Manipulating multiple tkinter windows from the main GUI - python

I need to build a simple image manipulation program in Python Tkinter. Is it possible to create a GUI which is capable of opening multiple TopLevels and can perform operation on the image from the most recently active Window?
This is the code so far:
def AddImage():
while True:
try:
filename = filedialog.askopenfilename(initialdir="/", title="Choose file",filetypes=[("Images", "*.jpg *.png *.tif *.bmp")])
image = Image.open(filename)
image = image.resize((300, 300), Image.ANTIALIAS)
image = ImageTk.PhotoImage(image)
window = tk.Toplevel()
window.title(filename)
window.geometry('300x300')
canvas = tk.Canvas(window, width=300, height=300, bg='#D4D4D4')
canvas.pack(expand='yes', fill='both')
canvas.create_image(0, 0, image=image, anchor='nw')
canvas.image = image
break
except AttributeError:
break
def Init():
root = tk.Tk()
my_menu = tk.Menu(root)
root.config(menu=my_menu)
my_menu.add_command(label='Open File',command=AddImage)
master = tk.Canvas(root, width=1200, height=600, bg='#D4D4D4')
master.pack()
root.mainloop()
Now, after opening a few images I want to do something with one of them, e.g. duplicate from the main interface.

As far as I understood, you are opening images in different windows and then trying to keep them on top-level of screen (in front of your root window),select them, and switch between the windows.
Lengthy method: "Windows inside root window"
By some work arounds , you can create the sub-windows containing
images inside the root window where they cannot get out of the root
window's bounds. Refer to
Window inside window
Basically, using image_window.transient(root) [where image_window is
the window with image] will keep those sub windows on top of the
root. Then, using conditional statements to keep the sub windows
inside root. Finally, you can try using window.focus_force()
wherever required in order to set a particular window in focus.
Don't open images in new windows- create frames with their own some custom bindings that allow you to move it around the root using place geometry manager. In the frame(s), open the images you want to.

Related

Tkinter Transparent Background macOS

I've been messing around with different code snippets and combinations for a while now, trying to make it so my .gif file would have a transparent background. I've been successful in making the actual background transparent, but I find that my .gif goes transparent with it:
import tkinter as tk
root = tk.Tk()
root.overrideredirect(1)
root.wm_attributes("-topmost", True)
root.wm_attributes("-transparent", True)
root.config(bg='systemTransparent')
root.geometry("+300+300")
root.image = tk.PhotoImage(file="sample.gif")
label = tk.Label(root, image=root.image)
label.config(bg='systemTransparent')
label.pack()
root.mainloop()
I have found that whenever I use both root.config(bg='systemTransparent') and label.config(bg='systemTransparent'), the entire window and gif go transparent, but when I use just one or neither, I am left with a light-gray background.

How do I change the size of a tkinter canvas through a new window?

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.

Widgets disappear when main window moved off screen

I have a tkinter window that I have given a background picture by creating a Label widget with a PhotoImage instance (referencing the image instance through Label attributing).
However when I run the script and move the main window below the start menu (am using Windows 10) or past the sides of the screens for even one moment, all the widgets packed onto the Label (w/ background pic) completely disappear.
They only come back (somewhat) upon hovering over them with the mouse it seems. Also the background picture remains and continues to fill the screen. Could it be that the background picture Label is being "lifted" and makes it seem like the widgets are disappearing? If so, how can I prevent this from happening?
The fix that I have found for now is to not use a Label with a PhotoImage as the parent "frame", but instead use a typical Frame widget with only a background color, but this is not ideal.
import tkinter as tk
root = tk.Tk()
root.geometry('600x350+600+300')
root.resizable(width=False, height=False)
boxBg = '#666'
frameBg = '#fff'
#problem method
backgroundImg = tk.PhotoImage(file='program_media/background.png')
bgFrame = tk.Label(root, image=backgroundImg)
bgFrame.image = backgroundImg
#less than ideal solution so far
#bgFrame = tk.Frame(root, bg='#fff')
bgFrame.pack(expand=1, fill=tk.BOTH)
mainFrame = tk.Frame(bgFrame)
mainFrame.pack(side=tk.TOP)
title = tk.Label(mainFrame, text='Test String')
title.pack(side=tk.TOP)
#widget creation code packed within mainFrame
#...
#... All these widgets (including mainFrame above) are disappearing
#...
#end of widget creation code
root.mainloop()
See what I mean in this screenshot of BEFORE and AFTER moving the main window below the start menu.

