CENTERING THE WINDOW IN PYTHON Tkinter This is the most easiest thing in tkinter because all we must know is the dimension of the window as well as the dimensions of the computer screen. I come up with the following code which can help someone somehow and i did add some comments so that they can follow up.
code
# create a window first
root = Tk()
# define window dimensions width and height
window_width = 800
window_height = 500
# get the screen size of your computer [width and height using the root object as foolows]
screen_width = root.winfo_screenwidth()
screen_height = root.winfo_screenheight()
# Get the window position from the top dynamically as well as position from left or right as follows
position_top = int(screen_height/2 -window_height/2)
position_right = int(screen_width / 2 - window_width/2)
# this is the line that will center your window
root.geometry(f'{window_width}x{window_height}+{position_right}+{position_top}')
# initialise the window
root.mainloop(0)
I have found a solution for the same question on this site
from tkinter import Tk
from tkinter.ttk import Label
root = Tk()
Label(root, text="Hello world").pack()
# Apparently a common hack to get the window size. Temporarily hide the
# window to avoid update_idletasks() drawing the window in the wrong
# position.
root.withdraw()
root.update_idletasks() # Update "requested size" from geometry manager
x = (root.winfo_screenwidth() - root.winfo_reqwidth()) / 2
y = (root.winfo_screenheight() - root.winfo_reqheight()) / 2
root.geometry("+%d+%d" % (x, y))
# This seems to draw the window frame immediately, so only call deiconify()
# after setting correct window position
root.deiconify()
root.mainloop()
sure, I changed it correspondingly to my purposes, it works.
Tk provides a helper function that can do this as tk::PlaceWindow, but I don't believe it has been exposed as a wrapped method in Tkinter. You would center a widget using the following:
from tkinter import *
app = Tk()
app.eval('tk::PlaceWindow %s center' % app.winfo_pathname(app.winfo_id()))
app.mainloop()
This function should deal with multiple displays correctly as well. It also has options to center over another widget or relative to the pointer (used for placing popup menus), so that they don't fall off the screen.
The simplest (but possibly inaccurate) method is to use tk::PlaceWindow, which takes the pathname of a toplevel window as an argument. The main window's pathname is .
import tkinter
root = tkinter.Tk()
root.eval('tk::PlaceWindow . center')
second_win = tkinter.Toplevel(root)
root.eval(f'tk::PlaceWindow {str(second_win)} center')
root.mainloop()
The problem
Simple solutions ignore the outermost frame with the title bar and the menu bar, which leads to a slight offset from being truly centered.
The solution
import tkinter # Python 3
def center(win):
"""
centers a tkinter window
:param win: the main window or Toplevel window to center
"""
win.update_idletasks()
width = win.winfo_width()
frm_width = win.winfo_rootx() - win.winfo_x()
win_width = width + 2 * frm_width
height = win.winfo_height()
titlebar_height = win.winfo_rooty() - win.winfo_y()
win_height = height + titlebar_height + frm_width
x = win.winfo_screenwidth() // 2 - win_width // 2
y = win.winfo_screenheight() // 2 - win_height // 2
win.geometry('{}x{}+{}+{}'.format(width, height, x, y))
win.deiconify()
if __name__ == '__main__':
root = tkinter.Tk()
root.attributes('-alpha', 0.0)
menubar = tkinter.Menu(root)
filemenu = tkinter.Menu(menubar, tearoff=0)
filemenu.add_command(label="Exit", command=root.destroy)
menubar.add_cascade(label="File", menu=filemenu)
root.config(menu=menubar)
frm = tkinter.Frame(root, bd=4, relief='raised')
frm.pack(fill='x')
lab = tkinter.Label(frm, text='Hello World!', bd=4, relief='sunken')
lab.pack(ipadx=4, padx=4, ipady=4, pady=4, fill='both')
center(root)
root.attributes('-alpha', 1.0)
root.mainloop()
With tkinter you always want to call the update_idletasks()
method
directly before retrieving any geometry, to ensure that the values returned are accurate.
There are four methods that allow us to determine the outer-frame's dimensions.
winfo_rootx()
will give us the window's top left x coordinate, excluding the outer-frame.
winfo_x()
will give us the outer-frame's top left x coordinate.
