Fixed problem with RealmRecyclerViewAdapter wanting to autoupdate data and clashing with already applied view positioning from drag'n'drop

Habitica/src/main/java/com/habitrpg/android/habitica/ui/adapter/tasks/RealmBaseTasksRecyclerViewAdapter.kt

@@ -3,6 +3,7 @@ package com.habitrpg.android.habitica.ui.adapter.tasks
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
+import androidx.recyclerview.widget.RecyclerView
 import com.habitrpg.android.habitica.helpers.TaskFilterHelper
 import com.habitrpg.android.habitica.models.responses.TaskDirection
 import com.habitrpg.android.habitica.models.tasks.ChecklistItem
@@ -12,38 +13,86 @@ import io.reactivex.BackpressureStrategy
 import io.reactivex.Flowable
 import io.reactivex.functions.Action
 import io.reactivex.subjects.PublishSubject
-import io.realm.OrderedRealmCollection
-import io.realm.OrderedRealmCollectionChangeListener
-import io.realm.RealmRecyclerViewAdapter
+import io.realm.*
 
-abstract class RealmBaseTasksRecyclerViewAdapter<VH : BaseTaskViewHolder>(private var unfilteredData: OrderedRealmCollection<Task>?, private val hasAutoUpdates: Boolean, private val layoutResource: Int, private val taskFilterHelper: TaskFilterHelper?) : RealmRecyclerViewAdapter<Task, VH>(null, true), TaskRecyclerViewAdapter {
+abstract class RealmBaseTasksRecyclerViewAdapter<VH : BaseTaskViewHolder>(
+        private var unfilteredData: OrderedRealmCollection<Task>?,
+        private val hasAutoUpdates: Boolean,
+        private val layoutResource: Int,
+        private val taskFilterHelper: TaskFilterHelper?
+) : RealmRecyclerViewAdapter<Task, VH>(null, false), TaskRecyclerViewAdapter {
     private var updateOnModification: Boolean = false
     override var ignoreUpdates: Boolean = false
-    private val listener: OrderedRealmCollectionChangeListener<OrderedRealmCollection<Task>> by lazy {
-        OrderedRealmCollectionChangeListener<OrderedRealmCollection<Task>> { _, changeSet ->
-            if (ignoreUpdates) {
-                return@OrderedRealmCollectionChangeListener
-            }
-            // null Changes means the async query returns the first time.
-            // For deletions, the adapter has to be notified in reverse order.
-            val deletions = changeSet.deletionRanges
-            deletions.indices.reversed()
-                    .map { deletions[it] }
-                    .forEach { notifyItemRangeRemoved(it.startIndex, it.length) }
 
-            val insertions = changeSet.insertionRanges
-            for (range in insertions) {
-                notifyItemRangeInserted(range.startIndex, range.length)
-            }
+    private val resultsListener: OrderedRealmCollectionChangeListener<RealmResults<Task>> by lazy {
+        OrderedRealmCollectionChangeListener<RealmResults<Task>> { _, changeSet ->
+            buildChangeSet(changeSet)
+        }
+    }
 
-            if (!updateOnModification) {
-                return@OrderedRealmCollectionChangeListener
-            }
+    private val listListener: OrderedRealmCollectionChangeListener<RealmList<Task>> by lazy {
+        OrderedRealmCollectionChangeListener<RealmList<Task>> { _, changeSet ->
+            buildChangeSet(changeSet)
+        }
+    }
 
