Develop Reference

how to fix titlebar behaving as transparent when using '-transparentcolor' in tkinter?

python 3.10, 3.11, windows 10
short:
transparency is affecting title bar when it shouldn't, simple code with example below, move the window to the middle of the screen, maximise and restore to reproduce the behaviour
long:
I know it looks so simple, but please bear with me. This thing is driving me nuts. I'm not sure what I could be doing wrong, it looks like a bug, maybe?
Maximising (or restoring to normal state after maximise) breaks the title bar. Title bar is not registering mouse clicks, I can't close the window or resize it because click goes through. It acts as it if it was transparent. In the main app I am using another hidden window with -alpha to grab mouse events on transparent canvas. Both windows are bound together and act as one. Having second window behind this one also doesn't help. Both windows are affected and unclickable (well, -alpha part of the window is clickable, but not the title bar).
I made a very short code to reproduce this behaviour. You can try it with frame instead of a canvas, or a button. Result is the same. Curious thing I have also discovered when using #000000 for colour - it breaks the window in even weirder way. Not sure what to make of it. #000001 works the same as yellow (or blue, red, etc.).
example:
from tkinter import Canvas, Tk
root = Tk()
root.attributes('-transparentcolor', 'yellow', '-topmost', True)
root.geometry("600x600")
x = Canvas(root, bg='yellow')
x.pack(expand=1, fill='both')
root.mainloop()
If I try different width and height values, sometimes I can grab only half of the title bar or close the window, but not minimise. It seems to depend on where the window is on the screen and the size of the object. Feels like the transparent part of the object is extending through the title bar making it unresponsive. I tried separating the title bar from the rest of the window with frames or shapes but it doesn't help (sometimes it works, but is dependent on size and location of the window - you may get lucky and not notice the behaviour)
x = Canvas(root, bg='yellow', height=600, width=600)
x.pack()
The best solution I've come up with so far:
def refresh(self):
self.state('iconic')
if self.state() == 'iconic':
self.state('normal')
self.focus_force() # needed for Entry widget
This function assigned to the button which is minimising the window to the taskbar and then returning it to normal state immediately. Obviously this is far from elegant, because the user have to perform an unnecessary action. I could use overrideredirect and hopefully recreate resize and close functionality of the window but it seems like an overkill for rather simple app.
Not sure what else to say. It's late, bye
edit:
trying this now and it somehow works, but sometimes the window blinks uncomfortably.
from tkinter import Canvas, Tk
class Window(Tk):
def __init__(self):
super().__init__()
self.bind("<Map>", self.refresh)
self.canv = Canvas(self)
self.canv.pack(expand=1, fill='both')
def refresh(self, event):
if self.state() == 'normal':
self.attributes('-transparentcolor', 'yellow', '-topmost', True)
self.canv.configure(bg='yellow')
elif self.state() == 'zoomed':
self.attributes('-transparentcolor', 'blue', '-topmost', True)
self.canv.configure(bg='blue')
if __name__ == '__main__':
w = Window()
w.mainloop()

Animation speed is increased when cursor is moving in app window using tkinter

I am trying to do simple animation in Tkinter, just red box is moving pixel by pixel from one side to another. The problem is that when I move cursor on application window the animation has correct speed (33 ms between frames) but when I stop then animation slows down (to about 46 ms). I am using windows 11, IDE PyCharm and python 3.10.
Here is my code:
import time
import tkinter
root = tkinter.Tk()
canvas = tkinter.Canvas(root, height=1000, width=1000, bg='white')
canvas.pack()
box = canvas.create_rectangle(0, 475, 50, 525, fill='red')
def animation():
global start
print(str(int((time.time() - start)*1000)) + "ms")
start = time.time()
canvas.move(box, 1, 0)
root.after(33, animation)
start = time.time()
animation()
root.mainloop()
After spending some time on searching forums for similar cases I found only one in which the solution was different version of python but I tried and it didn't work. Please help.
Thanks

How to make a tkinter canvas background transparent?

I am making a chess program and I want to be able to drag the pieces. In order to do this, I put the image of the piece on a Canvas so it can be dragged (I can also use a Label if I want). However, when I drag the piece there is a white square that surrounds the image of the piece.
When I researched the problem, many people gave this solution:
drag_canvas = Canvas(self, height=80, width=80, bg="yellow")
root.wm_attributes("-transparentcolor", "yellow")
This caused the background to be transparent but it was not the chessboard that was visible, it was the program behind the GUI
.
Is there any way I can have the background be transparent and show the chessboard behind rather than the program behind the tkinter window?
Note: I do not mind using any other widget (e.g. a Label) but they must use modules that come default with Python (so no PIL) as this program needs to be used in an environment where I cannot download other modules.

