CODEWITHSUNDEEP
python-3.xmacoseventstkintertkinter-canvas
William Pulford
William Pulford

Reputation: 43

Getting canvas/widget size in Tkinter 3.x

There was a previous question asked, here, regarding getting the dimensions of a widget, whenever the window's size is changed.

The linked question and answer work perfectly, but I have a follow up question, and sadly because my account is quite new, I'm not allowed to post comments yet!

My question is; what is the effective difference between:

event.width

and

event.widget.winfo_width()

My full code is below.

from tkinter import *

root = Tk()

display = Canvas(root, width=300, height=300, background="bisque")
display.pack(fill="both", expand=True)

display.create_text(10, 15, anchor="w", tags=["events"])
display.create_text(10, 30, anchor="w", tags=["winfos"])


def show_dims(event):
    display.itemconfigure("events", text="event.width: {0}, event.height: {1}".format(event.width, event.height))
    display.itemconfigure("winfos", text="winfo_width: {0}, winfo_height: {1}".format(event.widget.winfo_width(), event.widget.winfo_height()))

display.bind("<Configure>", show_dims)

root.mainloop()

As far as I can tell, the code works perfectly. As the window size is changed, the "< Configure>" event calls the show_dims function, which updates the displayed text to show the current width and height of the window in pixels.

Are the two ways I've used of getting window dimensions the same? Is one better for some reason?

Thanks,

Upvotes: 2

Views: 884

Answers (1)

rassar
rassar

Reputation: 5660

Looking at the event documentation:

width - width of the exposed window (Configure, Expose)

So in your particular case, event.width and event.widget.winfo_width() are exactly the same always.

But with a different event:

from tkinter import *

root = Tk()
d = Label(root, width=50, height=50, text="HI")
d.pack(expand=True)

def check(event):
    print(event.width)
    print(event.widget.winfo_width())

d.bind("<1>", check)
root.mainloop()

This code displays:

??
456

So the winfo methods must be used unless the event is Configure or Expose. event.width is probably more readable to a client.

Upvotes: 2

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