Rework feed new items handling

[litetex]

What is it?

• Bugfix (user facing)
• Feature (user facing)
• Codebase improvement (dev facing)
• Meta improvement to the project (dev facing)

Description of the changes in your PR

Follow up of #6686

Changes:

• Fixed the weird duplicate FeedSuccessEvents as seen in Fixed scrolling on refresh in the feed #6686 (comment) and Fixed scrolling on refresh in the feed #6686 (comment) by using a Maybe instead of Flowable
• New items are now highlighted with a border in the background
  
• If new items got fetched a "New feed items" button pops up
  
  • Clicking the button scrolls to the top of the list and hides it
  • The button automatically vanishes after 10s (when device animations are on)
  • The button automatically vanishes when scrolling to the top
  • The button automatically vanishes if the feed is reloaded

Before/After Screenshots/Screen Record

Before (click to expand)

Broken.mp4

After (click to expand)

NewPipeFeedReworkDemo1.mp4

Fixes the following issue(s)

• Fixes After Feed Update, Requires Manual Scroll Up to show Latest Videos #6650 indirectly

APK testing

The APK can be found by going to the "Checks" tab below the title. On the left pane, click on "CI", scroll down to "artifacts" and click "app" to download the zip file which contains the debug APK of this PR.

Due diligence

• I read the contribution guidelines.

How to test

• Install the apk / Checkout the branch
• optional Set your phone / emulator system time to 2021-07-15 at 23:55 (you might need to reset it as the clock counts)
• Import an old state of your feed, you can e.g. use this: NewPipeData-20210716_190308.zip
• Go to Feed/"What's New" and refresh it

[litetex]

@SameenAhnaf
Thank you for the feedback!

However most of these statements would blow up the current scope of this Pull Request.
Please create a new issue or check for existing similar ones like e.g. #7047, leave a comment and/or upvote them
This PullRequestis only meant to improve the handling of the "new items" as mentioned in it's predecessor #6686

Is 5. related to this PullRequest? I don't understand the statement...

New video titles should be bold instead of making it confined in the boxes

To the errors you found (6.x):
I can't reproduce them with my setup neither on the emulator nor on my real phone.
I also switched to the Grid-view to see if there are any problems however I was unable to find one...

Could you post your configuration (Settings>Content>Export database) here? (maybe clean it before posting it publicly)
I'm otherwise not able to reproduce the problem...

[nikhilCad]

Only a single line separating the old and new videos can be good as well

[tsiflimagas]

I got this after new items were loaded, couldn't reproduce it though

Exception

• User Action: ui error
• Request: ACRA report
• Content Country: US
• Content Language: en-US
• App Language: en_US
• Service: none
• Version: 0.21.9
• OS: Linux Android 11 - 30

Crash log

java.lang.NullPointerException
	at org.schabi.newpipe.local.feed.FeedFragment.getFeedBinding(FeedFragment.kt:87)
	at org.schabi.newpipe.local.feed.FeedFragment.hideNewItemsLoaded$lambda-26(FeedFragment.kt:639)
	at org.schabi.newpipe.local.feed.FeedFragment.$r8$lambda$vVY6QBNGtFe0us3zVVzOHMF1I-w(Unknown Source:0)
	at org.schabi.newpipe.local.feed.FeedFragment$$ExternalSyntheticLambda14.run(Unknown Source:2)
	at org.schabi.newpipe.ktx.ViewUtils$animateAlpha$2.onAnimationEnd(View.kt:192)
	at android.view.ViewPropertyAnimator$AnimatorEventListener.onAnimationEnd(ViewPropertyAnimator.java:1111)
	at android.animation.Animator$AnimatorListener.onAnimationEnd(Animator.java:554)
	at android.animation.ValueAnimator.endAnimation(ValueAnimator.java:1250)
	at android.animation.ValueAnimator.doAnimationFrame(ValueAnimator.java:1492)
	at android.animation.AnimationHandler.doAnimationFrame(AnimationHandler.java:146)
	at android.animation.AnimationHandler.access$100(AnimationHandler.java:37)
	at android.animation.AnimationHandler$1.doFrame(AnimationHandler.java:54)
	at android.view.Choreographer$CallbackRecord.run(Choreographer.java:1044)
	at android.view.Choreographer.doCallbacks(Choreographer.java:869)
	at android.view.Choreographer.doFrame(Choreographer.java:799)
	at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:1031)
	at android.os.Handler.handleCallback(Handler.java:938)
	at android.os.Handler.dispatchMessage(Handler.java:99)
	at android.os.Looper.loop(Looper.java:223)
	at android.app.ActivityThread.main(ActivityThread.java:7665)
	at java.lang.reflect.Method.invoke(Native Method)
	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:594)
	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:940)

---

[litetex]

Thanks for all the feedback!

