Move canMove/min/max logic into TaskAdapter

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

@@ -6,22 +6,6 @@ import org.tasks.data.TaskContainer
 import org.tasks.date.DateTimeUtils.toAppleEpoch
 
 open class CaldavTaskAdapter internal constructor(private val taskDao: TaskDao, private val caldavDao: CaldavDao, private val newTasksOnTop: Boolean = false) : TaskAdapter() {
-    override fun canMove(source: TaskContainer, from: Int, target: TaskContainer, to: Int) = !taskIsChild(source, to)
-
-    override fun maxIndent(previousPosition: Int, task: TaskContainer) = getTask(previousPosition).getIndent() + 1
-
-    override fun minIndent(nextPosition: Int, task: TaskContainer): Int {
-        (nextPosition until count).forEach {
-            if (isHeader(it)) {
-                return 0
-            }
-            if (!taskIsChild(task, it)) {
-                return getTask(it).indent
-            }
-        }
-        return 0
-    }
-
     override fun supportsParentingOrManualSort() = true
 
     override fun moved(from: Int, to: Int, indent: Int) {
@@ -42,25 +26,8 @@ open class CaldavTaskAdapter internal constructor(private val taskDao: TaskDao,
     }
 
     internal fun changeParent(task: TaskContainer, indent: Int, to: Int): Long {
-        val previous = if (to > 0) getTask(to - 1) else null
-        val newParent = when {
-            indent == 0 || previous == null -> 0
-            indent == previous.getIndent() -> previous.parent
-            indent > previous.getIndent() -> previous.id
-            else -> {
-                var newParent = previous.parent
-                var currentIndex = to
-                for (i in 0 until previous.getIndent() - indent) {
-                    var thisParent = newParent
-                    while (newParent == thisParent) {
-                        thisParent = getTask(--currentIndex).parent
-                    }
-                    newParent = thisParent
-                }
-                newParent
-            }
-        }
-        if (newParent != task.parent) {
+        val newParent = findParent(indent, to)?.id ?: 0
+        if (task.parent != newParent) {
             changeParent(task, newParent)
         }
         return newParent
@@ -79,18 +46,4 @@ open class CaldavTaskAdapter internal constructor(private val taskDao: TaskDao,
         caldavDao.update(caldavTask.cd_id, caldavTask.cd_remote_parent)
         taskDao.save(task.getTask(), null)
     }
-
-    private fun taskIsChild(source: TaskContainer, destinationIndex: Int): Boolean {
-        (destinationIndex downTo 0).forEach {
-            if (isHeader(it)) {
-                return false
-            }
-            when (getTask(it).parent) {
-                0L -> return false
-                source.parent -> return false
-                source.id -> return true
-            }
-        }
-        return false
-    }
 }

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

@@ -3,46 +3,15 @@ package com.todoroo.astrid.adapter
 import com.todoroo.astrid.dao.TaskDao
 import org.tasks.BuildConfig
 import org.tasks.data.GoogleTaskDao
-import org.tasks.data.TaskContainer
 
 open class GoogleTaskAdapter internal constructor(private val taskDao: TaskDao, private val googleTaskDao: GoogleTaskDao, private val newTasksOnTop: Boolean) : TaskAdapter() {
 
-    override fun canMove(source: TaskContainer, from: Int, target: TaskContainer, to: Int): Boolean {
-        return if (!source.hasChildren() || to <= 0 || to >= count - 1) {
-            true
-        } else if (from < to) {
-            when {
-                target.hasChildren() -> false
-                target.hasParent() -> !getTask(to + 1).hasParent()
-                else -> true
-            }
-        } else {
-            when {
-                target.hasChildren() -> true
-                target.hasParent() -> target.parent == source.id && target.secondarySort == 0L
-                else -> true
-            }
-        }
-    }
-
-    override fun maxIndent(previousPosition: Int, task: TaskContainer) = if (task.hasChildren()) 0 else 1
-
-    override fun minIndent(nextPosition: Int, task: TaskContainer) = if (task.hasChildren() || !getTask(nextPosition).hasParent()) 0 else 1
-
     override fun supportsParentingOrManualSort() = true
 
