What can cause unexpected tkinter widget resizing after frame resize? - python

One thing that can do it is assigning weights to non existent columns and rows. Maybe users know of others?
I recently had to track down this problem, and place it here in the hope it will be useful to others.
After resizing your window frame, tkinter will not resize widgets if you have assigned a non zero weight to non existent columns. I ran into this situation where I had a dynamic UI which hid a panel, and replaced it with some buttons. For these buttons to resize properly, I did a columnconfigure and assigned weights of 1 to these extra columns. When the UI was restored, these buttons were removed, and we went back to one column. However the weights for these non existent columns still influenced the resizing as seen in the attached figure.
To solve the problem I reset the weights of these extra columns that I had set to 1 back to zero (even though these columns did not exist in the UI any more).
Minimal code to illustrate the problem is shown below:
The problem line is labelled # ####### this is a problem
import tkinter as tk
class frame_resize:
def setupGUI(self):
self._root = tk.Tk()
self._font = 'helvetica 16'
self._mainFrame = tk.Frame(self._root, bg='pink')
self._label = tk.Label(self._mainFrame,
font=self._font,
bg='sky blue',
text='this is some text')
self._mainButton = tk.Button(self._mainFrame, text='Press here',
font=self._font)
# give weights so that widgets expand when outer frame expands
tk.Grid.rowconfigure(self._root, 0, weight=1)
tk.Grid.columnconfigure(self._root, 0, weight=1)
tk.Grid.rowconfigure(self._mainFrame, 0, weight=1)
tk.Grid.columnconfigure(self._mainFrame, 0, weight=1)
# ####### this is a problem, if we have no column 1
tk.Grid.columnconfigure(self._mainFrame, 1, weight=1)
#pop elemnts into grid
self._mainFrame.grid(column=0, row=0, sticky='nsew')
self._label.grid(column=0, row=0, sticky='nsew')
self._mainButton.grid(column=0, row=1, sticky='nsew')
self._root.mainloop()
fr = frame_resize()
fr.setupGUI()

Related

How to get .grid_columnconfigure() working inside Frame?

I want to create a GUI with tkinter in python using grid-Method and grid_columnconfigure/grid_rowconfigure.
Unfortunately, this is not working inside a Frame.
How can I get this work?
from tkinter import *
master = Tk()
master.state('zoomed')
f = Frame(master, width=800, height=400)
Label1 = Label(f, text='Label 1')
Label2 = Label(f, text='Label 2')
f.grid_columnconfigure(0, weight=1)
f.grid_columnconfigure(2, weight=1)
f.grid_columnconfigure(4, weight=1)
Label1.grid(row=0, column=1)
Label2.grid(row=0, column=3)
f.pack()
master.mainloop()
ADDITIONAL QUESTION:
I got great answers, all is working fine with pack-Manager.
But how could I do this if using grid-Manager?
The grid_columnconfigure is working fine. The problem is that your frame will by default set its size to the smallest possible size to fit the labels. Since empty columns don't have a size, the frame will be just wide enough to hold the two labels.
This will be easy to visualize if you give frame a distinctive color during development. It also sometimes helps to give the frame a visual border so you can see its boundaries.
While I don't know what your ultimate goal is, you can see the spaces between the column if you have the frame fill the entire window:
f.pack(fill="both", expand=True)
If you want to use grid instead of pack, you have to do a bit more work. In short, put the frame in row 0 column 0, and give that row and column a non-zero weight so that grid will give all unused space to that row and column.
f.grid(row=0, column=0, sticky="nsew")
master.grid_rowconfigure(0, weight=1)
master.grid_columnconfigure(0, weight=1)
If you want to force the window to be a specific size, you can use the geometry method of the master window:
master.geometry("800x400")

