Cleanup filterable list implementation

app/src/main/java/com/topjohnwu/magisk/databinding/FilterableDiffObservableList.kt

@@ -1,55 +1,38 @@
 package com.topjohnwu.magisk.databinding
 
-import android.os.Handler
-import android.os.HandlerThread
-import android.os.Looper
-import java.util.*
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
+import java.util.Collections
 
 class FilterableDiffObservableList<T>(
-    callback: Callback<T>
+    callback: Callback<T>,
+    private val scope: CoroutineScope
 ) : DiffObservableList<T>(callback) {
 
-    var filter: ((T) -> Boolean)? = null
-        set(value) {
-            field = value
-            queueUpdate()
-        }
-    @Volatile
-    private var sublist: MutableList<T> = super.list
+    private var sublist: MutableList<T> = list
+    private var job: Job? = null
 
     // ---
 
-    private val ui by lazy { Handler(Looper.getMainLooper()) }
-    private val handler = Handler(HandlerThread("List${hashCode()}").apply { start() }.looper)
-    private val updater = Runnable {
-        val filter = filter ?: { true }
-        val newList = super.list.filter(filter)
-        val diff = synchronized(this) { doCalculateDiff(sublist, newList) }
-        ui.post {
-            sublist = Collections.synchronizedList(newList)
-            diff.dispatchUpdatesTo(listCallback)
+    fun filter(filter: (T) -> Boolean) {
+        job?.cancel()
+        job = scope.launch(Dispatchers.Default) {
+            val newList = list.filter(filter)
+            val diff = synchronized(this) { doCalculateDiff(sublist, newList) }
+            withContext(Dispatchers.Main) {
+                sublist = Collections.synchronizedList(newList)
+                diff.dispatchUpdatesTo(listCallback)
+            }
         }
     }
 
-    private fun queueUpdate() {
-        handler.removeCallbacks(updater)
-        handler.post(updater)
-    }
-
-    fun hasFilter() = filter != null
-
-    fun filter(switch: (T) -> Boolean) {
-        filter = switch
-    }
-
-    fun reset() {
-        filter = null
-    }
-
     // ---
 
     override fun get(index: Int): T {
-        return sublist.get(index)
+        return sublist[index]
     }
 
     override fun add(element: T): Boolean {

app/src/main/java/com/topjohnwu/magisk/databinding/Helpers.kt

@@ -1,7 +1,9 @@
 package com.topjohnwu.magisk.databinding
 
+import kotlinx.coroutines.CoroutineScope
+
 fun <T : AnyDiffRvItem> diffListOf() =
     DiffObservableList(DiffRvItem.callback<T>())
 
-fun <T : AnyDiffRvItem> filterableListOf() =
-    FilterableDiffObservableList(DiffRvItem.callback<T>())
+fun <T : AnyDiffRvItem> filterableListOf(scope: CoroutineScope) =
+    FilterableDiffObservableList(DiffRvItem.callback<T>(), scope)

app/src/main/java/com/topjohnwu/magisk/databinding/RvItemAdapter.kt

@@ -15,8 +15,8 @@ import androidx.recyclerview.widget.RecyclerView
 import com.topjohnwu.magisk.BR
 
 class RvItemAdapter<T: RvItem>(
-    internal val items: List<T>,
-    private val extraBindings: SparseArray<*>?
+    val items: List<T>,
+    val extraBindings: SparseArray<*>?
 ) : RecyclerView.Adapter<RvItemAdapter.ViewHolder>() {
 
     private var lifecycleOwner: LifecycleOwner? = null
@@ -113,7 +113,8 @@ inline fun bindExtra(body: (SparseArray<Any?>) -> Unit) = SparseArray<Any?>().al
 @BindingAdapter("items", "extraBindings", requireAll = false)
 fun <T: RvItem> RecyclerView.setAdapter(items: List<T>?, extraBindings: SparseArray<*>?) {
     if (items != null) {
-        if ((adapter as? RvItemAdapter<T>)?.items !== items) {
+        val rva = (adapter as? RvItemAdapter<*>)
+        if (rva == null || rva.items !== items || rva.extraBindings !== extraBindings) {
             adapter = RvItemAdapter(items, extraBindings)
         }
     }

app/src/main/java/com/topjohnwu/magisk/ui/deny/DenyListViewModel.kt

@@ -3,6 +3,7 @@ package com.topjohnwu.magisk.ui.deny
 import android.annotation.SuppressLint
 import android.content.pm.PackageManager.MATCH_UNINSTALLED_PACKAGES
 import androidx.databinding.Bindable
+import androidx.lifecycle.viewModelScope
 import com.topjohnwu.magisk.BR
 import com.topjohnwu.magisk.arch.AsyncLoadViewModel
 import com.topjohnwu.magisk.core.di.AppContext
@@ -37,7 +38,7 @@ class DenyListViewModel : AsyncLoadViewModel() {
             query()
         }
 
-    val items = filterableListOf<DenyListRvItem>()
+    val items = filterableListOf<DenyListRvItem>(viewModelScope)
     val extraBindings = bindExtra {
         it.put(BR.viewModel, this)
     }
@@ -68,7 +69,7 @@ class DenyListViewModel : AsyncLoadViewModel() {
         query()
     }
 
-    fun query() {
+    private fun query() {
         items.filter {
             fun filterSystem() = isShowSystem || !it.info.isSystemApp()