Emit SectionedDataSource from TaskListViewModel

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

@@ -118,6 +118,7 @@ import org.tasks.preferences.Preferences
 import org.tasks.sync.SyncAdapters
 import org.tasks.tags.TagPickerActivity
 import org.tasks.tasklist.DragAndDropRecyclerAdapter
+import org.tasks.tasklist.SectionedDataSource
 import org.tasks.tasklist.TaskViewHolder
 import org.tasks.tasklist.ViewHolderFactory
 import org.tasks.themes.ColorProvider
@@ -188,7 +189,7 @@ class TaskListFragment : Fragment(), OnRefreshListener, Toolbar.OnMenuItemClickL
                         activity?.recreate()
                     }
                     if (data.getBooleanExtra(SortSettingsActivity.EXTRA_CHANGED_GROUP, false)) {
-                        taskAdapter.clearCollapsed()
+                        listViewModel.clearCollapsed()
                     }
                     listViewModel.invalidate()
                 }
@@ -237,7 +238,6 @@ class TaskListFragment : Fragment(), OnRefreshListener, Toolbar.OnMenuItemClickL
         super.onSaveInstanceState(outState)
         val selectedTaskIds: List<Long> = taskAdapter.getSelected()
         outState.putLongArray(EXTRA_SELECTED_TASK_IDS, selectedTaskIds.toLongArray())
-        outState.putLongArray(EXTRA_COLLAPSED, taskAdapter.getCollapsed().toLongArray())
     }
 
     override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
@@ -274,7 +274,6 @@ class TaskListFragment : Fragment(), OnRefreshListener, Toolbar.OnMenuItemClickL
 
         // set up list adapters
         taskAdapter = taskAdapterProvider.createTaskAdapter(filter)
-        taskAdapter.setCollapsed(savedInstanceState?.getLongArray(EXTRA_COLLAPSED))
         listViewModel.setFilter(filter)
         (recyclerView.itemAnimator as DefaultItemAnimator).supportsChangeAnimations = false
         recyclerView.layoutManager = LinearLayoutManager(context)
@@ -362,11 +361,19 @@ class TaskListFragment : Fragment(), OnRefreshListener, Toolbar.OnMenuItemClickL
         return binding.root
     }
 
-    private fun submitList(tasks: List<TaskContainer>) {
+    private fun submitList(tasks: SectionedDataSource) {
         if (recyclerAdapter !is DragAndDropRecyclerAdapter) {
             setAdapter(
                     DragAndDropRecyclerAdapter(
-                            taskAdapter, binding.bodyStandard.recyclerView, viewHolderFactory, this, tasks, preferences))
+                        adapter = taskAdapter,
+                        recyclerView = binding.bodyStandard.recyclerView,
+                        viewHolderFactory = viewHolderFactory,
+                        taskList = this,
+                        tasks = tasks,
+                        preferences = preferences,
+                        toggleCollapsed = { listViewModel.toggleCollapsed(it) },
+                    )
+            )
         } else {
             recyclerAdapter?.submitList(tasks)
         }
@@ -894,8 +901,6 @@ class TaskListFragment : Fragment(), OnRefreshListener, Toolbar.OnMenuItemClickL
         makeSnackbar(R.string.copy_multiple_tasks_confirmation, duplicates.size.toString())?.show()
     }
 
-    fun clearCollapsed() = taskAdapter.clearCollapsed()
-
     override fun onCompletedTask(task: TaskContainer, newState: Boolean) {
         if (task.isReadOnly) {
             return
@@ -1010,7 +1015,6 @@ class TaskListFragment : Fragment(), OnRefreshListener, Toolbar.OnMenuItemClickL
         const val ACTION_RELOAD = "action_reload"
         const val ACTION_DELETED = "action_deleted"
         private const val EXTRA_SELECTED_TASK_IDS = "extra_selected_task_ids"
-        private const val EXTRA_COLLAPSED = "extra_collapsed"
         private const val VOICE_RECOGNITION_REQUEST_CODE = 1234
         private const val EXTRA_FILTER = "extra_filter"
         private const val FRAG_TAG_REMOTE_LIST_PICKER = "frag_tag_remote_list_picker"

