fix(settings): force custom-source toggles off when legacy example.com URL present

Old installs that once enabled the custom TLE/transceiver toggles kept
the legacy "https://example.com/tle.txt" placeholder in preferences.
Under the new "toggle replaces the online-update default source"
semantics this pointed the All/SatNOGS fetch at a dead URL and broke
satellite updates after upgrading to 4.4.8.

Migration in getDataSourcesSettings(): example.com placeholders are
replaced by the real default URLs (Celestrak All / SatNOGS) and the
toggles are forced OFF unless a non-default, real user URL is set.
Also disable the reset (loop) icon buttons while their toggle is off.

Verified: core:data tests pass, settings + app compile. Version stays
4.4.8 (覆盖 per user).

.github/workflows/release.yml

@@ -4,10 +4,15 @@ on:
   push:
     tags:
       - v**
+  workflow_dispatch:
+    inputs:
+      tag_name:
+        description: 'Release tag name (e.g. v4.4.3)'
+        required: false
+        default: ''
 
 env:
-  TAG_NAME: ${{ github.ref_name }}
+  TAG_NAME: ${{ github.event.inputs.tag_name || github.ref_name }}
-  GITHUB_TOKEN: ${{ secrets.RELEASE_TOKEN }}
 
 jobs:
   release:
@@ -16,66 +21,40 @@ jobs:
       contents: write
     steps:
       - name: Checkout Repository
-        uses: actions/checkout@v7
+        uses: actions/checkout@v4
 
       - name: Setup Java
-        uses: actions/setup-java@v5
+        uses: actions/setup-java@v4
         with:
           distribution: 'temurin'
           java-version: '21'
 
       - name: Setup Gradle
-        uses: gradle/actions/setup-gradle@v6
+        uses: gradle/actions/setup-gradle@v4
 
-      - name: Assemble Artifacts
+      - name: Assemble APK
-        run: ./gradlew assembleRelease bundleRelease
+        run: ./gradlew assembleRelease
 
       - name: Sign APK
         run: |
           echo "${{ secrets.KEY_STORE }}" | base64 -d > keystore.jks
           APK=$(find app/build/outputs/apk/release -name "*.apk" | head -1)
+          VERSION=${TAG_NAME#v}
+          SIGNED_APK="app/build/outputs/apk/release/Look4Sat-Pro-${VERSION}.apk"
           BUILD_TOOLS=$(ls -d ${ANDROID_HOME}/build-tools/*/ | sort -V | tail -1)
           ${BUILD_TOOLS}apksigner sign \
             --ks keystore.jks \
             --ks-pass pass:${{ secrets.KEY_STORE_PASSWORD }} \
             --ks-key-alias ${{ secrets.KEY_ALIAS }} \
             --key-pass pass:${{ secrets.KEY_PASSWORD }} \
-            --out app/build/outputs/apk/release/look4sat.apk \
+            --out "$SIGNED_APK" \
             "$APK"
           rm keystore.jks
-
+          echo "SIGNED_APK=$SIGNED_APK" >> "$GITHUB_ENV"
-      - name: Sign Bundle
-        run: |
-          echo "${{ secrets.KEY_STORE }}" | base64 -d > keystore.jks
-          AAB=$(find app/build/outputs/bundle/release -name "*.aab" | head -1)
-          jarsigner -verbose -sigalg SHA256withRSA -digestalg SHA-256 \
-            -keystore keystore.jks \
-            -storepass ${{ secrets.KEY_STORE_PASSWORD }} \
-            -keypass ${{ secrets.KEY_PASSWORD }} \
-            "$AAB" ${{ secrets.KEY_ALIAS }}
-          rm keystore.jks
-
-      - name: Setup Ruby
-        uses: ruby/setup-ruby@v1
-        with:
-          ruby-version: '3.4'
-
-      - name: Deploy Bundle to Google Play
-        run: |
-          gem install multi_json
-          gem install fastlane --no-document
-          AAB=$(find app/build/outputs/bundle/release -name "*.aab" | head -1)
-          echo '${{ secrets.SERVICE_ACCOUNT_JSON }}' > service_account.json
-          fastlane supply \
-            --aab "$AAB" \
-            --json_key service_account.json \
-            --package_name com.rtbishop.look4sat \
-            --track production \
-            --skip_upload_images true \
-            --skip_upload_screenshots true \
-          rm service_account.json
 
       - name: Create Release
+        env:
+          GH_TOKEN: ${{ github.token }}
         run: |
           gh release create $TAG_NAME --title=$TAG_NAME --generate-notes
-          gh release upload $TAG_NAME app/build/outputs/apk/release/look4sat.apk
+          gh release upload $TAG_NAME "$SIGNED_APK"

.gitignore

@@ -39,8 +39,7 @@ captures/
 .idea/
 
 # Keystore files
-# Uncomment the following line if you do not want to check your keystore files in.
+*.jks
-#*.jks
 /*.properties
 /keystore.properties
 /app/keystore.jks

app/build.gradle.kts

@@ -1,3 +1,29 @@
+import java.util.Properties
+
 plugins {
     alias(libs.plugins.convention.applicationPlugin)
 }
+
+// Load signing config from keystore.properties (gitignored, never commit credentials)
+val keystoreProperties = Properties().apply {
+    val propsFile = rootProject.file("keystore.properties")
+    if (propsFile.exists()) propsFile.inputStream().use { load(it) }
+}
+
+android {
+    signingConfigs {
+        if (keystoreProperties["storeFile"] != null) {
+            create("release") {
+                storeFile = rootProject.file(keystoreProperties["storeFile"] as String)
+                storePassword = keystoreProperties["storePassword"] as String
+                keyAlias = keystoreProperties["keyAlias"] as String
+                keyPassword = keystoreProperties["keyPassword"] as String
+            }
+        }
+    }
+    buildTypes {
+        release {
+            signingConfig = signingConfigs.findByName("release")
+        }
+    }
+}

app/src/main/AndroidManifest.xml

@@ -43,7 +43,7 @@
 
         <meta-data
             android:name="android.telephony.PROPERTY_SATELLITE_DATA_OPTIMIZED"
-            android:value="com.rtbishop.look4sat" />
+            android:value="com.rtbishop.look4sat.bg7nta" />
 