-            val modifications = changeSet.changeRanges
-            for (range in modifications) {
-                notifyItemRangeChanged(range.startIndex, range.length)
-            }
+    private fun buildChangeSet(changeSet: OrderedCollectionChangeSet) {
+        if (ignoreUpdates) return
+        if (changeSet.state == OrderedCollectionChangeSet.State.INITIAL) {
+            notifyDataSetChanged()
+            return
+        }
+        // For deletions, the adapter has to be notified in reverse order.
+        val deletions = changeSet.deletionRanges
+        for (i in deletions.indices.reversed()) {
+            val range = deletions[i]
+            notifyItemRangeRemoved(range.startIndex + dataOffset(), range.length)
+        }
+
+        val insertions = changeSet.insertionRanges
+        for (range in insertions) {
+            notifyItemRangeInserted(range.startIndex + dataOffset(), range.length)
+        }
+
+        if (!updateOnModification) {
+            return
+        }
+
+        val modifications = changeSet.changeRanges
+        for (range in modifications) {
+            notifyItemRangeChanged(range.startIndex + dataOffset(), range.length)
+        }
+    }
+
+    override fun onAttachedToRecyclerView(recyclerView: RecyclerView) {
+        super.onAttachedToRecyclerView(recyclerView)
+        data?.takeIf { it.isValid }?.addListener()
+    }
+
+    override fun onDetachedFromRecyclerView(recyclerView: RecyclerView) {
+        super.onDetachedFromRecyclerView(recyclerView)
+        data?.takeIf { it.isValid }?.removeListener()
+    }
+
+    override fun updateData(tasks: OrderedRealmCollection<Task>?) {
+        data?.takeIf { it.isValid }?.removeListener()
+        tasks?.takeIf { it.isValid }?.addListener()
+        super.updateData(tasks)
+    }
+
+    private fun OrderedRealmCollection<Task>.addListener() {
+        when (this) {
+            is RealmResults<Task> -> addChangeListener(resultsListener)
+            is RealmList<Task> -> addChangeListener(listListener)
+            else -> throw IllegalArgumentException("RealmCollection not supported: $javaClass")
+        }
+    }
+
+    private fun OrderedRealmCollection<Task>.removeListener() {
+        when (this) {
+            is RealmResults<Task> -> removeChangeListener(resultsListener)
+            is RealmList<Task> -> removeChangeListener(listListener)
+            else -> throw IllegalArgumentException("RealmCollection not supported: $javaClass")
         }
     }
 

Habitica/src/main/java/com/habitrpg/android/habitica/ui/fragments/tasks/TaskRecyclerViewFragment.kt

@@ -10,6 +10,8 @@ import android.view.View
 import android.view.ViewGroup
 import androidx.core.content.ContextCompat
 import androidx.recyclerview.widget.ItemTouchHelper
+import androidx.recyclerview.widget.RecyclerView
+import androidx.recyclerview.widget.RecyclerView.NO_POSITION
 import com.habitrpg.android.habitica.R
 import com.habitrpg.android.habitica.components.UserComponent
 import com.habitrpg.android.habitica.data.ApiClient
@@ -63,18 +65,18 @@ open class TaskRecyclerViewFragment : BaseFragment(), androidx.swiperefreshlayou
     @Inject
     lateinit var configManager: AppConfigManager
 
-    internal var layoutManager: androidx.recyclerview.widget.RecyclerView.LayoutManager? = null
+    internal var layoutManager: RecyclerView.LayoutManager? = null
 
     internal var classType: String? = null
     internal var user: User? = null
-    private var mItemTouchCallback: ItemTouchHelper.Callback? = null
+    private var itemTouchCallback: ItemTouchHelper.Callback? = null
 
     internal val className: String
         get() = this.classType ?: ""
 
     // TODO needs a bit of cleanup
     private fun setInnerAdapter() {
-        val adapter: androidx.recyclerview.widget.RecyclerView.Adapter<*>? = when (this.classType) {
+        val adapter: RecyclerView.Adapter<*>? = when (this.classType) {
             Task.TYPE_HABIT -> {
                 HabitsRecyclerViewAdapter(null, true, R.layout.habit_item_card, taskFilterHelper)
             }
@@ -127,7 +129,7 @@ open class TaskRecyclerViewFragment : BaseFragment(), androidx.swiperefreshlayou
     }
 
     private fun allowReordering() {
-        val itemTouchHelper = mItemTouchCallback?.let { ItemTouchHelper(it) }
+        val itemTouchHelper = itemTouchCallback?.let { ItemTouchHelper(it) }
         itemTouchHelper?.attachToRecyclerView(recyclerView)
     }
 