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

@@ -34,11 +34,11 @@ class NavigationDrawerAdapter @Inject constructor(
     private val colorProvider: ColorProvider,
     private val subheaderClickHandler: SubheaderClickHandler,
 ) : RecyclerView.Adapter<RecyclerView.ViewHolder>(),
-    DragAndDropDiffer<FilterListItem, MutableList<FilterListItem>> {
+    DragAndDropDiffer<FilterListItem, ArrayList<FilterListItem>> {
 
     private lateinit var onClick: (FilterListItem?) -> Unit
-    override val channel = Channel<List<FilterListItem>>(Channel.UNLIMITED)
+    override val channel = Channel<ArrayList<FilterListItem>>(Channel.UNLIMITED)
-    override val updates: Queue<Pair<MutableList<FilterListItem>, DiffUtil.DiffResult?>> = LinkedList()
+    override val updates: Queue<Pair<ArrayList<FilterListItem>, DiffUtil.DiffResult?>> = LinkedList()
     override val scope: CoroutineScope =
         CoroutineScope(Executors.newSingleThreadExecutor().asCoroutineDispatcher() + Job())
     override var items = initializeDiffer(ArrayList())
@@ -84,9 +84,7 @@ class NavigationDrawerAdapter @Inject constructor(
 
     private fun getItem(position: Int) = items[position]
 
-    override fun transform(list: List<FilterListItem>) = list.toMutableList()
+    override fun diff(last: ArrayList<FilterListItem>, next: ArrayList<FilterListItem>) =
-
-    override fun diff(last: MutableList<FilterListItem>, next: MutableList<FilterListItem>) =
             DiffUtil.calculateDiff(DiffCallback(last, next))
 
     private class DiffCallback(val old: List<FilterListItem>, val new: List<FilterListItem>) : DiffUtil.Callback() {

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

@@ -22,7 +22,6 @@ import org.tasks.data.GoogleTaskDao
 import org.tasks.data.TaskContainer
 import org.tasks.date.DateTimeUtils.toAppleEpoch
 import org.tasks.date.DateTimeUtils.toDateTime
-import org.tasks.tasklist.SectionedDataSource.Companion.HEADER_COMPLETED
 import org.tasks.time.DateTimeUtils.millisOfDay
 
 open class TaskAdapter(
@@ -34,7 +33,6 @@ open class TaskAdapter(
         private val taskMover: TaskMover,
 ) {
     private val selected = HashSet<Long>()
-    private val collapsed = mutableSetOf(HEADER_COMPLETED)
     private lateinit var dataSource: TaskAdapterDataSource
 
     val count: Int
@@ -56,15 +54,6 @@ open class TaskAdapter(
 
     fun clearSelections() = selected.clear()
 
-    fun getCollapsed() = HashSet(collapsed)
-
-    fun setCollapsed(groups: LongArray?) {
-        clearCollapsed()
-        groups?.toList()?.let(collapsed::addAll)
-    }
-
-    fun clearCollapsed() = collapsed.retainAll(listOf(HEADER_COMPLETED))
-
     open fun getIndent(task: TaskContainer): Int = task.indent
 
     open fun canMove(source: TaskContainer, from: Int, target: TaskContainer, to: Int): Boolean {
@@ -125,14 +114,6 @@ open class TaskAdapter(
         }
     }
 
-    fun toggleCollapsed(group: Long) {
-        if (collapsed.contains(group)) {
-            collapsed.remove(group)
-        } else {
-            collapsed.add(group)
-        }
-    }
-
     open fun supportsAstridSorting(): Boolean = false
 
     open suspend fun moved(from: Int, to: Int, indent: Int) {

app/src/main/java/org/tasks/activities/DragAndDropDiffer.kt

@@ -13,25 +13,24 @@ import kotlinx.coroutines.flow.consumeAsFlow
 import kotlinx.coroutines.flow.drop
 import kotlinx.coroutines.flow.flowOn
 import kotlinx.coroutines.flow.launchIn
-import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.flow.onEach
 import kotlinx.coroutines.flow.scan
 import java.util.Queue
 