     </application>
 </manifest>

app/src/main/java/com/rtbishop/look4sat/MainScreen.kt

@@ -85,6 +85,7 @@ import com.rtbishop.look4sat.feature.mutual.MutualScreen
 import com.rtbishop.look4sat.feature.mutual.MutualViewModel
 import com.rtbishop.look4sat.feature.passes.PassesDestination
 import com.rtbishop.look4sat.feature.radar.RadarDestination
+import com.rtbishop.look4sat.feature.roaming.RoamingScreen
 import com.rtbishop.look4sat.feature.satellites.SatellitesDestination
 import com.rtbishop.look4sat.feature.settings.SettingsDestination
 
@@ -130,7 +131,7 @@ fun MainScreen(navigateToRadar: () -> Unit = {}) {
     val currentKey = backStack.lastOrNull()
     val navigateBack: () -> Unit = { backStack.removeLastOrNull() }
     val fadeTransition = fadeIn(animationSpec = tween(350)) togetherWith fadeOut(animationSpec = tween(350))
-    val navItems = listOf(Screen.Satellites, Screen.Passes, Screen.Radar, Screen.Mutual, Screen.Map, Screen.Settings)
+    val navItems = listOf(Screen.Satellites, Screen.Passes, Screen.Radar, Screen.Mutual, Screen.Roaming, Screen.Map, Screen.Settings)
 
     val context = LocalContext.current
     val container = (context.applicationContext as IContainerProvider).getMainContainer()
@@ -224,6 +225,9 @@ fun MainScreen(navigateToRadar: () -> Unit = {}) {
                                 }
                             )
                         }
+                        entry<Screen.Roaming> {
+                            RoamingScreen()
+                        }
                         entry<Screen.Settings> {
                             SettingsDestination()
                         }

build-logic/convention/src/main/java/com/rtbishop/look4sat/convention/ApplicationPlugin.kt

@@ -35,6 +35,7 @@ internal class ApplicationPlugin : Plugin<Project> {
             implementation(project(":feature:mutual"))
             implementation(project(":feature:passes"))
             implementation(project(":feature:radar"))
+            implementation(project(":feature:roaming"))
             implementation(project(":feature:satellites"))
             implementation(project(":feature:settings"))
             implementation(libs.androidx.core.splashscreen)

build-logic/convention/src/main/java/com/rtbishop/look4sat/convention/PluginSetupUtils.kt

@@ -57,7 +57,7 @@ internal fun Project.setupAndroidApp() {
         namespace = libs.versions.packageName.get()
         compileSdk = libs.versions.compileSdk.get().toInt()
         defaultConfig {
-            applicationId = libs.versions.packageName.get()
+            applicationId = libs.versions.applicationId.get()
             minSdk = libs.versions.minSdk.get().toInt()
             versionCode = libs.versions.appVersionCode.get().toInt()
             versionName = libs.versions.appVersionName.get()

core/data/src/main/java/com/rtbishop/look4sat/core/data/repository/DatabaseRepo.kt

@@ -69,11 +69,14 @@ class DatabaseRepo(
         val dataSourcesSettings = settingsRepo.dataSourcesSettings.value
         val tleUrls = buildMap {
             putAll(Sources.satelliteDataUrls)
-            if (dataSourcesSettings.useCustomTLE) put(customSourceType, dataSourcesSettings.tleUrl)
+            // 开关开且 URL 非空 -> All 用自定义 URL;否则用默认 URL(在线更新默认源)
+            put("All", if (dataSourcesSettings.useCustomTLE && dataSourcesSettings.tleUrl.isNotBlank())
+                dataSourcesSettings.tleUrl else Sources.defaultTleUrl)
         }.filterValues { it.isNotBlank() }
         val radioUrls = buildMap {
             putAll(Sources.transceiversDataUrls)
-            if (dataSourcesSettings.useCustomTransceivers) put(customSourceType, dataSourcesSettings.transceiversUrl)
+            put("SatNOGS", if (dataSourcesSettings.useCustomTransceivers && dataSourcesSettings.transceiversUrl.isNotBlank())
+                dataSourcesSettings.transceiversUrl else Sources.defaultTransceiversUrl)
         }.filterValues { it.isNotBlank() }
         // launch all network requests concurrently
         val tleJobs = tleUrls.values.map { url -> async { url to remoteSource.getNetworkStream(url) } }

core/data/src/main/java/com/rtbishop/look4sat/core/data/repository/SatelliteRepo.kt

@@ -95,14 +95,8 @@ class SatelliteRepo(
         }
     }
 
-    override suspend fun getRadios(
+    override suspend fun getRadios(satPos: OrbitalPos, radios: List<SatRadio>): List<SatRadio> {
-        sat: OrbitalObject,
-        pos: GeoPos,
-        radios: List<SatRadio>,
-        time: Long
-    ): List<SatRadio> {
         return withContext(dispatcher) {
-            val satPos = sat.getPosition(pos, time)
             radios.map { transmitter ->
                 transmitter.copy(
                     downlinkLow = transmitter.downlinkLow?.let { satPos.getDownlinkFreq(it) },
@@ -242,13 +236,16 @@ class SatelliteRepo(
             if (elevation > maxElevation) maxElevation = elevation
         } while (elevation < 0.0)
 
-        // refine AOS to ~500ms precision
+        // refine AOS to ~500ms precision via binary search.
-        calendarTimeMillis -= 60L * 1000L
+        // Elevation is monotonic across the horizon crossing, so binary search
-        do {
+        // finds the crossing in ~8 SGP4 calls instead of up to 120 linear steps.
-            calendarTimeMillis += 500L
+        var aosLo = calendarTimeMillis - 60L * 1000L // elevation < 0 (below horizon)
-            elevation = sat.getElevation(pos, calendarTimeMillis)
+        var aosHi = calendarTimeMillis // elevation >= 0 (above horizon)
-            if (elevation > maxElevation) maxElevation = elevation
+        while (aosHi - aosLo > 500L) {
-        } while (elevation < 0.0)
+            val mid = (aosLo + aosHi) / 2
+            if (sat.getElevation(pos, mid) < 0.0) aosLo = mid else aosHi = mid
+        }
+        calendarTimeMillis = aosHi
 
