Make pylauncher high DPI aware

[clin1234]

Linked PRs

• gh-140271: Add <dpiAware> and <dpiAwareness> in PC/python.manifest #140273

[AA-Turner]

@clin1234 can you provide screenshots of before/after?

[clin1234]

@clin1234 can you provide screenshots of before/after?

I don't have Python installed on Windows, but my display resolution is not set at 100% (mine is set at 125%). From prior experience with other apps that don't have their manifests modified to be high DPI aware, after launching such apps, the text becomes blurry.

[AA-Turner]

My laptop is also set to 125%, and I can't say I've noticed text blurriness in the launcher, hence the request for screenshots/etc with the before and after of the change.

A

[clin1234]

Comparison between the 3.15.0a1 installer and Notepad++, which is high DPI aware
125% scale

[clin1234]

Same comparison at 225% scale:

[zooba]

You'll notice the big "NOTE" in the screenshot of the installer saying that it will no longer be available (and in any case, it's not the launcher).

The only thing we would consider applying this change to is pythonw.exe, which would then have an impact on Tcl/Tk. That should determine the default (basically, if IDLE works better with the changed setting, let's set it), and then other frameworks can use SetThreadDpiAwarenessContext to override.

[clin1234]

You'll notice the big "NOTE" in the screenshot of the installer saying that it will no longer be available (and in any case, it's not the launcher).

The only thing we would consider applying this change to is pythonw.exe, which would then have an impact on Tcl/Tk. That should determine the default (basically, if IDLE works better with the changed setting, let's set it), and then other frameworks can use SetThreadDpiAwarenessContext to override.

pythonw references the same app manifest as pylauncher, so it and any PC app whose rc file references python.manifest would benefit

[zooba]

Please demonstrate the benefit. Before and after screenshots of IDLE will do for starters, but examples of PyQt and any other significant frameworks (is WxPython still around?) would also help make the case.

We can't simply state "all arbitrary users of Python are aware of OS DPI settings". That's actually a burden on our users, and could arguably require a deprecation period and multiple announcements, unless the range of commonly used UI frameworks are, indeed, already DPI aware and the change is going to be transparent for the vast majority of users.