-interface DragAndDropDiffer<T, R> : ListUpdateCallback {
+interface DragAndDropDiffer<T, R : List<T>> : ListUpdateCallback {
-    val channel: Channel<List<T>>
+    val channel: Channel<R>
     val updates: Queue<Pair<R, DiffUtil.DiffResult?>>
     var items: R
     var dragging: Boolean
     val scope: CoroutineScope
 
-    fun submitList(list: List<T>) {
+    fun submitList(list: R) {
         channel.trySend(list)
     }
 
     fun calculateDiff(last: Pair<R, DiffUtil.DiffResult?>, next: R): Pair<R, DiffUtil.DiffResult?> {
         AndroidUtilities.assertNotMainThread()
-        return Pair(next, diff(last.first!!, next))
+        return Pair(next, diff(last.first, next))
     }
 
     fun applyDiff(update: Pair<R, DiffUtil.DiffResult?>) {
@@ -53,11 +52,9 @@ interface DragAndDropDiffer<T, R> : ListUpdateCallback {
     }
 
     @ExperimentalCoroutinesApi
-    fun initializeDiffer(list: List<T>): R {
+    fun initializeDiffer(initial: R): R {
-        val initial = transform(list)
         channel
             .consumeAsFlow()
-            .map { transform(it) }
             .scan(Pair(initial, null)) { last: Pair<R, DiffUtil.DiffResult?>, next: R ->
                 calculateDiff(last, next)
             }
@@ -68,8 +65,6 @@ interface DragAndDropDiffer<T, R> : ListUpdateCallback {
         return initial
     }
 
-    fun transform(list: List<T>): R
-
     fun diff(last: R, next: R): DiffUtil.DiffResult
 
     fun dispose() {

app/src/main/java/org/tasks/activities/NavigationDrawerCustomization.kt

@@ -100,7 +100,7 @@ class NavigationDrawerCustomization : ThemedInjectingAppCompatActivity(), Toolba
     private fun updateFilters() = lifecycleScope.launch {
         filterProvider
                 .drawerCustomizationItems()
-                .let { adapter.submitList(it) }
+                .let { adapter.submitList(ArrayList(it)) }
     }
 
     private fun onClick(item: FilterListItem?) {

app/src/main/java/org/tasks/compose/edit/SubtaskRow.kt

@@ -44,6 +44,7 @@ import org.tasks.compose.SubtaskChip
 import org.tasks.compose.TaskEditIcon
 import org.tasks.compose.TaskEditRow
 import org.tasks.data.TaskContainer
+import org.tasks.tasklist.SectionedDataSource
 import org.tasks.ui.TaskListViewModel
 
 @Composable
@@ -90,7 +91,11 @@ fun SubtaskRow(
                 } else {
                     Spacer(modifier = Modifier.height(height = 8.dp))
                     if (existingSubtasks is TaskListViewModel.TasksResults.Results) {
-                        existingSubtasks.tasks.forEach { task ->
+                        existingSubtasks
+                            .tasks
+                            .filterIsInstance<TaskListViewModel.UiItem.Task>()
+                            .map { it.task }
+                            .forEach { task ->
                             ExistingSubtaskRow(
                                 task = task,
                                 desaturate = desaturate,
@@ -237,7 +242,7 @@ fun NoSubtasks() {
             filter = null,
             hasParent = false,
             desaturate = true,
-            existingSubtasks = TaskListViewModel.TasksResults.Results(emptyList()),
+            existingSubtasks = TaskListViewModel.TasksResults.Results(SectionedDataSource()),
             newSubtasks = emptyList(),
             openSubtask = {},
             completeExistingSubtask = { _, _ -> },
@@ -260,20 +265,22 @@ fun SubtasksPreview() {
             hasParent = false,
             desaturate = true,
             existingSubtasks = TaskListViewModel.TasksResults.Results(
-                listOf(
+                SectionedDataSource(
-                    TaskContainer(
+                    tasks = listOf(
-                        task = Task(
+                        TaskContainer(
-                            title = "Existing subtask 1",
+                            task = Task(
-                            priority = Task.Priority.HIGH,
+                                title = "Existing subtask 1",
+                                priority = Task.Priority.HIGH,
+                            ),
+                            indent = 0
                         ),
-                        indent = 0
+                        TaskContainer(
-                    ),
+                            task = Task(
-                    TaskContainer(
+                                title = "Existing subtask 2 with a really long title",
-                        task = Task(
+                                priority = Task.Priority.LOW,
-                            title = "Existing subtask 2 with a really long title",
+                            ),
-                            priority = Task.Priority.LOW,
+                            indent = 1
-                        ),
+                        )
-                        indent = 1
                     )
                 )
             ),