         // Get full position for AOS data (azimuth, altitude)
         val aosPos = sat.getFullPosition(pos, calendarTimeMillis)
@@ -262,13 +259,14 @@ class SatelliteRepo(
             if (elevation > maxElevation) maxElevation = elevation
         } while (elevation > 0.0)
 
-        // refine LOS to ~500ms precision
+        // refine LOS to ~500ms precision via binary search (same monotonic argument)
-        calendarTimeMillis -= 30L * 1000L
+        var losLo = calendarTimeMillis - 30L * 1000L // elevation > 0 (above horizon)
-        do {
+        var losHi = calendarTimeMillis // elevation <= 0 (below horizon)
-            calendarTimeMillis += 500L
+        while (losHi - losLo > 500L) {
-            elevation = sat.getElevation(pos, calendarTimeMillis)
+            val mid = (losLo + losHi) / 2
-            if (elevation > maxElevation) maxElevation = elevation
+            if (sat.getElevation(pos, mid) > 0.0) losLo = mid else losHi = mid
-        } while (elevation > 0.0)
+        }
+        calendarTimeMillis = losHi
 
         // Get full position for LOS data (azimuth, altitude)
         val losPos = sat.getFullPosition(pos, calendarTimeMillis)

core/data/src/main/java/com/rtbishop/look4sat/core/data/repository/SettingsRepo.kt

@@ -29,6 +29,7 @@ import com.rtbishop.look4sat.core.domain.model.OtherSettings
 import com.rtbishop.look4sat.core.domain.model.PassesSettings
 import com.rtbishop.look4sat.core.domain.model.RCSettings
 import com.rtbishop.look4sat.core.domain.model.RadioControlSettings
+import com.rtbishop.look4sat.core.domain.source.Sources
 import com.rtbishop.look4sat.core.domain.predict.GeoPos
 import com.rtbishop.look4sat.core.domain.repository.ISettingsRepo
 import com.rtbishop.look4sat.core.domain.utility.positionToQth
@@ -213,8 +214,8 @@ class SettingsRepo(
     }
 
     private fun setStationPosition(latitude: Double, longitude: Double, altitude: Double, locator: String) {
-        val newLat = latitude.round(4)
+        val newLat = latitude.round(5)
-        val newLon = longitude.round(4)
+        val newLon = longitude.round(5)
         val newAlt = altitude.round(1)
         val timestamp = System.currentTimeMillis()
         println("Received new Position($newLat, $newLon, $newAlt) & Locator $locator")
@@ -390,12 +391,20 @@ class SettingsRepo(
         _dataSourcesSettings.value = settings
     }
 
-    private fun getDataSourcesSettings(): DataSourcesSettings = DataSourcesSettings(
+    private fun getDataSourcesSettings(): DataSourcesSettings {
-        useCustomTLE = preferences.getBoolean(keyUseCustomTle, false),
+        // 4.4.8 修复: 旧版 example.com 占位 URL 视为未配置 -> 替换为真实默认 URL 且开关强制关闭,
-        useCustomTransceivers = preferences.getBoolean(keyUseCustomTransceivers, false),
+        // 否则在线更新的 All/SatNOGS 源会指向错误地址导致更新失败
-        tleUrl = preferences.getString(keyTleUrl, "https://example.com/tle.txt") ?: "",
+        val storedTleUrl = preferences.getString(keyTleUrl, Sources.defaultTleUrl) ?: Sources.defaultTleUrl
-        transceiversUrl = preferences.getString(keyTransceiversUrl, "https://example.com/radio.json") ?: ""
+        val storedTxUrl = preferences.getString(keyTransceiversUrl, Sources.defaultTransceiversUrl) ?: Sources.defaultTransceiversUrl
-    )
+        val tleUrl = if (storedTleUrl == "https://example.com/tle.txt") Sources.defaultTleUrl else storedTleUrl
+        val txUrl = if (storedTxUrl == "https://example.com/radio.json") Sources.defaultTransceiversUrl else storedTxUrl
+        return DataSourcesSettings(
+            useCustomTLE = preferences.getBoolean(keyUseCustomTle, false) && tleUrl != Sources.defaultTleUrl,
+            useCustomTransceivers = preferences.getBoolean(keyUseCustomTransceivers, false) && txUrl != Sources.defaultTransceiversUrl,
+            tleUrl = tleUrl,
+            transceiversUrl = txUrl
+        )
+    }
     //endregion
 
     //region # Radio control settings

core/data/src/test/java/com/rtbishop/look4sat/core/data/repository/DatabaseRepoTest.kt

@@ -102,7 +102,8 @@ class DatabaseRepoTest {
         repository.updateFromRemote()
 
         assertTrue(localSource.insertedEntries.any { it.catnum == 25544 })
-        assertEquals(listOf(25544), settingsRepo.satelliteTypeIdsByType["Other"])
+        // 新语义: 开关开 + URL 非空 -> All 源用自定义 URL, 数据归入 All 类型
+        assertEquals(listOf(25544), settingsRepo.satelliteTypeIdsByType["All"])
     }
 
     private fun validCsvStream(): InputStream = """

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/repository/ISatelliteRepo.kt

@@ -61,7 +61,7 @@ interface ISatelliteRepo {
     suspend fun getTrack(sat: OrbitalObject, pos: GeoPos, start: Long, end: Long): List<OrbitalPos>
 
     /** Get Doppler-shifted radio frequencies for a satellite at the given time. */
-    suspend fun getRadios(sat: OrbitalObject, pos: GeoPos, radios: List<SatRadio>, time: Long): List<SatRadio>
+    suspend fun getRadios(satPos: OrbitalPos, radios: List<SatRadio>): List<SatRadio>
 
     /** Fetch radio transceivers for a satellite by its catalog number. */
     suspend fun getRadiosWithId(id: Int): List<SatRadio>