Question: How to make a tkinter canvas background transparent?
The only possible config(... option, to set the background to nothing
c.config(bg='')
results with: _tkinter.TclError: unknown color name ""
To get this result:
you have to hold the chess board and figures within the same .Canvas(....
self.canvas = Canvas(self, width=500, height=200, bd=0, highlightthickness=0)
self.canvas.create_rectangle(245,50,345,150, fill='white')
self.image = tk.PhotoImage(file='chess.png')
self.image_id = self.canvas.create_image(50,50, image=self.image)
self.canvas.move(self.image_id, 245, 100)
Tested with Python: 3.5 - TkVersion: 8.6

A windows only solution is to use the pywin32 module that can be installed with:
pip install pywin32
With pywin32 you can alter the window exstyle and set the canvas to a layered window. A layered window can have a transparent colorkey and is done in the example below:
import tkinter as tk
import win32gui
import win32con
import win32api
root = tk.Tk()
root.configure(bg='yellow')
canvas = tk.Canvas(root,bg='#000000')#full black
hwnd = canvas.winfo_id()
colorkey = win32api.RGB(0,0,0) #full black in COLORREF structure
wnd_exstyle = win32gui.GetWindowLong(hwnd, win32con.GWL_EXSTYLE)
new_exstyle = wnd_exstyle | win32con.WS_EX_LAYERED
win32gui.SetWindowLong(hwnd,win32con.GWL_EXSTYLE,new_exstyle)
win32gui.SetLayeredWindowAttributes(hwnd,colorkey,255,win32con.LWA_COLORKEY)
canvas.create_rectangle(50,50,100,100,fill='blue')
canvas.pack()
Explaination:
First we need the handle of the window which is called hwnd and we can get it in tkinter by .winfo_id().
Next we get the actual extended window style by GetWindowLong and ask specific for extended style information with win32con.GWL_EXSTYLE.
After that we do a bitwise operation in hexadezimal to alter the style with wnd_exstyle | win32con.WS_EX_LAYERED the result is our new_style.
Now we can set the extended style to the window with SetWindowLong. Finally we have our LayeredWindow which has additional Attributes we can work with. A transparent ColorKey can be set with SetLayeredWindowAttributes while we just use LWA_COLORKEY the alpha parameter has no use to us.
Important note: After defining a transparent colorkey, everything in that canvas with that color will be transparent.

tkinter: Can't make frame scrollable

On python tkinter, I am using 2 different frames on a Toplevel window, one on the right and another on the left.
The frame which is on right side is not scrollable. I have created a canvas on top of the frame on that frame and one more frame on top of that canvas. I have made that canvas scrollable and pasted the widgets on that canvas but it's not scrollable. I am attaching the code of the scrollable part.
w1 = Canvas(frame2, width=600, height=300,background="white", scrollregion=(1500,1500,3000,3000))
scr_h1 = ttk.Scrollbar(frame2,orient=HORIZONTAL)
scr_h1.pack(side=BOTTOM,fill=X)
scr_h1.config(command=w1.xview)
scr_v1 = ttk.Scrollbar(frame2,orient=VERTICAL)
scr_v1.pack(side=RIGHT,fill=Y)
scr_v1.config(command=w1.yview)
w1.config(xscrollcommand=scr_h1.set,yscrollcommand=scr_v1.set)
w1.pack(fill=BOTH,expand=True)

This code works for me running Python 3.4 - a tkinter window pops up with a red oval (for testing), and the scrollbar allows you to navigate the frame. If you are using Python 2, change tkinter to Tkinter (capital T).
from tkinter import *
root = Tk()
frame2 = Frame(root)
frame2.pack(side=RIGHT)
w1 = Canvas(frame2, width=600, height=300,background="white", scrollregion=(0,0,3000,3000))
scr_h1 = Scrollbar(frame2,orient=HORIZONTAL)
scr_h1.pack(side=BOTTOM,fill=X)
scr_h1.config(command=w1.xview)
scr_v1 = Scrollbar(frame2,orient=VERTICAL)
scr_v1.pack(side=RIGHT,fill=Y)
scr_v1.config(command=w1.yview)
w1.config(xscrollcommand=scr_h1.set,yscrollcommand=scr_v1.set)
w1.pack(fill=BOTH,expand=True)
# inserted to see if it's actually scrolling
w1.create_oval(0,0,50,50,fill='red')
root.mainloop()
Two Possible Issues
Why were you using a ttk ScrollBar? The simple tkinter scroll bar will suffice for your code. When things aren't working, it might help to go back to the simpler model.
Why your starting scroll region was 1500 - any object placed on the canvas in the first 1500 units in either direction were not visible, with this setting, which may have given you the illusion that the scrollbar was not working. See http://effbot.org/zone/tkinter-scrollbar-patterns.htm for more information on using scroll bars.
It should not matter that there are two frames or their orientation, though you may run into problems if you try to mix managers (grid,pack,etc.). These problems are more along the lines of stalled programs, not stationary scrollbars.

my tkinter gui is invisible for unknown reasons

I've been trying to create a basic gui using tkinter, I've done it before on a different computer but for some reason its invisible. Is there something wrong with my code or the computer (windows)?
import sys
from tkinter import *
mygui = Tk()
mygui.geometry('300x300+0+982')
mygui.title("my gui")
mygui.mainloop()

Is your screen height is bigger than 982 pixel?
Following line place the window at (0, 982) with width 300, height 300. If your screen height smaller than 982 pixel, you can't see it.
mygui.geometry('300x300+0+982')
Replace it with following:
mygui.geometry('300x300+0+0')
and you will see it.