Place widgets into Frames? - python

I was trying out something new on Tkinter (I am still a newbie), but it keeps failing...maybe someone could help out?
I wanted to create a window with several Frames, so that I can open and close them and show that way different content. However I am already stuck with not being able to "place" the, in this case a button, to the frame. Instead I get a blank frame with nothing inside...
The reason I want to use the place manager is so that I can easily choose the x and y coordinates. I don't want to create empty columns just in order to get a button appear in the middle of the screen.
Here the code:
from Tkinter import *
root = Tk()
root.title("Tkinter window")
root.geometry("800x600")
StartFrame = Frame(root)
StartFrame.pack()
Button1 = Button(StartFrame, command = StartTkinter, text = "Start", bg = "white", fg = "black", height = 2, width = 15)
Button1.place(x=0, y=50)
root.mainloop()

The problem is that you forgot to specify the dimensions of the frame. So, by default, it is created to be just 1 pixel high and 1 pixel wide. This means that its contents will not be visible on the window.
To fix the problem, you can either set exact values for these dimensions when you create the frame:
StartFrame = Frame(root, height=600, width=800)
or you can do:
StartFrame.pack(expand=True, fill="both")
to have the frame fill all available space.

Related

How can i change frame widget width in python

I'm trying to resize a frame in tkinter, but the width does not change and function winfo_width() returns 1. How can i fix it?
from tkinter import *
root = Tk()
root.geometry('400x300')
Frame = LabelFrame(root, text="Test", width = 200)
Frame.grid(row = 0, column = 0)
label = Label(Frame, text = '').grid(row = 0, column=0)
print(Frame.winfo_width()) #output is 1 instead of 200
root.mainloop()
The width is returning 1 because the window hasn't been drawn yet. The actual width depends on the window being drawn since the actual width depends on many factors which can't be known before the window is actually drawn.
If you call root.update() before calling Frame.winfo_width() to force the window to be drawn, you will see it displaying the actual value.
As for how to change the width, that question is too broad to answer. Normally it's not wise to directly set the width of a frame. Tkinter by default will automaticaly resize a frame to fit its children. So, one way to make the frame wider is to add more widgets.
The width can also depend on how it is added to the display - whether you're using pack or grid or place, and how you have configured them. So, another way to make the frame wider is to use non-default options that cause the frame to grow or shrink to fit the space given to it.
If you want to specify an explicit size and ignore tkinter's automatic resizing, you can do that by turning off geometry propagation and then setting the width and height parameters for the frame. Depending on whether you're using grid or pack, you can call grid_propagate or pack_propagate with a False argument to disable propagation (place doesn't support geometry propagation).
Note that turning off geometry propagation is usually the least desirable solution because it requires you to do a lot more work to create a responsive UI. The best way to design GUI with tkinter is to focus on the size of the inner widgets and let tkinter compute the most efficient size for frames and the window itself.
As the others have pointed out how to set a static size frame using grid_propagate() I will show you how to set up your frame to resize automatically.
You need to tell the row and column to expand that the frame is in. This is done with columnconfigure() and rowconfigure(). Then you need to tell the frame to stick to all sides with sticky='nsew'. Adding widgets to the frame is no different then any other container. Simply tell the widget to be in the frame.
One potention issue I see is you are overwriting Frame() on this line: Frame = LabelFrame(root, text="Test", width = 200). This is a good example why you should not use import *. Instead do import tkinter as tk and use the tk. prefix for anything that needs it.
Example:
import tkinter as tk
root = tk.Tk()
root.geometry('400x300')
root.columnconfigure(0, weight=1)
root.rowconfigure(0, weight=1)
frame = tk.LabelFrame(root, text='Test', width=200)
frame.grid(row=0, column=0, sticky='nsew')
label = tk.Label(frame, text='label').grid(row=0, column=0)
root.mainloop()
Results:
Update:
If you do want something static make sure you define both height and width. If you only define one or the other then you will not see the frame in the window.
For a testable example for a static frame size:
import tkinter as tk
root = tk.Tk()
root.geometry('400x300')
root.rowconfigure(0, weight=1)
root.columnconfigure(0, weight=1)
frame = tk.LabelFrame(root, text='Test', height=200, width=200)
frame.grid(row=0, column=0)
frame.grid_propagate(False)
label = tk.Label(frame, text='label').grid(row=0, column=0)
root.mainloop()
Results:
Your frame can propagate on the grid based on the widgets on it, and not have fixed dimensions.
The output of 1 is due there being nothing on the Frame other than an empty Label. (It would still show 1 if there was no Label)
To get the output as 200, set the grid_propagate flag to False (only after setting your height and widht parameters), as follows:
frame = Frame(..., width=200)
frame.grid(row=0, column=0)
frame.grid_propagate(False)