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

@@ -30,7 +30,7 @@ internal class DiffCallback(
         return if (isHeader) {
             old.groupMode == new.groupMode && old.getHeaderValue(oldPosition) == new.getHeaderValue(newPosition)
         } else {
-            old.getItem(oldPosition)!!.id == new.getItem(newPosition)!!.id
+            old.getItem(oldPosition).id == new.getItem(newPosition).id
         }
     }
 
@@ -38,8 +38,8 @@ internal class DiffCallback(
         if (new.isHeader(newPosition)) {
             return old.getSection(oldPosition).collapsed == new.getSection(newPosition).collapsed
         }
-        val oldItem = old.getItem(oldPosition)!!
+        val oldItem = old.getItem(oldPosition)
-        val newItem = new.getItem(newPosition)!!
+        val newItem = new.getItem(newPosition)
         return !refreshDates && oldItem == newItem && oldItem.indent == adapter.getIndent(newItem)
     }
 }

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

@@ -14,7 +14,6 @@ import androidx.recyclerview.widget.ItemTouchHelper.UP
 import androidx.recyclerview.widget.RecyclerView
 import com.todoroo.astrid.activity.TaskListFragment
 import com.todoroo.astrid.adapter.TaskAdapter
-import com.todoroo.astrid.api.AstridOrderingFilter
 import com.todoroo.astrid.utility.Flags
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Job
@@ -24,6 +23,7 @@ import kotlinx.coroutines.runBlocking
 import org.tasks.activities.DragAndDropDiffer
 import org.tasks.data.TaskContainer
 import org.tasks.preferences.Preferences
+import org.tasks.ui.TaskListViewModel.UiItem
 import java.util.LinkedList
 import java.util.Queue
 import java.util.concurrent.Executors
@@ -31,21 +31,18 @@ import kotlin.math.max
 import kotlin.math.min
 
 class DragAndDropRecyclerAdapter(
-        private val adapter: TaskAdapter,
+    private val adapter: TaskAdapter,
-        private val recyclerView: RecyclerView,
+    private val recyclerView: RecyclerView,
-        viewHolderFactory: ViewHolderFactory,
+    viewHolderFactory: ViewHolderFactory,
-        private val taskList: TaskListFragment,
+    private val taskList: TaskListFragment,
-        tasks: List<TaskContainer>,
+    tasks: SectionedDataSource,
-        preferences: Preferences) : TaskListRecyclerAdapter(adapter, viewHolderFactory, taskList, preferences), DragAndDropDiffer<TaskContainer, SectionedDataSource> {
+    preferences: Preferences,
-    private val disableHeaders = taskList.getFilter().let {
+    private val toggleCollapsed: (Long) -> Unit,
-        !it.supportsSorting()
+) : TaskListRecyclerAdapter(adapter, viewHolderFactory, taskList, preferences), DragAndDropDiffer<UiItem, SectionedDataSource> {
-                || (it.supportsManualSort() && preferences.isManualSort)
-                || (it is AstridOrderingFilter && preferences.isAstridSort)
-    }
     private val itemTouchHelper = ItemTouchHelper(ItemTouchHelperCallback()).apply {
         attachToRecyclerView(recyclerView)
     }
-    override val channel = Channel<List<TaskContainer>>(Channel.UNLIMITED)
+    override val channel = Channel<SectionedDataSource>(Channel.UNLIMITED)
     override val updates: Queue<Pair<SectionedDataSource, DiffUtil.DiffResult?>> = LinkedList()
     override var dragging = false
     override val scope: CoroutineScope =
@@ -70,7 +67,7 @@ class DragAndDropRecyclerAdapter(
 
     override fun getItemViewType(position: Int) = if (items.isHeader(position)) 1 else 0
 