     override fun moved(from: Int, to: Int, indent: Int) {
         val task = getTask(from)
         val googleTask = task.googleTask
-        if (indent == 0) {
-            if (googleTask.indent == 0) {
-                return
-            }
-            googleTaskDao.move(
-                    googleTask, 0, if (newTasksOnTop) 0 else googleTaskDao.getBottom(googleTask.listId, 0))
-        } else {
-            val previous = if (to > 0) getTask(to - 1) else null
-            val newParent = if (previous!!.hasParent()) previous.parent else previous.id
+        val newParent = findParent(indent, to)?.id ?: 0
         if (googleTask.parent == newParent) {
             return
         }
@@ -50,7 +19,6 @@ open class GoogleTaskAdapter internal constructor(private val taskDao: TaskDao,
                 googleTask,
                 newParent,
                 if (newTasksOnTop) 0 else googleTaskDao.getBottom(googleTask.listId, newParent))
-        }
         taskDao.touch(task.id)
         if (BuildConfig.DEBUG) {
             googleTaskDao.validateSorting(task.googleTaskList!!)

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

@@ -4,7 +4,9 @@ import com.todoroo.astrid.dao.TaskDao
 import org.tasks.BuildConfig
 import org.tasks.data.GoogleTaskDao
 
-class GoogleTaskManualSortAdapter internal constructor(val taskDao: TaskDao, val googleTaskDao: GoogleTaskDao) : GoogleTaskAdapter(taskDao, googleTaskDao, false) {
+class GoogleTaskManualSortAdapter internal constructor(val taskDao: TaskDao, val googleTaskDao: GoogleTaskDao) : TaskAdapter() {
+
+    override fun supportsParentingOrManualSort() = true
 
     override fun supportsManualSorting() = true
 

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

@@ -45,11 +45,52 @@ open class TaskAdapter {
 
     open fun getIndent(task: TaskContainer): Int = task.getIndent()
 
-    open fun canMove(source: TaskContainer, from: Int, target: TaskContainer, to: Int): Boolean = false
+    open fun canMove(source: TaskContainer, from: Int, target: TaskContainer, to: Int): Boolean {
+        if (target.isGoogleTask) {
+            return if (!source.hasChildren() || to <= 0 || to >= count - 1) {
+                true
+            } else if (from < to) {
+                when {
+                    target.hasChildren() -> false
+                    target.hasParent() -> !getTask(to + 1).hasParent()
+                    else -> true
+                }
+            } else {
+                when {
+                    target.hasChildren() -> true
+                    target.hasParent() -> target.parent == source.id && target.secondarySort == 0L
+                    else -> true
+                }
+            }
+        } else {
+            return !taskIsChild(source, to)
+        }
+    }
 
-    open fun maxIndent(previousPosition: Int, task: TaskContainer): Int = 0
+    open fun maxIndent(previousPosition: Int, task: TaskContainer): Int {
+        val previous = getTask(previousPosition)
+        return if (previous.isGoogleTask) {
+            if (task.hasChildren()) 0 else 1
+        } else {
+            previous.indent + 1
+        }
+    }
 
-    open fun minIndent(nextPosition: Int, task: TaskContainer): Int = 0
+    fun minIndent(nextPosition: Int, task: TaskContainer): Int {
+        (nextPosition until count).forEach {
+            if (isHeader(it)) {
+                return 0
+            }
+            val next = getTask(it)
+            if (next.isGoogleTask) {
+                return if (task.hasChildren() || !next.hasParent()) 0 else 1
+            }
+            if (!taskIsChild(task, it)) {
+                return next.indent
+            }
+        }
+        return 0
+    }
 
     fun isSelected(task: TaskContainer): Boolean = selected.contains(task.id)
 