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/source/Sources.kt

@@ -18,6 +18,10 @@
 package com.rtbishop.look4sat.core.domain.source
 
 object Sources {
+    // 在线更新的默认 URL(用户可通过"自定义URL"对话框修改/重置)
+    val defaultTleUrl = "https://celestrak.org/NORAD/elements/gp.php?GROUP=active&FORMAT=csv"
+    val defaultTransceiversUrl = "https://db.satnogs.org/api/transmitters/?format=json&status=active"
+
     val satelliteDataUrls = mapOf(
         "All" to "https://celestrak.org/NORAD/elements/gp.php?GROUP=active&FORMAT=csv",
         "Amateur" to "https://celestrak.org/NORAD/elements/gp.php?GROUP=amateur&FORMAT=csv",

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/utility/QthConverter.kt

@@ -19,31 +19,78 @@ package com.rtbishop.look4sat.core.domain.utility
 
 import com.rtbishop.look4sat.core.domain.predict.GeoPos
 
+/**
+ * Converts a Maidenhead locator (QTH grid square) to a GeoPos.
+ * Supports 6-char (3 pair), 8-char (4 pair) and 10-char (5 pair) locators.
+ * The returned position is the center of the finest cell encoded by the locator:
+ *  - 6 char: 5' lon x 2.5' lat cell center
+ *  - 8 char: 30" lon x 15" lat cell center
+ *  - 10 char: 1.25" lon x 0.625" lat cell center
+ */
 fun qthToPosition(locator: String): GeoPos? {
-    val trimmedQth = locator.take(6)
+    val trimmedQth = locator.trim().uppercase()
     if (!isValidLocator(trimmedQth)) return null
-    val lonFirst = (trimmedQth[0].uppercaseChar().code - 65) * 20
+    val lonFirst = (trimmedQth[0].code - 65) * 20
-    val latFirst = (trimmedQth[1].uppercaseChar().code - 65) * 10
+    val latFirst = (trimmedQth[1].code - 65) * 10
     val lonSecond = trimmedQth[2].toString().toInt() * 2
     val latSecond = trimmedQth[3].toString().toInt()
-    val lonThird = (((trimmedQth[4].lowercaseChar().code - 97) / 12.0) + (1.0 / 24.0)) - 180
+    val lonThird = (trimmedQth[4].lowercaseChar().code - 97) / 12.0
-    val latThird = (((trimmedQth[5].lowercaseChar().code - 97) / 24.0) + (1.0 / 48.0)) - 90
+    val latThird = (trimmedQth[5].lowercaseChar().code - 97) / 24.0
-    val longitude = (lonFirst + lonSecond + lonThird).round(4)
+    var longitude = lonFirst + lonSecond + lonThird - 180
-    val latitude = (latFirst + latSecond + latThird).round(4)
+    var latitude = latFirst + latSecond + latThird - 90
-    return GeoPos(latitude, longitude)
+    // 8-char extension: 4th pair, digits, 30" lon x 15" lat cells
+    if (trimmedQth.length >= 8) {
+        longitude += trimmedQth[6].toString().toInt() / 120.0
+        latitude += trimmedQth[7].toString().toInt() / 240.0
+    }
+    // 10-char extension: 5th pair, letters, 1.25" lon x 0.625" lat cells
+    if (trimmedQth.length >= 10) {
+        longitude += (trimmedQth[8].lowercaseChar().code - 97) / 2880.0
+        latitude += (trimmedQth[9].lowercaseChar().code - 97) / 5760.0
+    }
+    // Offset to the center of the finest encoded cell
+    when (trimmedQth.length) {
+        8 -> {
+            longitude += 1.0 / 240.0
+            latitude += 1.0 / 480.0
+        }
+        10 -> {
+            longitude += 1.0 / 5760.0
+            latitude += 1.0 / 11520.0
+        }
+        else -> {
+            longitude += 1.0 / 24.0
+            latitude += 1.0 / 48.0
+        }
+    }
+    return GeoPos(latitude.round(6), longitude.round(6))
 }
 
-fun positionToQth(latitude: Double, longitude: Double): String? {
+/**
+ * Converts a GeoPos to a Maidenhead locator (QTH grid square).
+ * Default precision is 8 characters (4 pairs) giving 30" lon x 15" lat resolution,
+ * matching common 8-char grid square tools. Pass precision = 6 for the classic
+ * 5' x 2.5' resolution, or precision = 10 for the finest 1.25" x 0.625" resolution.
+ */
+fun positionToQth(latitude: Double, longitude: Double, precision: Int = 8): String? {
     if (!isValidPosition(latitude, longitude)) return null
-    val newLongitude = if (longitude > 180.0) longitude else longitude + 180
+    val newLongitude = longitude + 180
     val newLatitude = latitude + 90
-    val lonFirst = (65 + (newLongitude / 20)).toInt().toChar()
+    val lonFirst = (65 + (newLongitude / 20).toInt().coerceIn(0, 17)).toChar()
-    val latFirst = (65 + (newLatitude / 10)).toInt().toChar()
+    val latFirst = (65 + (newLatitude / 10).toInt().coerceIn(0, 17)).toChar()
-    val lonSecond = ((newLongitude / 2) % 10).toInt()
+    val lonSecond = ((newLongitude % 20) / 2).toInt()
     val latSecond = (newLatitude % 10).toInt()
     val lonThird = (65 + (newLongitude % 2) * 12).toInt().toChar().lowercaseChar()
     val latThird = (65 + (newLatitude % 1) * 24).toInt().toChar().lowercaseChar()
-    return "$lonFirst$latFirst$lonSecond$latSecond$lonThird$latThird"
+    val qth = "$lonFirst$latFirst$lonSecond$latSecond$lonThird$latThird"
+    if (precision < 8) return qth
+    val lonFourth = ((newLongitude % (1.0 / 12.0)) * 120).toInt()
+    val latFourth = ((newLatitude % (1.0 / 24.0)) * 240).toInt()
+    val qth8 = "$qth$lonFourth$latFourth"
+    if (precision < 10) return qth8
+    val lonFifth = (65 + (newLongitude % (1.0 / 120.0)) * 2880).toInt().toChar().lowercaseChar()
+    val latFifth = (65 + (newLatitude % (1.0 / 240.0)) * 5760).toInt().toChar().lowercaseChar()
+    return "$qth8$lonFifth$latFifth"
 }
 
