Feature request: Document how to display an empty screen [159054196]

Fixed

Bug

Status Update

No update yet.

Description

ri...@soundcloud.com

created issue #1

Jun 16, 2020 09:13AM

The doc about how to load and display paged data with Paging 3.0 clearly explains how to show progress and error views but it doesn't cover how to handle the case of an empty result. Also the samples seem to not support that case.

I'm new to the Paging library and I find it non trivial to determine what is the right LoadingState to listen to. I assume it's the refresh state, but even there it's not clear how to determine whether the result is empty or not.

Maybe this suggestion should go to a separate issue but I think it would be nice to reuse the same LoadStateAdapter approach as that would allow to build nice reusable loading-empty-error page components.

Comments

le...@gmail.com <le...@gmail.com> #2Jun 16, 2020 01:29PM

A couple of questions:

1. Have you saw crash in real device or only in simulators?
2. Do you use dynamic feature for language ID?

du...@google.com <du...@google.com> #3Jun 16, 2020 03:14PM

Tested on Android 12 Emulator with custom executor, but cannot repro this issue.

cc...@google.com <cc...@google.com> #4Jun 16, 2020 04:06PM

Second crash in the description is from a real device. Experienced it myself on two different Xiaomi phones, plus lots of crashes from users in the Google Play console.
Dynamic features are not used in the application.

As a wild guess, I have downgraded build tools from 31.0.0 to 30.0.3, compileSdk from 31 to 30, and moved all work with Language ID to the service in a separate process (just to be sure that crash can kill secondary process instead of main). This combination is in beta for 2 days by now and I don't see any SIGSEGV crashes.

du...@google.com <du...@google.com> #5Jun 16, 2020 04:30PM

Hmm, I feel the crash might be something related to separate/secondary process.

I also changed compileSdk and targetSDK to 31 but still cannot repro this issue.

ap...@google.com <ap...@google.com> #6Jun 16, 2020 04:48PM

On the contrary, there was no separate process before, when crashes started.

In the new build (with the aforementioned changes) I can see SIGSEGV crash, but only one instead of dozens and it has a bit different backtrace:

signal 11 (SIGSEGV), code 1 (SEGV_MAPERR)
liblanguage_id_jni.so (offset 0x11e000)

backtrace:
  #00  pc 000000000003c7c0  /data/app/azagroup.reedy-mF7zTu2bv_ELlbFArwNgqA==/split_config.arm64_v8a.apk!lib/arm64-v8a/liblanguage_id_jni.so (offset 0x11e000)
  #00  pc 000000000003b960  /data/app/azagroup.reedy-mF7zTu2bv_ELlbFArwNgqA==/split_config.arm64_v8a.apk!lib/arm64-v8a/liblanguage_id_jni.so (offset 0x11e000)
  #00  pc 000000000003bb48  /data/app/azagroup.reedy-mF7zTu2bv_ELlbFArwNgqA==/split_config.arm64_v8a.apk!lib/arm64-v8a/liblanguage_id_jni.so (offset 0x11e000)
  #00  pc 000000000003bafc  /data/app/azagroup.reedy-mF7zTu2bv_ELlbFArwNgqA==/split_config.arm64_v8a.apk!lib/arm64-v8a/liblanguage_id_jni.so (offset 0x11e000)
  #00  pc 0000000000036c98  /data/app/azagroup.reedy-mF7zTu2bv_ELlbFArwNgqA==/split_config.arm64_v8a.apk!lib/arm64-v8a/liblanguage_id_jni.so (offset 0x11e000)
  #00  pc 0000000000032714  /data/app/azagroup.reedy-mF7zTu2bv_ELlbFArwNgqA==/split_config.arm64_v8a.apk!lib/arm64-v8a/liblanguage_id_jni.so (offset 0x11e000)
  #00  pc 0000000000031cac  /data/app/azagroup.reedy-mF7zTu2bv_ELlbFArwNgqA==/split_config.arm64_v8a.apk!lib/arm64-v8a/liblanguage_id_jni.so (offset 0x11e000)
  #00  pc 0000000000057438  /data/app/azagroup.reedy-mF7zTu2bv_ELlbFArwNgqA==/oat/arm64/base.odex (offset 0x57000)

cc...@google.com <cc...@google.com> Jun 16, 2020 05:11PM

Reassigned to du...@google.com.

ap...@google.com <ap...@google.com> #7Jun 17, 2020 11:33PM

Marked as fixed.

FYI, ML Kit launched a new language ID SDK in the latest release, which uses a new language ID model. https://developers.google.com/ml-kit/release-notes#august_11_2021

Could you try the new SDK version(17.0.0) to check if you can still repro this native crash? Thanks!