I am trying to create a "movie" style credit reel using tkinter's canvas. I'd like to iterate through a list of names and have them scroll across the window. While I've successfully gotten a single name to scroll, I'm struggling to iterate over several names.

I appreciate your help and apologies for any gross oversights on my part.

from tkinter import *
import time

window = Tk()
window.geometry("1920x1080")
window.title("Window 1")

canvas1 = Canvas(window, width=1920, height=1080, bg="green", bd=0, highlightthickness=0, relief='ridge')
canvas1.pack()


class CreditList:
    def __init__(self, text):
        self.text = text
        self.location = 1080

    def credit_roll_function(self):
        text = canvas1.create_text(960,self.location, text=self.text, anchor=S, fill="black",
                                   font="Time 40")
        while True:
            canvas1.move(text, 0, -3)
            window.update()
            time.sleep(.03)


credit_list = ["First Name", "Second Name", "Third Name"]

for credit in credit_list:
    item = CreditList(credit)
    item.credit_roll_function()


window.mainloop()

CodePudding user response：

Here's a simple way to do it that uses the universal widget after() method instead of calling time.sleep() which interferes with tkinter's mainloop(). Each time the class' roll_credits() method is called, it moves the text upward a little and schedules another call to itself if the text isn't at the top of the window yet.

import tkinter as tk
from tkinter.constants import *

class CreditList:
    def __init__(self, text):
        self.location = HEIGHT
        self.text = canvas.create_text(960, self.location, text='\n'.join(text),
                                       anchor=S, fill='black', font='Time 40')

    def roll_credits(self):
        xl, yt, xr, yb = canvas.bbox(self.text)
        if yb <= 0:  # Completely off top of screen?
            canvas.pack_forget()
            tk.Button(text='Quit', font=('Arial', 20), relief=GROOVE, bg='orange',
                      command=window.quit).place(x=WIDTH/2, y=HEIGHT/2, anchor=NW)
            return  # Stop.
        canvas.move(self.text, 0, -3)
        self.location -= 3
        window.after(DELAY, self.roll_credits)  # Keep going.


DELAY = 10  # Millisecs.

window = tk.Tk()
window.attributes('-fullscreen', True)
window.update_idletasks()
WIDTH, HEIGHT = window.winfo_width(), window.winfo_height()  # Get screen size.
window.geometry(f'{WIDTH}x{HEIGHT} 0 0')
window.title('Window 1')

canvas = tk.Canvas(window, width=WIDTH, height=HEIGHT, bg='green', bd=0,
                    highlightthickness=0, relief='ridge')
canvas.pack()

credits = 'First Name', 'Second Name', 'Third Name'
cl = CreditList(credits)
window.after(DELAY, cl.roll_credits)  # Start rolling credits "loop".
window.mainloop()

CodePudding user response：

If you give all of your text items the same tag, you can move them all at the same time. Another solution is to create a single text item that is created by joining all of your strings with a newline.

For example, the following code illustrates how to create all of the items with a given tag, then moves them all one pixel at a time every 33 ms until they no longer are visible.

import tkinter as tk

class CreditList(tk.Canvas):
    def __init__(self, master, **kwargs):
        super().__init__(master, **kwargs)

    def roll_credits(self, credit_list):
        x = self.winfo_width() // 2
        y = self.winfo_height()
        temp = self.create_text(0,0,text="Hello")
        bbox = self.bbox(temp)
        self.delete(temp)
        lineheight = bbox[3]-bbox[1]
        linespacing = 4

        for credit in credit_list:
            self.create_text(x, y, text=credit, anchor="n", tags=("credit",))
            y  = lineheight   linespacing

        self._animate()

    def _animate(self):
        self.move("credit", 0, -1)
        x0, y0, x1, y1 = self.bbox("credit")
        if y1 > 0:
            self.after(33, self._animate)

root = tk.Tk()
credits = CreditList(root)
credits.pack(side="top", fill="both", expand=True)

credit_list = 'First Name', 'Second Name', 'Third Name'
root.after(1000, credits.roll_credits, credit_list)

root.mainloop()