Dynamically resize two panels in tkinter - python

I have setup 2 panels in a frame as so:
frameA = Frame(master)
frameA.pack(side=LEFT, fill=BOTH, expand=YES)
frameB = Frame(master)
frameB.pack(side=RIGHT, fill=BOTH, expand=YES)
recale = 0.4
self.img = ImageTk.PhotoImage(img.resize((int(rescale*width), int(recale*height)), Image.ANTIALIAS)
self.panelA = Label(frameA, image=self.img)
self.pabelA.pack(side=LEFT, fill=BOTH, expand=YES)
self.panelB = Label(frameB, image=self.img)
self.pabelB.pack(side=LEFT, fill=BOTH, expand=YES)
Now, the size of the 2 panels are determined by the image size which I have resized to 0.4 times the original size. How can I dynamically set rescale such that the width of each of the panels takes up the entire width of the master frame when I press the maximize button(this is not a button I made, but rather the little square button next to minimize, and close on the top right) on the GUI?

When you use pack(fill=BOTH, expand=YES) then tkinter automatically resizes Frame and Label to fit window - so you don't have to resize it manually. But it will never resize PhotoImage and Image so it may looks like it doesn't resize Label and Frame. So your real problem probably is "how to resize Image when you change window's size"
Using
root.bind('<Configure>', on_resize)
you can run function when window changed size and then you can generate new image and replace in Label
This function will be executed not only for window but also fro every widget in window so I use str(event.widget) == '.' to resize it only when it is executed for window.
import tkinter as tk
from PIL import Image, ImageTk
def on_resize(event):
global rescaled_img
global photo
#print('[DEBUG] on_resize:', event.widget)
# resize only when root window changes size
if str(event.widget) == '.':
# generate new image
width = event.width//2 # -2 # -2*border
height = event.height # -2 # -2*border
rescaled_img = original_img.resize((width, height), Image.ANTIALIAS)
photo = ImageTk.PhotoImage(rescaled_img)
# replace images in labels
label_left['image'] = photo
label_right['image'] = photo
# ---- main ---
# resize at start
original_img = Image.open('image.jpg')
rescale = 0.4
width = int(rescale * original_img.width)
height = int(rescale * original_img.height)
rescaled_img = original_img.resize((width, height), Image.ANTIALIAS)
root = tk.Tk()
photo = ImageTk.PhotoImage(rescaled_img)
label_left = tk.Label(root, image=photo, border=0) # if border > 0 then you have to use `-2*border` in on_resize
label_left.pack(side='left', fill='both', expand=True)
label_right = tk.Label(root, image=photo, border=0) # if border > 0 then you have to use `-2*border` in on_resize
label_right.pack(side='left', fill='both', expand=True)
# resize when window changed size
root.bind('<Configure>', on_resize)
root.mainloop()
I tried to bind to label as you can see in some code in Tkinter resize background image to window size but it didn't work correctly - at start it makes images bigger and bigger till window fill all screen. Or at start it makes images small and small till window has no size.
if Label has border bigger then 0 then you have to substract 2*border from image size.

Related

How do I keep this image in the center of the window?

I'm making a hangman-like game; for that, I need all the different stages of the man to be visualized, hence images. I want the entire tkinter window to be an image, when I change the size it pushes the image right.
from tkinter import *
root=Tk()
root.geometry("600x350")
canvas = Canvas(root, width=1600, height=900)
canvas.pack()
img = PhotoImage(file="4.png")
canvas.create_image(470,190, image=img, )
root.mainloop()
If canvas is bigger than window then when you resize then it show more canvas but and it can looks like it moves image.
But if you use smaller canvas then pack() will try to keep centered horizontally. And if you add pack(expand=True) then it will try to keep it centered vertically.
In example code I added red background to window to show where is canvas
import tkinter as tk # PEP8: import *
root = tk.Tk()
root.geometry("600x350")
root['bg'] = 'red'
img = tk.PhotoImage(file="lenna.png")
canvas = tk.Canvas(root, width=600, height=350)
canvas.pack(expand=True)
canvas.create_image(300, 175, image=img)
root.mainloop()
Image Lenna from Wikipedia
PEP 8 -- Style Guide for Python Code
Before resizing:
After resizing:
If you want to draw only image then you could use Label(image=img)
import tkinter as tk # PEP8: import *
root = tk.Tk()
root.geometry("600x350")
root['bg'] = 'red'
img = tk.PhotoImage(file="lenna.png")
label = tk.Label(root, image=img)
label.pack(expand=True)
root.mainloop()
Before resizing:
After resizing:
BTW:
tkinter can bind() some function to event <Configure> and it will execute this function everytime when you resize window (and/or move window) - and this function may also move or resize image in window.
import tkinter as tk # PEP8: import *
from PIL import Image, ImageTk
def resize(event):
global img
lower = min(event.width, event.height)
#print(event.width, event.height, 'lower:', lower)
new_image = original_image.resize((lower, lower))
img = ImageTk.PhotoImage(new_image) # need to assign to global variable because there is bug in PhotoImage
label['image'] = img
# --- main ---
root = tk.Tk()
root.geometry("350x350")
root['bg'] = 'red'
original_image = Image.open("lenna.png")
img = ImageTk.PhotoImage(original_image)
label = tk.Label(root, image=img)
label.pack(expand=True)
root.bind('<Configure>', resize)
root.mainloop()
Before (it resized image at start to fit window):
After (it resized image to fit window):

