import tkinter
import time

################################################################################

class Splash:

    def __init__(self, root, file, wait):
        self.__root = root
        self.__file = file
        self.__wait = wait + time.clock()

    def __enter__(self):
        # Hide the root while it is built.
        self.__root.withdraw()
        # Create components of splash screen.
        window = tkinter.Toplevel(self.__root)
        canvas = tkinter.Canvas(window)
        splash = tkinter.PhotoImage(master=window, file=self.__file)
        # Get the screen's width and height.
        scrW = window.winfo_screenwidth()
        scrH = window.winfo_screenheight()
        # Get the images's width and height.
        imgW = splash.width()
        imgH = splash.height()
        # Compute positioning for splash screen.
        Xpos = (scrW - imgW) // 2
        Ypos = (scrH - imgH) // 2
        # Configure the window showing the logo.
        window.overrideredirect(True)
        window.geometry('+{}+{}'.format(Xpos, Ypos))
        # Setup canvas on which image is drawn.
        canvas.configure(width=imgW, height=imgH, highlightthickness=0)
        canvas.grid()
        # Show the splash screen on the monitor.
        canvas.create_image(imgW // 2, imgH // 2, image=splash)
        window.update()
        # Save the variables for later cleanup.
        self.__window = window
        self.__canvas = canvas
        self.__splash = splash

    def __exit__(self, exc_type, exc_val, exc_tb):
        # Ensure that required time has passed.
        now = time.clock()
        if now < self.__wait:
            time.sleep(self.__wait - now)
        # Free used resources in reverse order.
        del self.__splash
        self.__canvas.destroy()
        self.__window.destroy()
        # Give control back to the root program.
        self.__root.update_idletasks()
        self.__root.deiconify()