Fix zoom in draw area task

app/src/main/java/org/groundplatform/android/ui/common/AbstractMapContainerFragment.kt

@@ -33,8 +33,6 @@ import org.groundplatform.android.ui.map.NewCameraPositionViaBounds
 import org.groundplatform.android.ui.map.NewCameraPositionViaCoordinates
 import org.groundplatform.android.ui.map.NewCameraPositionViaCoordinatesAndZoomLevel
 import org.groundplatform.android.util.createComposeView
-import org.groundplatform.domain.model.geometry.Coordinates
-import org.groundplatform.domain.model.map.Bounds
 import org.groundplatform.ui.map.MapConfig
 import timber.log.Timber
 
@@ -79,7 +77,7 @@ abstract class AbstractMapContainerFragment : AbstractFragment() {
     launchWhenStarted { map.startDragEvents.collect { viewModel.onMapDragged() } }
     launchWhenStarted { viewModel.locationLock.collect { onLocationLockStateChange(it, map) } }
     launchWhenStarted {
-      viewModel.getCameraUpdateRequests().collect { onCameraUpdateRequest(it, map) }
+      viewModel.getCameraUpdateRequests().collect { applyCameraUpdateRequest(it) }
     }
 
     applyMapConfig(map)
@@ -153,17 +151,8 @@ abstract class AbstractMapContainerFragment : AbstractFragment() {
     Toast.makeText(context, messageId, Toast.LENGTH_LONG).show()
   }
 
-  /** Moves the camera to the given bounds. */
-  fun moveToBounds(bounds: Bounds, padding: Int, shouldAnimate: Boolean) {
-    onCameraUpdateRequest(NewCameraPositionViaBounds(bounds, padding, shouldAnimate), map)
-  }
-
-  /** Moves the camera to a given position. */
-  fun moveToPosition(coordinates: Coordinates) {
-    onCameraUpdateRequest(NewCameraPositionViaCoordinates(coordinates, shouldAnimate = true), map)
-  }
-
-  private fun onCameraUpdateRequest(request: CameraUpdateRequest, map: MapFragment) {
+  /** Moves the camera as described by the given [CameraUpdateRequest]. */
+  fun applyCameraUpdateRequest(request: CameraUpdateRequest) {
     Timber.v("Update camera: $request")
     when (request) {
       is NewCameraPositionViaCoordinates -> {

app/src/main/java/org/groundplatform/android/ui/datacollection/tasks/AbstractTaskMapFragment.kt

@@ -30,6 +30,7 @@ import androidx.lifecycle.Lifecycle
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import androidx.lifecycle.lifecycleScope
 import androidx.lifecycle.repeatOnLifecycle
+import androidx.lifecycle.withStarted
 import java.math.RoundingMode
 import java.text.DecimalFormat
 import kotlinx.coroutines.flow.Flow
@@ -153,8 +154,7 @@ abstract class AbstractTaskMapFragment<TVM : AbstractTaskViewModel> :
       getMapViewModel().getCurrentCameraPosition().collect { onMapCameraMoved(it) }
     }
     launchWhenStarted { renderFeatures().collect { map.setFeatures(it) } }
-    // Allow the fragment to restore map viewport to previously drawn feature.
-    launchWhenStarted { setDefaultViewPort() }
+    lifecycleScope.launch { withStarted { setDefaultViewPort() } }
   }
 
   /** Must be overridden by subclasses. */

app/src/main/java/org/groundplatform/android/ui/datacollection/tasks/point/DropPinTaskMapFragment.kt

@@ -22,6 +22,7 @@ import kotlinx.coroutines.flow.combine
 import org.groundplatform.android.ui.datacollection.tasks.AbstractTaskMapFragment
 import org.groundplatform.android.ui.map.Feature
 import org.groundplatform.android.ui.map.MapFragment
+import org.groundplatform.android.ui.map.NewCameraPositionViaCoordinates
 import org.groundplatform.domain.model.map.CameraPosition
 
 @AndroidEntryPoint
@@ -58,6 +59,6 @@ class DropPinTaskMapFragment @Inject constructor() :
   override fun setDefaultViewPort() {
     val feature = taskViewModel.features.value?.firstOrNull() ?: return
     val coordinates = feature.geometry.center()
-    moveToPosition(coordinates)
+    applyCameraUpdateRequest(NewCameraPositionViaCoordinates(coordinates, shouldAnimate = true))
   }
 }

app/src/main/java/org/groundplatform/android/ui/datacollection/tasks/polygon/DrawAreaTaskMapFragment.kt

@@ -24,7 +24,7 @@ import kotlinx.coroutines.flow.combine
 import kotlinx.coroutines.flow.map
 import org.groundplatform.android.ui.datacollection.tasks.AbstractTaskMapFragment
 import org.groundplatform.android.ui.map.Feature
-import org.groundplatform.domain.model.map.Bounds
+import org.groundplatform.android.ui.map.NewCameraPositionViaCoordinates
 import org.groundplatform.domain.model.map.CameraPosition
 
 @AndroidEntryPoint
@@ -51,15 +51,15 @@ class DrawAreaTaskMapFragment @Inject constructor() :
     }
 
     launchWhenStarted {
-      taskViewModel.cameraMoveEvents.collect { coordinates -> moveToPosition(coordinates) }
+      taskViewModel.cameraMoveEvents.collect { coordinates ->
+        applyCameraUpdateRequest(NewCameraPositionViaCoordinates(coordinates, shouldAnimate = true))
+      }
     }
   }
 
   override fun setDefaultViewPort() {
-    val feature = taskViewModel.draftArea.value
-    val geometry = feature?.geometry ?: return
-    val bounds = Bounds.fromGeometry(geometry) ?: return
-    moveToBounds(bounds, padding = 200, shouldAnimate = false)
+    val request = taskViewModel.getDefaultViewPort() ?: return
+    applyCameraUpdateRequest(request)
   }
 
   override fun renderFeatures(): Flow<Set<Feature>> =

app/src/main/java/org/groundplatform/android/ui/datacollection/tasks/polygon/DrawAreaTaskViewModel.kt