 private fun isValidPosition(lat: Double, lon: Double): Boolean {
@@ -51,5 +98,49 @@ private fun isValidPosition(lat: Double, lon: Double): Boolean {
 }
 
 private fun isValidLocator(locator: String): Boolean {
-    return locator.matches("[a-xA-X][a-xA-X]\\d\\d[a-xA-X][a-xA-X]".toRegex())
+    return locator.matches("[a-xA-X]{2}\\d{2}[a-xA-X]{2}(?:\\d{2}(?:[a-xA-X]{2})?)?".toRegex())
 }
+
+/**
+ * Returns the 4-char field+square part of a locator, e.g. "OL42ih45" -> "OL42".
+ * A 4-char input is returned as-is when valid.
+ */
+fun qthToSquare(locator: String): String {
+    val upper = locator.trim().uppercase()
+    return when {
+        upper.length >= 4 && isValidLocator(upper) -> upper.take(4)
+        upper.length == 4 && upper.matches("[a-xA-X]{2}\\d{2}".toRegex()) -> upper
+        else -> "----"
+    }
+}
+
+/**
+ * Builds the 3x3 grid of 4-char squares surrounding [square] (e.g. "OL42").
+ * Row 0 = north (lat +1), col 0 = west (lon -1). Handles field/square carry
+ * at boundaries (e.g. "AA00" wraps to "RR99" at the south-west corner).
+ * Mirrors the neighbor logic decompiled from the QTH定位器 app.
+ */
+fun qthNeighbors(square: String): List<String> {
+    if (square.length != 4) return emptyList()
+    val lonField = (square[0].uppercaseChar().code - 65).coerceIn(0, 17)
+    val latField = (square[1].uppercaseChar().code - 65).coerceIn(0, 17)
+    val lonSquare = square[2].digitToCharOrNull() ?: return emptyList()
+    val latSquare = square[3].digitToCharOrNull() ?: return emptyList()
+    val result = mutableListOf<String>()
+    for (dLat in 1 downTo -1) {          // north -> south
+        for (dLon in -1..1) {            // west -> east
+            var lf = lonField
+            var tf = latField
+            var ls = lonSquare + dLon
+            var ts = latSquare + dLat
+            if (ls < 0) { lf -= 1; ls = 9 } else if (ls > 9) { lf += 1; ls = 0 }
+            if (ts < 0) { tf -= 1; ts = 9 } else if (ts > 9) { tf += 1; ts = 0 }
+            lf = (lf + 18) % 18
+            tf = (tf + 18) % 18
+            result += "${('A' + lf).toChar()}${('A' + tf).toChar()}$ls$ts"
+        }
+    }
+    return result
+}
+
+private fun Char.digitToCharOrNull(): Int? = digitToIntOrNull()

core/domain/src/test/java/com/rtbishop/look4sat/core/domain/QthConverterTest.kt

@@ -18,7 +18,9 @@
 package com.rtbishop.look4sat.core.domain
 
 import com.rtbishop.look4sat.core.domain.utility.positionToQth
+import com.rtbishop.look4sat.core.domain.utility.qthNeighbors
 import com.rtbishop.look4sat.core.domain.utility.qthToPosition
+import com.rtbishop.look4sat.core.domain.utility.qthToSquare
 import org.junit.Test
 
 class QthConverterTest {
@@ -26,21 +28,36 @@ class QthConverterTest {
     @Test
     fun `Given valid QTH returns correct POS`() {
         var result = qthToPosition("io91VL39FX")
-        assert(result?.latitude == 51.4792 && result.longitude == -0.2083)
+        assert(result?.latitude == 51.499913 && result.longitude == -0.22309)
         result = qthToPosition("gf15vc")
-        assert(result?.latitude == -34.8958 && result.longitude == -56.2083)
+        assert(result?.latitude == -34.895833 && result.longitude == -56.208333)
+        // 8-char locators: finer 30" x 15" cell center
+        result = qthToPosition("io91vl47")
+        assert(result?.latitude == 51.489583 && result.longitude == -0.2125)
+        result = qthToPosition("jn58td25")
+        assert(result?.latitude == 48.147917 && result.longitude == 11.604167)
     }
 
     @Test
     fun `Given invalid QTH returns null`() {
         assert(qthToPosition("ZZ00zz") == null)
         assert(qthToPosition("JN58") == null)
+        assert(qthToPosition("io9") == null)
+        assert(qthToPosition("IO91VL7") == null)
+        assert(qthToPosition("IO91VL4X") == null)
     }
 
     @Test
     fun `Given valid POS returns correct QTH`() {
-        assert(positionToQth(51.4878, -0.2146) == "IO91vl")
+        // default precision is 8 chars
-        assert(positionToQth(48.1466, 11.6083) == "JN58td")
+        assert(positionToQth(51.4878, -0.2146) == "IO91vl47")
+        assert(positionToQth(48.1466, 11.6083) == "JN58td25")
+        // 6-char precision still available for backwards compatibility
+        assert(positionToQth(51.4878, -0.2146, 6) == "IO91vl")
+        assert(positionToQth(48.1466, 11.6083, 6) == "JN58td")
+        // 10-char precision
+        assert(positionToQth(51.4878, -0.2146, 10) == "IO91vl47fb")
+        assert(positionToQth(48.1466, 11.6083, 10) == "JN58td25xe")
     }
 
