Add MainActivity and TaskList event buses

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

@@ -13,7 +13,9 @@ import android.os.Bundle
 import android.view.View
 import android.view.inputmethod.InputMethodManager
 import androidx.appcompat.view.ActionMode
+import androidx.lifecycle.Lifecycle
 import androidx.lifecycle.lifecycleScope
+import androidx.lifecycle.repeatOnLifecycle
 import com.todoroo.andlib.utility.AndroidUtilities
 import com.todoroo.astrid.activity.TaskEditFragment.Companion.newTaskEditFragment
 import com.todoroo.astrid.activity.TaskListFragment.TaskListFragmentCallbackHandler
@@ -23,7 +25,12 @@ import com.todoroo.astrid.data.Task
 import com.todoroo.astrid.service.TaskCreator
 import com.todoroo.astrid.timers.TimerControlSet.TimerControlSetCallback
 import dagger.hilt.android.AndroidEntryPoint
-import kotlinx.coroutines.*
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.async
+import kotlinx.coroutines.coroutineScope
+import kotlinx.coroutines.flow.collect
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
 import org.tasks.BuildConfig
 import org.tasks.LocalBroadcastManager
 import org.tasks.R
@@ -49,6 +56,8 @@ import org.tasks.themes.ThemeColor
 import org.tasks.ui.DeadlineControlSet.DueDateChangeListener
 import org.tasks.ui.EmptyTaskEditFragment.Companion.newEmptyTaskEditFragment
 import org.tasks.ui.ListFragment.OnListChanged
+import org.tasks.ui.MainActivityEventBus
+import org.tasks.ui.MainActivityEvent
 import org.tasks.ui.NavigationDrawerFragment
 import org.tasks.ui.NavigationDrawerFragment.Companion.newNavigationDrawer
 import timber.log.Timber
@@ -67,6 +76,7 @@ class MainActivity : InjectingAppCompatActivity(), TaskListFragmentCallbackHandl
     @Inject lateinit var locationDao: LocationDao
     @Inject lateinit var tagDataDao: TagDataDao
     @Inject lateinit var alarmDao: AlarmDao
+    @Inject lateinit var eventBus: MainActivityEventBus
 
     private var currentNightMode = 0
     private var currentPro = false
@@ -88,6 +98,17 @@ class MainActivity : InjectingAppCompatActivity(), TaskListFragmentCallbackHandl
             applyTheme()
         }
         handleIntent()
+
+        lifecycleScope.launch {
+            repeatOnLifecycle(Lifecycle.State.RESUMED) {
+                eventBus.collect(this@MainActivity::process)
+            }
+        }
+    }
+
+    private suspend fun process(event: MainActivityEvent) = when (event) {
+        is MainActivityEvent.OpenTask ->
+            onTaskListItemClicked(event.task)
     }
 
     public override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
@@ -377,7 +398,7 @@ class MainActivity : InjectingAppCompatActivity(), TaskListFragmentCallbackHandl
         finish()
     }
 
-    val taskListFragment: TaskListFragment?
+    private val taskListFragment: TaskListFragment?
         get() = supportFragmentManager.findFragmentByTag(FRAG_TAG_TASK_LIST) as TaskListFragment?
 
     val taskEditFragment: TaskEditFragment?

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

@@ -50,7 +50,6 @@ import org.tasks.databinding.FragmentTaskEditBinding
 import org.tasks.date.DateTimeUtils.newDateTime
 import org.tasks.dialogs.DialogBuilder
 import org.tasks.dialogs.Linkify
-import org.tasks.extensions.Context.openUri
 import org.tasks.files.FileHelper
 import org.tasks.fragments.TaskEditControlSetFragmentManager
 import org.tasks.markdown.MarkdownProvider
@@ -265,22 +264,7 @@ class TaskEditFragment : Fragment(), Toolbar.OnMenuItemClickListener {
         return model
     }
 
-    /** Save task model from values in UI components  */
+    suspend fun save() = editViewModel.save()
-    suspend fun save() = withContext(NonCancellable) {
-        val tlf = (activity as MainActivity?)?.taskListFragment
-        val saved = editViewModel.save()
-        if (saved && editViewModel.isNew) {
-            tlf?.let { taskListFragment ->
-                val model = editViewModel.task!!
-                taskListFragment.onTaskCreated(model.uuid)
-                if (!isNullOrEmpty(model.calendarURI)) {
-                    taskListFragment.makeSnackbar(R.string.calendar_event_created, model.title)
-                            ?.setAction(R.string.action_open) { context.openUri(model.calendarURI) }
-                            ?.show()
-                }
-            }
-        }
-    }
 
