Display message when hovering over something with

问题:

I have a GUI made with TKinter in Python. I would like to be able to display a message when my mouse cursor goes, for example, on top of a label or button. The purpose of this is to explain to the user what the button/label does or represents.

Is there a way to display text when hovering over a tkinter object in Python?

回答1:

You need to set a binding on the <Enter> and <Leave> events.

Note: if you choose to pop up a window (ie: a tooltip) make sure you don't pop it up directly under the mouse. What will happen is that it will cause a leave event to fire because the cursor leaves the label and enters the popup. Then, your leave handler will dismiss the window, your cursor will enter the label, which causes an enter event, which pops up the window, which causes a leave event, which dismisses the window, which causes an enter event, ... ad infinitum.

Here's an example that merely updates a label, similar to a statusbar that some apps use.

import Tkinter as tk

class Example(tk.Frame):
    def __init__(self, *args, **kwargs):
        tk.Frame.__init__(self, *args, **kwargs)
        self.l1 = tk.Label(self, text="Hover over me")
        self.l2 = tk.Label(self, text="", width=40)
        self.l1.pack(side="top")
        self.l2.pack(side="top", fill="x")

        self.l1.bind("<Enter>", self.on_enter)
        self.l1.bind("<Leave>", self.on_leave)

    def on_enter(self, event):
        self.l2.configure(text="Hello world")

    def on_leave(self, enter):
        self.l2.configure(text="")

if __name__ == "__main__":
    root = tk.Tk()
    Example(root).pack(side="top", fill="both", expand="true")
    root.mainloop()

回答2:

I think this would meet your requirements.

Here's what the output looks like:

First, I created a class named ToolTip which has methods showtip and hidetip.

from tkinter import *

class ToolTip(object):

    def __init__(self, widget):
        self.widget = widget
        self.tipwindow = None
        self.id = None
        self.x = self.y = 0

    def showtip(self, text):
        "Display text in tooltip window"
        self.text = text
        if self.tipwindow or not self.text:
            return
        x, y, cx, cy = self.widget.bbox("insert")
        x = x + self.widget.winfo_rootx() + 57
        y = y + cy + self.widget.winfo_rooty() +27
        self.tipwindow = tw = Toplevel(self.widget)
        tw.wm_overrideredirect(1)
        tw.wm_geometry("+%d+%d" % (x, y))
        label = Label(tw, text=self.text, justify=LEFT,
                      background="#ffffe0", relief=SOLID, borderwidth=1,
                      font=("tahoma", "8", "normal"))
        label.pack(ipadx=1)

    def hidetip(self):
        tw = self.tipwindow
        self.tipwindow = None
        if tw:
            tw.destroy()

def CreateToolTip(widget, text):
    toolTip = ToolTip(widget)
    def enter(event):
        toolTip.showtip(text)
    def leave(event):
        toolTip.hidetip()
    widget.bind('<Enter>', enter)
    widget.bind('<Leave>', leave)

The widget is where you want to add the tip. For example, if you want the tip when you hover over a button or entry or label, the instance of the same should be provided at the call time.

Quick note: the code above uses from tkinter import * which is not suggested by some of the programmers out there, and they have valid points. You might want to make necessary changes in such case.

To move the tip to your desired location, you can change x and y in the code. The function CreateToolTip() helps to create this tip easily. Just pass the widget and string you want to display in the tipbox to this function, and you're good to go.

This is how you call the above part:

button = Button(root, text = 'click mem')
button.pack()
CreateToolTip(button, text = 'Hello World\n'
                 'This is how tip looks like.'
                 'Best part is, it\'s not a menu.\n'
                 'Purely tipbox.')

Do not forget to import the module if you save the previous outline in different python file, and don't save the file as CreateToolTip or ToolTip to avoid confusion.