Python - placing Entry with relative X/Y position changes background stretch in Tkinter

I have an application with Tkinter in Python.
I put an image as a background, and the user can resize the window's size and the image is stretched.
I added an Entry and put it in the center of the application, but now if the user resizes the window - now the background is not streched well.
Resize function:
def bg_resize(e):
global heig, wid, bbg, resized_bbg, newBg, clicked
bbg = Image.open(r"C:\backround.png")
resized_bbg = bbg.resize((e.width, e.height), Image.ANTIALIAS)
heig = e.height
wid = e.width
newBg = ImageTk.PhotoImage(resized_bbg)
cnv.create_image(0, 0, image=newBg, anchor="nw")
Widget placement:
searchEntry = Entry(cnv, width=100).place(rely=.5, relx=.5, anchor= "center")
before resize:
after resize:

How to center an image in tkinter with PIL

I want to center an image in tkinter canvas. The only thing I could think of is using anchor = 'c' but that does not seem to work. I have also tried using it on the stage.
def newsetup(filelocation):
global width, height
for widgets in root.winfo_children():
widgets.destroy()
stage = Canvas(root, width = 1000, height = 700, highlightbackground = 'red', highlightthickness = 2)
stage.pack()
imgtk = ImageTk.PhotoImage(Image.open(filelocation))
stage.create_image(stage.winfo_width() + 2, stage.winfo_height() + 2, image = imgtk, anchor = CENTER)
stage.image = imgtk
if you want to center on canvas then you need
stage.winfo_width()/2, stage.winfo_height()/2
(even without anchor= which as default has value center)
But if you put image before it runs mainloop() then stage.winfo_width() stage.winfo_height() gives 0,0 instead of expected width, height (because mainloop creates window and it sets all sizes for widgets) and it may need root.update() to run mainloop once and it will calculate all sizes.
import tkinter as tk
from PIL import ImageTk, Image
root = tk.Tk()
stage = tk.Canvas(root, width=1000, height=700)
stage.pack()
root.update() # force `mainloop()` to calculate current `width`, `height` for canvas
# and later `stage.winfo_width()` `stage.winfo_height()` will get correct values instead `0`
#imgtk = ImageTk.PhotoImage(Image.open('lenna.png'))
imgtk = ImageTk.PhotoImage(file='lenna.png')
stage.create_image((stage.winfo_width()/2, stage.winfo_height()/2), image=imgtk, anchor='center')
stage.image = imgtk
root.mainloop()
Result:
Image Lenna from Wikipedia.
EDIT:
If you want to keep it centered when you resize window then you can bind event <Configure> to canvas and it will execute assigned function - and it can move image.
But it needs image ID which you can get when you create image
img_id = stage.create_image(...)
Because <Configure> is executed when it creates window so code doesn't need root.update() because on_resize() will set correct position at start.
import tkinter as tk
from PIL import ImageTk, Image
# --- functions ---
def on_resize(event):
# it respects anchor
x = event.width/2
y = event.height/2
stage.coords(img_id, x, y)
# it DOESN'T respects anchor so you have to add offset
#x = (event.width - imgtk.width())/2
#y = (event.height - imgtk.height())/2
#stage.moveto(img_id, x, y) # doesn't respect anchor
#stage.itemconfigure(img_id, ...)
# --- main ---
root = tk.Tk()
stage = tk.Canvas(root, width=1000, height=700)
stage.pack(fill='both', expand=True)
#root.update() # force `mainloop()` to calculate current `width`, `height` for canvas
# and later `stage.winfo_width()` `stage.winfo_height()` will get correct values instead `0`
#imgtk = ImageTk.PhotoImage(Image.open('lenna.png'))
imgtk = ImageTk.PhotoImage(file='lenna.png')
img_id = stage.create_image((stage.winfo_width()/2, stage.winfo_height()/2), image=imgtk, anchor='center')
stage.image = imgtk
stage.bind('<Configure>', on_resize) # run function when Canvas change size
root.mainloop()

