Scalebar: Refactor ViewModel

microapps/ScalebarApp/app/src/main/java/com/arcgismaps/toolkit/scalebarapp/screens/MainScreen.kt

@@ -49,9 +49,9 @@ fun MainScreen(modifier: Modifier) {
         mutableStateOf(
             ArcGISMap(BasemapStyle.ArcGISTopographic).apply {
                 initialViewpoint = Viewpoint(
-                    latitude = 39.8,
-                    longitude = -98.6,
-                    scale = 10e7
+                    latitude = 33.751765,
+                    longitude = -117.935518,
+                    scale = 44016.65596653387
                 )
             }
         )
@@ -78,7 +78,7 @@ fun MainScreen(modifier: Modifier) {
                 .align(Alignment.BottomStart)
         ) {
             Scalebar(
-                maxWidth = 175.0,
+                maxDisplayWidth = 175.0,
                 unitsPerDip = unitsPerDip,
                 viewpoint = viewpoint,
                 spatialReference = spatialReference,

toolkit/scalebar/src/androidTest/java/com/arcgismaps/toolkit/scalebar/ScalebarComputationTest.kt

@@ -0,0 +1,141 @@
+/*
+ * Copyright 2025 Esri
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.arcgismaps.toolkit.scalebar
+
+import androidx.compose.ui.test.junit4.createComposeRule
+import androidx.compose.ui.text.TextStyle
+import androidx.compose.ui.unit.sp
+import com.arcgismaps.geometry.Point
+import com.arcgismaps.geometry.SpatialReference
+import com.arcgismaps.mapping.Viewpoint
+import com.arcgismaps.toolkit.scalebar.theme.LabelTypography
+import com.google.common.truth.Truth.assertThat
+import kotlinx.coroutines.test.runTest
+import org.junit.Rule
+import org.junit.Test
+
+class ScalebarCalculationsTest {
+    @get:Rule
+    val composeTestRule = createComposeRule()
+
+    private val esriRedlands = Point(-13046081.04434825, 4036489.208008117, SpatialReference.webMercator())
+    private val defaultLabelTypography = LabelTypography(labelStyle = TextStyle(fontSize = 11.sp))
+
+    /**
+     * Given map properties and device properties
+     * When the properties of a line style scalebar are computed
+     * Then the display length and labels should be correct
+     *
+     * @since 200.7.0
+     */
+    @Test
+    fun testLineStyle() {
+        testScalebarCalculations(
+            point = esriRedlands,
+            style = ScalebarStyle.Line,
+            maxWidth = 175.0,
+            units = ScalebarUnits.METRIC,
+            scale = 10000000.0,
+            unitsPerDip = 2645.833333330476,
+            labelTypography = defaultLabelTypography,
+            expectedDisplayLength = 171.0,
+            expectedLabels = listOf("375 km")
+        )
+    }
+
+    /**
+     * Given map properties and device properties
+     * When the properties of a bar scalebar are calculated
+     * Then the display length and labels should be correct
+     *
+     * @since 200.7.0
+     */
+    @Test
+    fun testBarStyle() = runTest {
+        testScalebarCalculations(
+            point = esriRedlands,
+            style = ScalebarStyle.Bar,
+            maxWidth = 175.0,
+            units = ScalebarUnits.METRIC,
+            scale = 10000000.0,
+            unitsPerDip = 2645.833333330476,
+            labelTypography = defaultLabelTypography,
+            expectedDisplayLength = 171.0,
+            expectedLabels = listOf("375 km")
+        )
+    }
+
+
+    /**
+     * Executes the scalebar calculations and verifies the results.
+     *
+     * @since 200.7.0
+     */
+    private fun testScalebarCalculations(
+        point: Point,
+        style: ScalebarStyle,
+        maxWidth: Double,
+        units: ScalebarUnits,
+        scale: Double,
+        unitsPerDip: Double,
+        labelTypography: LabelTypography,
+        expectedDisplayLength: Double,
+        expectedLabels: List<String>,
+        spatialReference: SpatialReference = SpatialReference.webMercator(),
+        useGeodeticCalculations: Boolean = true,
+    ) {
+        composeTestRule.setContent {
+
+            val viewpoint = Viewpoint(
+                center = Point(
+                    x = point.x,
+                    y = point.y,
+                    spatialReference = spatialReference
+                ),
+                scale = scale
+            )
+
+            val scalebarProperties = calculateScalebarProperties(
+                minScale = 0.0,
+                useGeodeticCalculations = useGeodeticCalculations,
+                scalebarUnits = units,
+                spatialReference = spatialReference,
+                viewpoint = viewpoint,
+                unitsPerDip = unitsPerDip,
+                maxDisplayLength = maxWidth,
+            )
+            val minSegmentWidth = measureMinSegmentWidth(
+                scalebarLineLength = scalebarProperties?.lineLength ?: 0.0,
+                labelTypography = labelTypography,
+            )
+            val scalebarLabels = generateScalebarLabels(
+                minSegmentWidth = minSegmentWidth,
+                displayLength = scalebarProperties?.displayLength ?: 0.0,
+                scalebarLineLength = scalebarProperties?.lineLength ?: 0.0,
+                displayUnit = scalebarProperties?.displayUnit,
+                style = style,
+                labelTypography = labelTypography,
+            )
+
+            assertThat(scalebarProperties?.displayLength).isWithin(.5).of(expectedDisplayLength)
+            assertThat(scalebarLabels.size).isEqualTo(expectedLabels.size)
+            for (i in expectedLabels.indices) {
+                assertThat(scalebarLabels[i].label).isEqualTo(expectedLabels[i])
+            }
+        }
+    }
+}

toolkit/scalebar/src/androidTest/java/com/arcgismaps/toolkit/scalebar/ScalebarTests.kt

@@ -102,7 +102,7 @@ class ScalebarTests {
      * @since 200.7.0
      */
     @Test
-    fun testLineScaleBarColorChange() {
+    fun testLineScalebarColorChange() {
         composeTestRule.setContent {
             Box(
                 modifier = Modifier.fillMaxSize(),