import tkinter as tk
import tkinter.ttk as ttk

root = tk.Tk()
var_x = tk.IntVar()
var_bug = tk.DoubleVar()
var_adj = tk.DoubleVar()

def _Mouse_XY(event):
    var_x.set(event.x)
    var_bug.set(round(
        event.widget.fraction(event.x, event.y), 3
        ))
    #If the ttk.Scrollbar.fraction has a 1.0 output when there's 16 pixels left in the trough,
    #then divide those 16 pixels in the trough so that it appears longer than is.
    #When the fraction output is 0.0, add 0 pixels
    #When the fraction output is 0.5, add 8 pixels
    #When the fraction output is 1.0, add 16 pixels
    if event.widget.winfo_name() == 'ttk':
        adj = 16*var_bug.get()
        var_adj.set(round(
            event.widget.fraction(event.x - adj, event.y), 3
            ))

frame = tk.Frame(root, width=400, bg='red')
frame.grid_propagate(False)
frame.pack(fill='both', expand=True)
frame.columnconfigure(0, weight=True)

tk_scrl = tk.Scrollbar(frame, orient='horizontal', name='tk')
ttk_scrl = ttk.Scrollbar(frame, orient='horizontal', name='ttk')

tk_scrl.set(0, .01)
ttk_scrl.set(0, .01)

tk_scrl.bind("<B1-Motion>", _Mouse_XY)
ttk_scrl.bind("<B1-Motion>", _Mouse_XY)

container = tk.Frame(frame)
container.grid(sticky='w')
tk.Label(container, text="Mouse x coordinate: ", font='Courier').grid(row=0, column=0)
tk.Label(container, text=".function() output: ", font='Courier').grid(row=1, column=0)
tk.Label(container, text="Fixed ttk.function: ", font='Courier').grid(row=2, column=0)
tk.Label(container, textvariable=var_x, font='Courier', anchor='w').grid(row=0, column=1, sticky='w')
tk.Label(container, textvariable=var_bug, font='Courier', anchor='w').grid(row=1, column=1, sticky='w')
tk.Label(container, textvariable=var_adj, font='Courier', anchor='w').grid(row=2, column=1, sticky='w')

tk_scrl.grid(sticky='we')
ttk_scrl.grid(sticky='we')

frame.update_idletasks()
frame.configure(height=frame.bbox('all')[3])

root.mainloop()