tkinter get background image to fill entire window

I've been trying to have an image as background for my project. I found some code that places it in a label and this works fine except the sizing of it doesn't seem to work and empty spaces show up on the sides (see picture)
My code is:
from tkinter import *
from PIL import ImageTk, Image
#make a window
ws = Tk()
ws.title("window")
#get wigth & height of screen
width= ws.winfo_screenwidth()
height= ws.winfo_screenheight()
#set screensize as fullscreen and not resizable
ws.geometry("%dx%d" % (width, height))
ws.resizable(False, False)
# put image in a label and place label as background
imgTemp = Image.open("images/wallpaper.png")
img2 = imgTemp.resize((height,1800))
img = ImageTk.PhotoImage(img2)
label = Label(ws,image=img)
label.pack(side='top',fill=Y,expand=True)
#text = Text(ws,height=10,width=53)
#text.place(x=30, y=50)
#button = Button(ws,text='SEND',relief=RAISED,font=('Arial Bold', 18))
#button.place(x=190, y=250)
ws.mainloop()

Tkinter - rotate image with slider simultaneously

UPDATED -
New to tkinter
Is it possible to rotate a picture by using a slider simultaneously.
I have an image of a rotatory dial, beneath this image is a slider listed from 0 to 360. I would like the image to rotate clockwise as the slider is moved from 0 to 360, and anticlockwise as the slider is returned from 360 to 0.
ROTATION OF IMAGE WITH SLIDER WORKS CORRECTLY
I have ran into a bug, the image is black. Perhaps the image is too zoomed in? Apologies, I am new to python and tkinter.
Here is how the GUI should look Correct GUI
THIS IS HOW THE GUI LOOKS NOW Incorrect GUI with Slider
THIS IS HOW THE GUI LOOKS REMOVING THUMBNAIL LINE THUMBNAIL
Here is the updated code
# import necessary modules
from tkinter import *
from tkinter import ttk
from PIL import Image, ImageTk
root = Tk()
root.title("Gesture Detection Application")
root.geometry("400x320") # set starting size of window
root.maxsize(400, 320) # width x height
root.config(bg="#6FAFE7") # set background color of root window
Heading = Label(root, text="Demonstrator Application2", bg="#2176C1", fg='white', relief=RAISED)
Heading.pack(ipady=5, fill='x')
Heading.config(font=("Font", 20)) # change font and size of label
image = Image.open("rotate_dial.png")
width, height = image.size
image.thumbnail((width/5, height/5))
photoimage = ImageTk.PhotoImage(image)
image_label = Label(root, image=photoimage, bg="white", relief=SUNKEN)
image_label.image = photoimage
image_label.pack(pady=5)
def rotate_image(degrees):
new_image = image.rotate(-int(degrees))
photoimage = ImageTk.PhotoImage(new_image)
image_label.image = photoimage #Prevent garbage collection
image_label.config(image = photoimage)
w2 = Scale(root, from_=0, to=360, tickinterval= 30, orient=HORIZONTAL, length=300, command = rotate_image)
w2.pack()
w2.set(0)
root.mainloop()
You can rotate the image using PIL (which you've already imported). You can link it to the Scale by adding a command.
image = Image.open("rotate_dial.png")
width, height = image.size
image.thumbnail((width/5, height/5))
photoimage = ImageTk.PhotoImage(image)
image_label = Label(root, image=photoimage, bg="white", relief=SUNKEN)
image_label.pack(pady=5)
def rotate_image(degrees):
new_image = image.rotate(-int(degrees))
photoimage = ImageTk.PhotoImage(new_image)
image_label.image = photoimage #Prevent garbage collection
image_label.config(image = photoimage)
w2 = Scale(root, from_=0, to=360, tickinterval= 30, orient=HORIZONTAL, length=300, command = rotate_image)
Instead of creating a PhotoImage initially, it now creates a PIL Image object. It then uses the height and width and the thumbnail function to replace the subsample. Then it uses ImageTk to turn it into a tkinter PhotoImage which is shown in the label. The Scale now has a command, rotate_image, which recieves the scale value, which is the number of degrees, and then uses PIL to create a new rotated image, which is then turned into a PhotoImage and displayed in the label by changing it's image with .config. Now when you move the slider, the image rotates with it.

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