-    override fun submitList(list: List<TaskContainer>) {
+    override fun submitList(list: SectionedDataSource) {
         super.submitList(list)
     }
 
@@ -81,8 +78,7 @@ class DragAndDropRecyclerAdapter(
     }
 
     private fun toggleGroup(group: Long) {
-        adapter.toggleCollapsed(group)
+        toggleCollapsed(group)
-        taskList.loadTaskListContent()
     }
 
     override fun dragAndDropEnabled() = taskList.getFilter().supportsSubtasks()
@@ -93,18 +89,8 @@ class DragAndDropRecyclerAdapter(
 
     override fun getItem(position: Int) = items.getItem(position)
 
-    override fun transform(list: List<TaskContainer>): SectionedDataSource =
-            SectionedDataSource(
-                tasks = list,
-                disableHeaders = disableHeaders,
-                groupMode = preferences.groupMode,
-                subtaskMode = preferences.subtaskMode,
-                collapsed = adapter.getCollapsed(),
-                completedAtBottom = preferences.completedTasksAtBottom,
-            )
-
     override fun diff(last: SectionedDataSource, next: SectionedDataSource) =
-            DiffUtil.calculateDiff(DiffCallback(last, next, adapter), next.size < LONG_LIST_SIZE)
+        DiffUtil.calculateDiff(DiffCallback(last, next, adapter), next.size < LONG_LIST_SIZE)
 
     override fun drainQueue() {
         val recyclerViewState = recyclerView.layoutManager!!.onSaveInstanceState()

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

@@ -6,6 +6,7 @@ import com.todoroo.andlib.utility.DateUtilities.now
 import com.todoroo.astrid.core.SortHelper
 import org.tasks.data.TaskContainer
 import org.tasks.time.DateTimeUtils.startOfDay
+import org.tasks.ui.TaskListViewModel.UiItem
 
 class SectionedDataSource(
     tasks: List<TaskContainer> = emptyList(),
@@ -14,7 +15,7 @@ class SectionedDataSource(
     val subtaskMode: Int = SortHelper.SORT_MANUAL,
     private val collapsed: Set<Long> = emptySet(),
     private val completedAtBottom: Boolean = true,
-) {
+): List<UiItem> {
     private val tasks = tasks.toMutableList()
 
     private val sections = if (disableHeaders || groupMode == SortHelper.GROUP_NONE) {
@@ -23,7 +24,7 @@ class SectionedDataSource(
         getSections()
     }
 
-    fun getItem(position: Int): TaskContainer? = tasks.getOrNull(sectionedPositionToPosition(position))
+    fun getItem(position: Int): TaskContainer = tasks[sectionedPositionToPosition(position)]
 
     fun getHeaderValue(position: Int): Long = getSection(position).value
 
@@ -48,9 +49,52 @@ class SectionedDataSource(
     val taskCount: Int
         get() = tasks.size
 
-    val size: Int
+    override val size: Int
         get() = tasks.size + sections.size()
 
+    override fun get(index: Int) =
+        sections[index]
+            ?.let { UiItem.Header(it.value) }
+            ?: UiItem.Task(getItem(index))
+
+    override fun isEmpty() = size == 0
+
+    override fun iterator(): Iterator<UiItem> {
+        return object : Iterator<UiItem> {
+            private var index = 0
+            override fun hasNext() = index < size
+            override fun next(): UiItem = get(index++)
+        }
+    }
+
+    override fun listIterator(): ListIterator<UiItem> {
+        TODO("Not yet implemented")
+    }
+
+    override fun listIterator(index: Int): ListIterator<UiItem> {
+        TODO("Not yet implemented")
+    }
+
+    override fun subList(fromIndex: Int, toIndex: Int): List<UiItem> {
+        TODO("Not yet implemented")
+    }
+
+    override fun lastIndexOf(element: UiItem): Int {
+        TODO("Not yet implemented")
+    }
+
+    override fun indexOf(element: UiItem): Int {
+        TODO("Not yet implemented")
+    }
+
+    override fun containsAll(elements: Collection<UiItem>): Boolean {
+        TODO("Not yet implemented")
+    }
+
+    override fun contains(element: UiItem): Boolean {
+        TODO("Not yet implemented")
+    }
+
     fun getSection(position: Int): AdapterSection = sections[position]
 
     fun add(position: Int, task: TaskContainer) = tasks.add(sectionedPositionToPosition(position), task)

