From de792be47d8f6a08ef4af012b862b86a5013d25f Mon Sep 17 00:00:00 2001
From: Darryl Lynch <dlynch@esri.com>
Date: Fri, 27 Dec 2024 14:09:49 +0000
Subject: [PATCH] Move string handling to UI

---
 .../components/ProjectGeometryViewModel.kt    | 27 +++++++------------
 .../screens/ProjectGeometryScreen.kt          | 24 ++++++++++++++++-
 2 files changed, 33 insertions(+), 18 deletions(-)

diff --git a/samples/project-geometry/src/main/java/com/esri/arcgismaps/sample/projectgeometry/components/ProjectGeometryViewModel.kt b/samples/project-geometry/src/main/java/com/esri/arcgismaps/sample/projectgeometry/components/ProjectGeometryViewModel.kt
index 15896bd89..456290f53 100644
--- a/samples/project-geometry/src/main/java/com/esri/arcgismaps/sample/projectgeometry/components/ProjectGeometryViewModel.kt
+++ b/samples/project-geometry/src/main/java/com/esri/arcgismaps/sample/projectgeometry/components/ProjectGeometryViewModel.kt
@@ -35,9 +35,10 @@ import com.arcgismaps.toolkit.geoviewcompose.MapViewProxy
 import com.esri.arcgismaps.sample.projectgeometry.R
 import com.esri.arcgismaps.sample.sampleslib.components.MessageDialogViewModel
 import kotlinx.coroutines.flow.MutableStateFlow
-import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
 import kotlinx.coroutines.launch
-import java.util.Locale
+
+data class PointProjection (val original: Point, val projection: Point)
 
 class ProjectGeometryViewModel(val app: Application) : AndroidViewModel(app) {
     // create a map with a navigation night basemap style
@@ -55,6 +56,10 @@ class ProjectGeometryViewModel(val app: Application) : AndroidViewModel(app) {
     // Create a message dialog view model for handling error messages
     val messageDialogVM = MessageDialogViewModel()
 
+    // state flow of a point and its projection for presentation in UI
+    private val _pointProjectionFlow = MutableStateFlow<PointProjection?>(null)
+    val pointFlow = _pointProjectionFlow.asStateFlow()
+
     // setup the red pin marker image as bitmap drawable
     private val markerDrawable: BitmapDrawable by lazy {
         // load the bitmap from resources and create a drawable
@@ -80,9 +85,6 @@ class ProjectGeometryViewModel(val app: Application) : AndroidViewModel(app) {
         graphics.add(markerGraphic)
     }
 
-    private val _infoText = MutableStateFlow(app.resources.getString(R.string.tap_to_begin))
-    val infoText: StateFlow<String> = _infoText
-
     init {
         viewModelScope.launch {
             arcGISMap.load().onFailure { error ->
@@ -109,18 +111,9 @@ class ProjectGeometryViewModel(val app: Application) : AndroidViewModel(app) {
                     geometry = point,
                     spatialReference = SpatialReference.wgs84()
                 )
-            _infoText.value = app.resources.getString(
-                R.string.projection_info_text,
-                point.toDisplayFormat(),
-                projectedPoint?.toDisplayFormat()
-            )
+            projectedPoint?.let { projection ->
+                _pointProjectionFlow.value = PointProjection(point, projection)
+            }
         }
     }
 }
-
-/**
- * Extension function for the Point type that returns
- * a float-precision formatted string suitable for display
- */
-private fun Point.toDisplayFormat() =
-    "${String.format(Locale.getDefault(),"%.5f", x)}, ${String.format(Locale.getDefault(),"%.5f", y)}"
diff --git a/samples/project-geometry/src/main/java/com/esri/arcgismaps/sample/projectgeometry/screens/ProjectGeometryScreen.kt b/samples/project-geometry/src/main/java/com/esri/arcgismaps/sample/projectgeometry/screens/ProjectGeometryScreen.kt
index 4a763d10e..7e2a61c55 100644
--- a/samples/project-geometry/src/main/java/com/esri/arcgismaps/sample/projectgeometry/screens/ProjectGeometryScreen.kt
+++ b/samples/project-geometry/src/main/java/com/esri/arcgismaps/sample/projectgeometry/screens/ProjectGeometryScreen.kt
@@ -30,11 +30,13 @@ import androidx.compose.ui.Modifier
 import androidx.compose.ui.res.stringResource
 import androidx.compose.ui.unit.dp
 import androidx.lifecycle.viewmodel.compose.viewModel
+import com.arcgismaps.geometry.Point
 import com.arcgismaps.toolkit.geoviewcompose.MapView
 import com.esri.arcgismaps.sample.projectgeometry.R
 import com.esri.arcgismaps.sample.projectgeometry.components.ProjectGeometryViewModel
 import com.esri.arcgismaps.sample.sampleslib.components.MessageDialog
 import com.esri.arcgismaps.sample.sampleslib.components.SampleTopAppBar
+import java.util.Locale
 
 /**
  * Main screen layout for the sample app
@@ -42,7 +44,20 @@ import com.esri.arcgismaps.sample.sampleslib.components.SampleTopAppBar
 @Composable
 fun ProjectGeometryScreen(sampleName: String) {
     val mapViewModel: ProjectGeometryViewModel = viewModel()
-    val infoText by mapViewModel.infoText.collectAsState()
+    val projectionInfo by mapViewModel.pointFlow.collectAsState()
+
+    val infoText =
+        if (projectionInfo == null) {
+            "Tap to begin"
+        }
+        else {
+            stringResource(
+                R.string.projection_info_text,
+                projectionInfo?.original?.toDisplayFormat()!!,
+                projectionInfo?.projection?.toDisplayFormat()!!
+            )
+        }
+
     Scaffold(
         topBar = { SampleTopAppBar(title = sampleName) },
         content = {
@@ -88,3 +103,10 @@ fun ProjectGeometryScreen(sampleName: String) {
         }
     )
 }
+
+/**
+ * Extension function for the Point type that returns
+ * a float-precision formatted string suitable for display
+ */
+private fun Point.toDisplayFormat() =
+    "${String.format(Locale.getDefault(),"%.5f", x)}, ${String.format(Locale.getDefault(),"%.5f", y)}"