How to scale label font size inside a 'Toplevel' Tkinter Window?

Question

Working on displaying some information inside a tkinter 'Toplevel' window. I want the text size to increase as you increase the size of the window. For this I am just using the label widget inside a toplevel widget.

I've made a function that triggers during a resize event of the window, and update a global font variable.

    def showResults(self):

        self.top = Toplevel(master = None, height=750,width=750, relief="sunken")
        self.top.title("Results")
        self.font = ("Times", 20, "bold")
        self.fontSize = IntVar()
        self.fontSize.set(20)
        self.resultX = Label(self.top, text="Name: X", font=("Times", self.fontSize.get(), "bold")).pack(side = "left", fill = "both", expand=True)
        self.top.bind('<Configure>', self.resize)
        print(self.fontSize.get())


    def resize(self, event):
        self.fontSize.set(self.top.winfo_height())

I expected self.fontSize to update once resize is called, however, it isn't being updated. If I move that print statement in showResults to resize however, it does print the updated size. It's just not refreshing the label widget. Anyone know of a simple way to perhaps 'refresh' label widgets to display the proper information? Thank you!

Answer 1

You can do this by defining a font.Font object and set it as the font of your Label widget:

from tkinter import *
from tkinter import font

class Body(Frame):
    def __init__(self,master=None,**kwargs):
        super().__init__(master,**kwargs)
        self.button = Button(self,text="Click",command=self.showResults)
        self.button.pack()

    def showResults(self):
        self.font = font.Font(self.master, family="Times", size=20, weight="bold")
        self.top = Toplevel(master=None, height=750, width=750, relief="sunken")
        self.top.title("Results")
        self.resultX = Label(self.top, text="Name: X", font=self.font)
        self.resultX.pack(side="left",fill="both",expand=True)
        self.update()
        self.top.bind('<Configure>', self.resize)

    def resize(self, event):
        self.font['size'] = self.top.winfo_height()

root = Tk()
Body(root).pack()

root.mainloop()