There is a post of this code, posted by mgilson, that I don't understand. All up to the reference to big_widget makes sense. But, what does the reference to big_widget contribute? The particular post is here. I am trying to refine my code and, I think, use the Frame object. But, the reference to Canvas threw me. I tried to comment but I need 50+ reputation to do so. Not there yet.
import Tkinter as Tk
root = Tk.Tk()
f = Tk.Frame(root)
f.grid(row=0,column=0)
#place buttons on the *frame*
b1 = Tk.Button(f,text="Button1")
b1.grid(row=0,column=0)
b2 = Tk.Button(f,text="Button2")
b2.grid(row=0,column=1)
big_widget = Tk.Canvas(root)
big_widget.grid(row=1,column=0) #don't need columnspan any more.
big_widget = Tk.Canvas(root)
--> A Canvas object is initialized, anchored to root and assigned to big_widget
The next line places the canvas (big_widget) at row=1 column=0 on the grid
(in the same way, a frame (f) was previously initialized and placed at row=0 column=0 on the grid inside root)
Related
Very simple question that I cannot find the answer to on Stack Exchange. (Only this misleading thread: Python3 Tkinter: Grids Within Grids? Frames Alongside Other Frames? which sadly does not answer the question).
I am using tkinter with Python to attempt a program with a GUI. Unfortunately, I completely do not understand the grid system.
I was under the impression that each frame contains its own grid system, where 0,0 is the top-left of that frame.
I created this code:
root = Tk()
main_frame = Frame(root, width='1520', height='1080', bg='#a1a1a1').grid(row=0, column=1)
side_frame = Frame(root, width='400', height='1080', bg='#757575').grid(row=0, column=0)
header_label = Label(main_frame, text='Heading', font=('Agency', 48), bg='#a1a1a1', fg='#ffffff').grid(row=0, column=0)
And hoped that because the label is set to (0,0) in the main frame, that the label would appear in the main frame. However, it didn't. I find that a bit odd and upsetting. Below is a picture of what is instead happening - the header label is appearing in the 'side_frame'.
Faulty layout picture
Could someone please explain to me how the grid system works? I wasn't really having trouble until I tried to add a scrollbar to the main_frame - I then realised that there's some serious awkwardness embedded within tkinter and I'd like to properly understand it.
Thanks!
The problem is that you're setting main_frame and side_frame to None, so passing that as the parent for any other widget will make that widget a child of the root widget.
That is because in python x=y().z() sets the value of x to z(). Thus, when you do main_frame = Frame(...).grid(...) sets main_frame to the result of .grid(...), and grid always returns None.
You should separate widget creation from widget layout, and this is one of the reasons why. The other big reason is that it makes the code easier to read and visualize.
main_frame = Frame(root, width='1520', height='1080', bg='#a1a1a1')
side_frame = Frame(root, width='400', height='1080', bg='#757575')
main_frame.grid(row=0, column=1)
side_frame.grid(row=0, column=0)
I'm aware this is probably a newb question, but I have yet to be able to find an answer. Here's a snippet of my code, that has a root window containing a button to open a Toplevel. The Toplevel pulls a random line from a text file to function as a sort of idea generator.
import random, fileinput
import tkinter as tk
from tkinter import *
root = tk.Tk()
root.title('Daydreamer')
#fname should be the file name of the image in working directory
fname = "bg.gif"
bg_image = tk.PhotoImage(file=fname)
#get width and height of image
w = bg_image.width()
h = bg_image.height()
#size window correctly
root.geometry("500x400")
cv = tk.Canvas(width=w, height=h)
cv.pack(side='top', fill='both', expand='yes')
cv.create_image(0,0,image=bg_image,anchor='nw')
#add a frame for text
mainframe=tk.Frame(root)
#new window for inspirations
def inspirations():
top = Toplevel(root)
top.geometry=("100x100")
top.title("Inspiration")
def idea():
textidea=None
for line in fileinput.input('textlist.txt'):
if random.randrange(fileinput.lineno())==0:
textidea=line
entrytext=tk.Text(top)
entrytext.insert(INSERT, textidea)
entrytext.insert(END, "Or press the Inspire Me button again for another idea!")
entrytext.pack()
idea()
top.mainloop()
#add buttons
btn1 = tk.Button(cv, text="Inspire Me", command=inspirations)
btn1.pack(side='left', padx=10, pady=5, anchor='sw')
root.mainloop()
Problem is, that Toplevel always comes out absolutely huge (larger than my root window), which looks incredibly silly for the small amount of content being displayed in it. Am I missing something really minute and stupid here? Help much appreciated.
