SceneView current viewpoint camera (#256)

* add getCurrentViewpointCamera in proxy

* expose the currentViewpoint property

* impls current view camera

* adds a space for lambda

* merged with feature branch.

* Update toolkit/geo-compose/src/main/java/com/arcgismaps/toolkit/geocompose/SceneView.kt

Co-authored-by: Puneet Prakash <[email protected]>

---------

Co-authored-by: Puneet Prakash <[email protected]>

Author: changanxian

Diff for: toolkit/geo-compose/src/main/java/com/arcgismaps/toolkit/geocompose/SceneView.kt

@@ -32,6 +32,7 @@ import androidx.compose.ui.viewinterop.AndroidView
 import com.arcgismaps.geometry.SpatialReference
 import com.arcgismaps.mapping.ArcGISScene
 import com.arcgismaps.mapping.TimeExtent
+import com.arcgismaps.mapping.view.Camera
 import com.arcgismaps.mapping.view.CameraController
 import com.arcgismaps.mapping.view.DoubleTapEvent
 import com.arcgismaps.mapping.view.DownEvent
@@ -76,6 +77,7 @@ import java.time.Instant
  * @param onSpatialReferenceChanged lambda invoked when the spatial reference of the composable SceneView has changed
  * @param onLayerViewStateChanged lambda invoked when the composable SceneView's layer view state is changed
  * @param onInteractingChanged lambda invoked when the user starts and ends interacting with the composable SceneView
+ * @param onCurrentViewpointCameraChanged lambda invoked when the viewpoint camera of the composable SceneView has changed
  * @param onRotate lambda invoked when a user performs a rotation gesture on the composable SceneView
  * @param onScale lambda invoked when a user performs a pinch gesture on the composable SceneView
  * @param onUp lambda invoked when the user removes all their pointers from the composable SceneView
@@ -109,6 +111,7 @@ public fun SceneView(
     onSpatialReferenceChanged: ((spatialReference: SpatialReference?) -> Unit)? = null,
     onLayerViewStateChanged: ((GeoView.GeoViewLayerViewStateChanged) -> Unit)? = null,
     onInteractingChanged: ((isInteracting: Boolean) -> Unit)? = null,
+    onCurrentViewpointCameraChanged: ((camera: Camera) -> Unit)? = null,
     onRotate: ((RotationChangeEvent) -> Unit)? = null,
     onScale: ((ScaleChangeEvent) -> Unit)? = null,
     onUp: ((UpEvent) -> Unit)? = null,
@@ -167,6 +170,7 @@ public fun SceneView(
         onSpatialReferenceChanged,
         onLayerViewStateChanged,
         onInteractingChanged,
+        onCurrentViewpointCameraChanged,
         onRotate,
         onScale,
         onUp,
@@ -207,6 +211,7 @@ private fun SceneViewEventHandler(
     onSpatialReferenceChanged: ((spatialReference: SpatialReference?) -> Unit)?,
     onLayerViewStateChanged: ((GeoView.GeoViewLayerViewStateChanged) -> Unit)?,
     onInteractingChanged: ((isInteracting: Boolean) -> Unit)?,
+    onCurrentViewpointCameraChanged: ((camera: Camera) -> Unit)?,
     onRotate: ((RotationChangeEvent) -> Unit)?,
     onScale: ((ScaleChangeEvent) -> Unit)?,
     onUp: ((UpEvent) -> Unit)?,
@@ -223,6 +228,7 @@ private fun SceneViewEventHandler(
     val currentOnSpatialReferenceChanged by rememberUpdatedState(onSpatialReferenceChanged)
     val currentOnLayerViewStateChanged by rememberUpdatedState(onLayerViewStateChanged)
     val currentOnInteractingChanged by rememberUpdatedState(onInteractingChanged)
+    val currentOnViewpointCameraChanged by rememberUpdatedState(onCurrentViewpointCameraChanged)
     val currentOnRotate by rememberUpdatedState(onRotate)
     val currentOnScale by rememberUpdatedState(onScale)
     val currentOnUp by rememberUpdatedState(onUp)
@@ -255,6 +261,11 @@ private fun SceneViewEventHandler(
                 currentOnLayerViewStateChanged?.invoke(currentLayerViewState)
             }
         }
+        launch {
+            sceneView.viewpointChanged.collect {
+                currentOnViewpointCameraChanged?.invoke(sceneView.getCurrentViewpointCamera())
+            }
+        }
         launch(Dispatchers.Main.immediate) {
             sceneView.isInteracting.collect { isInteracting ->
                 currentOnInteractingChanged?.invoke(isInteracting)