Add TaskAdapterDataSource interface

app/src/main/java/com/todoroo/astrid/activity/TaskListFragment.kt

@@ -246,7 +246,7 @@ class TaskListFragment : InjectingFragment(), OnRefreshListener, Toolbar.OnMenuI
     private fun setAdapter(adapter: TaskListRecyclerAdapter) {
         recyclerAdapter = adapter
         recyclerView.adapter = adapter
-        taskAdapter.setHelper(adapter)
+        taskAdapter.setDataSource(adapter)
     }
 
     private fun setupMenu() {

app/src/main/java/com/todoroo/astrid/adapter/AstridTaskAdapter.kt

@@ -8,7 +8,6 @@ import com.todoroo.astrid.subtasks.SubtasksFilterUpdater
 import org.tasks.Strings.isNullOrEmpty
 import org.tasks.data.TaskContainer
 import org.tasks.data.TaskListMetadata
-import org.tasks.tasklist.ViewHolder
 import timber.log.Timber
 import java.util.*
 import kotlin.math.abs
@@ -23,7 +22,7 @@ class AstridTaskAdapter internal constructor(
 
     override fun getIndent(task: TaskContainer) = updater.getIndentForTask(task.uuid)
 
-    override fun canMove(source: ViewHolder, target: ViewHolder) = !updater.isDescendantOf(target.task.uuid, source.task.uuid)
+    override fun canMove(source: TaskContainer, from: Int, target: TaskContainer, to: Int) = !updater.isDescendantOf(target.uuid, source.uuid)
 
     override fun maxIndent(previousPosition: Int, task: TaskContainer): Int {
         val previous = getTask(previousPosition)

app/src/main/java/com/todoroo/astrid/adapter/CaldavTaskAdapter.kt

@@ -3,14 +3,9 @@ package com.todoroo.astrid.adapter
 import com.todoroo.astrid.dao.TaskDao
 import org.tasks.data.CaldavDao
 import org.tasks.data.TaskContainer
-import org.tasks.tasklist.ViewHolder
 
 class CaldavTaskAdapter internal constructor(private val taskDao: TaskDao, private val caldavDao: CaldavDao) : TaskAdapter() {
-    override fun canMove(sourceVh: ViewHolder, targetVh: ViewHolder): Boolean {
+    override fun canMove(source: TaskContainer, from: Int, target: TaskContainer, to: Int) = !taskIsChild(source, to)
-        val source = sourceVh.task
-        val to = targetVh.adapterPosition
-        return !taskIsChild(source, to)
-    }
 
     override fun maxIndent(previousPosition: Int, task: TaskContainer): Int {
         val previous = getTask(previousPosition)

app/src/main/java/com/todoroo/astrid/adapter/GoogleTaskManualSortAdapter.kt

@@ -4,18 +4,14 @@ import com.todoroo.astrid.dao.TaskDao
 import org.tasks.BuildConfig
 import org.tasks.data.GoogleTaskDao
 import org.tasks.data.TaskContainer
-import org.tasks.tasklist.ViewHolder
 
 open class GoogleTaskManualSortAdapter internal constructor(val taskDao: TaskDao, val googleTaskDao: GoogleTaskDao) : TaskAdapter() {
 
-    override fun canMove(sourceVh: ViewHolder, targetVh: ViewHolder): Boolean {
+    override fun canMove(source: TaskContainer, from: Int, target: TaskContainer, to: Int): Boolean {
-        val source = sourceVh.task
-        val to = targetVh.adapterPosition
         if (!source.hasChildren() || to <= 0 || to >= count - 1) {
             return true
         }
-        val target = targetVh.task
+        return if (from < to) {
-        return if (sourceVh.adapterPosition < to) {
             if (target.hasChildren()) {
                 return false
             }

app/src/main/java/com/todoroo/astrid/adapter/TaskAdapter.kt

@@ -7,19 +7,17 @@ package com.todoroo.astrid.adapter
 
 import com.todoroo.astrid.data.Task
 import org.tasks.data.TaskContainer
-import org.tasks.tasklist.TaskListRecyclerAdapter
-import org.tasks.tasklist.ViewHolder
 import java.util.*
 
 open class TaskAdapter {
     private val selected = HashSet<Long>()
-    private lateinit var helper: TaskListRecyclerAdapter
+    private lateinit var dataSource: TaskAdapterDataSource
 
     val count: Int
-        get() = helper.itemCount
+        get() = dataSource.itemCount
 
-    fun setHelper(helper: TaskListRecyclerAdapter) {
+    fun setDataSource(dataSource: TaskAdapterDataSource) {
-        this.helper = helper
+        this.dataSource = dataSource
     }
 
     val numSelected: Int
@@ -38,7 +36,7 @@ open class TaskAdapter {
 
     open fun getIndent(task: TaskContainer): Int = task.getIndent()
 
-    open fun canMove(source: ViewHolder, target: ViewHolder): Boolean = false
+    open fun canMove(source: TaskContainer, from: Int, target: TaskContainer, to: Int): Boolean = false
 
     open fun maxIndent(previousPosition: Int, task: TaskContainer): Int = 0
 
@@ -61,7 +59,7 @@ open class TaskAdapter {
 
     open fun moved(from: Int, to: Int, indent: Int) {}
 
-    fun getTask(position: Int): TaskContainer = helper.getItem(position)
+    fun getTask(position: Int): TaskContainer = dataSource.getItem(position)
 
     fun getItemUuid(position: Int): String = getTask(position).uuid
 

app/src/main/java/com/todoroo/astrid/adapter/TaskAdapterDataSource.kt

@@ -0,0 +1,9 @@
+package com.todoroo.astrid.adapter
+
+import org.tasks.data.TaskContainer
+
+interface TaskAdapterDataSource {
+    fun getItem(position: Int): TaskContainer
+
+    val itemCount: Int
+}

app/src/main/java/org/tasks/tasklist/DragAndDropRecyclerAdapter.java

@@ -159,7 +159,7 @@ public class DragAndDropRecyclerAdapter extends TaskListRecyclerAdapter {
       int fromPosition = src.getAdapterPosition();
       int toPosition = target.getAdapterPosition();
       ViewHolder source = (ViewHolder) src;
-      if (!adapter.canMove(source, (ViewHolder) target)) {
+      if (!adapter.canMove(source.task, fromPosition, ((ViewHolder) target).task, toPosition)) {
         return false;
       }
       if (from == -1) {

app/src/main/java/org/tasks/tasklist/TaskListRecyclerAdapter.java

@@ -10,6 +10,7 @@ import androidx.recyclerview.widget.RecyclerView;
 
 import com.todoroo.astrid.activity.TaskListFragment;
 import com.todoroo.astrid.adapter.TaskAdapter;
+import com.todoroo.astrid.adapter.TaskAdapterDataSource;
 import com.todoroo.astrid.api.Filter;
 import com.todoroo.astrid.dao.TaskDao;
 
@@ -20,7 +21,7 @@ import org.tasks.tasklist.ViewHolder.ViewHolderCallbacks;
 import java.util.List;
 
 public abstract class TaskListRecyclerAdapter extends RecyclerView.Adapter<ViewHolder>
-    implements ViewHolderCallbacks, ListUpdateCallback {
+    implements ViewHolderCallbacks, ListUpdateCallback, TaskAdapterDataSource {
 
   private final TaskAdapter adapter;
   private final TaskListFragment taskList;