Tab option underline to use mnemonic activation, reading and managing index position

Tkinter Notebook to create tabs and managing options to add image underline state with click events

We can add underline to the text string based on its index position (starting from 0).

my_tabs.add(tab1, text ='TabNo-0', underline=0) # adding tab
my_tabs.add(tab2, text ='TabNo-1', underline=1) # adding tab 
my_tabs.add(tab3, text ='TabNo-2', underline=2) # adding tab

With this option underline we can add mnemonic activation. For this we have to enable enable_traversal()

my_tabs.enable_traversal()

We can use Alt and the underlined char to select the tab. Full code is here

import tkinter  as tk 
from tkinter import *
from tkinter import ttk
my_w = tk.Tk()
my_w.geometry("400x200")  
my_tabs = ttk.Notebook(my_w,padding=10) # declaring 

tab1 = ttk.Frame(my_tabs)
tab2 = ttk.Frame(my_tabs)
tab3 = ttk.Frame(my_tabs)

my_tabs.add(tab1, text ='TabNo-0', underline=0) # adding tab
my_tabs.add(tab2, text ='TabNo-1', underline=1) # adding tab 
my_tabs.add(tab3, text ='TabNo-2', underline=2) # adding tab 
my_tabs.pack(expand = 1, fill ="both")

font1=('time',22,'normal')
l1=tk.Label(tab1,text='I am tab-0',bg='yellow',font=font1)
l1.place(relx=0.4,rely=0.2) # using place

l2=tk.Label(tab2,text='I am tab-1',bg='yellow',font=font1)
l2.place(relx=0.4,rely=0.2) # using grid 
l3=tk.Label(tab3,text='I am tab-2',bg='yellow',font=font1)
l3.place(relx=0.4,rely=0.2) # using place

my_tabs.enable_traversal()
my_w.mainloop()  # Keep the window open

Updating underline option

my_dict=my_tabs.tab(tab3) # reading all option values as dictionary
print(my_dict['underline']) # index position of underlined char
# shift underline char by one 
my_tabs.tab(tab3,underline=my_dict['underline']+1)

We can connect this to one click event of a button, on Click the underline char will move to next position.
Full code is here

import tkinter  as tk 
from tkinter import *
from tkinter import ttk
my_w = tk.Tk()
my_w.geometry("400x200")  
my_tabs = ttk.Notebook(my_w,padding=10) # declaring 

tab1 = ttk.Frame(my_tabs)
tab2 = ttk.Frame(my_tabs)
tab3 = ttk.Frame(my_tabs)

my_tabs.add(tab1, text ='TabNo-0',underline=0) # adding tab
my_tabs.add(tab2, text ='TabNo-1',underline=1) # adding tab 
my_tabs.add(tab3, text ='TabNo-2',underline=2) # adding tab 
my_tabs.pack(expand = 1, fill ="both")

font1=('time',22,'normal')
l1=tk.Label(tab1,text='I am tab-0',bg='yellow',font=font1)
l1.place(relx=0.4,rely=0.2) # using place


l2=tk.Label(tab2,text='I am tab-1',bg='yellow',font=font1)
l2.place(relx=0.4,rely=0.2) # using grid 
l3=tk.Label(tab3,text='I am tab-2',bg='yellow',font=font1)
l3.place(relx=0.4,rely=0.2) # using place

def my_move(): # Click event of the button
    my_dict=my_tabs.tab(tab3) # all option values as dictionary
    print(my_dict['underline']) # index position of underlined char
    # shift underline char by one
    my_tabs.tab(tab3,underline=my_dict['underline']+1)  

my_tabs.enable_traversal()
b1=tk.Button(my_w,text='Move underline',
     command=lambda:my_move())
b1.pack(side=LEFT)
my_w.mainloop()  # Keep the window open

By enabling traversal we can use following controls to navigate between tabs

Cltrl + Tab : Select the following tab of the currently selected one
Shift + Ctrl + Tab : Select the preceding tab
Alt + K : here K the underlined char used for the tab.
Notebook

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Subhendu Mohapatra

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underline Option of Notebook ( tabs )

Updating underline option

Subhendu Mohapatra