I have a frame that I fixed the size of using the grid_propagate() method. I'd like to center a frame within this frame. How do I go about this?
pack it to fill in all directions. Add padding as needed.
Or, use place which lets you use relative or absolute positioning. You can use a relative x/y of .5/.5 and an anchor of "c" (center).
import Tkinter as tk
root=tk.Tk()
f1 = tk.Frame(width=200, height=200, background="red")
f2 = tk.Frame(width=100, height=100, background="blue")
f1.pack(fill="both", expand=True, padx=20, pady=20)
f2.place(in_=f1, anchor="c", relx=.5, rely=.5)
root.mainloop()
If you want to center a widget (like a frame) inside a frame, the easiest way to do it is via .grid(). If you use .pack(), you end up stuck along one of the edges, since pack() has the side keyword.
If you use .place(), then you're stuck forcing the size of the outer frame (which normally you don't have to do, but you've already done it, so it's not an issue), because placed widgets aren't detected when the frame autosizes like with packed or gridded widgets. I'm not sure why, but that's the way it is.
So, in general, the best way to center a widget inside a frame is to grid the widget into the frame. (The sticky option defaults to CENTER.) And then, if you want to be able to resize the outer frame and have the widget stay centered, you need to allow the outer frame's cell to expand/grow. You would do this via the .grid_rowconfigure() etc commands. So, an example might be:
widget = Widget(frame, ...)
widget.grid(row=0, column=0, sticky="")
frame.grid_rowconfigure(0, weight=1)
frame.grid_columnconfigure(0, weight=1)
Related
I am trying to create a button with a fixed size. So, I created a Frame (grid) with the size I want and then a child Button (pack) inside of the Frame that takes all the space.
Here is a minimal example:
window = tk.Tk()
frame1 = tk.Frame(window, bg="#ffffff", height=50, width=100)
frame1.grid(row=0, column=0)
frame1.grid_propagate(0)
#frame1.propagate(False) # <----- This line makes it work.
button1 = tk.Button(frame1, bg="#000000")
button1.pack(expand=True, fill=tk.BOTH)
Without the commented line above, I expected that it would work (having a rectangle of the specified size), but I get a small square. Why is it not working?
I was not able to find documentation on that .propagate() function. I only found about the grid_propagate() and pack_propagate() functions.
Right now you have 2 containers: window and frame1. When you use frame1.grid(...), you actually tell the master of frame1, which is window that it should use the grid manager. When you use button1.pack(...), you tell the button's master (frame1) that it should use the pack manager inside itself.
So when you use frame1.grid_propagate(...), you tell the grid manager (that doesn't manage the widgets inside frame1), that it should do something, so it ignores you.
I would really appreciate some help with figuring out grid geometry manager.
Here is what I want to build.
I was thinking of using grid but I cannot find any good tutorials that would clearly
explain how to work with it.
There are lots of tutorials but mostly all are either very simple or really outdated.
I am not sure how to build what is shown in the picture using only grid because all
elements are nested inside each other and each element is supposed to hold more elements inside it.
It's not so hard to arrange outermost widgets using grid. I just place Toolbar into 0th row,
then outermost PanedWidow (green) into 1st row, and then Status Bar into 2nd row.
After that I need to arrange things inside green PanedWindow.
I place another PanedWindow (pink) into the right pane of the green PanedWindow and then
stick a Notebook into it's top pane.
Now, I need to add more widgets to these inner panes. For instance. I am going to add
some buttons to the bottom pane of the pink PanedWindow. And that's where I run into problems.
If I try to use pack() to arrange things inside these innermost panes, Python screams at me for
using more than one geometry manager.
But when I think about how to accomplish this with grid, I just can't find a way to subdivide
innermost panes into smaller grids.
Can there be grids inside Widgets which have been acted upon by an outer grid?
When I see widgets that take up the full width or full height of an area I usually use pack since since it's specifically designed to lay objects along a side of an empty cavity. You can use grid but it requires extra code since you have to both add the widget and configure the rows and columns. With pack all you have to do is add the widgets.
For example, it's clear you want a statusbar along the bottom, and a toolbar along the time, and a paned widget in-between. So, start with that, as in the following example:
import tkinter as tk
root = tk.Tk()
root.geometry("600x400")
toolbar = tk.Frame(root, background="#d5e8d4", height=40)
statusbar = tk.Frame(root, background="#e3e3e3", height=20)
main = tk.PanedWindow(root, background="#99fb99")
toolbar.pack(side="top", fill="x")
statusbar.pack(side="bottom", fill="x")
main.pack(side="top", fill="both", expand=True)
root.mainloop()
Note: widths, heights, and colors are added to the frame for illustrative purposes since otherwise, an empty frame would have a size of 1x1. Once you add widgets inside a frame you can remove the width and height options.