     /*
    * ======================================================================

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

@@ -30,7 +30,9 @@ import androidx.core.view.isVisible
 import androidx.core.view.setMargins
 import androidx.fragment.app.Fragment
 import androidx.fragment.app.viewModels
+import androidx.lifecycle.Lifecycle
 import androidx.lifecycle.lifecycleScope
+import androidx.lifecycle.repeatOnLifecycle
 import androidx.paging.PagedList
 import androidx.recyclerview.widget.DefaultItemAnimator
 import androidx.recyclerview.widget.LinearLayoutManager
@@ -67,6 +69,7 @@ import dagger.hilt.android.AndroidEntryPoint
 import kotlinx.coroutines.Job
 import kotlinx.coroutines.NonCancellable
 import kotlinx.coroutines.delay
+import kotlinx.coroutines.flow.collect
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
 import org.tasks.LocalBroadcastManager
@@ -88,6 +91,7 @@ import org.tasks.db.SuspendDbUtils.chunkedMap
 import org.tasks.dialogs.DateTimePicker.Companion.newDateTimePicker
 import org.tasks.dialogs.DialogBuilder
 import org.tasks.dialogs.SortDialog
+import org.tasks.extensions.Context.openUri
 import org.tasks.extensions.Context.toast
 import org.tasks.extensions.Fragment.safeStartActivityForResult
 import org.tasks.extensions.setOnQueryTextListener
@@ -106,6 +110,8 @@ import org.tasks.tasklist.TaskViewHolder
 import org.tasks.tasklist.ViewHolderFactory
 import org.tasks.themes.ColorProvider
 import org.tasks.themes.ThemeColor
+import org.tasks.ui.TaskListEventBus
+import org.tasks.ui.TaskListEvent
 import org.tasks.ui.TaskListViewModel
 import java.time.format.FormatStyle
 import javax.inject.Inject
@@ -141,6 +147,7 @@ class TaskListFragment : Fragment(), OnRefreshListener, Toolbar.OnMenuItemClickL
     @Inject lateinit var locale: Locale
     @Inject lateinit var firebase: Firebase
     @Inject lateinit var repeatTaskHelper: RepeatTaskHelper
+    @Inject lateinit var eventBus: TaskListEventBus
     
     private lateinit var swipeRefreshLayout: SwipeRefreshLayout
     private lateinit var emptyRefreshLayout: SwipeRefreshLayout
@@ -159,6 +166,15 @@ class TaskListFragment : Fragment(), OnRefreshListener, Toolbar.OnMenuItemClickL
     private lateinit var callbacks: TaskListFragmentCallbackHandler
     private lateinit var binding: FragmentTaskListBinding
 
+    private fun process(event: TaskListEvent) = when (event) {
+        is TaskListEvent.TaskCreated ->
+            onTaskCreated(event.uuid)
+        is TaskListEvent.CalendarEventCreated ->
+            makeSnackbar(R.string.calendar_event_created, event.title)
+                ?.setAction(R.string.action_open) { context?.openUri(event.uri) }
+                ?.show()
+    }
+
     override fun onRefresh() {
         syncAdapters.sync(true)
         lifecycleScope.launch {
@@ -263,6 +279,13 @@ class TaskListFragment : Fragment(), OnRefreshListener, Toolbar.OnMenuItemClickL
         toolbar.setOnMenuItemClickListener(this)
         toolbar.setNavigationOnClickListener { callbacks.onNavigationIconClicked() }
         setupMenu(toolbar)
+
+        lifecycleScope.launch {
+            viewLifecycleOwner.repeatOnLifecycle(Lifecycle.State.RESUMED) {
+                eventBus.collect(this@TaskListFragment::process)
+            }
+        }
+
         return binding.root
     }
 
@@ -500,7 +523,7 @@ class TaskListFragment : Fragment(), OnRefreshListener, Toolbar.OnMenuItemClickL
         refresh()
     }
 
-    fun makeSnackbar(@StringRes res: Int, vararg args: Any?): Snackbar? {
+    private fun makeSnackbar(@StringRes res: Int, vararg args: Any?): Snackbar? {
         return makeSnackbar(getString(res, *args))
     }
 

app/src/main/java/org/tasks/injection/ActivityRetainedModule.kt

@@ -0,0 +1,28 @@
+package org.tasks.injection
+
+import dagger.Module
+import dagger.Provides
+import dagger.hilt.InstallIn
+import dagger.hilt.android.components.ActivityRetainedComponent
+import dagger.hilt.android.scopes.ActivityRetainedScoped
+import kotlinx.coroutines.channels.BufferOverflow
+import kotlinx.coroutines.flow.MutableSharedFlow
+import org.tasks.ui.MainActivityEventBus
+import org.tasks.ui.TaskListEventBus
+
+@Module
+@InstallIn(ActivityRetainedComponent::class)
+class ActivityRetainedModule {
+    @Provides
+    @ActivityRetainedScoped
+    fun getTaskListBus(): TaskListEventBus = makeFlow()
+
+    @Provides
+    @ActivityRetainedScoped
+    fun getMainActivityBus(): MainActivityEventBus = makeFlow()
+
+    private fun <T> makeFlow() = MutableSharedFlow<T>(
+        extraBufferCapacity = 1,
+        onBufferOverflow = BufferOverflow.DROP_OLDEST
+    )
+}

