Webengine_qt WLX Plugin - Visual flash of DC window at first use

[advice2020]

As mentioned this plugin now works overall but I noticed a minor issue.
I was wondering if anyone would be willing to verify these examples below.

REQUIREMENTS
-DC QT6
-Webengine_qt WLX plugin set to view mhtml MIME type

TEST 1 (This is the test where the issue I am reporting can be experienced)
-Move cursor onto a mhtml file
-Open QPP
-This for some reason causes my entire DC window to flash, meaning my entire DC window disappears quickly (showing any windows that may be open under DC window) and then comes back then the QPP/the mhtml file is loaded.
It happens quickly but ideally would not occur.

TEST 2 (Issue does not happen)
-If right after you apply TEST 1 mentioned above
-You close QPP
-Then reopen QPP
-This issue does not occur, it is only after that first open, and ONLY if the QPP is first opened when cursor is on an mhtml file

TEST 3 (Issue does not happen)
-If you open the QPP when cursor is on the top "up arrow" entry (at top of file pane) or on other MIME types when QPP is first opened
-Then this issue does not occur
-You can close QPP and even put cursor on an mhtml file and open QPP again and it works fine

So this ONLY occurs when mhtml file is under cursor when QPP is launched, and only occurs that first time the QPP is launched.

Not a big deal because overall it does work, but if there are any ideas if this could be fixed I would still be interested because ideally I would rather not experience the DC window flashing if it is something that could be fixed? I just like things to be as smooth as possible, if possible :)

Either way thank you again for creating this plugin
Overall this still works great.

[j2969719]

its same as #50 probably. as i understand it, webengine needs an opengl window. with ctrl+q, this is noticeable because the window qt is switching is right in front of your eyes, whereas with the f3 viewer window, this happens when it created. but these are just my assumptions, naturally i have almost zero idea what is going on under the hood of qt/webengine

[Skif-off]

Maybe try to add option to disable GPU acceleration?

[j2969719]

doubt it will help

	view->settings()->setAttribute(QWebEngineSettings::WebGLEnabled, false);
	view->settings()->setAttribute(QWebEngineSettings::Accelerated2dCanvasEnabled, false);

[Skif-off]

I meant without compilation :)
Maybe there is an environment variable, Qt likes that.

[j2969719]

QTWEBENGINE_CHROMIUM_FLAGS="--disable-gpu"

[advice2020]

Thank you for the responses.
Sorry I am a little confused.
Not sure which to use / how to test these suggestions

---

view->settings()->setAttribute(QWebEngineSettings::WebGLEnabled, false);
view->settings()->setAttribute(QWebEngineSettings::Accelerated2dCanvasEnabled, false);

Would I add this to the plugins plugin.cpp file? and if so where?
If I test this and it works, would you be willing to add this to this file commented out, similar to how you did with the darkmode line.

Is this approach in essence doing the same thing as the environment variable below?
Any benefits to one of the other?

---

ENVIRONMENT VARIABLE
Being that this is in the form of a plugin, how would this be applied?
Are you guys saying that this environment variable would be added directly to the DC QT launch command?
Have never thought about it before but,
so even though DC application does not have anything to do with chromium, because a plugin containing it is run within DC, that this environment variable will recognize and webkits parameters and can be turned on/off?
Either way, can you show an example?
I just want to make sure that when I test it out that I am doing so correctly.

Thank you guys again

[j2969719]

try adding these lines there next to the line with dark mode or running dc with this environment variable, but dont hold hopes high

[advice2020]

j2969719
Thank you for response.
Luckily I did not not hold my hopes high, because I tried out both methods but same flashing result occurred.
Again it is not that bad, quick flash, but ideally it would have been nice to get rid of it.
This did not happen in QT5, they had to go messing around with something in QT6 just to cause this issue for us :)

Thanks again for ideas to try
If okay I will keep open if Skif replies, if not should I close this issue?

Skif-off
Probably not something you tried but if you did.
-Do you experience the flashing effect at first launch?
-Did either of these methods (2 "view" based code lines / qt environment variable) work for you?

Thanks again as well

[Skif-off]

@advice2020
-Yes, AFAIR.
-I haven't tried (I remembered that I saw reports of problems when applications unsuccessfully tried to access hardware acceleration by various reasons).

Maybe need try to find applications that use QtWebEngine and see what they do additionally? Maybe free AI?