@@ -89,4 +130,31 @@ open class TaskAdapter {
     open fun onTaskDeleted(task: Task) {}
 
     open fun supportsHiddenTasks(): Boolean = true
+
+    private fun taskIsChild(source: TaskContainer, destinationIndex: Int): Boolean {
+        (destinationIndex downTo 0).forEach {
+            if (isHeader(it)) {
+                return false
+            }
+            when (getTask(it).parent) {
+                0L -> return false
+                source.parent -> return false
+                source.id -> return true
+            }
+        }
+        return false
+    }
+
+    internal fun findParent(indent: Int, to: Int): TaskContainer? {
+        if (indent == 0 || to == 0) {
+            return null
+        }
+        for (i in to - 1 downTo 0) {
+            val previous = getTask(i)
+            if (indent > previous.getIndent()) {
+                return previous
+            }
+        }
+        return null
+    }
 }

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

@@ -5,6 +5,8 @@ import android.view.ViewGroup
 import androidx.core.util.Pair
 import androidx.recyclerview.widget.DiffUtil
 import androidx.recyclerview.widget.ItemTouchHelper
+import androidx.recyclerview.widget.ItemTouchHelper.*
+import androidx.recyclerview.widget.ItemTouchHelper.Callback.makeMovementFlags
 import androidx.recyclerview.widget.ListUpdateCallback
 import androidx.recyclerview.widget.RecyclerView
 import com.todoroo.andlib.utility.AndroidUtilities
@@ -113,7 +115,7 @@ class DragAndDropRecyclerAdapter(
         private var to = -1
         override fun onSelectedChanged(viewHolder: RecyclerView.ViewHolder?, actionState: Int) {
             super.onSelectedChanged(viewHolder, actionState)
-            if (actionState == ItemTouchHelper.ACTION_STATE_DRAG) {
+            if (actionState == ACTION_STATE_DRAG) {
                 taskList.startActionMode()
                 (viewHolder as TaskViewHolder?)!!.isMoving = true
                 dragging = true
@@ -123,12 +125,11 @@ class DragAndDropRecyclerAdapter(
         }
 
         override fun getMovementFlags(recyclerView: RecyclerView, viewHolder: RecyclerView.ViewHolder): Int {
-            return if (adapter.isHeader(viewHolder.adapterPosition)) {
-                makeMovementFlags(0, 0)
-            } else if (adapter.supportsParentingOrManualSort() && adapter.numSelected == 0) {
-                makeMovementFlags(ItemTouchHelper.UP or ItemTouchHelper.DOWN or ItemTouchHelper.LEFT or ItemTouchHelper.RIGHT, 0)
-            } else {
-                makeMovementFlags(0, 0)
+            return when {
+                !dragAndDropEnabled() -> NO_MOVEMENT
+                adapter.isHeader(viewHolder.adapterPosition) -> NO_MOVEMENT
+                adapter.numSelected > 0 -> NO_MOVEMENT
+                else -> ALLOW_DRAGGING
             }
         }
 
@@ -177,7 +178,7 @@ class DragAndDropRecyclerAdapter(
             val vh = viewHolder as TaskViewHolder
             val task = vh.task
             val shiftSize = vh.shiftSize
-            if (actionState == ItemTouchHelper.ACTION_STATE_DRAG) {
+            if (actionState == ACTION_STATE_DRAG) {
                 val currentIndent = viewHolder.indent
                 val maxIndent = vh.maxIndent
                 val minIndent = vh.minIndent
@@ -255,6 +256,8 @@ class DragAndDropRecyclerAdapter(
 
     companion object {
         private const val LONG_LIST_SIZE = 500
+        private val NO_MOVEMENT = makeMovementFlags(0, 0)
+        private val ALLOW_DRAGGING =  makeMovementFlags(UP or DOWN or LEFT or RIGHT, 0)
     }
 
     init {