The problem is that you aren't calling the geometry method, you're replacing it with a string.
Change this:
top.geometry=("100x100")
to this:
top.geometry("100x100")
So I have one Tkinter screen that has a canvas. I want to change the size of the canvas by creating a new window that has entry widgets. So I created a new screen and added 2 entry widgets. I want to get the value from those widgets and based on that...it should change the size of the canvas. I tried to do this for an hour, but no luck. Please assist me.
Here is my code
from tkinter import *
# create root window
root = Tk()
# Create Canvas
canvas = Canvas(root, width=50, height=50)
# Create an additional window (the one that is used to enter the new geometry)
dialog = Toplevel(root)
# Add entry widgets for width and height to the new window
width_entry = tk.Entry(dialog)
height_entry = tk.Entry(dialog)
# Add a button to the new window that applies the given width and height
apply_button = Button(dialog, text = 'Apply geometry', command = lambda: canvas.geometry(width_entry.get()+'x'+height_entry.get()))
# Its not possible to get the geometry of a canvas in tkinter...so how do I change the size.
# display the entry boxes and button
width_entry.pack()
height_entry.pack()
apply_button.pack()
# start the tk mainloop
root.mainloop()
Please Assist me
The command you are looking for is canvas.config
Here, I have adjusted the given code:
import tkinter as tk
# create root window
root = tk.Tk()
# Create Canvas
canvas = tk.Canvas(root, width=50, height=50)
canvas.pack()
# Create an additional window (the one that is used to enter the new geometry)
dialog = tk.Toplevel(root)
# Add entry widgets for width and height to the new window
width_entry = tk.Entry(dialog)
height_entry = tk.Entry(dialog)
# Add a button to the new window that applies the given width and height
apply_button = tk.Button(dialog, text = 'Apply geometry', command = lambda: canvas.config(width=width_entry.get(), height=height_entry.get()))
# display the entry boxes and button
width_entry.pack()
height_entry.pack()
apply_button.pack()
# start the tk mainloop
root.mainloop()
I also changed a couple other things:
You imported * from tkinter, but for some items you still led with tk.; I changed them all to match that and switched the import to match as well. (You could still use *, but then just don't have the leading tk.s.)
The canvas was never packed so you could never see what was going on there.
One more suggestion, that line where you make the button is really long. Maybe make a function that does what the lambda does and assign its command to that function instead of a lambda. You can probably see that a line that long is even hard to read here much less if someone (maybe a future version of yourself) was to try to read your code, and edit it or make sense of it. Generally, try to keep all lines down to 80 characters.
Let us know if you have any more questions etc.
I am doing a simple UI with TkInter in Python. I want a button at the top left, so I did something like
back = Button(explorer, text="Back")
back.pack(side="top", anchor="w")
where explorer is a frame, and I expected to see the button on top left, but it's stuck in the center. Any suggestions? I already tried to add side=TOP but it didn't work. What's the right way to do that?
As mentioned above, your parent frame should fill the x space.
This is an example of the parent frame not filling x:
import tkinter as tk
root = tk.Tk()
root.geometry('200x200')
element = tk.Frame(root)
element.pack() # No fill
tk.Button(element, text='No Fill').pack(anchor='w')
# To show the fill
tk.Label(root, text='Fill X', bg='green').pack(fill='x')
root.mainloop()
And the result is the button is in the center despite the anchor:
https://i.stack.imgur.com/DAgmH.png
But, make this change:
element.pack(fill='x')
And now your button will be in the top left like here:
https://i.stack.imgur.com/HoGGj.png
Your frame has to occupy all the horizontal space if you want to align its children. Something like (if you imported tkinter elements with from tkinter import *):
explorer.pack(fill=X)
Tkinter has 3 modules to set items:
.pack which puts everything more or less random
.grid where you can define the row and column
.place where you define everything in pixels
so you could use something like
import tkinter as tk
from tkinter import *
root = Tk()
button = Button(text = 'back')
button.grid(row = 1, column = 1)
root.mainloop()
This shows how to use the .grid function. Keep in mind that the size of each grid is defined by its largest content. If you have a long entry field , the column its placed in is going to be as wide as the entry.
