How to instantly update the plot by getting values from a Scale widget?

[OLE]

Actually, the previous code worked. I removed this line ax.figure.colorbar( c) in update().
Now I only need to move the slider initially to the toplevel window.

import tkinter as tk
import numpy as np
from matplotlib.figure import Figure
from matplotlib import cm
from matplotlib.colors import ListedColormap
from matplotlib.backends.backend_tkagg import (FigureCanvasTkAgg, NavigationToolbar2Tk)


class Data:
    def __init__(self):
        self.layer = tk.IntVar()


class SampleApp(tk.Tk):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)

        container = tk.Frame(self)
        container.pack()

        self.data = Data()

        self.frames = {}
        for F in (page1,):
            frame = F(container, self.data)
            self.frames[F] = frame
            frame.pack()

    def show_frame(self, c):
        frame = self.frames[c]
        frame.tkraise()


class page1(tk.Frame):
    def __init__(self, parent, data):
        super().__init__(parent)
        self.data = data

        frame1 = tk.Frame(self, width=200)
        frame1.pack()

        label1 = tk.Label(frame1, text="Layer number:")
        label1.grid(row=0, column=0, padx=10)

        self.h_slider1 = tk.Scale(frame1, from_=1, to=10, orient="horizontal", length=100, resolution=1, variable=self.data.layer)
        self.h_slider1.grid(row=0, column=1)

        self.button = tk.Button(frame1, text="plot", command=self.plot)
        self.button.grid(row=1, column=0, columnspan=2, pady=20)

        np.random.seed(2)
        self.num = list(np.random.randint(low=1, high=10, size=120))

        self.button['command'] = self.open
        self.h_slider1['command'] = self.update

    def plot(self, var, window):
        global ax, newcmp, nx, ny, x, y, num_reshaped
        nx = 3
        ny = 4
        num_reshaped = np.array(self.num).reshape(10, nx * ny)
        layer = num_reshaped[var - 1:var, :]
        layer = layer.reshape(nx, ny)
        x, y = np.mgrid[slice(0, nx + 1, 1), slice(0, ny + 1, 1)]

        self.figure = Figure(figsize=(4, 4))
        ax = self.figure.add_subplot(111)
        col_type = cm.get_cmap('rainbow', 256)
        newcolors = col_type(np.linspace(0, 1, 1000))
        white = np.array([1, 1, 1, 1])
        newcolors[:1, :] = white
        newcmp = ListedColormap(newcolors)

        c = ax.pcolormesh(x, y, layer, cmap=newcmp, edgecolor='lightgrey', linewidth=0.003)
        ax.figure.colorbar(c)
        self.canvas = FigureCanvasTkAgg(self.figure, window)
        self.canvas.draw()
        self.canvas.get_tk_widget().pack()

    def open(self):
        self.toplevel = tk.Toplevel()
        self.toplevel.geometry('+500+100')
        self.plot(self.data.layer.get(), self.toplevel)

    def update(self, *args):
        var = self.data.layer.get()
        layer = num_reshaped[var - 1:var, :]
        layer = layer.reshape(nx, ny)
        ax.pcolormesh(x, y, layer, cmap=newcmp, edgecolor='lightgrey', linewidth=0.003)
        self.canvas.draw()