You say the right will have a paned window, so add that on the right. We'll use a normal frame on the left.
left_pane = tk.Frame(main, background="#99fb99", width=100)
right_pane = tk.PanedWindow(main, background="#99fb99", width=200)
main.add(left_pane)
main.add(right_pane)
Next, add the two panes to the right. So that I can show colors with as little code as possible I'll use a frame on the top instead of a notebook:
notebook = tk.Frame(right_pane, background="#99ceff", height=70)
bottom_right = tk.Frame(right_pane, background="#ffe6cd", height=50)
right_pane.add(notebook)
right_pane.add(bottom_right)
With all that being said, you can use grid if you want. The trick is to use intermediate frames, since the layout in any widget is independent of the layout in parent or child widgets.
All you need to do is remove the first three calls to pack and replace it with these five lines:
root.grid_rowconfigure(0, weight=1)
root.grid_columnconfigure(0, weight=1)
toolbar.grid(row=0, column=0, sticky="ew")
main.grid(row=1, column=0, sticky="nsew")
statusbar.grid(row=2, column=0, sticky="ew")
Since the other widgets are children of paned widgets, there's nothing else to do. Any widgets you add to each pane have their own independent layout area, so you can use grid, pack, or place inside each frame.
To illustrate that point, I'll use grid to add several rows and columns of squares:
for row in range(6):
for column in range(30):
f = tk.Frame(bottom_right, background="white",
bd=2, relief="raised", width=10, height=10)
f.grid(row=row, column=column)
I found a post that's around two years old, which might be a little too old for your uses, but it has some information on nesting grids in Tkinter. It recommends using frames to nest the grids, essentially having children within children of a frame. Within these frames, you can place objects.
In my understanding, using the pack() manager, each frame gets placed relative to the position of the other frames in the code. So if I do:
frame1 = tk.Frame(root)
frame1.pack()
frame2 = tk.Frame(root)
frame2.pack()
frame3 = tk.Frame(root)
frame3.pack()
Then frame2 will appear below/after frame1, and before frame3.
My problem is when using the function frame2.pack_forget(), whenever I again do frame2.pack(), the order is not restored, but now I have frame1, frame3, frame2, as if frame2 was the last one to pack.
How can I use pack_forget() and then pack() in the exactly same location it was created?
How can I use pack_forget() and then pack() in the exactly same location it was created?
In a broad sense, you can't. The very nature of pack is that it puts widgets along an edge of available space. When you add and remove widgets, the available space changes. When you call pack_forget, tkinter forgets where the widget was.
That being said, pack has options to help work around this. You can use the before and after options to insert the widget before or after some other widget in the packing order. It's up to you to remember the order. For example, you could do frame2.pack(before=frame3) to have it inserted before frame3.
If you want to hide and remove widgets dynamically, grid is usually the better choice because grid_remove will cause grid to remember where a widget was.
I know this isn't the first time a question like this is asked, but even after like 2 hours of browsing the Internet I can't get it to work:
So I'm trying to create a Tkinter-Frame, that contains several Buttons (As Example I took 30). But Because I don't have enough space in my program, I need to add an Scrollbar next to it, so that one can scroll through the Buttons.
The Problems I had where, that the inner "moving part" of the bar was as big as the whole scrollbar and couldn't be moved, which I kinda solved by using scollregion=(0,0,1000,1000), but even then the moving of the bar had no effect on the canvas whatsoever.
Here Is the corresponding code that I extracted out of my program:
import Tkinter as tk
root = tk.Tk()
root.rowconfigure(0, weight=1)
root.columnconfigure(0, weight=50)
root.columnconfigure(1, weight=1)
root.minsize(300,400)
root.maxsize(300,400)
#Buttons
buttonFrame = tk.Canvas(root, bg='#bbb')
buttonFrame.grid(row=0, column=0, sticky=tk.N+tk.E+tk.S+tk.W)
buttonFrame.columnconfigure(0, weight=1)
scroll = tk.Scrollbar(root, command=buttonFrame.yview)
scroll.grid(row=0, column=1, sticky=tk.N+tk.E+tk.S+tk.W)
buttonFrame.configure(yscrollcommand=scroll.set)
for i in range(30):
tk.Button(buttonFrame, text=str(i+1)).grid(row=i, column=0, sticky=tk.N+tk.E+tk.S+tk.W)
root.mainloop()
As you (hopefully) see, the slider can't even be moved nor does it change anything on the canvas, even if I squeeze a scrollregion=(bla) somewhere in there.
2 Questions:
a.) What do I need to add (or remove), so that I can scroll through the list of Buttons
b.) Does the fix from a. still work when I make the Scrollbar a child of the buttonFrame instead of the root?