Their difference is the outer-frame's width.
frm_width = win.winfo_rootx() - win.winfo_x()
win_width = win.winfo_width() + (2*frm_width)
The difference between winfo_rooty()
and winfo_y()
will be our title-bar / menu-bar's height.
titlebar_height = win.winfo_rooty() - win.winfo_y()
win_height = win.winfo_height() + (titlebar_height + frm_width)
You set the window's dimensions and the location with the geometry method. The first half of the geometry string is the window's width and height excluding the outer-frame,
and the second half is the outer-frame's top left x and y coordinates.
win.geometry(f'{width}x{height}+{x}+{y}')
You see the window move
One way to prevent seeing the window move across the screen is to use
.attributes('-alpha', 0.0)
to make the window fully transparent and then set it to 1.0
after the window has been centered. Using withdraw()
or iconify()
later followed by deiconify()
doesn't seem to work well, for this purpose, on Windows 7. I use deiconify()
as a trick to activate the window.
Making it optional
You might want to consider providing the user with an option to center the window, and not center by default; otherwise, your code can interfere with the window manager's functions. For example, xfwm4 has smart placement, which places windows side by side until the screen is full. It can also be set to center all windows, in which case you won't have the problem of seeing the window move (as addressed above).
Multiple monitors
If the multi-monitor scenario concerns you, then you can either look into the screeninfo project, or look into what you can accomplish with Qt (PySide2) or GTK (PyGObject), and then use one of those toolkits instead of tkinter. Combining GUI toolkits results in an unreasonably large dependency.
Use:
import tkinter as tk
if __name__ == '__main__':
root = tk.Tk()
root.title('Centered!')
w = 800
h = 650
ws = root.winfo_screenwidth()
hs = root.winfo_screenheight()
x = (ws/2) - (w/2)
y = (hs/2) - (h/2)
root.geometry('%dx%d+%d+%d' % (w, h, x, y))
root.mainloop()
I use frame and expand option. Very simple. I want some buttons in the middle of screen. Resize window and button stay in the middle. This is my solution.
frame = Frame(parent_window)
Button(frame, text='button1', command=command_1).pack(fill=X)
Button(frame, text='button2', command=command_2).pack(fill=X)
Button(frame, text='button3', command=command_3).pack(fill=X)
frame.pack(anchor=CENTER, expand=1)
This method is cross-platform, works for multiple monitors/screens (targets the active screen), and requires no other libraries than Tk. The root window will appear centered without any unwanted "flashing" or animations:
import tkinter as tk
def get_geometry(frame):
geometry = frame.winfo_geometry()
match = re.match(r'^(\d+)x(\d+)\+(\d+)\+(\d+)$', geometry)
return [int(val) for val in match.group(*range(1, 5))]
def center_window(root):
"""Must be called after application is fully initialized
so that the root window is the true final size."""
# Avoid unwanted "flashing" by making window transparent until fully ready
root.attributes('-alpha', 0)
# Get dimensions of active screen/monitor using fullscreen trick; withdraw
# window before making it fullscreen to preserve previous dimensions
root.withdraw()
root.attributes('-fullscreen', True)
root.update_idletasks()
(screen_width, screen_height, *_) = get_geometry(root)
root.attributes('-fullscreen', False)
# Restore and get "natural" window dimensions
root.deiconify()
root.update_idletasks()
(window_width, window_height, *_) = get_geometry(root)
# Compute and set proper window center
pos_x = round(screen_width / 2 - window_width / 2)
pos_y = round(screen_height / 2 - window_height / 2)
root.geometry(f'+{pos_x}+{pos_y}')
root.update_idletasks()
root.attributes('-alpha', 1)
# Usage:
root = tk.Tk()
center_window(root)
Note that at every point where window geometry is modified, update_idletasks()
must be called to force the operation to occur synchronously/immediately. It uses Python 3 functionality but can easily be adapted to Python 2.x if necessary.
import tkinter as tk
win = tk.Tk() # Creating instance of Tk class
win.title("Centering windows")
win.resizable(False, False) # This code helps to disable windows from resizing
window_height = 500
window_width = 900
screen_width = win.winfo_screenwidth()
screen_height = win.winfo_screenheight()
x_cordinate = int((screen_width/2) - (window_width/2))
y_cordinate = int((screen_height/2) - (window_height/2))
win.geometry("{}x{}+{}+{}".format(window_width, window_height, x_cordinate, y_cordinate))
win.mainloop()
This works also in Python 3.x and centers the window on screen:
from tkinter import *
app = Tk()
app.eval('tk::PlaceWindow . center')
app.mainloop()
Source: Stackoverflow.com