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

@@ -8,15 +8,14 @@ import com.todoroo.astrid.adapter.TaskAdapter
 import com.todoroo.astrid.adapter.TaskAdapterDataSource
 import com.todoroo.astrid.api.AstridOrderingFilter
 import com.todoroo.astrid.core.SortHelper
-import org.tasks.data.TaskContainer
 import org.tasks.preferences.Preferences
 
 abstract class TaskListRecyclerAdapter internal constructor(
         private val adapter: TaskAdapter,
         internal val viewHolderFactory: ViewHolderFactory,
         private val taskList: TaskListFragment,
-        internal val preferences: Preferences)
+        internal val preferences: Preferences
-    : RecyclerView.Adapter<RecyclerView.ViewHolder>(), ListUpdateCallback, TaskAdapterDataSource {
+): RecyclerView.Adapter<RecyclerView.ViewHolder>(), ListUpdateCallback, TaskAdapterDataSource {
 
     override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): RecyclerView.ViewHolder
             = viewHolderFactory.newViewHolder(parent, taskList)
@@ -51,7 +50,7 @@ abstract class TaskListRecyclerAdapter internal constructor(
 
     abstract fun dragAndDropEnabled(): Boolean
 
-    abstract fun submitList(list: List<TaskContainer>)
+    abstract fun submitList(list: SectionedDataSource)
 
     override fun onInserted(position: Int, count: Int) {
         notifyItemRangeInserted(position, count)

app/src/main/java/org/tasks/ui/TaskListViewModel.kt

@@ -7,6 +7,7 @@ import android.content.Intent
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
 import com.todoroo.andlib.utility.DateUtilities
+import com.todoroo.astrid.api.AstridOrderingFilter
 import com.todoroo.astrid.api.Filter
 import com.todoroo.astrid.api.FilterImpl
 import com.todoroo.astrid.api.SearchFilter
@@ -19,7 +20,6 @@ import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.asStateFlow
 import kotlinx.coroutines.flow.distinctUntilChanged
-import kotlinx.coroutines.flow.filter
 import kotlinx.coroutines.flow.flowOn
 import kotlinx.coroutines.flow.launchIn
 import kotlinx.coroutines.flow.map
@@ -36,8 +36,10 @@ import org.tasks.data.TaskContainer
 import org.tasks.data.TaskDao
 import org.tasks.data.TaskListQuery.getQuery
 import org.tasks.db.QueryUtils
+import org.tasks.filters.MyTasksFilter
 import org.tasks.preferences.Preferences
 import org.tasks.preferences.QueryPreferences
+import org.tasks.tasklist.SectionedDataSource
 import javax.inject.Inject
 
 @HiltViewModel
@@ -53,18 +55,24 @@ class TaskListViewModel @Inject constructor(
     private val firebase: Firebase,
 ) : ViewModel() {
 
+    sealed class UiItem {
+        data class Header(val value: Long): UiItem()
+        data class Task(val task: TaskContainer): UiItem()
+    }
+
     sealed interface TasksResults {
         data object Loading : TasksResults
-        data class Results(val tasks: List<TaskContainer>) : TasksResults
+        data class Results(val tasks: SectionedDataSource) : TasksResults
     }
 
     data class State(
-        val filter: Filter? = null,
+        val filter: Filter = MyTasksFilter(""),
         val now: Long = DateUtilities.now(),
         val searchQuery: String? = null,
         val tasks: TasksResults = TasksResults.Loading,
         val begForSubscription: Boolean = false,
         val syncOngoing: Boolean = false,
+        val collapsed: Set<Long> = setOf(SectionedDataSource.HEADER_COMPLETED),
     )
 
