Prevent flashing empty inbox when switching lists

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

@@ -280,16 +280,18 @@ class TaskListFragment : Fragment(), OnRefreshListener, Toolbar.OnMenuItemClickL
         lifecycleScope.launch {
             viewLifecycleOwner.repeatOnLifecycle(Lifecycle.State.STARTED) {
                 listViewModel.state.collect {
-                    submitList(it.tasks)
-                    if (it.tasks.isEmpty()) {
-                        swipeRefreshLayout.visibility = View.GONE
-                        emptyRefreshLayout.visibility = View.VISIBLE
-                    } else {
-                        swipeRefreshLayout.visibility = View.VISIBLE
-                        emptyRefreshLayout.visibility = View.GONE
+                    if (it.tasks is TaskListViewModel.TasksResults.Results) {
+                        submitList(it.tasks.tasks)
+                        if (it.tasks.tasks.isEmpty()) {
+                            swipeRefreshLayout.visibility = View.GONE
+                            emptyRefreshLayout.visibility = View.VISIBLE
+                        } else {
+                            swipeRefreshLayout.visibility = View.VISIBLE
+                            emptyRefreshLayout.visibility = View.GONE
+                        }
+                        swipeRefreshLayout.isRefreshing = it.syncOngoing
+                        emptyRefreshLayout.isRefreshing = it.syncOngoing
                     }
-                    swipeRefreshLayout.isRefreshing = it.syncOngoing
-                    emptyRefreshLayout.isRefreshing = it.syncOngoing
                 }
             }
         }

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

@@ -3,14 +3,24 @@ package org.tasks.compose.edit
 import android.content.res.Configuration
 import androidx.compose.foundation.clickable
 import androidx.compose.foundation.focusable
-import androidx.compose.foundation.layout.*
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.width
 import androidx.compose.foundation.text.BasicTextField
 import androidx.compose.foundation.text.KeyboardActions
 import androidx.compose.foundation.text.KeyboardOptions
 import androidx.compose.material.ContentAlpha
 import androidx.compose.material.MaterialTheme
 import androidx.compose.material.Text
-import androidx.compose.runtime.*
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.draw.alpha
@@ -27,8 +37,14 @@ import com.google.android.material.composethemeadapter.MdcTheme
 import com.todoroo.astrid.api.Filter
 import com.todoroo.astrid.api.GtasksFilter
 import com.todoroo.astrid.data.Task
-import org.tasks.compose.*
+import org.tasks.compose.CheckBox
+import org.tasks.compose.ClearButton
+import org.tasks.compose.DisabledText
+import org.tasks.compose.SubtaskChip
+import org.tasks.compose.TaskEditIcon
+import org.tasks.compose.TaskEditRow
 import org.tasks.data.TaskContainer
+import org.tasks.ui.TaskListViewModel
 
 @Composable
 fun SubtaskRow(
@@ -36,7 +52,7 @@ fun SubtaskRow(
     filter: Filter?,
     hasParent: Boolean,
     desaturate: Boolean,
-    existingSubtasks: List<TaskContainer>,
+    existingSubtasks: TaskListViewModel.TasksResults,
     newSubtasks: List<Task>,
     openSubtask: (Task) -> Unit,
     completeExistingSubtask: (Task, Boolean) -> Unit,
@@ -73,15 +89,22 @@ fun SubtaskRow(
                     )
                 } else {
                     Spacer(modifier = Modifier.height(height = 8.dp))
-                    existingSubtasks.forEach { task ->
-                        ExistingSubtaskRow(
-                            task = task,
-                            desaturate = desaturate,
-                            indent = if (filter !is GtasksFilter) task.indent else 0,
-                            onRowClick = { openSubtask(task.task) },
-                            onCompleteClick = { completeExistingSubtask(task.task, !task.isCompleted) },
-                            onToggleSubtaskClick = { toggleSubtask(task.id, !task.isCollapsed) }
-                        )
+                    if (existingSubtasks is TaskListViewModel.TasksResults.Results) {
+                        existingSubtasks.tasks.forEach { task ->
+                            ExistingSubtaskRow(
+                                task = task,
+                                desaturate = desaturate,
+                                indent = if (filter !is GtasksFilter) task.indent else 0,
+                                onRowClick = { openSubtask(task.task) },
+                                onCompleteClick = {
+                                    completeExistingSubtask(
+                                        task.task,
+                                        !task.isCompleted
+                                    )
+                                },
+                                onToggleSubtaskClick = { toggleSubtask(task.id, !task.isCollapsed) }
+                            )
+                        }
                     }
                     newSubtasks.forEach { subtask ->
                         NewSubtaskRow(
@@ -214,7 +237,7 @@ fun NoSubtasks() {
             filter = null,
             hasParent = false,
             desaturate = true,
-            existingSubtasks = emptyList(),
+            existingSubtasks = TaskListViewModel.TasksResults.Results(emptyList()),
             newSubtasks = emptyList(),
             openSubtask = {},
             completeExistingSubtask = { _, _ -> },
@@ -236,20 +259,22 @@ fun SubtasksPreview() {
             filter = null,
             hasParent = false,
             desaturate = true,
-            existingSubtasks = listOf(
-                TaskContainer(
-                    task = Task().apply {
-                        title = "Existing subtask 1"
-                        priority = Task.Priority.HIGH
-                    },
-                    indent = 0
-                ),
-                TaskContainer(
-                    task = Task().apply {
-                        title = "Existing subtask 2 with a really long title"
-                        priority = Task.Priority.LOW
-                    },
-                    indent = 1
+            existingSubtasks = TaskListViewModel.TasksResults.Results(
+                listOf(
+                    TaskContainer(
+                        task = Task(
+                            title = "Existing subtask 1",
+                            priority = Task.Priority.HIGH,
+                        ),
+                        indent = 0
+                    ),
+                    TaskContainer(
+                        task = Task(
+                            title = "Existing subtask 2 with a really long title",
+                            priority = Task.Priority.LOW,
+                        ),
+                        indent = 1
+                    )
                 )
             ),
             newSubtasks = listOf(

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

@@ -47,11 +47,16 @@ class TaskListViewModel @Inject constructor(
     private val firebase: Firebase,
 ) : ViewModel() {
 
+    sealed interface TasksResults {
+        data object Loading : TasksResults
+        data class Results(val tasks: List<TaskContainer>) : TasksResults
+    }
+
     data class State(
         val filter: Filter? = null,
         val now: Long = DateUtilities.now(),
         val searchQuery: String? = null,
-        val tasks: List<TaskContainer> = emptyList(),
+        val tasks: TasksResults = TasksResults.Loading,
         val begForSubscription: Boolean = false,
         val syncOngoing: Boolean = false,
     )
@@ -116,7 +121,7 @@ class TaskListViewModel @Inject constructor(
             }
             .onEach { tasks ->
                 _state.update {
-                    it.copy(tasks = tasks)
+                    it.copy(tasks = TasksResults.Results(tasks))
                 }
             }
             .flowOn(Dispatchers.Default)