5 Best Ways to Display a Message When Hovering Over Something with Mouse Cursor in Tkinter Python

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💡 Problem Formulation: In designing a graphical user interface with Tkinter in Python, developers often need to provide additional context to users in the form of tooltips or messages. The problem is how to create a visual cue that displays a message when the mouse cursor hovers over a widget, such as a button or label. The input is the movement of the cursor over the widget, and the desired output is a pop-up message that provides information relevant to that element.

Method 1: Using Toplevel Widget for Custom Tooltips

This method involves creating a custom tooltip window using the Toplevel widget, which appears when the user hovers over the specified element. The tooltip is dismissed when the mouse leaves the element. It offers extensive customization options for the tooltip appearance and behavior.

Here’s an example:

import tkinter as tk

class CustomTooltip:
    def __init__(self, widget, text):
        self.widget = widget
        self.text = text
        self.widget.bind("<Enter>", self.enter)
        self.widget.bind("<Leave>", self.leave)
        self.tooltip_window = None

    def enter(self, event=None):
        x, y, cx, cy = self.widget.bbox("insert")
        x += self.widget.winfo_rootx() + 25
        y += self.widget.winfo_rooty() + 20
        self.tooltip_window = tk.Toplevel(self.widget)
        self.tooltip_window.wm_overrideredirect(True)
        self.tooltip_window.wm_geometry("+%d+%d" % (x, y))
        label = tk.Label(self.tooltip_window, text=self.text, justify='left',
                         background='#ffffff', relief='solid', borderwidth=1,
                         font=("tahoma", "8", "normal"))
        label.pack(ipadx=1)

    def leave(self, event=None):
        if self.tooltip_window:
            self.tooltip_window.destroy()

root = tk.Tk()
button = tk.Button(root, text="Hover me")
button.pack()
tooltip = CustomTooltip(button, "This is a tooltip message")
root.mainloop()

Output:

When the user hovers the cursor over the button, a small tooltip window pops up with the message “This is a tooltip message”. The tooltip will disappear as soon as the mouse leaves the button area.

This code snippet creates a CustomTooltip class that can be instantiated with a Tkinter widget and a text string for the tooltip. When the mouse enters the widget’s area, the tooltip window appears at a specific position relative to the widget, and when the mouse leaves, the tooltip is destroyed.

Method 2: Using Label Widgets as Inline Tooltips

For a simpler implementation, a Label widget can be configured to display like a tooltip. This method is straightforward and utilizes less resources as it doesn’t create a new window for the tooltip, instead it places a Label near the widget on hover.

Here’s an example:

import tkinter as tk

def show_tooltip(event):
    global tooltip
    tooltip = tk.Label(root, text="Inline tooltip message", bg="yellow")
    tooltip.place(x=event.x_root, y=event.y_root)

def hide_tooltip(event):
    global tooltip
    tooltip.place_forget()

root = tk.Tk()
button = tk.Button(root, text="Hover me")
button.pack()
button.bind("<Enter>", show_tooltip)
button.bind("<Leave>", hide_tooltip)
root.mainloop()

Output:

An inline yellow label with the text “Inline tooltip message” appears directly under the mouse cursor when hovering over the button. The label disappears when the cursor is no longer over the button.

The provided code snippet binds the show_tooltip and hide_tooltip functions to the Enter and Leave events of the button. These functions handle the creation and removal of a tooltip Label widget which is shown or hidden based on the cursor’s position relative to the widget.

Method 3: Utilizing Textvariable for Instant Feedback

Textvariable can be bound to a Label widget to provide instantaneous feedback when hovering over widgets. This method is efficient and keeps the design simple since the Label’s content dynamically changes based on the cursor’s interactions with different widgets.

Here’s an example:

import tkinter as tk

def update_tooltip(text):
    tooltip_text.set(text)

root = tk.Tk()
tooltip_text = tk.StringVar(root)
tooltip_label = tk.Label(root, textvariable=tooltip_text, bg="lightgray")
tooltip_label.pack(side="bottom")

button1 = tk.Button(root, text="Hover me", command=lambda: update_tooltip("Button tooltip"))
button1.bind("<Enter>", lambda event: update_tooltip("Button tooltip"))
button1.bind("<Leave>", lambda event: update_tooltip(""))
button1.pack()

root.mainloop()

Output:

A Label at the bottom of the window displays “Button tooltip” while the cursor is over the button. Once the cursor leaves the button, the Label is emptied.

In this code, a tooltip Label widget is bound to a StringVar. As the cursor interacts with the button, events trigger the update_tooltip function, which alters the content of the StringVar, therefore changing the tooltip text dynamically.

Method 4: Using Third-Party Libraries for Enhanced Tooltips

Various third-party libraries provide advanced tooltip functionalities. Libraries such as Pmw or Pygubu may feature built-in tooltip classes that can be easily integrated into the Tkinter application for a more feature-rich approach.

Here’s an example:

# Pmw library should be installed separately with `pip install pmw`
import tkinter as tk
import Pmw

root = tk.Tk()
Pmw.initialise(root)
button = tk.Button(root, text="Hover me")
button.pack()

balloon = Pmw.Balloon(root)
balloon.bind(widget=button, balloonmsg="Fancy tooltip message")

root.mainloop()

Output:

A professional-looking tooltip with “Fancy tooltip message” appears when the user hovers over the button.

This snippet initializes the Pmw tooltip functionality and binds it to a Tkinter button. The library takes care of all the interactions, providing a sophisticated tooltip without much additional code.

Bonus One-Liner Method 5: Minimal Inline Tooltip Using a Lambda

A terse yet effective method that creates a minimal inline tooltip for a widget using a single line of code, leveraging lambda functions to update a Label widget when the cursor hovers over a widget.

Here’s an example:

import tkinter as tk

root = tk.Tk()
tooltip_label = tk.Label(root, text="", bg="lightblue")
tooltip_label.pack(side="bottom")

button = tk.Button(root, text="Hover me")
button.pack()
button.bind("<Enter>", lambda event: tooltip_label.config(text="Quick tooltip"))
button.bind("<Leave>", lambda event: tooltip_label.config(text=""))

root.mainloop()

Output:

The Label at the bottom changes to display “Quick tooltip” when the mouse hovers over the button and clears when it leaves.

The code uses lambda functions to update a Label widget’s text property via the config method as the cursor enters or leaves the button widget, demonstrating the power of inline functions and on-the-fly updates to UI elements.

Summary/Discussion

  • Method 1: Using Toplevel Widget for Custom Tooltips. Offers rich customization and flexibility. Requires careful placement and disposing of the tooltip.
  • Method 2: Using Label Widgets as Inline Tooltips. Quick and resource-efficient. Limited in presentation, without elaborate styling or positioning.
  • Method 3: Utilizing Textvariable for Instant Feedback. Dynamic and keeps the interface uncluttered. The feedback is not positioned directly at the cursor, which could be less intuitive.
  • Method 4: Using Third-Party Libraries for Enhanced Tooltips. Provides out-of-the-box sophistication and features. Adds dependency on an external library.
  • Bonus Method 5: Minimal Inline Tooltip Using a Lambda. Straightforward and extremely concise. Lacks customization and may not be suitable for complex interfaces.