     @Test
@@ -48,4 +65,61 @@ class QthConverterTest {
         assert(positionToQth(91.0542, -170.1142) == null)
         assert(positionToQth(89.0542, -240.1142) == null)
     }
+
+    @Test
+    fun `Given boundary POS stays in valid grid`() {
+        // antipodal / edge cases must not overflow the A-R / 0-9 / a-x alphabet
+        assert(positionToQth(-90.0, -180.0, 8) == "AA00aa00")
+        assert(positionToQth(90.0, 180.0, 8) == "RR00aa00")
+        assert(positionToQth(0.0, 0.0, 8) == "JJ00aa00")
+        // roundtrip stability: 8-char roundtrip is stable across a sample of positions
+        val positions = listOf(
+            Pair(51.4878, -0.2146), Pair(48.1466, 11.6083), Pair(-33.8688, 151.2093),
+            Pair(39.9042, 116.4074), Pair(35.6895, 139.6917), Pair(41.714, -72.727)
+        )
+        positions.forEach { (lat, lon) ->
+            val qth = positionToQth(lat, lon, 8)
+            val pos = qthToPosition(qth!!)
+            val qth2 = positionToQth(pos!!.latitude, pos.longitude, 8)
+            assert(qth == qth2) { "Roundtrip failed for ($lat, $lon): $qth -> $qth2" }
+        }
+    }
+
+    @Test
+    fun `Given square returns correct 3x3 neighbors`() {
+        // Reference grid from the QTH定位器 screenshot: OL42
+        val neighbors = qthNeighbors("OL42")
+        assert(neighbors == listOf(
+            "OL33", "OL43", "OL53",
+            "OL32", "OL42", "OL52",
+            "OL31", "OL41", "OL51"
+        )) { "OL42 grid mismatch: $neighbors" }
+        // Center cell must be the input itself
+        assert(neighbors[4] == "OL42")
+        // 9 cells, all distinct
+        assert(neighbors.size == 9 && neighbors.toSet().size == 9)
+    }
+
+    @Test
+    fun `Given boundary square wraps fields correctly`() {
+        // South-west corner: AA00 neighbors wrap to RR99 / RA90 etc.
+        val sw = qthNeighbors("AA00")
+        assert(sw.size == 9 && sw.toSet().size == 9)
+        assert(sw[0] == "RA91" && sw[4] == "AA00" && sw[6] == "RR99" && sw[8] == "AR19")
+        // North-east corner: RR99 wraps to AA00
+        val ne = qthNeighbors("RR99")
+        assert(ne.size == 9 && ne.toSet().size == 9)
+        assert(ne[0] == "RA80" && ne[4] == "RR99" && ne[8] == "AR08")
+        // Field boundary: IO91's east neighbors cross into J field
+        val london = qthNeighbors("IO91")
+        assert(london[2] == "JO02" && london[5] == "JO01")
+    }
+
+    @Test
+    fun `Given full locator returns square part`() {
+        assert(qthToSquare("OL42ih45") == "OL42")
+        assert(qthToSquare("io91VL39FX") == "IO91")
+        assert(qthToSquare("JN58") == "JN58")
+        assert(qthToSquare("garbage!!") == "----")
+    }
 }

core/presentation/src/main/java/com/rtbishop/look4sat/core/presentation/Navigation.kt

@@ -38,6 +38,9 @@ sealed class Screen(val iconResId: Int, val titleResId: Int) : NavKey {
     @Serializable
     data object Mutual : Screen(R.drawable.ic_match, R.string.nav_mutual)
 
+    @Serializable
+    data object Roaming : Screen(R.drawable.ic_roaming, R.string.nav_roaming)
+
     @Serializable
     data object Settings : Screen(R.drawable.ic_settings, R.string.nav_prefs)
 }

core/presentation/src/main/res/drawable/ic_reset.xml

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="utf-8"?>
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24">
+    <path
+        android:fillColor="@android:color/white"
+        android:pathData="M12,6v3l4,-4 -4,-4v3c-4.42,0 -8,3.58 -8,8 0,1.57 0.46,3.03 1.24,4.26L6.7,14.8c-0.45,-0.83 -0.7,-1.79 -0.7,-2.8 0,-3.31 2.69,-6 6,-6zM18.76,7.74L17.3,9.2c0.44,0.84 0.7,1.79 0.7,2.8 0,3.31 -2.69,6 -6,6v-3l-4,4 4,4v-3c4.42,0 8,-3.58 8,-8 0,-1.57 -0.46,-3.03 -1.24,-4.26z" />
+</vector>

core/presentation/src/main/res/drawable/ic_roaming.xml

@@ -0,0 +1,25 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="96"
+    android:viewportHeight="96">
+
+    <!-- Crosshair / grid-locator style icon: concentric rings + center dot -->
+    <path
+        android:fillColor="@android:color/transparent"
+        android:strokeColor="@android:color/white"
+        android:strokeWidth="6"
+        android:strokeLineCap="round"
+        android:strokeLineJoin="round"
+        android:pathData="M 48 12 L 48 84 M 12 48 L 84 48" />
+
+    <path
+        android:fillColor="@android:color/transparent"
+        android:strokeColor="@android:color/white"
+        android:strokeWidth="6"
+        android:pathData="M 48 26 A 22 22 0 1 0 48.1 26" />
+
+    <path
+        android:fillColor="@android:color/white"
+        android:pathData="M 44 44 L 52 44 L 52 52 L 44 52 Z" />
+</vector>

core/presentation/src/main/res/values-tr/strings.xml

@@ -51,11 +51,12 @@
         \n\nDoğru tahminler alabilmek için veritabanını en az haftada bir güncelleyin.</string>
     <string name="pass_whatsnew_title" translatable="false">What\'s new in Look4Sat</string>
     <string name="pass_whatsnew_message" translatable="false">
-        * Switched to short-form commands in NetworkReporter, by theojalba
+        * Roaming sayfası QTH定位器 2.0\'dan birebir taşındı: 8 haneli konum, 3x3 ızgara, kırmızı işaret, canlı GPS
-        \n* Added CAT radio control for full-duplex SAT operation, by jcmerg
+        \n\n* İçeriğin sistem durum/gezinme çubuklarıyla çakışması düzeltildi; ızgara sütunları referans düzenle eşleşiyor
-        \n* Added normalized time for passes AOS/LOS, fixed refresh state bug
+        \n\n* Roaming sayfası renkleri uygulama temasını takip eder - kırmızı gece modunda tamamen görünür
-        \n* Added multiple performance tweaks, improved passes calculation
+        \n\n* Ayarlar: sıkışan anahtar satırları ve teşekkür aralığı düzeltildi
-        \n* Fixed UTC pass time problem mentioned in issue #201
+        \n\n* Uygulama adı artık Look4Sat Pro
+        \n\n* Ayarlar: "İçe aktar" düğmesi "Özel URL" olarak yeniden adlandırıldı - TLE/alıcı-verici kaynak URL\'leri doğrudan düzenlenebilir
     </string>
 