tkinter sticky not working for some frames

I'm using tkinter to write a card game, and I'm having trouble with he grid layout manager 'sticky' configuration. I would like help fixing my code to make the frames display in the desired location. In my code and illustration below, there is a frame (b2) that contains two other (one green, b2a; and one red; b2b) frames. I would like to display frame b2 at the bottom of the parent frame (frame b). I've tried various combinations of N+S+E+W as arguments for 'sticky', for both frame b2 and the child frames b2a and b2b. However, I've been unable to make frame b2 (and more importantly b2a and b2b) appear in the desired location (the bottom image below with the correct placement was made in Illustrator).
In particular, it seems that sticky arguments in lines 27, 36 and 37 have no effect on the placement of frame b2, b2a and b2b inside of frame b.
from tkinter import *
from PIL import Image, ImageTk
def main(root):
cons = Frame(root)
cons.grid()
frameDict = setup_frames(cons)
populate_frames(frameDict)
def setup_frames(cons):
frame = {}
# Parental Frames
frame['a'] = Frame(cons, borderwidth=2, relief='groove')
frame['b'] = Frame(cons, borderwidth=2, relief='groove')
frame['c'] = Frame(cons, borderwidth=2, relief='groove')
frame['a'].grid(row=0, column=0, sticky=N+S+E+W)
frame['b'].grid(row=0, column=1, sticky=N+S+E+W)
frame['c'].grid(row=1, column=0, columnspan=2)
# Progeny 0 Frames:
frame['b1'] = Frame(frame['b'], borderwidth=2, relief='groove')
frame['b2'] = Frame(frame['b'], borderwidth=2, relief='groove')
frame['b1'].grid(row=0, column=0, sticky=N+S+E+W)
frame['b2'].grid(row=1, column=0, sticky=N+S+E+W)
# Progeny 1 Frames:
frame['b2a'] = Frame(frame['b2'], borderwidth=2, relief='groove',
background='green')
frame['b2b'] = Frame(frame['b2'], borderwidth=2, relief='groove',
background='red')
frame['b2a'].grid(row=0, column=0, sticky=S)
frame['b2b'].grid(row=0, column=1, sticky=SW)
return frame
def populate_frames(fr):
# Populating 'a' frame
aLab = Label(fr['a'], image=img[0])
aLab.grid()
# Populating b2a & b2b frames
bLab = Label(fr['b2a'], image=img[1])
bLab.grid(row=0, column=0)
bLab = Label(fr['b2b'], image=img[2])
bLab.grid(row=0, column=1)
# Populating c1 frame
cLab = Label(fr['c'], image=img[3])
cLab.grid()
if __name__ == '__main__':
root = Tk()
img = []
w = [40, 160, 80, 480]
h = [180, 60, 60, 60]
for i in range(4):
a = Image.new('RGBA', (w[i], h[i]))
b = ImageTk.PhotoImage(a)
img.append(b)
main(root)
The images below illustrate where the offending frames (green and red) are displaying (top) and where I would like them displayed (bottom).
Could someone please help me display frame b2 (and ultimately b2a and b2b) in the correct position (Edit: at the bottom of frame b, and spanning from the right side of frame a to the right side of frame c)?
Update:
I've solved both problems (vertical placement and horizontal justification of frame b2) using grid weights, as Bryan suggested. The solution to the vertical placement problem is straightforward, but I would not have predicted the solution to the horizontal justification issue.
I solved the vertical placement problem by giving weight=1 to row 0 in frame b (resulting in the upper panel of the figure below).
I solved the horizontal justification problem (wherein frames b1 and b2 were not stretching to fill frame b) by assigning weight=1 to column 0 in frame b. The frame outlines in the figure below show that frame b is already stretched from the right side of frame a to the right side of frame c. It's strange to me that giving weight to the only column in a frame would be required to allow child frames to fill horizontally. In any case, I've pasted my working code below. Lines 40 and 41 solved the issue I was having.
from tkinter import *
from PIL import Image, ImageTk
def main(root):
cons = Frame(root)
cons.grid()
frameDict = setup_frames(cons)
populate_frames(frameDict)
def setup_frames(cons):