@@ -142,33 +144,27 @@ open class TaskRecyclerViewFragment : BaseFragment(), androidx.swiperefreshlayou
             taskFilterHelper.setActiveFilter(Task.TYPE_TODO, Task.FILTER_ACTIVE)
         }
 
-        mItemTouchCallback = object : ItemTouchHelper.Callback() {
-            private var fromPosition: Int? = null
-            private var movingTaskID: String? = null
+        itemTouchCallback = object : ItemTouchHelper.Callback() {
 
-            override fun onSelectedChanged(viewHolder: androidx.recyclerview.widget.RecyclerView.ViewHolder?, actionState: Int) {
+            override fun onSelectedChanged(viewHolder: RecyclerView.ViewHolder?, actionState: Int) {
                 super.onSelectedChanged(viewHolder, actionState)
-                if (viewHolder != null) {
-                    if (fromPosition == null) {
-                        fromPosition = viewHolder.adapterPosition
-                    }
-                    if (movingTaskID == null && (viewHolder as? BaseTaskViewHolder)?.task?.isValid == true) {
-                        movingTaskID = (viewHolder as? BaseTaskViewHolder)?.task?.id
-                    }
+                if (viewHolder == null || viewHolder.adapterPosition == NO_POSITION) return
+                val taskViewHolder = viewHolder as? BaseTaskViewHolder
+                if (taskViewHolder != null) {
+                    taskViewHolder.movingFromPosition = viewHolder.adapterPosition
                 }
                 refreshLayout.isEnabled = false
             }
 
-            override fun onMove(recyclerView: androidx.recyclerview.widget.RecyclerView, viewHolder: androidx.recyclerview.widget.RecyclerView.ViewHolder, target: androidx.recyclerview.widget.RecyclerView.ViewHolder): Boolean {
+            override fun onMove(recyclerView: RecyclerView, viewHolder: RecyclerView.ViewHolder, target: RecyclerView.ViewHolder): Boolean {
                 recyclerAdapter?.notifyItemMoved(viewHolder.adapterPosition, target.adapterPosition)
-                //taskRepository.swapTaskPosition(viewHolder.getAdapterPosition(), target.getAdapterPosition());
                 return true
             }
 
-            override fun onSwiped(viewHolder: androidx.recyclerview.widget.RecyclerView.ViewHolder, direction: Int) { /* no-on */ }
+            override fun onSwiped(viewHolder: RecyclerView.ViewHolder, direction: Int) { /* no-on */ }
 
             //defines the enabled move directions in each state (idle, swiping, dragging).
-            override fun getMovementFlags(recyclerView: androidx.recyclerview.widget.RecyclerView, viewHolder: androidx.recyclerview.widget.RecyclerView.ViewHolder): Int {
+            override fun getMovementFlags(recyclerView: RecyclerView, viewHolder: RecyclerView.ViewHolder): Int {
                 return makeFlag(ItemTouchHelper.ACTION_STATE_DRAG,
                         ItemTouchHelper.DOWN or ItemTouchHelper.UP)
             }
@@ -177,26 +173,31 @@ open class TaskRecyclerViewFragment : BaseFragment(), androidx.swiperefreshlayou
 
             override fun isLongPressDragEnabled(): Boolean = true
 
-            override fun clearView(recyclerView: androidx.recyclerview.widget.RecyclerView, viewHolder: androidx.recyclerview.widget.RecyclerView.ViewHolder) {
+            override fun clearView(recyclerView: RecyclerView, viewHolder: RecyclerView.ViewHolder) {
                 super.clearView(recyclerView, viewHolder)
                 refreshLayout?.isEnabled = true
 
