How to add more speech bubbles? - Tkinter Chatbot - python-3.x

Question

I've been working on a chatbot in tkinter and have been using this, https://stackoverflow.com/a/56032923/12406236 as a starting point for my code. I want to be able to add more speech bubbles (I can only make three) and then scroll through them.
How would I be able to accomplish this?
My code:
from tkinter import *
root = Tk()
frame = Frame(root,width=200,height=200)
frame.grid(row=0,column=0,columnspan=2)
canvas = Canvas(frame,bg="white",width=300,height=300,scrollregion=(0,0,500,500))
canvas.pack(side=LEFT,expand=True,fill=BOTH)
vbar = Scrollbar(frame,orient="vertical",command=canvas.yview)
vbar.pack(side=RIGHT,fill=Y)
canvas.configure(yscrollcommand=vbar.set)
bubbles = []
class BotBubble:
def __init__(self,master,message=""):
self.master = master
self.frame = Frame(master,bg="light grey")
self.i = self.master.create_window(90,160,window=self.frame)
Label(self.frame, text=message,font=("Helvetica", 9),bg="light grey").grid(row=1,column=0)
root.update_idletasks()
self.master.create_polygon(self.draw_triangle(self.i),fill="light grey",outline="light grey")
def draw_triangle(self,widget):
x1, y1, x2, y2 = self.master.bbox(widget)
return x1, y2 - 8, x1 - 10, y2 + 5, x1, y2
def send_message(event):
if bubbles:
canvas.move(ALL, 0, -65)
a = BotBubble(canvas,message=entry.get())
bubbles.append(a)
entry = Entry(root,width=100)
entry.grid(row=1,column=0)
entry.bind("<Return>",send_message)
root.mainloop()

Answer 1

I have modified your code:
do not set scrollregion when creating canvas
update scrollregion of canvas after new bubble is added or window is resized
do not scroll up old bubbles, just add the new bubble below last bubble
Updated code:
from tkinter import *
root = Tk()
frame = Frame(root)
frame.pack(fill=BOTH, expand=1)
canvas = Canvas(frame, bg="white")
canvas.pack(side=LEFT, expand=True, fill=BOTH)
vbar = Scrollbar(frame, orient="vertical", command=canvas.yview)
vbar.pack(side=RIGHT, fill=Y)
canvas.configure(yscrollcommand=vbar.set)
bubbles = []
LINE_GAP = 10 # gap between bubbles
class BotBubble:
def __init__(self, master, message=""):
self.master = master
self.frame = Frame(master, bg="light grey")
bbox = self.master.bbox(ALL)
y = (bbox[3] if bbox else 0) + LINE_GAP
self.i = self.master.create_window(15, y, window=self.frame, anchor='nw')
Label(self.frame, text=message, font=("Helvetica",9), bg="light grey").grid(row=1, column=0)
self.master.update()
self.master.create_polygon(self.draw_triangle(self.i), fill="light grey", outline="light grey")
def draw_triangle(self,widget):
x1, y1, x2, y2 = self.master.bbox(widget)
return x1, y2-8, x1-10, y2+5, x1, y2
def update_scrollregion(event=None):
canvas.config(scrollregion=canvas.bbox(ALL))
canvas.yview_moveto(1) # scroll to bottom
def send_message(event):
a = BotBubble(canvas, message=entry.get())
bubbles.append(a)
update_scrollregion()
entry = Entry(root, width=100)
entry.pack(fill=X)
entry.bind("<Return>", send_message)
entry.focus_force()
frame.bind('<Configure>', update_scrollregion)
root.mainloop()