Keep the map design across configuration changes

build.gradle.kts

@@ -89,6 +89,11 @@ dependencies {
     } else {
         api("com.mapconductor:compose:$libraryVersion")
     }
+
+    testImplementation(libs.junit)
+    // Saver の保存 → 復元を実機の Bundle / Parcel で確かめる（SaverRoundTripTest）。
+    androidTestImplementation(libs.androidx.junit)
+    androidTestImplementation(libs.androidx.espresso.core)
 }
 
 // Set project version for NMCP plugin

src/androidTest/java/com/mapconductor/longdo/LongdoMapViewSaverTest.kt

@@ -0,0 +1,97 @@
+package com.mapconductor.longdo
+
+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 org.junit.Assert.assertEquals
+import org.junit.Test
+import org.junit.runner.RunWith
+import android.os.Bundle
+import android.os.Parcel
+
+/**
+ * 回転などの構成変更で state が [LongdoMapViewSaver] 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 LongdoMapViewSaverTest {
+    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 keepsDesignOutsideThePresets() {
+        // 以前は id だけを保存して fromId で戻しており、定義に無い id は Normal になっていた。
+        val design = LongdoDesign(id = "my-gray", layerName = "GRAY")
+        val state = LongdoViewState(mapDesignType = design, id = "longdo-1", initialCameraPosition = camera)
+        state.uiSettings = MapUISettings(rotateGesture = false, tiltGesture = false)
+
+        val restored = roundTrip(LongdoMapViewSaver().createSaver(), state)
+
+        assertEquals(design, restored.mapDesignType)
+        assertCommon(restored, "longdo-1")
+    }
+
+    @Test
+    fun keepsAttributionRulesOfAnAppDesign() {
+        val design =
+            object : LongdoMapDesignTypeInterface {
+                override val id: String = "app-design"
+                override val layerName: String = "POLITICAL"
+                override val attributionRules: List<AttributionRule> = rules
+
+                override fun getValue(): String = id
+            }
+        val restored = roundTrip(LongdoMapViewSaver().createSaver(), LongdoViewState(design, "longdo-2"))
+
+        assertEquals("app-design", restored.mapDesignType.id)
+        assertEquals("POLITICAL", restored.mapDesignType.layerName)
+        assertEquals(rules, restored.mapDesignType.attributionRules)
+    }
+
+    @Test
+    fun keepsPresetDesign() {
+        val restored = roundTrip(LongdoMapViewSaver().createSaver(), LongdoViewState(LongdoDesign.Pastel, "longdo-3"))
+        assertEquals(LongdoDesign.Pastel, restored.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/longdo/LongdoViewStateImpl.kt

@@ -6,9 +6,12 @@ import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.saveable.rememberSaveable
 import androidx.compose.runtime.setValue
 import com.mapconductor.compose.map.BaseMapViewSaver
+import com.mapconductor.core.InternalMapConductorApi
+import com.mapconductor.core.map.AttributionRule
 import com.mapconductor.core.map.MapCameraPosition
 import com.mapconductor.core.map.MapCameraPositionInterface
 import com.mapconductor.core.map.MapViewState
+import com.mapconductor.core.map.MapViewStateBundle
 import com.mapconductor.core.map.MapViewStateInterface
 import android.os.Bundle
 
@@ -62,27 +65,44 @@ class LongdoViewState(
 
 /**
  * [LongdoViewState] の保存・復元を行う Saver。
- * デザインは [LongdoMapDesignTypeInterface.id] を保存し、[LongdoDesign.fromId] で復元する。
+ * デザインは id・レイヤ名・attributionRules を保存する。id だけで [LongdoDesign.fromId] に
+ * 頼ると、定義に無いデザインは [LongdoDesign.Normal] に化け、attributionRules も落ちる。
  */
 class LongdoMapViewSaver : BaseMapViewSaver<LongdoViewState>() {
     override fun saveMapDesign(
         state: LongdoViewState,
         bundle: Bundle,
     ) {
-        bundle.putString(KEY_DESIGN_ID, state.mapDesignType.id)
+        val design = state.mapDesignType
+        bundle.putString(KEY_DESIGN_ID, design.id)
+        bundle.putString(KEY_LAYER_NAME, design.layerName)
+        MapViewStateBundle.putAttributionRules(bundle, design.attributionRules)
     }
 
     override fun createState(
         stateId: String,
         mapDesignBundle: Bundle?,
         cameraPosition: MapCameraPosition,
-    ): LongdoViewState {
-        val designId = mapDesignBundle?.getString(KEY_DESIGN_ID)
-        return LongdoViewState(
-            mapDesignType = LongdoDesign.fromId(designId),
+    ): LongdoViewState =
+        LongdoViewState(
+            mapDesignType = restoreDesign(mapDesignBundle),
             id = stateId,
             initialCameraPosition = cameraPosition,
         )
+
+    private fun restoreDesign(bundle: Bundle?): LongdoMapDesignTypeInterface {
+        val designId = bundle?.getString(KEY_DESIGN_ID)
+        // レイヤ名を持たない以前の形式は id から引く。
+        val layerName = bundle?.getString(KEY_LAYER_NAME) ?: return LongdoDesign.fromId(designId)
+        val id = designId ?: LongdoDesign.Normal.id
+        val rules = MapViewStateBundle.getAttributionRules(bundle)
+        // LongdoDesign は attributionRules を持てない。規則が無ければ LongdoDesign で戻し、
+        // 定義済み（LongdoDesign.Gray など）と等しくなるようにする。
+        return if (rules.isEmpty()) {
+            LongdoDesign(id = id, layerName = layerName)
+        } else {
+            RestoredLongdoDesign(id = id, layerName = layerName, attributionRules = rules)
+        }
     }
 
     override fun getStateId(state: LongdoViewState): String = state.id
@@ -92,6 +112,19 @@ class LongdoMapViewSaver : BaseMapViewSaver<LongdoViewState>() {
     }
 }
 
+// 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_LAYER_NAME = "longdo_layer_name"
+
+/** attributionRules を持つデザインを復元するときの入れ物（[LongdoDesign] は規則を持てない）。 */
+@InternalMapConductorApi
+internal data class RestoredLongdoDesign(
+    override val id: String,
+    override val layerName: String,
+    override val attributionRules: List<AttributionRule>,
+) : LongdoMapDesignTypeInterface {
+    override fun getValue(): String = id
+}
+
 /**
  * [LongdoViewState] を生成・記憶する Composable ファクトリ。
  *