Decouple TaskDataHandler and TaskSequenceHandler by binding the corou…

…tine in DataCollectionViewModel
google · Jan 9, 2025 · af94eb3 · af94eb3
1 parent fc0d384
commit af94eb3
Show file tree

Hide file tree

Showing 3 changed files with 16 additions and 22 deletions.
diff --git a/ground/src/main/java/com/google/android/ground/ui/datacollection/DataCollectionViewModel.kt b/ground/src/main/java/com/google/android/ground/ui/datacollection/DataCollectionViewModel.kt
@@ -57,6 +57,7 @@ import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.SharingStarted
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.flow.collectLatest
 import kotlinx.coroutines.flow.filterNotNull
 import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.flow.flow
@@ -143,8 +144,8 @@ internal constructor(
 
   lateinit var submissionId: String
 
-  private val taskSequenceHandler: TaskSequenceHandler = TaskSequenceHandler(tasks)
-  private val taskDataHandler = taskSequenceHandler.taskDataHandler
+  private val taskSequenceHandler = TaskSequenceHandler(tasks)
+  private val taskDataHandler = TaskDataHandler()
 
   init {
     if (currentTaskId.value == "") {
@@ -154,6 +155,11 @@ internal constructor(
 
     check(currentTaskId.value.isNotBlank()) { "Task ID can't be blank" }
     _uiState.update { UiState.TaskListAvailable(tasks, getTaskPosition(currentTaskId.value)) }
+
+    // Refresh the computed sequence whenever the collected task's data is updated.
+    viewModelScope.launch {
+      taskDataHandler.dataState.collectLatest { taskSequenceHandler.refreshSequence() }
+    }
   }
 
   fun setLoiName(name: String) {
@@ -326,11 +332,9 @@ internal constructor(
       return taskSequenceHandler.isLastPosition(task.id)
     }
 
+    val taskSelections = taskDataHandler.getTaskSelections(taskValueOverride = task.id to value)
     val sequence =
-      taskSequenceHandler.generateTaskSequence(
-        "isLastPositionWithTaskData",
-        taskValueOverride = task.id to value,
-      )
+      taskSequenceHandler.generateTaskSequence("isLastPositionWithTaskData", taskSelections)
     return task.id == sequence.last().id
   }
 

diff --git a/ground/src/main/java/com/google/android/ground/ui/datacollection/TaskDataHandler.kt b/ground/src/main/java/com/google/android/ground/ui/datacollection/TaskDataHandler.kt
@@ -9,7 +9,7 @@ import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.asStateFlow
 import kotlinx.coroutines.flow.update
 
-class TaskDataHandler(private val taskSequenceHandler: TaskSequenceHandler) {
+class TaskDataHandler {
 
   private val _dataState = MutableStateFlow(LinkedHashMap<Task, TaskData?>())
 
@@ -25,7 +25,6 @@ class TaskDataHandler(private val taskSequenceHandler: TaskSequenceHandler) {
   fun setData(key: Task, newValue: TaskData?) {
     if (getData(key) == newValue) return
     _dataState.update { it.apply { set(key, newValue) } }
-    taskSequenceHandler.refreshSequence()
   }
 
   /**

diff --git a/ground/src/main/java/com/google/android/ground/ui/datacollection/TaskSequenceHandler.kt b/ground/src/main/java/com/google/android/ground/ui/datacollection/TaskSequenceHandler.kt
@@ -15,8 +15,8 @@
  */
 package com.google.android.ground.ui.datacollection
 
-import com.google.android.ground.model.submission.TaskData
 import com.google.android.ground.model.task.Task
+import com.google.android.ground.model.task.TaskSelections
 import timber.log.Timber
 
 /**
@@ -30,8 +30,6 @@ import timber.log.Timber
  */
 class TaskSequenceHandler(private val tasks: List<Task>) {
 
-  val taskDataHandler = TaskDataHandler(this)
-
   private var sequence: Sequence<Task> = emptySequence()
   private var isInitialized = false
 
@@ -50,12 +48,9 @@ class TaskSequenceHandler(private val tasks: List<Task>) {
   }
 
   /** Generates the task sequence based on conditions and overrides. */
-  fun generateTaskSequence(
-    tag: String,
-    taskValueOverride: Pair<String, TaskData?>? = null,
-  ): Sequence<Task> {
+  fun generateTaskSequence(tag: String, taskSelections: TaskSelections? = null): Sequence<Task> {
     Timber.d("Task Sequence Generated: $tag")
-    return tasks.filter { shouldIncludeTaskInSequence(it, taskValueOverride) }.asSequence()
+    return tasks.filter { shouldIncludeTaskInSequence(it, taskSelections) }.asSequence()
   }
 
   /** Lazily retrieves the task sequence. */
@@ -68,12 +63,8 @@ class TaskSequenceHandler(private val tasks: List<Task>) {
   }
 
   /** Determines if a task should be included with the given overrides. */
-  private fun shouldIncludeTaskInSequence(
-    task: Task,
-    taskValueOverride: Pair<String, TaskData?>?,
-  ): Boolean {
-    if (task.condition == null) return true
-    val taskSelections = taskDataHandler.getTaskSelections(taskValueOverride)
+  private fun shouldIncludeTaskInSequence(task: Task, taskSelections: TaskSelections?): Boolean {
+    if (task.condition == null || taskSelections == null) return true
     return task.condition.fulfilledBy(taskSelections)
   }