@@ -39,7 +39,10 @@ import org.groundplatform.android.ui.datacollection.components.ButtonActionState
 import org.groundplatform.android.ui.datacollection.tasks.AbstractMapTaskViewModel
 import org.groundplatform.android.ui.datacollection.tasks.DataCollectionEvent
 import org.groundplatform.android.ui.datacollection.tasks.TaskPositionInterface
+import org.groundplatform.android.ui.map.CameraUpdateRequest
 import org.groundplatform.android.ui.map.Feature
+import org.groundplatform.android.ui.map.NewCameraPositionViaBounds
+import org.groundplatform.android.ui.map.NewCameraPositionViaCoordinates
 import org.groundplatform.android.ui.util.LocaleAwareMeasureFormatter
 import org.groundplatform.android.ui.util.VibrationHelper
 import org.groundplatform.android.ui.util.getDefaultColor
@@ -50,6 +53,7 @@ import org.groundplatform.domain.model.geometry.LineString
 import org.groundplatform.domain.model.geometry.LinearRing
 import org.groundplatform.domain.model.geometry.Polygon
 import org.groundplatform.domain.model.job.Job
+import org.groundplatform.domain.model.map.Bounds
 import org.groundplatform.domain.model.settings.MeasurementUnits
 import org.groundplatform.domain.model.submission.DrawAreaTaskData
 import org.groundplatform.domain.model.submission.DrawAreaTaskIncompleteData
@@ -124,6 +128,19 @@ internal constructor(
       .stateIn(viewModelScope, WhileSubscribed(5_000), emptyList())
   }
 
+  /** Restores the viewport to the area drawn so far or null if nothing has been drawn yet. */
+  fun getDefaultViewPort(): CameraUpdateRequest? {
+    val vertices = session.vertices.distinct()
+    return when (vertices.size) {
+      0 -> null
+      1 -> NewCameraPositionViaCoordinates(vertices.first())
+      else ->
+        Bounds.fromCoordinates(vertices)?.let {
+          NewCameraPositionViaBounds(it, padding = 200, shouldAnimate = false)
+        }
+    }
+  }
+
   override fun initialize(
     job: Job,
     task: Task,

app/src/test/java/org/groundplatform/android/ui/datacollection/tasks/polygon/DrawAreaTaskViewModelTest.kt

@@ -42,12 +42,15 @@ import org.groundplatform.android.ui.datacollection.components.ButtonAction
 import org.groundplatform.android.ui.datacollection.tasks.TaskPositionInterface
 import org.groundplatform.android.ui.datacollection.tasks.polygon.PolygonDrawingSession.Companion.DISTANCE_THRESHOLD_DP
 import org.groundplatform.android.ui.map.Feature
+import org.groundplatform.android.ui.map.NewCameraPositionViaBounds
+import org.groundplatform.android.ui.map.NewCameraPositionViaCoordinates
 import org.groundplatform.domain.model.geometry.Coordinates
 import org.groundplatform.domain.model.geometry.LineString
 import org.groundplatform.domain.model.geometry.LinearRing
 import org.groundplatform.domain.model.geometry.Polygon
 import org.groundplatform.domain.model.job.Job
 import org.groundplatform.domain.model.job.Style
+import org.groundplatform.domain.model.map.Bounds
 import org.groundplatform.domain.model.settings.MeasurementUnits
 import org.groundplatform.domain.model.submission.DrawAreaTaskData
 import org.groundplatform.domain.model.submission.DrawAreaTaskIncompleteData
@@ -105,6 +108,47 @@ class DrawAreaTaskViewModelTest : BaseHiltTest() {
     assertThat(viewModel.isMarkedComplete()).isFalse()
   }
 
+  @Test
+  fun `getDefaultViewPort returns null when nothing has been drawn`() {
+    setupViewModel()
+
+    assertThat(viewModel.getDefaultViewPort()).isNull()
+  }
+
+  @Test
+  fun `getDefaultViewPort centers on the first vertex`() {
+    setupViewModel()
+
+    updateLastVertexAndAdd(COORDINATE_1)
+
+    assertThat(viewModel.getDefaultViewPort())
+      .isEqualTo(NewCameraPositionViaCoordinates(COORDINATE_1))
+  }
+
+  @Test
+  fun `getDefaultViewPort centers on a restored draft of a single vertex`() {
+    setupViewModel(taskData = DrawAreaTaskIncompleteData(LineString(listOf(COORDINATE_1))))
+
+    assertThat(viewModel.getDefaultViewPort())
+      .isEqualTo(NewCameraPositionViaCoordinates(COORDINATE_1))
+  }
+
+  @Test
+  fun `getDefaultViewPort fits the camera to a draft covering an area`() {
+    setupViewModel()
+    updateLastVertexAndAdd(COORDINATE_1)
+
+    updateLastVertex(COORDINATE_2)
+
+    assertThat(viewModel.getDefaultViewPort())
+      .isEqualTo(
+        NewCameraPositionViaBounds(
+          Bounds.fromCoordinates(listOf(COORDINATE_1, COORDINATE_2))!!,
+          padding = 200,
+        )
+      )
+  }
+
   @Test
   fun `Removing last vertex on complete polygon`() {
     setupViewModel()