Keep the map design across configuration changes

src/androidTest/java/com/mapconductor/tomtom/TomTomMapViewSaverTest.kt

@@ -0,0 +1,87 @@
+package com.mapconductor.tomtom
+
+import androidx.compose.runtime.saveable.Saver
+import androidx.compose.runtime.saveable.SaverScope
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import com.mapconductor.core.features.GeoPoint
+import com.mapconductor.core.map.AttributionRule
+import com.mapconductor.core.map.MapCameraPosition
+import com.mapconductor.core.map.MapUISettings
+import com.tomtom.sdk.map.display.style.StyleDescriptor
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertSame
+import org.junit.Assert.assertTrue
+import org.junit.Test
+import org.junit.runner.RunWith
+import android.net.Uri
+import android.os.Bundle
+import android.os.Parcel
+
+/**
+ * 回転などの構成変更で state が [TomTomMapViewSaver] を通って作り直されても、デザイン（id・
+ * attributionRules ほか）と uiSettings・カメラが落ちないこと。Bundle は実機の Parcel を一度通す。
+ */
+@RunWith(AndroidJUnit4::class)
+class TomTomMapViewSaverTest {
+    private val rules =
+        listOf(AttributionRule("© test"), AttributionRule("© ranged", minZoom = 3, maxZoom = 15))
+
+    private val camera =
+        MapCameraPosition(
+            position = GeoPoint(21.38, -157.93),
+            zoom = 12.0,
+            bearing = 20.0,
+            tilt = 10.0,
+        )
+
+    @Test
+    fun keepsCustomDesignWithItsStyleDescriptor() {
+        val descriptor = StyleDescriptor(Uri.parse("https://example.com/style.json"))
+        val design = TomTomMapDesign.Custom("my-style", descriptor, rules)
+        val state = TomTomMapViewState(id = "tomtom-1", mapDesignType = design, cameraPosition = camera)
+        state.uiSettings = MapUISettings(rotateGesture = false, tiltGesture = false)
+
+        val restored = roundTrip(TomTomMapViewSaver().createSaver(), state)
+
+        // 以前は id だけを保存して create(id) で戻しており、Standard になっていた。
+        val actual = restored.mapDesignType
+        assertTrue(actual is TomTomMapDesign.Custom)
+        actual as TomTomMapDesign.Custom
+        assertEquals("my-style", actual.id)
+        assertEquals(descriptor, actual.styleDescriptor)
+        assertEquals(rules, actual.attributionRules)
+        assertCommon(restored, "tomtom-1")
+    }
+
+    @Test
+    fun keepsPresetDesignAsTheSameObject() {
+        val state = TomTomMapViewState(id = "tomtom-2", mapDesignType = TomTomMapDesign.Satellite)
+        assertSame(TomTomMapDesign.Satellite, roundTrip(TomTomMapViewSaver().createSaver(), state).mapDesignType)
+    }
+
+    private fun assertCommon(restored: com.mapconductor.core.map.MapViewStateInterface<*>, id: String) {
+        assertEquals(id, restored.id)
+        assertEquals(false, restored.uiSettings.rotateGesture)
+        assertEquals(false, restored.uiSettings.tiltGesture)
+        assertEquals(true, restored.uiSettings.scrollGesture)
+        assertEquals(12.0, restored.cameraPosition.zoom, 1e-9)
+        assertEquals(20.0, restored.cameraPosition.bearing, 1e-9)
+        assertEquals(21.38, restored.cameraPosition.position.latitude, 1e-9)
+    }
+
+    private fun <T : Any> roundTrip(
+        saver: Saver<T, Bundle>,
+        value: T,
+    ): T {
+        val saved = with(saver) { SaverScope { true }.save(value) }!!
+        // 一度 Parcel に書いて読み戻す（プロセスが落ちたあとの復元と同じ経路）。
+        val parcel = Parcel.obtain()
+        try {
+            parcel.writeBundle(saved)
+            parcel.setDataPosition(0)
+            return saver.restore(parcel.readBundle(javaClass.classLoader)!!)!!
+        } finally {
+            parcel.recycle()
+        }
+    }
+}