frame = {}
# Parental Frames
frame['a'] = Frame(cons, borderwidth=2, relief='groove')
frame['b'] = Frame(cons, borderwidth=2, relief='groove')
frame['c'] = Frame(cons, borderwidth=2, relief='groove')
frame['a'].grid(row=0, column=0, sticky=N+S+E+W)
frame['b'].grid(row=0, column=1, sticky=N+S+E+W)
frame['c'].grid(row=1, column=0, columnspan=2)
# Progeny 0 Frames:
frame['b1'] = Frame(frame['b'], borderwidth=2, relief='groove')
frame['b2'] = Frame(frame['b'], borderwidth=2, relief='groove')
frame['b1'].grid(row=0, column=0, sticky=N+S+E+W)
frame['b2'].grid(row=1, column=0, sticky=N+S+E+W)
# Progeny 1 Frames:
frame['b2a'] = Frame(frame['b2'], borderwidth=2, relief='groove',
background='green')
frame['b2b'] = Frame(frame['b2'], borderwidth=2, relief='groove',
background='red')
frame['b2a'].grid(row=0, column=0, sticky=S)
frame['b2b'].grid(row=0, column=1, sticky=SW)
# Weighting
frame['b'].grid_rowconfigure(0, weight=1)
frame['b'].grid_columnconfigure(0, weight=1)
return frame
def populate_frames(fr):
# Populating 'a' frame
aLab = Label(fr['a'], image=img[0])
aLab.grid()
# Populating b2a & b2b frames
bLab = Label(fr['b2a'], image=img[1])
bLab.grid(row=0, column=0)
bLab = Label(fr['b2b'], image=img[2])
bLab.grid(row=0, column=1)
# Populating c1 frame
cLab = Label(fr['c'], image=img[3])
cLab.grid()
if __name__ == '__main__':
root = Tk()
img = []
w = [40, 160, 80, 480]
h = [180, 60, 60, 60]
for i in range(4):
a = Image.new('RGBA', (w[i], h[i]))
b = ImageTk.PhotoImage(a)
img.append(b)
main(root)
Consistent with Bryan's advice, it does seem to be a good rule of thumb to assign a weight to at least one column and one row in every container.
Here's before and after I fixed the horizontal justification problem:
Using Python 3.4, Yosemite
You must give some rows and columns a weight, so tkinter knows how to allocate extra space.
As a rule of thumb when using grid, every container using grid should give at least one row and one column weight.
What I would do is start over. Be methodical. Get the main three areas working first before tackling other problems. What is making this problem hard to solve is that nothing is behaving right, so you're trying to adjust many things at once. Focus on one area at a time, get it working just right, and then move on.
Given your diagram, pack seems like a much simpler solution than using grid for the children of the root window Using grid inside of frames inside of other frames using grid can be confusing.
It looks like frame C is a status bar of some sort that stretches across the bottom, so pack it first. Above that you have two areas - frame a is to the left and looks to be a fixed width, and frame c is to the right and takes up all of the extra space. Using pack, it would look like this:
frame['c'].pack(side="bottom", fill="x")
frame['a'].pack(side="left", fill="y")
frame['b'].pack(side="right", fill="both", expand=True)
Of course, you can get the exact same appearance with grid, but it will take a couple more lines of code since you have to give column 1 and row 1 a weight.
That should get the three main areas working just fine. Now all you have to worry about is the contents of frame B.
Your diagram shows that you want b2a and b2b at the bottom of frame b, with more widgets above it. Is that correct? If that's the case, you need to leave at least one extra row above it to fill the extra space.
The blank row with a positive weight will force all of the widgets to be moved toward the bottom of the area. They will take up only as much space as they need vertically, with the empty row with the non-zero weight taking up all the extra.
You then only have to worry about horizontal placement. It's unclear exactly what you expect, but the solution again revolves around giving columns weight. If you want both b2a and b2b to expand equally, give both columns an equal weight. If you want b2a to do all of the expanding, give only column zero a weight.