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

@@ -0,0 +1,11 @@
+package org.tasks.ui
+
+import com.todoroo.astrid.data.Task
+import kotlinx.coroutines.flow.MutableSharedFlow
+
+typealias MainActivityEventBus = MutableSharedFlow<MainActivityEvent>
+
+sealed interface MainActivityEvent {
+    data class OpenTask(val task: Task) : MainActivityEvent
+}
+

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

@@ -24,7 +24,6 @@ import com.todoroo.andlib.sql.Criterion
 import com.todoroo.andlib.sql.Join
 import com.todoroo.andlib.sql.QueryTemplate
 import com.todoroo.andlib.utility.DateUtilities.now
-import com.todoroo.astrid.activity.MainActivity
 import com.todoroo.astrid.api.Filter
 import com.todoroo.astrid.api.GtasksFilter
 import com.todoroo.astrid.dao.TaskDao
@@ -60,6 +59,7 @@ class SubtaskControlSet : TaskEditControlFragment(), SubtaskViewHolder.Callbacks
     @Inject lateinit var locale: Locale
     @Inject lateinit var checkBoxProvider: CheckBoxProvider
     @Inject lateinit var chipProvider: ChipProvider
+    @Inject lateinit var eventBus: MainActivityEventBus
     
     private val listViewModel: TaskListViewModel by viewModels()
     private val refreshReceiver = RefreshReceiver()
@@ -197,7 +197,9 @@ class SubtaskControlSet : TaskEditControlFragment(), SubtaskViewHolder.Callbacks
     }
 
     override fun openSubtask(task: Task) {
-        (activity as MainActivity).taskListFragment?.onTaskListItemClicked(task)
+        lifecycleScope.launch {
+            eventBus.emit(MainActivityEvent.OpenTask(task))
+        }
     }
 
     override fun toggleSubtask(taskId: Long, collapsed: Boolean) {

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

@@ -28,6 +28,7 @@ import dagger.hilt.android.qualifiers.ApplicationContext
 import kotlinx.coroutines.NonCancellable
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.runBlocking
+import kotlinx.coroutines.withContext
 import net.fortuna.ical4j.model.Recur
 import org.tasks.Event
 import org.tasks.R
@@ -79,7 +80,8 @@ class TaskEditViewModel @Inject constructor(
         private val googleTaskDao: GoogleTaskDao,
         private val caldavDao: CaldavDao,
         private val taskCompleter: TaskCompleter,
-        private val alarmService: AlarmService
+        private val alarmService: AlarmService,
+        private val taskListEvents: TaskListEventBus,
 ) : ViewModel() {
 
     val cleared = MutableLiveData<Event<Boolean>>()
@@ -320,13 +322,13 @@ class TaskEditViewModel @Inject constructor(
     fun cleared() = cleared.value?.value == true
 
     @MainThread
-    suspend fun save(): Boolean {
+    suspend fun save() = withContext(NonCancellable) {
         if (cleared()) {
-            return false
+            return@withContext
         }
         if (!hasChanges()) {
             discard()
-            return false
+            return@withContext
         }
         clear()
         task.title = if (title.isNullOrBlank()) context.getString(R.string.no_title) else title
@@ -428,7 +430,13 @@ class TaskEditViewModel @Inject constructor(
             taskCompleter.setComplete(task, completed!!)
         }
 
-        return true
+        if (isNew) {
+            val model = task
+            taskListEvents.emit(TaskListEvent.TaskCreated(model.uuid))
+            model.calendarURI?.takeIf { it.isNotBlank() }?.let {
+                taskListEvents.emit(TaskListEvent.CalendarEventCreated(model.title, it))
+            }
+        }
     }
 
     private suspend fun applyCalendarChanges() {
@@ -478,7 +486,7 @@ class TaskEditViewModel @Inject constructor(
     override fun onCleared() {
         cleared.value.let {
             if (it == null || !it.value) {
-                runBlocking(NonCancellable) {
+                runBlocking {
                     save()
                 }
             }

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

@@ -0,0 +1,10 @@
+package org.tasks.ui
+
+import kotlinx.coroutines.flow.MutableSharedFlow
+
+typealias TaskListEventBus = MutableSharedFlow<TaskListEvent>
+
+sealed interface TaskListEvent {
+    data class TaskCreated(val uuid: String) : TaskListEvent
+    data class CalendarEventCreated(val title: String?, val uri: String) : TaskListEvent
+}