Fix lags for UWP application in full screen mode

[mykhailopylyp]

Summary of the Pull Request

What is this about:
Remove retries from get_process_path as this function is used in different places and should be generic. For example, when used in low-level keyboard hook it is unacceptable to block execution for 1 second(it happens for full screen UWP applications).

When alt+tab is pressed in full-screen UWP application we receive WM_PRIV_WINDOWCREATED message and FancyZones::WndProc is blocked for one second. Take into account, that Move newly created windows to their last known zone should be checked. So basically we have cases when EnumChildWindows doesn't find a different pid and retry doesn't make sense in this case.

What is include in the PR:

How does someone test / validate:
Test for KBM

• Add remapping Ctrl(Left) + Q -> Play/Pause Media for video.ui.exe(Movies & TV)
  
• Verify that remapping works when Movies & TV is in full screen mode

Test for fancy zones

• Enable Fancy zones
• Check Move newly created windows to their last known zone
• Open Movies & TV in full-screen mode
• Press Alt+Tab
• Verify absence of lag

@SeraphimaZ
Any idea how we can keep #12284 changes?

Quality Checklist

• Linked issue: Lag when PowerToys running in background and trying to Alt-Tab from Microsoft Movies & TV #12639, The Keyboard Manager causes keyboard input delays in Forza Horizon 4 #12775
• Communication: I've discussed this with core contributors in the issue.
• Tests: Added/updated and all pass
• Installer: Added/updated and all pass
• Localization: All end user facing strings can be localized
• Docs: Added/ updated
• Binaries: Any new files are added to WXS / YML
  • No new binaries
  • YML for signing for new binaries
  • WXS for installer for new binaries

Contributor License Agreement (CLA)

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[jaimecbernardo]

If this is used on places where we might need to do retries and other places where we might not need to do retries, why not make retryAttempts an argument for the function?
It could be called with 10 from fancyzones and 1 from everywhere else.

[jaimecbernardo]

Just make sure you don't sleep at the end if this is the last retry, also.

[mykhailopylyp]

If this is used on places where we might need to do retries and other places where we might not need to do retries, why not make retryAttempts an argument for the function?
It could be called with 10 from fancyzones and 1 from everywhere else.

We also need to call it with one retry from fancyzones because FancyZones::WndProc is blocked for 1 second on WM_PRIV_WINDOWCREATED message and as a result, we get the lag when switching(Alt+Tab) from a full-screen UWP app.

@SeraphimaZ
Can you list calls to get_process_path that should be retried in order to keep #12284?

[SeraphimaZykova]

@mykhailopylyp those calls should be retried.

PowerToys/src/modules/fancyzones/FancyZonesLib/util.cpp

Line 479 in fce3864

auto process_path = get_process_path(window);

PowerToys/src/modules/fancyzones/FancyZonesLib/util.cpp

Line 498 in fce3864

return IsZonableByProcessPath(get_process_path(window), excludedApps);

PowerToys/src/modules/fancyzones/FancyZonesLib/FancyZonesData.cpp

Line 382 in fce3864

auto processPath = get_process_path(window);

[mykhailopylyp]

@SeraphimaZ
If we add retry to the following call

PowerToys/src/modules/fancyzones/FancyZonesLib/FancyZonesData.cpp

Line 382 in fce3864

auto processPath = get_process_path(window);

we still would have the lag on switching(Alt+Tab) from full-screen uwp applications.

What is weird is that the following code is called on switching(Alt+Tab) from full-screen uwp applications

PowerToys/src/modules/fancyzones/FancyZonesLib/FancyZones.cpp

Lines 682 to 686 in 0440a89

	else if (message == WM_PRIV_WINDOWCREATED)
	{
	auto hwnd = reinterpret_cast<HWND>(wparam);
	WindowCreated(hwnd);
	}

Probably we should add some checks here.

[mykhailopylyp]

@SeraphimaZ
Can you reproduce EnumChildWindows fails on the first call? Can you share the steps to reproduce?

[SeraphimaZykova]

@SeraphimaZ
Can you reproduce EnumChildWindows fails on the first call? Can you share the steps to reproduce?

I tested it with the Windows Settings app when I worked on #12284, only the second or third attempt was successful. The window was opening and after a short time it was moved to a zone. However, now it succeeds on the first attempt, I can't reproduce the same behavior.

[mykhailopylyp]

@SeraphimaZ
How important this retry is? Do we know how much users are impacted by it?

IMO, even if sometimes uwp window is not moved to a last know fancy zone, it's not a big deal. On the other hand, lag for alt+tab or not usable keyboard in full-screen uwp apps should be fixed in this release.
Also, it doesn't worth adding hackish retry solutions. Honestly, I don't know how to do it now.
Furthermore, we haven't completely solved 'move newly created window to the last known zone' issue. #9590 (comment)

@SeraphimaZ, @jaimecbernardo, thoughts?

[SeraphimaZykova]

@mykhailopylyp I agree that the lag is more important to fix. I think we could try to find another solution for moving uwp window to the last zone.

[jaimecbernardo]

Fixing the lag is more important. While 'move newly created window to the last known zone' failing is an annoyance, causing delays in other applications, especially making some unusable, such as games, is worse.

Let's get this in then.

[jaimecbernardo]

LGTM! Great work.