[Tutor] Dynamic variables changed via Tkinter button

[Alan Gauld]

On 15/04/2020 21:09, Jon Davies wrote:
> I need to implement two labels (displaying dynamic variables) that will change based on a button being held.
Here is some runnable code that illustrates what you want, i think...

import tkinter as tk

class App():
    def __init__(self,parent):
         self.main = tk.Frame(parent)
         self.main.pack()
         self.state='idle'
         self.count = 0
         self.lbl = tk.Label(self.main, text="Count = 0")
         self.lbl.pack()
         self.btn = tk.Button(self.main, text="Press & Hold")
         self.btn.pack()
         self.btn.bind('<Button-1>', self.press)
         self.btn.bind("<ButtonRelease-1>", self.stop)

    def press(self,evt):
        self.state='working'
        self.btn.after(100,self.update)

    def update(self):
        self.count += 0.1
        self.lbl['text'] = "Count = %f" % self.count
        self.main.update_idletasks()
        if self.state == 'working':
            self.btn.after(100, self.update)

    def stop(self,evt):
        self.state = 'idle'

top = tk.Tk()
app = App(top)
top.mainloop()




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Alan G
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