     <!-- Radar screen -->
@@ -103,7 +104,7 @@
     <string name="map_visible">Görünür</string>
 
     <!-- Settings screen -->
-    <string name="prefs_app_title" translatable="false">Look4Sat v%s</string>
+    <string name="prefs_app_title" translatable="false">Look4Sat Pro v%s</string>
     <string name="prefs_app_url" translatable="false">https://play.google.com/store/apps/details?id=com.rtbishop.look4sat</string>
     <string name="prefs_donate_title">Bağış yap</string>
     <string name="prefs_donate_url" translatable="false">https://ko-fi.com/rt_bishop</string>
@@ -137,7 +138,7 @@
     <string name="prefs_data_entries">Uydular: %s</string>
     <string name="prefs_data_radios">Transceiver\'lar: %s</string>
     <string name="prefs_data_update">Güncelle</string>
-    <string name="prefs_data_import">İçe aktar</string>
+    <string name="prefs_data_import">Özel URL</string>
     <string name="prefs_data_clear">Temizle</string>
     <string name="prefs_data_clear_success">Veriler başarıyla temizlendi</string>
     <string name="prefs_data_update_success">Güncelleme başarıyla tamamlandı</string>
@@ -146,6 +147,7 @@
     <string name="prefs_data_sources_tle_switch">Özel TLE URL</string>
     <string name="prefs_data_sources_transceivers_switch">Özel transceiver URL</string>
     <string name="prefs_data_sources_url_title" translatable="false">URL (HTTPS)</string>
+    <string name="prefs_data_reset_url">Varsayılan URL\'ye sıfırla</string>
 
     <string name="prefs_data_output_title">Veri aktarımı</string>
     <string name="prefs_net_output">Ağ</string>
@@ -192,14 +194,16 @@
     <string name="prefs_highlight_mid">Orta %1$d-%2$d°</string>
     <string name="prefs_highlight_high">Yüksek &gt; %1$d°</string>
 
-    <string name="prefs_outro_title">Teşekkürler</string>
+    <string name="prefs_outro_title">BG7NTA ve orijinal yazar teşekkür eder</string>
     <string name="prefs_outro_thanks" translatable="false">
         • Look4Sat users and contributors!
         \n• David A. B. Johnson (predict4java)
         \n• Dave Moten (predict4java)
         \n• Alexandru Csete (Gpredict)
         \n• Dr T.S. Kelso (Celestrak)
-        \n• Libre Space Foundation (SatNOGS)</string>
+        \n• Libre Space Foundation (SatNOGS)
+        \n• BA7OPF (pass matching feature)
+        \n• BG7NTA</string>
     <string name="prefs_outro_license">Bu uygulama herhangi bir garanti sunmaz</string>
 
 </resources>

core/presentation/src/main/res/values-zh/strings.xml

@@ -10,6 +10,7 @@
     <string name="nav_pass">过境</string>
     <string name="nav_radar">雷达</string>
     <string name="nav_mutual">匹配</string>
+    <string name="nav_roaming">漫游</string>
     <string name="nav_map">地图</string>
     <string name="nav_prefs">设置</string>
 
@@ -38,6 +39,15 @@
     <string name="pass_error_message">没有即将过境的卫星</string>
     <string name="pass_welcome_title">欢迎来到 Look4Sat\!</string>
     <string name="pass_welcome_message">请务必在设置中通过GPS、经纬度或QTH定位您的位置\n建议至少每周更新一次数据库，以确保预测结果的准确性</string>
+    <string name="pass_whatsnew_title">Look4Sat Pro 更新内容</string>
+    <string name="pass_whatsnew_message">
+        * 漫游页完整移植 QTH定位器 2.0：8 位网格、3x3 九宫格、红点查表定位、实时 GPS
+        \n\n* 修复内容被系统状态栏/导航栏遮挡；九宫格列宽与原版一致
+        \n\n* 漫游页配色跟随应用主题，红色夜间模式下清晰可见
+        \n\n* 设置：修复开关行挤压与感谢列表间距
+        \n\n* 应用名现为 Look4Sat Pro
+        \n\n* 设置：导入文件按钮更名为自定义URL，可直接编辑 TLE/收发机数据源地址
+    </string>
 
     <!-- Radar screen -->
     <string name="radar_back">后退</string>
@@ -110,7 +120,7 @@
     <string name="prefs_data_entries">卫星：%s</string>
     <string name="prefs_data_radios">收发器：%s</string>
     <string name="prefs_data_update">在线更新</string>
-    <string name="prefs_data_import">导入文件</string>
+    <string name="prefs_data_import">自定义URL</string>
     <string name="prefs_data_clear">清空</string>
     <string name="prefs_data_clear_success">数据清空成功</string>
     <string name="prefs_data_update_success">更新成功</string>
@@ -167,7 +177,7 @@
     <string name="prefs_highlight_mid">中 %1$d-%2$d°</string>
     <string name="prefs_highlight_high">高 &gt; %1$d°</string>
 
-    <string name="prefs_outro_title">我要感谢：</string>
+    <string name="prefs_outro_title">BG7NTA 与原作者感谢：</string>
     <string name="prefs_outro_thanks" translatable="false">
         • Look4Sat 所有用户及贡献者!
         \n• David A. B. Johnson (predict4java)
@@ -175,7 +185,9 @@
         \n• Alexandru Csete (Gpredict)
         \n• Dr T.S. Kelso (Celestrak)
         \n• Libre Space Foundation (SatNOGS)
-        \n• xdsopl 和 Robot36 贡献者!</string>
+        \n• xdsopl 和 Robot36 贡献者!
+        \n• BA7OPF(过境匹配功能)
+        \n• BG7NTA</string>
     <string name="prefs_outro_license">该应用程序不提供任何保修.</string>
 