Why does winfo_width() return a larger size of button widget than the size of what it exactly looks like?

I want buttons/labels in the same column will share the same width with a specific/first button/label. The problem is winfo_width() seems not to return what I want. The return value of winfo_width() is multiple times the button.
I don't want to make width fixed by a number I select. Thus, I did not find a solution to my problem.
Here is part of my code:
button_1.update_idletasks()
print(button_1.winfo_width())
new_label = Label(frame_1, bg= "#8432C7", width = 30, height = 5)
new_label.grid(row = 2, column = 0)
Since I don't have 10 reputation to post images, here is the link for the generated interface:
If you could see the above image, you should find the lower label (width = 30) is larger than the upper button (width = 157 ?).
But, according to my attempts, 157 seems not to be the width of button_1. I feel confused about what exactly winfo_width() returns here. Thus, I want to know what winfo_width() returns (why winfo_width() return 157 which should be a smaller number than 30) and how to get the exact width of the button.
I am stuck here for an hour since I just started to learn Tkinter recently.
Thanks in advance for anyone who can give me suggestions.
Fun fact: you don't have to bother with this at all.
Just pass sticky when you grid your widgets:
import tkinter as tk
root = tk.Tk()
button_1 = tk.Button(root,text="button_1")
button_1.grid(row = 1, column = 0, sticky="ew")
new_label = tk.Label(root, bg= "#8432C7", height = 5)
new_label.grid(row = 2, column = 0, sticky="ew")
root.mainloop()
Then your columns will be auto-fit and scaled to the same size.
This is because the width used in the arguments to create a button are in different units than what tkinter uses.
From the Documentation of a Button in tkinter. Width is The width of the button. If the button displays text, the size is given in text units. If the button displays an image, the size is given in pixels (or screen units). If the size is omitted, or zero, it is calculated based on the button contents. (width/Width)
You will find that if you use tkinters .place() to set a size, the size that .winfo_width() returns will be the same.
For example:
button_1.update_idletasks()
print(button_1.winfo_width())
new_label = Label(frame_1, bg= "#8432C7")
new_label.place(x=40, y=0, width=157, height=20)
You will find that the new_label will now have the same width as the button

