我可以在一个Tkinter（tk.Tk）根窗口中使用两个不同的TTK主题吗？

Question

This question concerns Python and Tkinter.

I'd like to use two different ttk themes simultaneously, eg 'clam' and 'vista' in one Tkinter window. So I wrote this:

import tkinter as tk
import tkinter.ttk as ttk

class GUI(tk.Tk):

    def __init__(self):

        super().__init__()
        Button_v1()
        Button_v2()


class Button_v1(ttk.Button):

    def __init__(self, default_text="Test"):

        super().__init__(text=default_text)

        s = ttk.Style()
        s.theme_use('clam')
        s.configure(self.winfo_class(), foreground='blue')
        self.pack()


class Button_v2(ttk.Button):

    def __init__(self, default_text="Test2"):

        super().__init__(text=default_text)

        s2 = ttk.Style()
        s2.theme_use('vista')
        s2.configure(self.winfo_class(), foreground='red')
        self.pack()


GUI().mainloop()

The code loads, however:

1. I expected the first Button's foreground to be blue and the second Button's foreground to be red, and for two separate themes to be used.

2. Instead, both buttons have a red foreground, and both apply the same theme.

Is it possible to use two separate ttk themes in one Tkinter program?

Answer 1

No, it's not possible, because theme has a global meaning in this context. You can represent theme as a set of styles for widgets ( for widget layout elements, actually ), you can change style and/or create a new one, but you can't use more than one of themes at the time, because widget's layout depends heavily on it.

When you call theme_use('theme_name') tkinter rebuilds all widget's layouts and redraws your entire application , and you can easily check this, thanks to <<ThemeChanged>> virtual event.

Here's a snippet. You will see three prints, caused by each button and by root himself.

try:
    import tkinter as tk
    import tkinter.ttk as ttk
except ImportError:
    import Tkinter as tk
    import ttk


class GUI(tk.Tk):
    def __init__(self):
        super().__init__()
        self.bind('<<ThemeChanged>>', lambda event: print('theme changed in root and across all widgets!'))
        Button_v1()
        Button_v2()


class Button_v1(ttk.Button):
    def __init__(self, default_text="Test"):
        super().__init__(text=default_text)
        s = ttk.Style()
        s.theme_use('clam')
        s.configure(self.winfo_class(), foreground='blue')
        self.pack()


class Button_v2(ttk.Button):
    def __init__(self, default_text="Test2"):
        super().__init__(text=default_text)
        s2 = ttk.Style()
        s2.theme_use('vista')
        s2.configure(self.winfo_class(), foreground='red')
        self.pack()

GUI().mainloop()

If you need different foreground for each button - then create a new style for each of them and use the style parameter:

Here's an another snippet:

try:
    import tkinter as tk
    import tkinter.ttk as ttk
except ImportError:
    import Tkinter as tk
    import ttk


class GUI(tk.Tk):
    def __init__(self):
        super().__init__()

        s = ttk.Style()
        s.configure('blue.TButton', foreground='blue')
        s.configure('red.TButton', foreground='red')

        Button_v1()
        Button_v2()


class Button_v1(ttk.Button):
    def __init__(self, default_text="Test"):
        super().__init__(text=default_text, style='blue.TButton')
        self.pack()


class Button_v2(ttk.Button):
    def __init__(self, default_text="Test2"):
        super().__init__(text=default_text, style='red.TButton')
        self.pack()

GUI().mainloop()

Everything is well described here and there .

Answer 2

No, it is not possible to use two different themes at the same time.

From the canonical documentation [1] for the function underlying the theme_use method (emphasis added by me):

Without an argument the result is the name of the current theme. Otherwise this command sets the current theme to themeName, and refreshes all widgets.

Here is a simple example showing how you can switch themes on the fly:

# python  2
import Tkinter as tk
import ttk

# python 3
#import tkinter as tk
#import tkinter.ttk as ttk

def switch_theme(theme):
    style = ttk.Style()
    style.theme_use(theme)

root = tk.Tk()

style = ttk.Style()
for theme in style.theme_names():
    button = ttk.Button(root, text=theme,
                        command=lambda theme=theme: switch_theme(theme))
    button.pack(side="top", padx=4, pady=4)

root.mainloop()

Answer 3

No. You can't use two different themes. But, you can create a style:

style = ttk.Style()
style.configure("BW.TLabel", foreground="black", background="white")

l1 = ttk.Label(text="Test", style="BW.TLabel")
l2 = ttk.Label(text="Test", style="BW.TLabel")

You can create another style for a different widget