Alt+Tab to Notepad++ sometimes the cursor/inputpoint is nowhere

[libove]

Description of the Issue

Starting .. recently? 7.9.1 update? Apologies, I don't know exactly, the following:
(Windows 10 20H2, 64-bit) Alt+Tab into Notepad++, the cursor/input point will be 'nowhere'.
Historically - and still today mostly - upon Alt+Tabbing into Notepad++ the cursor/input point will be wherever it most recently was in whatever buffer happens to be the current buffer.
However, for some weeks now, on multiple computers, upon Alt+Tabbing into Notepad++, occasionally, the cursor/input point will be 'nowhere'. That is, no keystroke will work. (I admit, I may not have tried Alt+ commands, but I HAVE hit ESC a couple of times to cancel possible unintended half Alt- keystrokes, and that hasn't worked, so it's not that a menu option has been partly activated). There is no blinking cursor. No menubar item is highlighted the way it would be if the user had simply tapped "Alt" for example.
It requires clicking with the mouse anywhere in Notepad++ to get the keyboard active again.

Steps to Reproduce the Issue

1. (unreliably) Alt+Tab into Notepad++
2. Cursor may be 'nowhere'

Expected Behavior

Cursor would always be live, somewhere in the Notepad++ window, with never the need to mouseclick before being able to start typing into the current buffer.

Actual Behavior

Occasionally, unpredictably, the cursor is 'nowhere', and a mouseclick is required.

Debug Information

Notepad++ v7.9.1 (64-bit)
Build time : Nov 2 2020 - 01:07:46
Path : C:\Program Files\Notepad++\notepad++.exe
Admin mode : OFF
Local Conf mode : OFF
OS Name : Windows 10 Pro (64-bit)
OS Version : 2009
OS Build : 19042.685
Current ANSI codepage : 1252
Plugins : none

Hm. MAYBE it might occur after a buffer has updated because Notepad++ noticed that the underlying file had changed. This happened, once, as I was Alt+Tabbing quite a lot just to see if I could reproduce the problem, and in fact in a couple of dozen Alt+Tabs in and out of Notepad++ it did occur twice. I noticed in that particular case - Alt+Tab in, Notepad++ notices that an underlying file had changed and asks me if I want to update; I click yes and the cursor is nowhere until I Alt+Tab out and back in again. HOWEVER this is NOT the usual case - usually when I've encountered this issue in recent weeks, I did NOT also see a do-you-want-to-update prompt, the underlying file had not changed. (I do not have the option set to automatically reload buffers when underlying files change). I've continued lots of Alt+Tabbing and cannot reproduce the issue again just at the moment.

[zanud]

In my practice this problem frequently happens after switching from the "Find" (Ctrl-F) dialog to the main window. (File been editing is not changed externally.)

[libove]

Thank you @zanud .
I tried to reproduce that, but in my case if the Find dialog is open then the Find dialog is the only thing to which I can Alt+Tab. That is, I cannot use Alt+Tab to switch between the (Notepad++) Find dialog and the (Notepad++) main window. Windows seems to treat the Notepad++ Find dialog as the only part of Notepad++ which is selectable by Alt+Tab. So I think that can't be exactly what I'm seeing. Regardless, it's good to hear that I'm not the only person experiencing it, even if we end of provoking it in different ways!

[sasumner]

Not sure I've ever noticed this happening to me, but I have heard of this "trick" as a workaround, that may ease the situation (or maybe not):

When it happens, try pressing the Windows key twice.

[zanud]

That is, I cannot use Alt+Tab to switch between the (Notepad++) Find dialog and the (Notepad++) main window. Windows seems to treat the Notepad++ Find dialog as the only part of Notepad++ which is selectable by Alt+Tab.

Not exactly. If you are currently in the Find dialog, then first Alt+Tab will switch to the main Notepad++ window. After that the Find dialog becomes unreachable, and any subsequent Alt+Tab switches between Notepad++ main window and windows of other applications. At least, on Windows XP.

Right now in freshly launched Notepad++ I can not reproduce the problem. But during the last week I was actively working with a dozen of simultaneously opened files without closing the editor, and all this week the disappearing cursor (caret) drove me nuts (as I prefer to use keyboard only, without mouse).
So, perhaps, Ctrl-Tab also has some impact.

[libove]

Hi @zanud - that's simply not how it's working for me. If a Notepad++ Find dialog is open, that becomes "The" (only) Notepad++ window that Alt+Tab will see as being available to switch to. I did a quick search to see if Alt+Tab behavior is customisable, and found only size/transparency/position Registry settings, nothing that would seem to cause this difference in experience between our systems.