
self.f2e1 = tk.Entry(self.frame2,width=8,bg='white',fg='black',font=('Arial',12))
self.f2e1.grid(row=1,column=1,pady=5)
self.f2l2 = tk.Label(self.frame2,text='Frame1 Entry2',font=('Arial',12))
self.f2l2.grid(row=2,column=0,pady=5)
self.f2e2 = tk.Entry(self.frame2,width=8,bg='white',fg='black',font=('Arial',12))
self.f2e2.grid(row=2,column=1,pady=5)
self.f2l3 = tk.Label(self.frame2,text='Frame1 Entry3',font=('Arial',12))
self.f2l3.grid(row=3,column=0,pady=5)
self.f2e3 = tk.Entry(self.frame2,width=8,bg='white',fg='black',font=('Arial',12))
self.f2e3.grid(row=3,column=1,pady=5)
self.f2e3.bind("<Tab> <FocusOut>", lambda refocus: self.f2e1.focus())  # and there
self.root.mainloop()
if __name__ == '__main__':
Frame_Tab()