Displaying an image in python via Button and Canvas

I am a begginer in python, tkinter. I have written a code that should normally display an image in a canvas.
What happens is that the main frame (gui) is displayed with the menu bar, then when I click on load image, the gui window shrinks (to 100x100 I guess) but nothing is displayed within.
Could you please explain to me why this is happening so I can understand where the error occurs, and how to correct it?
# -*- coding:utf-8 -*-
# Imports
from tkinter import Tk, Menu, Canvas
from PIL import Image, ImageTk
# Function definitions
def deleteImage(canvas):
canvas.delete("all")
return
def loadImage(canvas, img):
filename = ImageTk.PhotoImage(img)
canvas.image = filename
canvas.create_image(0,0,anchor='nw',image=filename)
return
def quitProgram():
gui.destroy()
# Main window
gui = Tk()
# Inside the main gui window
#Creating an object containing an image
# A canvas with borders that adapt to the image within it
img = Image.open("fleur.jpg")
canvas = Canvas(gui,height=img.size[0],width=img.size[0])
canvas.pack()
# Menu bar
menubar = Menu(gui)
# Adding a cascade to the menu bar:
filemenu = Menu(menubar, tearoff=0)
menubar.add_cascade(label="Files", menu=filemenu)
# Adding a load image button to the cascade menu "File"
filemenu.add_command(label="Load an image", command=loadImage)
# Adding a delete image button to the cascade menu "File"
filemenu.add_command(label="Delete image", command=deleteImage)
filemenu.add_separator()
filemenu.add_command(label="Quit", command=quitProgram)
menubar.add_separator()
menubar.add_cascade(label="?")
# Display the menu bar
gui.config(menu=menubar)
gui.mainloop()
EDIT:
The second problem is that I want to create a canvas and the image in the main gui window, and pass them as arguments to the menu buttons (See code above, where img and canvas are created separately from the function loadImage). Seeing as putting parenthesis in the command=loadImage() created a problem on its own.
Another point that rises a question in my head : Regarding the first problem which was solved by keeping a reference to the filename=ImageTk.PhotoImage(img). Wouldn't it normally be pointless to keep a reference inside the function since it's a local variable anyway?
As stated in effbot's PhotoImage page, you have to keep a reference of your image to ensure it's not garbage collected.
You must keep a reference to the image object in your Python program,
either by storing it in a global variable, or by attaching it to
another object.
Note: When a PhotoImage object is garbage-collected by Python (e.g.
when you return from a function which stored an image in a local
variable), the image is cleared even if it’s being displayed by a
Tkinter widget.
To avoid this, the program must keep an extra reference to the image
object. A simple way to do this is to assign the image to a widget
attribute, like this:
Your loadImage() method should look like below.
def loadImage():
img = Image.open("fleur.jpg")
filename = ImageTk.PhotoImage(img)
canvas = Canvas(gui,height=100,width=100)
canvas.image = filename # <--- keep reference of your image
canvas.create_image(0,0,anchor='nw',image=filename)
canvas.pack()

Python Tkinter: How do I apply a new background image when opening a new tk window?

I used the code below (with different variable names for each section) to create a background image for each tkinter window. Each of these is initiated in a function and both work fine independently.
When loading one function from another however, the second fails to display an image. (I have tried importing all relevant in each function aswell). It works in the case that use tk.destruct(), however if If I want to keep it open, or hide it with . withdraw(), the image fails to display, rendering the second window useless.
background_image=tk.PhotoImage(...)
background_label = tk.Label(parent, image=background_image)
background_label.place(x=0, y=0, relwidth=1, relheight=1)
Ok I've made up a solution for you. Basically all you need is to use tk.Toplevel() for the second tkinter window and make sure that the 'parent' is root2 so the image will appear in the second window.
I have used buttons for the images, you had labels so you may wish to change this, but buttons gave me a way to open a new tk window easily, I have also used .pack(), not .place(), as it was faster for me. May also be helpful for you to know that I used python 3.3 with windows so you might need a capital T for tkinter.
import tkinter as tk
root1 = tk.Tk()
def new_window():
root2 = tk.Toplevel()
# click the last button and all tk windows close
def shutdown():
root1.destroy()
root2.destroy()
background_image2 = tk.PhotoImage(file = '...')
background_button2 = tk.Button(root2, image = background_image2, command = shutdown)
background_button2.pack()
root2.mainloop()
background_image1 = tk.PhotoImage(file = '...')
# have used a button not a label for me to make another tk window
background_button1 = tk.Button(root1, image = background_image1, command = new_window)
background_button1.pack()
root1.mainloop()
#user2589273 Next time you should add more code so answers can be easily given, and tailored to you, just a suggestion. Hope this helps.

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