To add widgets to a Canvas you have to use the create_window method, not grid(). Then you have to update the canvas before setting the scrollregion.
for i in range(30):
btn = tk.Button(buttonFrame, text=str(i+1))
buttonFrame.create_window((100,i*50), window=btn)
root.update()
buttonFrame.config(scrollregion=buttonFrame.bbox("all"))
If you try that I suspect it's not what you were looking for, since the create_window method requires absolute positioning (you can't use grid or pack). That's why most people put a Frame in the Canvas, and add their widgets to that instead. Many people have abstracted this faux Frame that is actually a Frame in a Canvas in another Frame, including me.
I know there have been many questions on grid and pack in the past but I just don't understand how to combine the two as I'm having difficulties expanding my 'table' in both directions (row/column).
Buttons I wish to keep the same size but always stay at the bottom of the window.
The 'table' however I wish to expand automatically with resizing the window but can't seem to make it work. Changing 'win1' to pack worked in the sense that it stays central but that's it.
How can I achieve the same effects such as sticky etc with pack as I know I'll need to change the terminology.
Code is as follows (showing basic frames and several widgets, not complete code):
root = Tk()
win1 = Frame(root)
win1.pack()
win1.grid_columnconfigure(0, weight=1)
win1.grid_rowconfigure(1, weight=1)
frame_table = ttk.Frame(win1, style="Black.TLabel", relief='sunken', borderwidth=1)
frame_table.pack(row=2, column=0, padx=1, pady=1, sticky= "nsew")
frame_table.grid_columnconfigure(0, weight=1)
frame_table.grid_rowconfigure(1, weight=1)
text_table1 = Label(frame_table, text='Number1', bg='white', borderwidth=0)
text_table1.grid(row=1, column=0, sticky="nsew", padx=1, pady=1)
empty1 = Label(frame_table, bg='white', borderwidth=0)
empty1.grid(row=2, column=0, sticky="nsew", padx=1, pady=1)
text_table2 = Label(frame_table, text='Number2', bg='white', borderwidth=0, width=12)
text_table2.grid(row=1, column=1, sticky="nsew", padx=1, pady=1)
empty2 = Label(frame_table, bg='white', borderwidth=0)
empty2.grid(row=2, column=1, sticky="nsew", padx=1, pady=1)
frame_but = ttk.Frame(win1)
frame_but.grid(sticky=S, padx=1, pady=1)
frame_but.grid_columnconfigure(0, weight=1)
frame_but.grid_rowconfigure(1, weight=1)
but1 = ttk.Button(frame_but, text='Start', command=Start)
but1.grid(row=3, column=0, padx=2, pady=1, sticky="S")
Your first problem is that the main frame, win1 is packed with no options. The default is for it to not fill the part of its container that it is in. Thus, no matter what you do to the inner widgets, the whole thing will stack anchored to the top portion of the window. The first thing you should do, then, is tell win1 to fill the whole window (assuming that's actually what you want it to do):
win1.pack(side="top", fill="both", expand=True)
That will cause this frame to properly expand and shrink when you resize the window.
The second problem is that you're giving row 0 in win a weight of 1, but you are putting frame_table in row 3 which has a default weight of 0. I don't know if that's intentional or not, but that is what keeps the labels and entry widgets stuck to the bottom of the screen, because the empty row 0 of win1 is expanding and shrinking to take up the extra space.
How to learn to lay out your widgets
Proper resize behavior is pretty easy to get right, but it's fairly hard to learn how to get it right. My recommendation is, get some paper and a pencil. Draw out the main regions of your application -- the areas that each have different properties. For example, a row along the bottom that should stay at the bottom (status bar, or row of buttons perhaps). Maybe something at the top (toolbar, for example) that should stay at the top, etc. Typically there will be only one region that is expandable, though that expandable region may itself be divided into two or more regions.
In this case I'm guessing you have two regions: a table, and a row of buttons. Drawing this out is easy. Next, create a frame for each region, and only a frame for each region. Give them separate background colors, and place them in the window using grid or pack, whichever one gives you the resize behavior you want. pack is great if you have a simple layout (every region is sticked either top-to-bottom or left-to-right), grid is great if you truly have a grid. Work with just this, tweaking options until you get the behavior you want for the main regions. The different colors will help you see which areas are resizing and which are not.
Once you have the main regions working exactly right, you can then start to focus on the inner portions. Get out that pencil and paper again, and do the same with each of these sub-regions. Draw out the inner regions, and figure out which ones will grow within their container and which ones will not. Maybe there's only one main sub-region so you can skip this part. Finally, create frames if you have sub-regions, again giving them different colors so you can see what is resizing. Tweak the settings until everything resizes just the way you want. Lather, rinse, repeat.
Finally, you will not be able to sub-divide your window any more. Usually there are only a couple of regions so this process is quick. Once you have the different regions of your program all resizing how you want, it's time to add the actual widgets. Once you've done that you can go back and remove the color from the frames.
It's simple, but it requires a methodical approach. Just throwing a bunch of widgets into a frame and trying random things to get it to work is not the right approach. Be methodical, lay out your design on paper, transfer to frames with distinct colors, and then add your real widgets and add the final polish.