TK, understanding pack and expanding space

I have a window that is resizeable, where i want to have two listboxes with scroll bars that expand to fill all space available.
when i have only one listbox packed as fill=both, expand=1, side=left and one scrollbar packed as fill=Y, expand=0, side=right then it will expand only horizontally, even though it is set to fill both directions. when i resize the window, the listbox only fill the sides. the bottom of the window remain empty.
then i moved on to add another listbox. Now instead of packing the scroll bar on right, i packed everything to left, so they are stacked. the listboxes continue to have fill=both, expand=1. Now when i resize the window both list boxes only fill vertically! the horizontal space remains empty.
what is going on? why does it ignore the vertical space with one element packed left and another right? and why it refuses to fill horizontally when everything is stacked left?
the fact that once it fill the vertical or the horizontal space leads me to believe the parent frame is expanding fine... or should i investigate that more as well?
Without seeing your actual code it's impossible to know what you're doing wrong. Here's an example to prove that pack works as documented:
import Tkinter as tk
root = tk.Tk()
lb1 = tk.Listbox(root)
lb2 = tk.Listbox(root)
vsb1 = tk.Scrollbar(root, orient="vertical", command=lb1.yview)
vsb2 = tk.Scrollbar(root, orient="vertical", command=lb2.yview)
lb1.configure(yscrollcommand=vsb1.set)
lb2.configure(yscrollcommand=vsb2.set)
lb1.pack(side="left", fill="both", expand=True)
vsb1.pack(side="left", fill="y", expand=False)
lb2.pack(side="left", fill="both", expand=True)
vsb2.pack(side="left", fill="y", expand=False)
root.mainloop()
workaround i'm using (downvote if not the right tk way)
i created two frames, both side=LEFT, expand=1, fill=BOTH and then put each pair of listbox+scrollbar there. now everything expands/fills just fine.
previously the listboxes were in the yellow frame. The ones i just created are the the blue and green.
still not sure with the pack manager would not expand the listboxes when they had scrollbars without expansion between them...

Is it possible to easily center side-stacked frames in a frame in tkinter?

I am faced with the problem to center side-stacked frames in a parent frame. I know how to center a single frame in a frame but I did not find a simple way to do this for several of them.
I get the following window
from the code below:
import Tkinter as tk
root = tk.Tk()
root.geometry("200x200")
# main frame
f = tk.Frame(root, background='black')
f.pack(expand=True, fill="both")
# two side-by-side frames inside, they fill up their space
f1 = tk.Frame(f, background='green')
f1.pack(side=tk.LEFT, expand=True, fill="both")
f2 = tk.Frame(f, background='red')
f2.pack(side=tk.LEFT, expand=True, fill="both")
# three fixed-size frames in the left frame above; I would like them to be centered in the frame
tk.Frame(f1, width=20, height=20, background="orange").pack(side=tk.LEFT, fill=None, expand=False)
tk.Frame(f1, width=20, height=20, background="white").pack(side=tk.LEFT, fill=None, expand=False)
tk.Frame(f1, width=20, height=20, background="gray50").pack(side=tk.LEFT, fill=None, expand=False)
root.mainloop()
I would like the three square frames to be centered in the green one. I had to use tk.LEFT to position them, otherwise they would have been stacked up by default.
In my complete program, the green frame is there to exclusively contain the three square frames.
What is the most standard way to center the three square frames in the green one?
While thinking about furas's comment I realized that I did not understand the true difference between expand and fill (it is still a bit vague). It is possible to center the three frames by changing the f1.pack() line to:
f1.pack(side=tk.LEFT, expand=True, fill=None)
The f1 frame is tight around the three square (fill=None) ones buts tries to take as much space as possible in all directions (expand=True), effectively being centered. Note that the green background is not visible, the frame being tight around its content.

