White flash when reopening a closed tab

[jingyu9575]

It is reported that this extension causes white flash when reopening a closed tab. The reason is still unknown.

[jingyu9575]

It is found that artificially increasing the extension's work can cause the white flash. Probably this extension's work is delaying Stylus from applying the dark background. Also, it seems that the white flash becomes worse if there is more tabs open.

@EstherMoellman :

1. Could you try if my new extension has any effect on the white flash?
2. How many tabs do you use typically?
3. Do you remember if the white flash got better or worse after the fix in #13 (Firefox Nightly 20181128100125)?

Thank you.

[EstherMoellman]

Hi @jingyu9575,

Your new add-on reduces the duration of the white-flash: a) It doesn't eliminate the white-flash. b) The frequency of the white-flashes seems unchanged. In other words, the new add-on doesn't seem to prevent or to reduce the number of white-flashes. c) The duration of the white-flash was reduced by this add-on, I would say something between -30% to -60% duration. So now, the white-flash is a kind of short white-spark.

In one hand, congratulations! good job!, because you really reduced the duration of the white-flash. Thank you for your effort. In the other hand, my opinion is that the goal should be the elimination of the white-flash. So, it doesn't make much sense to install an add-on that only partially reduces the issue. It will be great, if you can totally eliminate the white-flash.

Now, answering your questions:

2. I have around 42 tabs opened. My tabs are managed by an add-on (PowerTabs), that creates 7 groups of around 6 tabs each. When one group is active, all the other tabs are discarded (unloaded/hibernating). In other words, it is like to have only 6 tabs opened each time. I also have another add-on (BasicAutomaticTabsUnloader), that keeps a maximum of 3 tabs opened, all the rest are discarded/unloaded.

3. Sadly I don't remember how was the white-flash before the fix #13. Usually when an issue is under work, or is a FF' bug, I just don't pay attention, try to ignore, and I patiently wait for the fix. So, sorry, I can help here.

You said that the white-flash may have relation with Stylus. You may be right. I did the following test:

• I disabled Stylus.
• I made a dark theme for webpages, using internal FF' font & background colors (about:preferences).
• I did the test again and... zero white-flashes!
• I also disabled your new add-on, I did the test again and... zero white-flashes!

So, at first sight, it really seems to be something related to your add-on and Stylus. You may be right! The problem is that dark theme for webpages, is unusable from internal FF' controls (it is pretty ugly). So, users (like me) willing to use dark theme for webpages, always will use Stylus or darkening add-ons. Stylus never created me white-flashes (only with your add-on). But dark theme add-ons for webpages are terrible, they create huge white-flashes. What I am trying to say, is that dark theme users (like me), using Stylus or add-ons for darkening webpages... they are going to have white-flashes with your add-on.

Once again, please remember what I said, the white-flash created by your add-on is not the end of the world. Even if you don't fix the white-flash, I will keep your add-on, because is very useful for me.

Thank you! :-)

[EstherMoellman]

Hi again @jingyu9575 ,

I believe I solved the white-flash caused by SACC add-on. At least, I solved for me, I tested a lot and no more white-flash. This is my solution:

Go to about:config => browser.display.background_color => insert the dark color you want (I used "#1a1a1a"). Another way to do the same: Go to about:preferences => General => Font & Colors => Colors => Background => Pick the dark color you want. My solution works even if the option here is "Never" for "Override the colors specified by the page with your selection above". By the way, this a mystery for me, because by choosing "Never", no colors have effects, but the white-flash disappears... I can't explain how, but it works for me removing white-flashes with SACC add-on.

My solution doesn't require your new add-on.

If other users test my solution and works for them, I think @jingyu9575 you can consider the issue as "SOLVED" and you can close it.

Cheers!

[jingyu9575]

about:preferences => General => Font & Colors => Colors => Background

It is quite mysterious. This is one of the things that I tested and it did not have effects for me.

Anyway, at least there is a workaround. I'd keep the issue open for a while, in case other users have the same problem.

[EstherMoellman]

Hi @jingyu9575 ,

Since yesterday, I still have zero white-flashes after my workaround (and I tested it heavily). But please, let me add some more info:

1. Shame on me! Yesterday I didn't mention that my workaround uses userContent CSS' codes in order to avoid white-flashes. One of them is specifically related to SACC add-on. I am a newbie at CSS, and I have no idea if this is helping (or not) to avoid the SACC' white flashing... since yesterday I have not had time to test if these CSS' codes are helping or not. If you are good at CSS, perhaps you can take a look (let me know and I will share the codes with you).

2. Also yesterday, I should have mentioned that my workaround has a small collateral effect: Some web-page backgrounds turn into the chosen color at "browser.display.background_color". This is irrelevant for users like me, that have universal dark theme for all web-pages. But this may affect users having customized web-pages.

3. There is a small chance that my user.js and preferences.js also are helping to avoid white-flashes. I need to test.

Perhaps these are the reasons my workaround worked for me, but sadly not for you.