PYTHON: How to anchor two labels to top using tkinter

import tkinter as tk
root = tk.Tk()
root.title("window")
yellow_header = tk.Label(root, text = 'Header', bg = 'light yellow')
yellow_header.pack(side = tk.TOP, anchor = tk.N, expand = 1, fill = tk.X)
yellow_header2 = tk.Label(root, text = 'paragraph', bg = 'light yellow')
yellow_header2.pack(side = tk.TOP, anchor = tk.N, expand = 1, fill = tk.X)
root.mainloop()
For the above code I am trying to have both these labels anchored to the top and directly below one another. Although the first label (yellow_header) anchors to the top, where as the second label (yellow_header2) when expanded move towards the centre. How can I fix this?
Thank you in advance!
Don't use expand=1. From effbot:
The expand option tells the manager to assign additional space to the widget box. If the parent widget is made larger than necessary to hold all packed widgets, any exceeding space will be distributed among all widgets that have the expand option set to a non-zero value.
With expand=1, when you make the window larger, the space is distributed between the two labels. So even though you only tell them to fill it in the X direction, they are given the space in both directions. The second label is placed directly under the space that is available to the first label, which is half of the window.
I've tried to explain and visualize the difference between expand and fill in this answer.
P.S. You don't need anchor=tk.N either. When the space available to the widget and the size of the widget are the same, the anchor option makes no difference. Also, side=tk.TOP is the default so you could decide to omit that too, leaving you with only fill=tk.X.
Looking at the docs I see:
The Text widget is used to display text in multiple lines.
and this seems to work:
import tkinter as tk
root = tk.Tk()
root.title("window")
yellow_header = tk.Label(root, text = 'Header\nParagraph', bg = 'light yellow')
yellow_header.pack(side = tk.TOP, anchor = tk.N, expand = 1, fill = tk.X)
That might be a bit OS specific and perhaps the proper way would be:
import os
...
yellow_header = tk.Label(root, text = 'Header' + os.linesep + 'Paragraph', bg = 'light yellow')
When increasing the length of the first string the second still remains in the center.

change size of Frame even if there widget python

hi is there any way to change width and height of widget even if there's widget?
i have code like this
form = Tk()
form.geometry("500x500")
def click():
global frame
frame.config(height = 0 ,width = 0)
frame = LabelFrame(form , text = "vaaja")
frame.place(x = 20 , y = 30)
Label(frame, text ="1").grid(row = 0,column = 0 )
Label(frame, text = "2").grid(row = 1 ,column = 0 )
Button(form , text="Click", command = click).place(x = 200 , y = 200)
form.mainloop()
and when I click the button the size of the frame is the same ( I'cant use grid_forget() for labels and then change the size of frame)
Because you are using place, you have two solutions: you can use place to set the width and height to zero, or you can turn geometry propagation off.
Using place to set the width and height
place allows you to define the width and the height of the placed widget, so in your click function you can do this:
def click():
frame.place_configure(width=0, height=0)
Turning geometry propagation off
A frame is resized to fit its contents by something called "geometry propagation". If you turn this off, you can control the size of the frame with the width and height options of the frame itself. Usually it's better to let Tkinter decide the size for you, but sometimes there's a need to have an explicit size, which is why it's possible to turn geometry propagation off.
Since you are using grid to manage the widgets internal to the frame, you need to use grid_propagate(False) to turn geometry propagation off for that frame:
frame.grid_propagate(False)
By doing so, you're responsible for setting the initial width and height of the widget, though you could leave propagation on to get the initial size, then turn it off with the button click in order to work around that issue.
There's an interesting bug (or feature...) in that if you set the width and height to zero, Tkinter won't redraw the window. At least, it doesn't on the Mac. I don't recall the workaround for that because I never, ever need to set a widget to a zero size, but setting it to 1x1 pixel makes it nearly invisible.

Tkinter Frame container color not visible

Why can't I see a red frame with the following code?
import Tkinter
root = Tkinter.Tk()
root.geometry("220x300")
container_frame = Tkinter.Frame(background = "red", width = 100, height = 120)
container_frame.pack()
widget_button = Tkinter.Button(master = container_frame)
widget_button.pack()
root.mainloop()
You don't see it because you have no padding between the button and the frame. By default, containers "shrink to fit" around their contents. Even if you add an explicit width or height to the frame, it will shrink to exactly fit its children.
There are several ways to achieve the effect you're looking for, but it's not clear exactly what effect you want. You can turn off this "shrink-to-fit" behavior (using container_frame.pack_propagate(False)). Or, you can add padding around the widget. Or, you can apply the background to the container of the frame. Or you could pack the frame to fill its container (the main window), then make sure the containing window is large enough to expose the frame.
For an example of that last suggestion, you can change one line to be this:
container_frame.pack(side="top", fill="both", expand=True)
If you change to:
widget_button.pack(padx=10, pady=10)
You can see that the frame has been resized when call widget_button.pack(...)

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