回答3:

You can refer to this- HoverClass

It is exactly what you need. Nothing more, nothing less

from Tkinter import *
import re

class HoverInfo(Menu):
    def __init__(self, parent, text, command=None):
       self._com = command
       Menu.__init__(self,parent, tearoff=0)
       if not isinstance(text, str):
          raise TypeError('Trying to initialise a Hover Menu with a non string type: ' + text.__class__.__name__)
       toktext=re.split('\n', text)
       for t in toktext:
          self.add_command(label = t)
       self._displayed=False
          self.master.bind("<Enter>",self.Display )
          self.master.bind("<Leave>",self.Remove )

    def __del__(self):
       self.master.unbind("<Enter>")
       self.master.unbind("<Leave>")

    def Display(self,event):
       if not self._displayed:
          self._displayed=True
          self.post(event.x_root, event.y_root)
       if self._com != None:
          self.master.unbind_all("<Return>")
          self.master.bind_all("<Return>", self.Click)

    def Remove(self, event):
     if self._displayed:
       self._displayed=False
       self.unpost()
     if self._com != None:
       self.unbind_all("<Return>")

    def Click(self, event):
       self._com()

Example app using HoverInfo:

from Tkinter import *
from HoverInfo import HoverInfo
class MyApp(Frame):
   def __init__(self, parent=None):
      Frame.__init__(self, parent)
      self.grid()
      self.lbl = Label(self, text='testing')
      self.lbl.grid()

      self.hover = HoverInfo(self, 'while hovering press return \n for an exciting msg', self.HelloWorld)

   def HelloWorld(self):
      print('Hello World')

app = MyApp()
app.master.title('test')
app.mainloop()

Screenshot:

回答4:

Here is an example using <enter> and <leave> as @bryanoakley suggested with a toplevel (with overridedirect set to true). Use the hover_timer class for easy use of this. This needs the widget and help-text (with an optional delay argument - default 0.5s) and can be easily called just by initiating the class and then cancelling it.

import threading, time
from tkinter import *

class hover_window (Toplevel):

    def __init__ (self, coords, text):
        super ().__init__ ()
        self.geometry ("+%d+%d" % (coords [0], coords [1]))
        self.config (bg = "white")
        Label (self, text = text, bg = "white", relief = "ridge", borderwidth = 3, wraplength = 400, justify = "left").grid ()
        self.overrideredirect (True)
        self.update ()
        self.bind ("<Enter>", lambda event: self.destroy ())

class hover_timer:

    def __init__ (self, widget, text, delay = 2):
        self.wind, self.cancel_var, self.widget, self.text, self.active, self.delay = None, False, widget, text, False, delay
        threading.Thread (target = self.start_timer).start ()

    def start_timer (self):
        self.active = True
        time.sleep (self.delay)
        if not self.cancel_var: self.wind = hover_window ((self.widget.winfo_rootx (), self.widget.winfo_rooty () + self.widget.winfo_height () + 20), self.text)
        self.active = False

    def delayed_stop (self):
        while self.active: time.sleep (0.05)
        if self.wind:
            self.wind.destroy ()
            self.wind = None

    def cancel (self):
        self.cancel_var = True
        if not self.wind: threading.Thread (target = self.delayed_stop).start ()
        else:
            self.wind.destroy ()
            self.wind = None

def start_help (event):
    # Create a new help timer
    global h
    h = hover_timer (l, "This is some additional information.", 0.5)

def end_help (event):
    # If therre is one, end the help timer
    if h: h.cancel ()

if __name__ == "__main__":

    # Create the tkinter window
    root = Tk ()
    root.title ("Hover example")

    # Help class not created yet
    h = None

    # Padding round label
    Frame (root, width = 50).grid (row = 1, column = 0)
    Frame (root, height = 50).grid (row = 0, column = 1)
    Frame (root, width = 50).grid (row = 1, column = 2)
    Frame (root, height = 50).grid (row = 2, column = 1)

    # Setup the label
    l = Label (root, text = "Hover over me for information.", font = ("sans", 32))
    l.grid (row = 1, column = 1)
    l.bind ("<Enter>", start_help)
    l.bind ("<Leave>", end_help)

    # Tkinter mainloop
    root.mainloop ()

回答5:

I have a very hacky solution but it has some advantages over the current answers so I figured I would share it.

lab=Label(root,text="hover me")
lab.bind("<Enter>",popup)

def do_popup(event):
    # display the popup menu
    root.after(1000, self.check)
    popup = Menu(root, tearoff=0)
    popup.add_command(label="Next")
    popup.tk_popup(event.x_root, event.y_root, 0)

def check(event=None):
    x, y = root.winfo_pointerxy()
    widget = root.winfo_containing(x, y)
    if widget is None:
        root.after(100, root.check)
    else:
        leave()

def leave():
    popup.delete(0, END)

The only real issue with this is it leaves behind a small box that moves focus away from the main window If anyone knows how to solve these issues let me know