Tcl/Tk 9.x support?

[ajkessel]

I'm happy to see this project revived! Python is starting to ship with Tcl/Tk 9.x upstream. I was hesitant to move my projects that depend on customtkinter to 9.x as the original project had been pretty dormant. Has this fork been tested much with 9.x? There were some bugs with original customtkinter with that move; have you been testing/developing against 9.x?

[FedericoSpada]

Hi,
No, I didn't know about this change. Thanks for pointing it out: I'm going to download it and check if this library works with the new version too.
If you are already aware of any problems, please list them here so I can take a closer look at them first.

[ajkessel]

I had one issue in CTKToolTip; I haven't yet checked if it persists with your implementation here: Akascape/CTkToolTip#39

[ajkessel]

Just tested your tooltip implementation with Python 3.15.0b2 on Mac, which ships with Tk/Tcl 9.0. I don't see the same issue I was having with the Akascape implementation. So this is promising:

[FedericoSpada]

Well, I don't see the rounded corners I would expect either...
Try running ctk.run_showroom() and, in the Windows tab, have a look at how those CTkToolTips appear.
Thanks.

[ajkessel]

Actually, it is the same issue. MacOS Python 3.15 with Tk 9.0:

Python 3.13 with Tk 8.6:

[FedericoSpada]

Probably, they changed the management of the "systemTransparent" color.
I don't have a Mac to try any changes I could make. If you find a proper solution that works with both versions, feel free to open a PR.

[ajkessel]

I've been looking into this and I'm afraid there is no good solution. This explanation summarizes the problem:

To make a ⁠Toplevel⁠ tooltip transparent in Tk 8.6, Tkinter sent a specific command down to the macOS window manager (⁠systemTransparent⁠), asking the OS to render the background of that specific, borderless window as invisible, leaving only the text.

In Tk 9.0, the core C code that bridges Tkinter to macOS's modern ⁠CALayer⁠ drawing system fundamentally changed. The new bridge does not properly translate the request for a transparent background on a borderless ⁠Toplevel⁠ window. Instead of passing the transparency command to the OS, the window manager defaults to rendering a solid, opaque box (usually white, gray, or black, depending on your system's Dark Mode state).

[FedericoSpada]

But is this a problem in tkinter or inside Tcl itself?
Maybe we can open an Issue somewhere else.

[ajkessel]

But is this a problem in tkinter or inside Tcl itself?

It does seem like Tcl 9.x has a real conflict with modern MacOS transparency and there may be no easy fix, at least not in the Python code. I've started a thread on comp.lang.tcl and will report back if I get anywhere.

So one possibility would be to disable rounded corners on tooltips by default for TkVersion >= 9.0. Of course, the developer could do that manually, but I don't think anyone is going to want rounded tooltips if the cost is a weird looking outline.

[ajkessel]

Progress! This patch fixes the transparency issue on MacOS+Tk 9.x for me in my own little test script, but it doesn't fix run_showroom(). Is there something in run_showroom() that is conflicting with my proposed fix?

Here's the script that works fine with that edit:

import customtkinter as ctk
app = ctk.CTk(fg_color="blue")
app.geometry("150x150")
app.title("Simple Button")
def on_button_click():
    print("Button was clicked!")
button = ctk.CTkButton(
    master=app,
    text="Click Me",
    command=on_button_click,
    corner_radius=20
)
button.pack(pady=40)
tooltip = ctk.CTkToolTip(button, label={"wraplength": 200}, title="CTkToolTip", text="This tooltip will have correct transparency around the edges.",corner_radius=20)
app.mainloop()

[FedericoSpada]

I don't know. I don't even understand how it is supposed to work... In the previous version, you indicated which parts should be transparent. Now you just set corner_radius to 0 as for Linux, which doesn't support transparency, and it magically works... It feels like I'm not looking at the code that produced those images.
Moreover, are you sure about invoking self._toplevel.wm_attributes(...) every time after deiconify() and for all OS?

Can you report the link to the post where you reported the problem? Or was it a private conversation? Thanks.

[ajkessel]

I don't know. I don't even understand how it is supposed to work... In the previous version, you indicated which parts should be transparent. Now you just set corner_radius to 0 as for Linux, which doesn't support transparency, and it magically works... It feels like I'm not looking at the code that produced those images. Moreover, are you sure about invoking self._toplevel.wm_attributes(...) every time after deiconify() and for all OS?

Can you report the link to the post where you reported the problem? Or was it a private conversation? Thanks.

The most relevant threads begins here. There have been a few different places talking about the Tcl 9.x incorporation into cpython, but this is where I found the solution that worked here.

I did a bunch of trial and error based on that thread and this was the first implementation that worked -- the code I linked to is definitely the code that generated those screenshots.

Without reapplying wm_attributes after deiconify() the style wasn't sticking. But you're right--it should only do that for MacOS and Tk>=9.0 since that is the only place we see this issue. I've fixed.

I don't fully understand it either but @culler in that thread seems to be the MacOS Tkinter subject matter expert. He's also commented on some related Tcl tickets I've raised.

Happy to test some code on various MacOS boxes if you like.

[FedericoSpada]

Maybe you can open a PR with this change, but for now, I prefer to leave it as a draft. Maybe before the official Python 3.15 release, there will be other changes, and this fix won't be needed.

[ajkessel]

Maybe you can open a PR with this change, but for now, I prefer to leave it as a draft. Maybe before the official Python 3.15 release, there will be other changes, and this fix won't be needed.

Will do. But I'm fairly certain the Python 3.15 release won't fix this because it relates to an underlying architectural change with Tcl/Tk -- they aren't relying on unsupported MacOS APIs, which means the method that was used for transparency before isn't going to be supported.