you could also use the .place function, but this one requires the most work. For me its always guessing and rerunning until im happy with it.
import tkinter as tk
from tkinter import *
root = Tk()
button = Button(text = 'back')
root.geometry("150x100")
button.place(x=30, y=30)
root.mainloop()
So in summary, use .pack if you dont care, .grid if you want some kind of control and .place if you want to be accurate. And keep in mind to use only ONE at a time.
Hi I didn't really understand how furas made the below code work. Why didn't he get an error message about grid and pack on the same root when he added a box? In the addbox function he sets a frame to the root which is pack already and even uses the pack inside the function and then uses the grid.
Can someone please explain to me how this "magic" works?
a link to the his answer:
Creating new entry boxes with button Tkinter
from Tkinter import *
#------------------------------------
def addBox():
print "ADD"
frame = Frame(root)
frame.pack()
Label(frame, text='From').grid(row=0, column=0)
ent1 = Entry(frame)
ent1.grid(row=1, column=0)
Label(frame, text='To').grid(row=0, column=1)
ent2 = Entry(frame)
ent2.grid(row=1, column=1)
all_entries.append( (ent1, ent2) )
#------------------------------------
def showEntries():
for number, (ent1, ent2) in enumerate(all_entries):
print number, ent1.get(), ent2.get()
#------------------------------------
all_entries = []
root = Tk()
showButton = Button(root, text='Show all text', command=showEntries)
showButton.pack()
Thanks
There's no magic, it's just working as designed. The code uses pack in the root window, and uses grid inside a frame. Each widget that acts as a container for other widgets can use either grid or pack. You just can't use both grid and pack together for widgets that have the same master.
not really an answer but I think you will be helped by the link.
tkinter and it's layout is indeed a bit hard to understand.
I never understood how to deal with it until I stumbled over this presentation which explained the layout particulars in a way where I finally could get the hang of it.
Just putting it out there for others to find as well.
tkinter tutorial by beazley
I think you miss out on what pack and grid actually are. Consider such code:
import tkinter as tk
root = tk.Tk()
myFrame = tk.Frame(root)
myFrame.pack()
myButton1 = tk.Button(myFrame, text='This is button 1')
myButton2 = tk.Button(myFrame, text='This is button 2')
myButton1.grid(row=0, column=0)
myButton2.grid(row=1, column=0)
root.mainloop()
By creating root we create a new window. In this window we will put everything else. Then we create myFrame. Note, that the actual "thing" (in more adequate terms - widget) is created in line myFrame = tk.Frame(root). Note, that we have to specify where we are going to put this widget in brackets and we've written that it is going to be root - our main window. Blank frame probably isn't the best example since you can not see it being placed (not unless you use some more specifications at least), but still. We have created it, but not placed it in our user interface. The we use .pack() to place it. Now you refer to widgets as being used as packs or grids. That is not true though. Pack and grid are just the set of rules, on which the widgets are being placed inside some kind of window. Because of that, if you want to add something more to the root in our case, you will have to use .pack() again. Why? If you will give two sets of rules on how to place things on the screen for your computer - they will most likely conflict with each other. However, if we go one more level down and now want to place something inside our myFrame, we can again choose which set of rules to use. It is because it does not matter, where our frame is going to end up inside root, we now just want to specify where our Buttons 1 and 2 are going to end up inside the frame. Therefore we can again use .pack() or switch to .grid().
To conclude: .pack(), .grid() and .place() are sets of rules on how place widgets inside other widgets. In more general terms though these are rules on how place boxes in other boxes. One boxes in which we arrange other boxes can only have one set of rules.
I hope this example helps.