1639391 - Flashing of new windows is annoying during session restore

Status: VERIFIED FIXED

(Core :: Widget: Win32, defect)

Description

[(No longer employed by Mozilla) Aaron Klotz]

At

https://searchfox.org/mozilla-central/source/widget/windows/nsWindow.cpp#1618

We flicker a newly-shown window if it is unable to take focus. This is really annoying if it happens during session restore with multiple windows, because all the inactive windows that were opened by Firefox flicker and are left in that state indefinitely until the user clicks on every single window.

We probably should not do the flickering during session restore, since the user is expecting a whole bunch of new windows to appear anyway.

Comment 1

[(No longer employed by Mozilla) Aaron Klotz]

https://treeherder.mozilla.org/#/jobs?repo=try&revision=6c05bfe739ed2a217756fc54137801957e7290dd

Comment 2

[(No longer employed by Mozilla) Aaron Klotz]

Attachment: Bug 1639391: Do not call nsWindow::GetAttention for top-level windows being shown during session restore; r=jmathies,mhowell

When we call nsWindow::Show but Firefox is not foreground, we show the window
and also flash it on the taskbar to get the user's attention.

This is really annoying when restoring a session with N windows, as the
user's taskbar ends up with all N of them stuck in a flashed state until the
user goes through and manually activates every single window.

There are several ways I thought of to address this, but I think the
simplest one is just to track whether or not we're in the middle of restoring a
session and skip flashing when we are doing so.

Comment 3

[(No longer employed by Mozilla) Aaron Klotz]

I tested this with the above try build and it worked as expected.

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/f952cd9d37fb
Do not call nsWindow::GetAttention for top-level windows being shown during session restore; r=mhowell

Comment 5

[Atila Butkovits]

https://hg.mozilla.org/mozilla-central/rev/f952cd9d37fb

Comment 6

[Bogdan Maris, Desktop Test Engineering]

Reproduced the behavior on an old Nightly from 2020-05-19, verified that after restoring the session on Firefox 78.0 Release Candidates, the Fx icon does not flash in the taskbar on Windows 10 64bit.