@nikhilCad

Only a single line separating the old and new videos can be good as well

Adding a completely different element in the video list between all the same elements doesn't work / is too difficult to implement. The list is also manage by the groupie framework, which would require additional effort

[litetex]

@SameenAhnaf
I think that's generally a good idea however e-mails can't contain additional formatting in the header. YouTube videos e.g. can (don't know if other services can also do that):

So I think bold titles only aren't the best expression that something is new.
However I will additionally make the video-text bold to the already bordered background so people clearly see the difference.

[litetex]

@tsiflimagas
Thank you for the report!

I got this after new items were loaded, couldn't reproduce it though
...

I think that happens because the view isn't anymore there e.g. switching the view.
I made the corresponding lambda more-null safe.

[litetex]

@SameenAhnaf
Thank you for the export!

However when I tried to import your data, there seem to be no subscriptions where the feed is fetched from and I end up with an empty page.
Please resend/post a corrected version where I can reproduce the problem 😄

[litetex]

@SameenAhnaf
I think I managed to fix the vanishing "new feed items" button by checking if animations are on in the system and maybe the other problems as well :)
If they are off the button doesn't vanish after 10s anymore.

[Stypox]

Code looks almost good :-D
I tested and it works :-)

[TobiGr]

why is the chip / button at the bottom?
I think it is more intuitive to have it at the top for two reasons:

1. the new items are at the top, so I'd also look at the top after refreshing, not at the bottom
2. the refresh gesture starts at the top and usually stops at 1/3 of the height, i.e. the finger is still in the upper part of the screen when the gesture is finished and most likely also when the list is updated / the chip is shown.

On another note: the button us quite near at the bottom of the screen which caused my fat fingers to trigger the O button which closed the app.

[litetex]

@TobiGr
I think the button would obscure the newly loaded feed items at the top that's why I put it at the bottom.

Moving the button up a bit shouldn't be a problem 😄

[tsiflimagas]

A small issue was caused from latest changes, "new feed items" button appears on every app start, and when returning to "what's new" from search.

[litetex]

@tsiflimagas

Thanks for noticing.
I accidentally forgot to set the default visibility to gone while removing the layout.

Should be fixed now

[Stypox]

Thank you, I tested on API 19 emulated, API 30 tablet emulated and API 30 real, and everything works well.

[tsiflimagas]

Here's another crash I got. It seems that it happens if you refresh the feed, there are new videos, but you quickly go and open a playlist while the feed's still loading.

Exception

• User Action: ui error
• Request: ACRA report
• Content Country: US
• Content Language: en-US
• App Language: en_US
• Service: none
• Version: 0.21.10
• OS: Linux Android 11 - 30

Crash log

java.lang.NullPointerException
	at org.schabi.newpipe.local.feed.FeedFragment.getFeedBinding(FeedFragment.kt:89)
	at org.schabi.newpipe.local.feed.FeedFragment.hideNewItemsLoaded$lambda-26(FeedFragment.kt:653)
	at org.schabi.newpipe.local.feed.FeedFragment.$r8$lambda$vVY6QBNGtFe0us3zVVzOHMF1I-w(Unknown Source:0)
	at org.schabi.newpipe.local.feed.FeedFragment$$ExternalSyntheticLambda14.run(Unknown Source:2)
	at org.schabi.newpipe.ktx.ViewUtils$animateAlpha$2.onAnimationEnd(View.kt:192)
	at android.view.ViewPropertyAnimator$AnimatorEventListener.onAnimationEnd(ViewPropertyAnimator.java:1111)
	at android.animation.Animator$AnimatorListener.onAnimationEnd(Animator.java:554)
	at android.animation.ValueAnimator.endAnimation(ValueAnimator.java:1250)
	at android.animation.ValueAnimator.doAnimationFrame(ValueAnimator.java:1492)
	at android.animation.AnimationHandler.doAnimationFrame(AnimationHandler.java:146)
	at android.animation.AnimationHandler.access$100(AnimationHandler.java:37)
	at android.animation.AnimationHandler$1.doFrame(AnimationHandler.java:54)
	at android.view.Choreographer$CallbackRecord.run(Choreographer.java:1044)
	at android.view.Choreographer.doCallbacks(Choreographer.java:869)
	at android.view.Choreographer.doFrame(Choreographer.java:799)
	at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:1031)
	at android.os.Handler.handleCallback(Handler.java:938)
	at android.os.Handler.dispatchMessage(Handler.java:99)
	at android.os.Looper.loop(Looper.java:223)
	at android.app.ActivityThread.main(ActivityThread.java:7665)
	at java.lang.reflect.Method.invoke(Native Method)
	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:594)
	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:940)

---

[TobiGr]

I'd also squash a few of these commits, because some of them improve or re-do stuff that is done in previous commits of this PR, e.g. c871ca8, 3c5e77f or 5d7815e

[litetex]

Rebased and squashed the branch.

[Redirion]

lgtm

[Stypox]

Obviously I am late, but yes, this looks good :-)