src/main/java/com/mapconductor/tomtom/TomTomMapView.kt

@@ -157,14 +157,24 @@ fun TomTomMapView(
                 }
                 mapController.setMapClickListener(onMapClick)
                 mapController.setMapLongClickListener(onMapLongClick)
-                mapController.setMapDesignTypeChangeListener(state::onMapDesignTypeChange)
                 cameraRestriction?.let { mapController.setCameraRestriction(it) }
                 // 大量マーカーをラスタタイル化するため、マーカータイル用ラスタレイヤーの
                 // 実体化（スタイル合成 + loadStyle）を配線する。
                 mapController.setupMarkerTileRaster(
                     apiKey = tomtomApiKey(context),
                     cacheDir = context.cacheDir,
                 )
+                // 地図は MapOptions の既定スタイル（= Standard）で作られる。state のデザインが
+                // それ以外なら載せる。そのあとでリスナーを繋ぐ: 先に繋ぐとコントローラの既定値
+                // （Standard）が state へ返り、アプリが渡した（あるいは回転後に復元した）
+                // デザインが Standard に化ける。
+                val initialDesign = state.mapDesignType
+                if (initialDesign === TomTomMapDesign.Standard) {
+                    mapController.mapDesignType = initialDesign
+                } else {
+                    mapController.setMapDesignType(initialDesign)
+                }
+                mapController.setMapDesignTypeChangeListener(state::onMapDesignTypeChange)
                 holder.mapView.post {
                     // Style loading can reset the camera, so reapply it once the view is attached.
                     mapController.moveCamera(initialCameraPosition)

src/main/java/com/mapconductor/tomtom/TomTomMapViewStateImpl.kt

@@ -9,7 +9,9 @@ import com.mapconductor.core.map.MapCameraPosition
 import com.mapconductor.core.map.MapCameraPositionInterface
 import com.mapconductor.core.map.MapPaddings
 import com.mapconductor.core.map.MapViewState
+import com.mapconductor.core.map.MapViewStateBundle
 import com.mapconductor.core.map.MapViewStateInterface
+import com.tomtom.sdk.map.display.style.StyleDescriptor
 import java.util.UUID
 import android.os.Bundle
 import kotlinx.coroutines.flow.MutableStateFlow
@@ -61,7 +63,14 @@ class TomTomMapViewSaver : BaseMapViewSaver<TomTomMapViewState>() {
         state: TomTomMapViewState,
         bundle: Bundle,
     ) {
-        bundle.putString("id", state.mapDesignType.id)
+        val design = state.mapDesignType
+        bundle.putString("id", design.id)
+        // 定義済み（Standard など）以外は、地図に読み込ませる StyleDescriptor（Parcelable）ごと
+        // 保存して Custom で戻す。id だけだと Custom は Standard に化け、attributionRules も落ちる。
+        if (design is TomTomMapDesign && design !== TomTomMapDesign.create(design.id)) {
+            bundle.putParcelable(KEY_STYLE_DESCRIPTOR, design.styleDescriptor)
+        }
+        MapViewStateBundle.putAttributionRules(bundle, design.attributionRules)
     }
 
     override fun createState(
@@ -71,16 +80,30 @@ class TomTomMapViewSaver : BaseMapViewSaver<TomTomMapViewState>() {
     ): TomTomMapViewState =
         TomTomMapViewState(
             id = stateId,
-            mapDesignType =
-                TomTomMapDesign.create(
-                    id = mapDesignBundle?.getString("id") ?: TomTomMapDesign.Standard.id,
-                ),
+            mapDesignType = restoreDesign(mapDesignBundle),
             cameraPosition = cameraPosition,
         )
 
+    private fun restoreDesign(bundle: Bundle?): TomTomMapDesign {
+        val id = bundle?.getString("id") ?: return TomTomMapDesign.Standard
+        val rules = MapViewStateBundle.getAttributionRules(bundle)
+
+        @Suppress("DEPRECATION")
+        val descriptor = bundle.getParcelable<StyleDescriptor>(KEY_STYLE_DESCRIPTOR)
+        val preset = TomTomMapDesign.create(id)
+        return when {
+            descriptor != null -> TomTomMapDesign.Custom(id, descriptor, rules)
+            rules.isNotEmpty() -> TomTomMapDesign.Custom(id, preset.styleDescriptor, rules)
+            else -> preset
+        }
+    }
+
     override fun getStateId(state: TomTomMapViewState): String = state.id
 }
 
+// 公開 API の門番（javap）にコンパニオンの定数が載らないよう、ファイル private にする。
+private const val KEY_STYLE_DESCRIPTOR = "styleDescriptor"
+
 @Composable
 fun rememberTomTomMapViewState(
     mapDesign: TomTomMapDesign = TomTomMapDesign.Standard,