From 851ee81486cae0286ed021b5c808d81817540062 Mon Sep 17 00:00:00 2001
From: Viktor De Pasquale <info@depasquale.wiki>
Date: Fri, 24 Jan 2020 17:52:31 +0100
Subject: [PATCH] Updated removing of "empty list" messages

Before this commit, the loader removed messages _after_ it updated the
 list. Coincidentally the list updating mechanism is asynchronous to
 some extent and so slower devices might've had the message removed
 after changes have been dispatched which confused the recyclerview and
 caused the crash.
Now, the loader is stripped of the responsibility update the list
 holding helper messages. The responsibility is for the user itself to
 notify listeners and then clear the helper list. This should hopefully
 delay the removal to the point where choreographer had enough time to
 traverse through the hierarchy.

Stupid recycler view / layout managers. Literally unnecessary crash.
---
 .../topjohnwu/magisk/extensions/XBinding.kt   | 65 ++++++++++++++++++-
 .../magisk/ui/module/ModuleViewModel.kt       | 26 +++++---
 2 files changed, 82 insertions(+), 9 deletions(-)

diff --git a/app/src/main/java/com/topjohnwu/magisk/extensions/XBinding.kt b/app/src/main/java/com/topjohnwu/magisk/extensions/XBinding.kt
index c0c5c8dd1..cb496a4fa 100644
--- a/app/src/main/java/com/topjohnwu/magisk/extensions/XBinding.kt
+++ b/app/src/main/java/com/topjohnwu/magisk/extensions/XBinding.kt
@@ -1,8 +1,71 @@
 package com.topjohnwu.magisk.extensions
 
+import androidx.databinding.ObservableList
 import com.topjohnwu.magisk.utils.KObservableField
 
 
 fun KObservableField<Boolean>.toggle() {
     value = !value
-}
\ No newline at end of file
+}
+
+fun <T> ObservableList<T>.addOnListChangedCallback(
+    onChanged: ((sender: ObservableList<T>) -> Unit)? = null,
+    onItemRangeRemoved: ((sender: ObservableList<T>, positionStart: Int, itemCount: Int) -> Unit)? = null,
+    onItemRangeMoved: ((sender: ObservableList<T>, fromPosition: Int, toPosition: Int, itemCount: Int) -> Unit)? = null,
+    onItemRangeInserted: ((sender: ObservableList<T>, positionStart: Int, itemCount: Int) -> Unit)? = null,
+    onItemRangeChanged: ((sender: ObservableList<T>, positionStart: Int, itemCount: Int) -> Unit)? = null
+) = addOnListChangedCallback(object : ObservableList.OnListChangedCallback<ObservableList<T>>() {
+    override fun onChanged(sender: ObservableList<T>?) {
+        onChanged?.invoke(sender ?: return)
+    }
+
+    override fun onItemRangeRemoved(
+        sender: ObservableList<T>?,
+        positionStart: Int,
+        itemCount: Int
+    ) {
+        onItemRangeRemoved?.invoke(
+            sender ?: return,
+            positionStart,
+            itemCount
+        )
+    }
+
+    override fun onItemRangeMoved(
+        sender: ObservableList<T>?,
+        fromPosition: Int,
+        toPosition: Int,
+        itemCount: Int
+    ) {
+        onItemRangeMoved?.invoke(
+            sender ?: return,
+            fromPosition,
+            toPosition,
+            itemCount
+        )
+    }
+
+    override fun onItemRangeInserted(
+        sender: ObservableList<T>?,
+        positionStart: Int,
+        itemCount: Int
+    ) {
+        onItemRangeInserted?.invoke(
+            sender ?: return,
+            positionStart,
+            itemCount
+        )
+    }
+
+    override fun onItemRangeChanged(
+        sender: ObservableList<T>?,
+        positionStart: Int,
+        itemCount: Int
+    ) {
+        onItemRangeChanged?.invoke(
+            sender ?: return,
+            positionStart,
+            itemCount
+        )
+    }
+})
\ No newline at end of file
diff --git a/app/src/main/java/com/topjohnwu/magisk/ui/module/ModuleViewModel.kt b/app/src/main/java/com/topjohnwu/magisk/ui/module/ModuleViewModel.kt
index 7a20c2db7..a461c520f 100644
--- a/app/src/main/java/com/topjohnwu/magisk/ui/module/ModuleViewModel.kt
+++ b/app/src/main/java/com/topjohnwu/magisk/ui/module/ModuleViewModel.kt
@@ -13,6 +13,7 @@ import com.topjohnwu.magisk.core.tasks.RepoUpdater
 import com.topjohnwu.magisk.data.database.RepoByNameDao
 import com.topjohnwu.magisk.data.database.RepoByUpdatedDao
 import com.topjohnwu.magisk.databinding.ComparableRvItem
+import com.topjohnwu.magisk.extensions.addOnListChangedCallback
 import com.topjohnwu.magisk.extensions.reboot
 import com.topjohnwu.magisk.extensions.subscribeK
 import com.topjohnwu.magisk.model.entity.internal.DownloadSubject
@@ -156,6 +157,21 @@ class ModuleViewModel(
             }
             update(subject.module, progress.times(100).roundToInt())
         }
+
+        itemsInstalled.addOnListChangedCallback(
+            onItemRangeInserted = { sender, _, count ->
+                if (count > 0 || sender.size > 0) {
+                    itemsInstalledHelpers.clear()
+                }
+            }
+        )
+        itemsUpdatable.addOnListChangedCallback(
+            onItemRangeInserted = { sender, _, count ->
+                if (count > 0 || sender.size > 0) {
+                    itemsUpdatableHelpers.clear()
+                }
+            }
+        )
     }
 
     // ---
@@ -175,19 +191,13 @@ class ModuleViewModel(
         .observeOn(AndroidSchedulers.mainThread())
         .map {
             itemsInstalled.update(it.first, it.second)
-            if (itemsInstalled.isNotEmpty())
-                itemsInstalledHelpers.remove(itemNoneInstalled)
             it.first
         }
         .observeOn(Schedulers.io())
         .map { loadUpdates(it) }
         .map { it to itemsUpdatable.calculateDiff(it) }
         .observeOn(AndroidSchedulers.mainThread())
-        .doOnSuccess {
-            itemsUpdatable.update(it.first, it.second)
-            if (itemsUpdatable.isNotEmpty())
-                itemsUpdatableHelpers.remove(itemNoneUpdatable)
-        }
+        .doOnSuccess { itemsUpdatable.update(it.first, it.second) }
         .ignoreElement()!!
 
     @Synchronized
@@ -261,7 +271,7 @@ class ModuleViewModel(
     @WorkerThread
     private fun List<ModuleItem>.loadDetail() = onEach { module ->
         Single.fromCallable { dao.getRepoById(module.item.id)!! }
-            .subscribeK { module.repo = it }
+            .subscribeK(onError = {}) { module.repo = it }
             .add()
     }