-                val fromPosition = fromPosition
-                val movingTaskID = movingTaskID
-                if (fromPosition != null && movingTaskID != null) {
+                if (viewHolder.adapterPosition == NO_POSITION) return
+                val taskViewHolder = viewHolder as? BaseTaskViewHolder
+                val validTaskId = taskViewHolder?.task?.takeIf { it.isValid }?.id
+                if (viewHolder.adapterPosition != taskViewHolder?.movingFromPosition) {
+                    taskViewHolder?.movingFromPosition = null
+                    updateTaskInRepository(validTaskId, viewHolder)
+                }
+            }
+
+            private fun updateTaskInRepository(validTaskId: String?, viewHolder: RecyclerView.ViewHolder) {
+                if (validTaskId != null) {
                     recyclerAdapter?.ignoreUpdates = true
-                    itemAnimator.skipAnimations = true
-                    compositeSubscription.add(taskRepository.updateTaskPosition(classType ?: "", movingTaskID, viewHolder.adapterPosition)
+                    compositeSubscription.add(taskRepository.updateTaskPosition(
+                            classType ?: "", validTaskId, viewHolder.adapterPosition
+                    )
                             .delay(1, TimeUnit.SECONDS)
                             .observeOn(AndroidSchedulers.mainThread())
                             .subscribe(Consumer {
                                 recyclerAdapter?.ignoreUpdates = false
-                                recyclerAdapter?.notifyDataSetChanged()
-                                itemAnimator.skipAnimations = false
                             }, RxErrorHandler.handleEmptyError()))
                 }
-                this.fromPosition = null
-                this.movingTaskID = null
             }
         }
         if (savedInstanceState != null) {
@@ -212,7 +213,7 @@ open class TaskRecyclerViewFragment : BaseFragment(), androidx.swiperefreshlayou
 
     override fun onDestroyView() {
         super.onDestroyView()
-        mItemTouchCallback = null
+        itemTouchCallback = null
     }
 
     override fun onDestroy() {
@@ -228,7 +229,7 @@ open class TaskRecyclerViewFragment : BaseFragment(), androidx.swiperefreshlayou
     override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
         super.onViewCreated(view, savedInstanceState)
         recyclerView.setScaledPadding(context, 0, 0, 0, 48)
-        recyclerView.adapter = recyclerAdapter as? androidx.recyclerview.widget.RecyclerView.Adapter<*>
+        recyclerView.adapter = recyclerAdapter as? RecyclerView.Adapter<*>
         recyclerAdapter?.filter()
 
         layoutManager = getLayoutManager(context)
@@ -264,10 +265,10 @@ open class TaskRecyclerViewFragment : BaseFragment(), androidx.swiperefreshlayou
 
         refreshLayout.setOnRefreshListener(this)
 
-        recyclerView.addOnScrollListener(object : androidx.recyclerview.widget.RecyclerView.OnScrollListener() {
-            override fun onScrollStateChanged(recyclerView: androidx.recyclerview.widget.RecyclerView, newState: Int) {
+        recyclerView.addOnScrollListener(object : RecyclerView.OnScrollListener() {
+            override fun onScrollStateChanged(recyclerView: RecyclerView, newState: Int) {
                 super.onScrollStateChanged(recyclerView, newState)
-                if (newState == androidx.recyclerview.widget.RecyclerView.SCROLL_STATE_IDLE) {
+                if (newState == RecyclerView.SCROLL_STATE_IDLE) {
                     refreshLayout?.isEnabled = (activity as? MainActivity)?.isAppBarExpanded ?: false
                 }
             }

Habitica/src/main/java/com/habitrpg/android/habitica/ui/viewHolders/tasks/BaseTaskViewHolder.kt

@@ -23,6 +23,7 @@ abstract class BaseTaskViewHolder constructor(itemView: View, var scoreTaskFunc:
 
 
     var task: Task? = null
+    var movingFromPosition: Int? = null
     var errorButtonClicked: Action? = null
     protected var context: Context
     private val titleTextView: EllipsisTextView by bindView(itemView, R.id.checkedTextView)