     private val _state = MutableStateFlow(State())
@@ -104,7 +112,7 @@ class TaskListViewModel @Inject constructor(
     }
 
     suspend fun getTasksToClear(): List<Long> {
-        val filter = _state.value.filter ?: return emptyList()
+        val filter = _state.value.filter
         val deleteFilter = FilterImpl(
             sql = QueryUtils.removeOrder(QueryUtils.showHiddenAndCompleted(filter.sql!!)),
         )
@@ -130,13 +138,12 @@ class TaskListViewModel @Inject constructor(
         localBroadcastManager.registerRefreshReceiver(refreshReceiver)
 
         _state
-            .filter { it.filter != null }
             .map { it.copy(tasks = TasksResults.Loading) }
             .distinctUntilChanged()
             .throttleLatest(333)
             .map {
                 val filter = when {
-                    it.searchQuery == null -> it.filter!!
+                    it.searchQuery == null -> it.filter
                     it.searchQuery.isBlank() -> BuiltInFilterExposer.getMyTasksFilter(context.resources)
                     else -> context.createSearchQuery(it.searchQuery)
                 }
@@ -144,7 +151,20 @@ class TaskListViewModel @Inject constructor(
             }
             .onEach { tasks ->
                 _state.update {
-                    it.copy(tasks = TasksResults.Results(tasks))
+                    it.copy(
+                        tasks = TasksResults.Results(
+                            SectionedDataSource(
+                                tasks = tasks,
+                                disableHeaders = !it.filter.supportsSorting()
+                                        || (it.filter.supportsManualSort() && preferences.isManualSort)
+                                        || (it.filter is AstridOrderingFilter && preferences.isAstridSort),
+                                groupMode = preferences.groupMode,
+                                subtaskMode = preferences.subtaskMode,
+                                collapsed = it.collapsed,
+                                completedAtBottom = preferences.completedTasksAtBottom,
+                            )
+                        )
+                    )
                 }
             }
             .flowOn(Dispatchers.Default)
@@ -163,6 +183,24 @@ class TaskListViewModel @Inject constructor(
         localBroadcastManager.unregisterReceiver(refreshReceiver)
     }
 
+    fun clearCollapsed() {
+        _state.update {
+            it.copy(collapsed = setOf(SectionedDataSource.HEADER_COMPLETED))
+        }
+    }
+
+    fun toggleCollapsed(group: Long) {
+        _state.update {
+            it.copy(
+                collapsed = if (it.collapsed.contains(group)) {
+                    it.collapsed.minus(group)
+                } else {
+                    it.collapsed.plus(group)
+                }
+            )
+        }
+    }
+
     companion object {
         fun Context.createSearchQuery(query: String): Filter =
             SearchFilter(getString(R.string.FLA_search_filter, query), query)

app/src/main/java/org/tasks/widget/TasksWidgetViewFactory.kt

@@ -92,7 +92,7 @@ internal class TasksWidgetViewFactory(
 
     override fun getViewTypeCount(): Int = 2
 
-    override fun getItemId(position: Int) = getTask(position)?.id ?: 0
+    override fun getItemId(position: Int) = getTask(position).id
 
     override fun hasStableIds(): Boolean = true
 
@@ -145,7 +145,7 @@ internal class TasksWidgetViewFactory(
 
     private fun buildUpdate(position: Int): RemoteViews? {
         return try {
-            val taskContainer = getTask(position) ?: return null
+            val taskContainer = getTask(position)
             val task = taskContainer.task
             val textColorTitle = when {
                 task.isHidden -> onSurfaceVariant
@@ -258,7 +258,7 @@ internal class TasksWidgetViewFactory(
         }
     }
 
-    private fun getTask(position: Int): TaskContainer? = tasks.getItem(position)
+    private fun getTask(position: Int): TaskContainer = tasks.getItem(position)
 
     private suspend fun getQuery(filter: Filter): List<String> {
         subtasksHelper.applySubtasksToWidgetFilter(filter, widgetPreferences)