Having trouble with resizing multiple grids

I have the following code. My problem is that I can't manage to resize properly the frames. When I run the program, everything is as expected. But when I resize it, I want to keep the original view.
from Tkinter import *
import os
import sys
ALL=N+S+E+W
class Application(Frame):
def __init__(self,master=None):
Frame.__init__(self,master)
self.master.rowconfigure(0,weight=1)
self.master.columnconfigure(0,weight=1)
self.grid(sticky=ALL)
self.rowconfigure(0,weight=1)
myframe1=Frame(self,bg='green')
myframe1.bind("<Button-1>",self.handler1)
myframe1.grid(row=0,column=0,rowspan=1,columnspan=2,sticky=ALL)
self.rowconfigure(1,weight=1)
myframe2=Frame(self,bg='blue')
myframe2.bind("<Button-1>",self.handler2)
myframe2.grid(row=1,column=0,rowspan=1,columnspan=2,sticky=ALL)
buttons=('Red','Blue','Green','Black')
button=[0]*4
for c in range(4):
self.rowconfigure(c+2,weight=1)
self.columnconfigure(c,weight=1)
button[c]=Button(self,text="{0}".format(buttons[c]),command=lambda x=buttons[c]:self.colors(x))
button[c].grid(row=2,column=c,sticky=E+W)
self.columnconfigure(4,weight=1)
self.rowconfigure(6,weight=1)
button1=Button(self,text='{0}'.format('Open'),command=self.content)
button1.grid(row=2,column=4,sticky=E+W)
f=Frame(self,bg='red')
self.myentry=Entry(f)
self.myentry.grid(row=0,column=4,sticky=ALL)
self.text=Text(f)
self.text.grid(row=1,column=4,sticky=ALL)
f.grid(row=0,column=2,rowspan=2,columnspan=3,sticky=ALL)
...
I tried many combinations of rowconfigure, columnconfigure, rowspan, columnspan, but I failed!
My original view is:
After resizing in one direction:
In another direction:
The white area is the Text widget which I want to be resizable (also the blue and green areas).
Your problem is that you seem to not quite understand how grid works. For example, you are putting only two widgets in the red frame (self.myentry and self.text) yet you are putting them in column 2 and 4. Are you aware that the columns are relative to their parent, not the GUI as a whole? You want them in column 0 of the red frame, then you want the red frame in the second column of it's parent.
The way to solve this is to divide and conquer. First, divide the main screen up into it's logical parts, and lay out those logical parts so they resize properly. Then, for anything inside each part, lather, rinse repeat. Using frames for organization is the way to go.
Here's how I would tackle your problem (though there's certainly more than one way to solve this problem). First, you have two major areas of the screen: the top portion which has the green, blue and red frames and their contents, and the bottom part which holds the buttons. The top area should grow and shrink in all directions, the bottom area only grows in the X direction. I would create two frames for this, one for each part, and use pack since pack is the simplest geometry manager. The top frame should be configured to fill both directions and expand. The bottom part (with the buttons) should only fill in the X direction.
You now have two areas that are independent of each other and have proper resize behavior: the "main" area and the "toolbar" area. You are free to arrange the inner contents of these frames however you wish without having to worry about how that affects the main layout.
In the bottom frame, if you want all the widgets to be the same size, use pack and have them all fill X and expand, and they will equally fill the area. If you want them to be different sizes, use grid so you can control each column separately.
For the top part, it has three sub-sections: the red, green and blue frames. Since they are not all arranged horizontally or vertically I would use grid. Place green in cell 0,0, blue in cell 0,1, and red in cell 1,1 spanning two rows. Give row 0 and column 1 a weight of 1 so it takes up all the slack.
As I wrote earlier, this isn't the only way to "divide and conquer" this specific problem. Instead of seeing the main app as two parts -- top and bottom, with the top part having three sub-parts, another choice is to see that your main window has four parts: green, blue, red and toolbar. The key isn't to pick the perfect definition, but to break the layout problem down into chunks working from the outside in.
Here is a working example:
from Tkinter import *
ALL=N+S+E+W
class Application(Frame):
def __init__(self,master=None):
Frame.__init__(self,master)
# the UI is made up of two major areas: a bottom row
# of buttons, and a top area that fills the result of
# UI
top_frame = Frame(self)
button_frame = Frame(self)
button_frame.pack(side="bottom", fill="x")
top_frame.pack(side="top", fill="both", expand=True)
# top frame is made up of three sections: two smaller
# regions on the left, and a larger region on the right
ul_frame = Frame(top_frame, background="green", width=200)
ll_frame = Frame(top_frame, background="blue", width=200)
right_frame = Frame(top_frame, background="red")
ul_frame.grid(row=0, column=0, sticky=ALL)
ll_frame.grid(row=1, column=0, sticky=ALL)
right_frame.grid(row=0, column=1, rowspan=2, sticky=ALL)
top_frame.columnconfigure(1, weight=1)
top_frame.rowconfigure(0, weight=1)
top_frame.rowconfigure(1, weight=1)
# the right frame is made up of two widgets, an entry
# on top and a text below
entry = Entry(right_frame)
text = Text(right_frame)
entry.pack(side="top", fill="x")
text.pack(side="top", fill="both", expand=True)
# the button frame has five equally spaced buttons
for color in ('Red', 'Blue', 'Green', 'Black'):
b = Button(button_frame, text=color)
b.pack(side="left", fill="x", expand=True)
quit_button = Button(button_frame, text="Quit")
quit_button.pack(side="left", fill="x", expand=True)
root = Tk()
app = Application(root)
app.pack(fill="both", expand=True)
root.mainloop()

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