Blank page when removing all mentions of grid()-CodePudding

I've switched from .grid() to .place() in my program, so I decided to remove a frame that contained the grid widgets:

BackButtonR = Button(registerPage, text="Back", command=lambda: show_frame(Menu))
BackButtonR.grid(row=0, column=0, sticky=W)
Button2F3 = Button(registerPage, text="Find")
Button2F3.grid(row=1, column=1)

Button3F3 = Button(registerPage, text="Calculate").grid(row=6, column=1)

LabelTitleF3 = Label(registerPage, text="Calculate Buy Price").grid(row=0, column=3)
label1F3 = Label(registerPage, text="Enter Ticker Symbol:").grid(row=1, column=0)
label2F3 = Label(registerPage, text="Expected CAGR").grid(row=2, column=0)
label3F3 = Label(registerPage, text="Years of Analysis").grid(row=3, column=0)
label4F3 = Label(registerPage, text="Expected PE Ratio").grid(row=4, column=0)
label5F3 = Label(registerPage, text="Desired Annual Return").grid(row=5, column=0)

entry1F3 = Entry(registerPage, width=7).grid(row=1, column=1, padx=0)
entry2F3 = Entry(registerPage).grid(row=2, column=1, pady=10, padx=0)
entry3F3 = Entry(registerPage).grid(row=3, column=1, pady=10, padx=0)
entry4F3 = Entry(registerPage).grid(row=4, column=1, pady=10, padx=0)
entry5F3 = Entry(registerPage).grid(row=, column=1, pady=10, padx=0)

But weirdly, when I rerun my program everything turns blank. This shouldn't happen, since I've removed any reference to .grid(), so the program should be working fine with .place(). Here is my full code:

print(220 135)
from tkinter import *
root = Tk()
root.title("Account Signup")
DarkBlue = "#2460A7"
LightBlue = "#B3C7D6"
root.geometry('350x230')

Menu = Frame(root)
loginPage = Frame(root)
registerPage = Frame(root)
for AllFrames in (Menu, loginPage, registerPage):
    AllFrames.grid(row=0, column=0, sticky='nsew')
    AllFrames.configure(bg=LightBlue)

def show_frame(frame):
    frame.tkraise()

show_frame(Menu)

# ============= Menu Page =========

Menu.grid_columnconfigure(0, weight=1)

menuTitle = Label(Menu, text="Menu", font=("Arial", 25), bg=LightBlue)
menuTitle.place(x=130, y=25)

loginButton1 = Button(Menu, width=25, text="Login", command=lambda: show_frame(loginPage))
loginButton1.place(x=85, y=85)

registerButton1 = Button(Menu, width=25, text="Register", command=lambda: show_frame(registerPage))
registerButton1.place(x=85, y=115)

# ======== Login Page ===========

loginUsernameL = Label(loginPage, text='Username').place(x=30, y=60)
loginUsernameE = Entry(loginPage).place(x=120, y=60)
loginPasswordL = Label(loginPage, text='Password').place(x=30, y=90)
loginPasswordE = Entry(loginPage).place(x=120, y=90)
backButton = Button(loginPage, text='Back', command=lambda: show_frame(Menu)).place(x=0, y=0)
loginButton = Button(loginPage, text='Login', width=20).place(x=100, y=150)

# ======== Register Page ===========
root.mainloop()

Why is my program turning blank?

CodePudding user response：

You need to call root.grid_rowconfigure(0, weight=1) and root.grid_columnconfigure(0, weight=1) so that the shown frame use all the space of root window, otherwise the size of those frames are 1x1.

Also Menu.grid_columnconfigure(0, weight=1) is useless because widgets inside Menu are using .place().

CodePudding user response：

When you use pack and grid, these functions will normally adjust the size of a widget's parent to fit all of its children. It's one of the most compelling reasons to use these geometry managers.

When you use place this doesn't happen. If you use place to put a widget in a frame, the frame will not grow or shrink to fit the widget.

In your case you're creating Menu, loginPage and registerPage and not giving them a size so they default to 1x1 pixels. When you use place to add a widget to the frame, the frame will remain at 1x1 pixels, rendering it virtually invisible.

The solution is to either give these frames an explicit size, or add the frames to the window with options that cause them to fill the window.

For illustrative purposes I've changed the background color of the window to pink, and set the size of Menu to 200x200. As you can see in the following screenshot, the frame with the widgets is there, and becomes visible when you give it a larger size. Of course, one problem with place is it's up to you to calculate the appropriate size.

The better solution in this specific case would be to use the appropriate grid options to have the frames fill the window. You can do that by giving a weight to the row and column that the frames are in. Unused space in the parent frame will be allocated to the row and column with the widget.

root.grid_rowconfigure(0, weight=1)
root.grid_columnconfigure(0, weight=1)

Generally speaking, grid and pack are superior to place for implementing most layouts because they are able to automatically make all widgets fit into a window with very little work. With place it's up to you to do calculations for position and size, and to make sure that all ancestors are appropriately sized and are visible.