π‘ Problem Formulation: When using the Tkinter module in Python to create GUI applications, developers often need to display message boxes for alerts, information, warnings, etc. However, by default, these message boxes appear in the center of the screen. This article addresses how to change the default position of a Tkinter messagebox, with the input being the desired coordinates and the desired output being the messagebox appearing at a specified location on the screen.
Method 1: Overriding the Messagebox with Toplevel
This method involves creating a custom message box by using the Toplevel widget in Tkinter. By doing this, we can set the geometry of our message box window, including its position on the screen. The Toplevel
widget functions similarly to the default messagebox but provides more flexibility.
Here’s an example:
from tkinter import Tk, Toplevel, Label root = Tk() root.withdraw() # Hides the main window def custom_msgbox(x, y): msg_window = Toplevel() msg_window.title("Custom Message Box") msg_window.geometry(f"+{x}+{y}") Label(msg_window, text="This is a custom message box.").pack() custom_msgbox(200, 200) root.mainloop()
Output:
A custom message box window positioned at coordinates (200, 200) relative to the top-left corner of the screen.
This code defines a custom message box using the Toplevel
widget. The custom_msgbox
function is defined to take x
and y
parameters, which are used to position the custom message box on the screen. The geometry
method is called with a formatted string that includes the desired screen coordinates, placing the top left corner of the message box window at that spot.
Method 2: Setting Position Before Showing Messagebox
By altering the root window’s properties before calling a messagebox, you can influence where the messagebox appears. The updated property is applied to subsequent window elements, resulting in a relocated messagebox. It’s an indirect method of setting the messagebox’s position without direct control over the messagebox itself.
Here’s an example:
import tkinter as tk from tkinter import messagebox def move_msgbox(): root.geometry('1x1+300+300') # Shrink and move the root window messagebox.showinfo("Title", "Message box at 300x300 position") root.geometry('') # Reset geometry root = tk.Tk() root.withdraw() # Hide the root window as we only need the messagebox move_msgbox()
Output:
A standard messagebox window appears at the position where the root window was last placed, in this case, approximately at the (300, 300) screen coordinates.
This code alters the position of the root window to where we want the messagebox to appear, albeit in an obfuscated manner (minimal size at the desired coordinates), then displays a messagebox. After the messagebox is shown, the root window’s size is reset. It’s important to note that this method assumes the placement of the messagebox is dependent on the location of the root window, which may not always be accurate.
Method 3: Using the wm_attributes Method
The wm_attributes
method allows you to control various window manager attributes, including the position of a messagebox indirectly by setting the placement of the main root window right before displaying the messagebox. This method gives you some control over where the messagebox might appear in relation to the main window.
Here’s an example:
import tkinter as tk from tkinter import messagebox root = tk.Tk() root.withdraw() def position_messagebox(x, y): root.geometry(f"+{x}+{y}") root.wm_attributes("-topmost", 1) messagebox.showinfo("Positioned Messagebox", "This messagebox is positioned using wm_attributes.") root.wm_attributes("-topmost", 0) position_messagebox(400, 400) root.mainloop()
Output:
An information messagebox positioned in such a way that it takes into account the main window’s position, here aimed to be around screen coordinates (400, 400).
In the provided code, the wm_attributes
method with the “-topmost” attribute is set to 1 to ensure that the root window is above all other windows. This positional adjustment generally influences where the messagebox will appear, though its effects can vary depending on the window manager and operating system.
Method 4: Using Python’s win32gui Module
For systems running on Windows, Python’s win32gui
module can be used to change the position of any window, including a Tkinter messagebox. It enables greater control but requires the additional step of identifying the window handle of the messagebox.
Here’s an example:
import tkinter as tk from tkinter import messagebox import win32gui import time root = tk.Tk() root.withdraw() def move_messagebox(x, y): def _enum_cb(hwnd, extra): if 'messagebox' in win32gui.GetWindowText(hwnd).lower(): win32gui.SetWindowPos(hwnd, 0, x, y, 0, 0, 0x0001) messagebox.showinfo("Title", "Message box at custom position") time.sleep(0.1) # Wait a bit for the messagebox to appear win32gui.EnumWindows(_enum_cb, None) move_messagebox(500, 500) root.mainloop()
Output:
A windows message box at the custom coordinates (500, 500).
This method requires the use of additional Python libraries to manipulate the operating system’s GUI elements. The win32gui
library finds and repositions the messagebox based on its title. This approach is Windows-specific and may require adjustments for different window titles or locales, as well as consideration for race conditions between the messagebox appearance and the win32gui callbacks.
Bonus One-Liner Method 5: Using PyAutoGUI
PyAutoGUI allows you to programmatically control the mouse and keyboard, which can be used to change the position of the messagebox window after it has appeared. This method is not recommended due to its reliance on timing and screen coordinates, which can be unreliable and vary between systems.
Here’s an example:
import tkinter as tk from tkinter import messagebox import pyautogui root = tk.Tk() root.withdraw() messagebox.showinfo("Title", "Message box") pyautogui.moveRel(None, 600, 600) # Move the messagebox 600 pixels down and right root.mainloop()
Output:
The messagebox, originally centered, will move 600 pixels to the right and 600 pixels down.
This code snippet demonstrates how to use PyAutoGUI to move an active message box window after it has been displayed. The moveRel
method from PyAutoGUI takes x and y offsets to relocate the messagebox relative to its current position. It’s useful for quick scripts but not stable for consistent GUI operations, especially in professional applications.
Summary/Discussion
- Method 1: Overriding with Toplevel: Customizable. Requires more coding. Not a native messagebox look.
- Method 2: Setting Position Before Showing: Easy to implement. Depends on root window position. Indirect control over messagebox.
- Method 3: Using wm_attributes: Simple to use. Not a direct manipulation of the messagebox. May vary by OS.
- Method 4: Using win32gui Module: Precise control on Windows OS. Additional library required. Windows-specific.
- Bonus Method 5: Using PyAutoGUI: Quick and easy. Unreliable and system-dependent. Not suitable for precise positioning.