Tkinter Canvas Scrollbar Frame Label Expansion-CodePudding

I've found multiple proposed solutions to this issue, but all variations on the function proposed below either don't work or result in errors when applied to my code. As noted, I want my elements in the canvas frame to expand left & right, the issue appears to be with the canvas_configure() function. This is a minimised version of the script I am using:

from tkinter import *

# Master frame
app = Tk()
app.columnconfigure(0, weight=1)
app.rowconfigure(0, weight=1)


def load_files():

    # Do stuff which gives list of company names
    companies_list = [x for x in range(0, 30)]

    # Generates Tkinter elements
    y = 0
    for x in companies_list:
        y  = 1
        old_co = Entry(frame)
        old_co.insert(0, x)
        old_co.grid(row=y, column=0, sticky=E W)

        new_co = Entry(frame)
        new_co.grid(row=y, column=1, sticky=E W)

        prefix = Entry(frame)
        prefix.grid(row=y, column=2, sticky=E W)


# Sub-Frame
company_header_frame = LabelFrame(app, text='Company Name')
company_header_frame.grid(row=0, column=0, sticky=N S E W)
company_header_frame.columnconfigure(0, weight=1)
company_header_frame.rowconfigure(0, weight=1)

# Canvas
canvas = Canvas(company_header_frame, height=100)
canvas.grid(row=0, column=0, sticky=N S E W)

# Canvas Frame
frame = Frame(canvas)
canvas.create_window((0, 0), window=frame, anchor='nw')

# Sidebar
scroll_y = Scrollbar(company_header_frame, orient="vertical")
scroll_y.grid(row=0, column=1, sticky=N S)
scroll_y.config(command=canvas.yview)


def canvas_configure(event):
    canvas_width = event.width
    event.itemconfig(frame, width=canvas_width)


def config_frame(_):
    canvas.configure(scrollregion=canvas.bbox('all'), yscrollcommand=scroll_y.set)


canvas.bind('<Configure>', canvas_configure)
frame.bind('<Configure>', config_frame)


load_files()


app.mainloop()

This results in the following error:

AttributeError: 'Event' object has no attribute 'itemconfig'

I attempted adjusting the function to use .winfo_width() in place of width, replacing event with the actual canvas, but similar attribute errors result relating to either width or itemconfig. Any advise would be much appreciated.

CodePudding user response：

The error is telling you exactly what is wrong: an Event object doesn't have an itemconfig method. The canvas widget does, however, and the Event object can give you the canvas widget:

def canvas_configure(event):
    canvas_width = event.width
    event.widget.itemconfig(frame, width=canvas_width)
    #    ^^^^^^^

Unrelated to the specific question that was asked, you also need to pass a valid item id to itemconfig -- you can't pass the frame itself.

You either need to save the value returned from create_window or you need to give the window a tag.

For example:

canvas.create_window(..., tags=("inner_frame",))
...
def canvas_configure(event):
    canvas_width = event.width
    event.widget.itemconfigure("inner_frame", width=canvas_width)