 </resources>

core/presentation/src/main/res/values/strings.xml

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
     <!-- Commmon -->
-    <string name="app_name" translatable="false">Look4Sat</string>
+    <string name="app_name" translatable="false">Look4Sat Pro</string>
     <string name="btn_accept">Accept</string>
     <string name="btn_cancel">Cancel</string>
     <string name="empty_list_message">No data to show</string>
@@ -11,6 +11,7 @@
     <string name="nav_pass">Passes</string>
     <string name="nav_radar">Radar</string>
     <string name="nav_mutual">Match</string>
+    <string name="nav_roaming">Roaming</string>
     <string name="nav_map">Map</string>
     <string name="nav_prefs">Settings</string>
 
@@ -52,8 +53,12 @@
         \n\nPlease update the database at least weekly to get accurate predictions.</string>
     <string name="pass_whatsnew_title" translatable="false">What\'s new in Look4Sat</string>
     <string name="pass_whatsnew_message" translatable="false">
-        * Added required tweaks to support Android 17 (API 37)
+        * Roaming page ported verbatim from QTH定位器 2.0: 8-char locator, 3x3 grid, red marker lookup, live GPS
-        \n\n* Added ACCESS_LOCAL_NETWORK permission check to support network data output
+        \n\n* Fixed content overlapping the system status/navigation bars; grid columns now match the reference layout
+        \n\n* Roaming page colors follow the app theme - fully visible in red night mode
+        \n\n* Settings: fixed squeezed toggle rows and credits spacing
+        \n\n* App name is now Look4Sat Pro
+        \n\n* Settings: "Import" button renamed to "Custom URL" - edit TLE/transceiver source URLs directly
     </string>
 
     <!-- Radar screen -->
@@ -111,7 +116,7 @@
     <string name="map_visible">Visible</string>
 
     <!-- Settings screen -->
-    <string name="prefs_app_title" translatable="false">Look4Sat v%s</string>
+    <string name="prefs_app_title" translatable="false">Look4Sat Pro v%s</string>
     <string name="prefs_app_url" translatable="false">https://play.google.com/store/apps/details?id=com.rtbishop.look4sat</string>
     <string name="prefs_donate_title">Donate</string>
     <string name="prefs_donate_url" translatable="false">https://ko-fi.com/rt_bishop</string>
@@ -145,7 +150,7 @@
     <string name="prefs_data_entries">Satellites: %s</string>
     <string name="prefs_data_radios">Transceivers: %s</string>
     <string name="prefs_data_update">Update</string>
-    <string name="prefs_data_import">Import</string>
+    <string name="prefs_data_import">Custom URL</string>
     <string name="prefs_data_clear">Clear</string>
     <string name="prefs_data_clear_success">Data was cleared successfully</string>
     <string name="prefs_data_update_success">Update completed successfully</string>
@@ -156,6 +161,7 @@
     <string name="prefs_data_sources_tle_switch">Custom TLE URL</string>
     <string name="prefs_data_sources_transceivers_switch">Custom transceivers URL</string>
     <string name="prefs_data_sources_url_title" translatable="false">URL (HTTPS)</string>
+    <string name="prefs_data_reset_url">Reset to default URL</string>
 
     <string name="prefs_data_output_title">Data output</string>
     <string name="prefs_net_output">Network</string>
@@ -202,7 +208,7 @@
     <string name="prefs_highlight_mid">Mid %1$d–%2$d°</string>
     <string name="prefs_highlight_high">High &gt; %1$d°</string>
 
-    <string name="prefs_outro_title">I would like to say thanks to</string>
+    <string name="prefs_outro_title">BG7NTA &amp; the original author would like to thank</string>
     <string name="prefs_outro_thanks" translatable="false">
         * Look4Sat users and contributors!
         \n* David A. B. Johnson (predict4java)
@@ -211,6 +217,8 @@
         \n* Dr T.S. Kelso (Celestrak)
         \n* Libre Space Foundation (SatNOGS)
         \n* xdsopl and Robot36 contributors!
+        \n* BA7OPF (pass matching feature)
+        \n* BG7NTA
     </string>
     <string name="prefs_outro_license">The app comes with no warranty</string>
 

feature/radar/src/main/java/com/rtbishop/look4sat/feature/radar/RadarView.kt

@@ -94,14 +94,21 @@ fun RadarViewCompose(
         animationSpec = infiniteRepeatable(tween(1000)),
         label = "animScale"
     )
-    // Drive the sweep from the animation framework to eliminate state mutation inside the draw block
+    // Drive the sweep from the animation framework to eliminate state mutation inside the draw block.
-    val sweepTransition = rememberInfiniteTransition(label = "sweep")
+    // Only create the infinite transition when the sweep is enabled — otherwise the canvas would
-    val sweepDegrees by sweepTransition.animateFloat(
+    // be invalidated every frame for an effect that isn't visible, wasting GPU and battery.
-        initialValue = 0f,
+    val sweepDegrees = if (shouldShowSweep) {
-        targetValue = 360f,
+        val sweepTransition = rememberInfiniteTransition(label = "sweep")
-        animationSpec = infiniteRepeatable(tween(SWEEP_DURATION_MS, easing = LinearEasing)),
+        val animatedSweep by sweepTransition.animateFloat(
-        label = "sweepDegrees"
+            initialValue = 0f,
-    )
+            targetValue = 360f,
+            animationSpec = infiniteRepeatable(tween(SWEEP_DURATION_MS, easing = LinearEasing)),
+            label = "sweepDegrees"
+        )
+        animatedSweep
+    } else {
+        0f
+    }
     val measurer = rememberTextMeasurer()
     val sunPainter = painterResource(R.drawable.ic_sun)
     val moonPainter = painterResource(R.drawable.ic_moon)

feature/radar/src/main/java/com/rtbishop/look4sat/feature/radar/RadarViewModel.kt

@@ -181,7 +181,7 @@ class RadarViewModel(
                 orbitalPos = pos, sunPosition = cachedSunPos, moonPosition = cachedMoonPos
             )
         }
-        processRadios(allRadios, pass.orbitalObject, timeNow)
+        processRadios(allRadios, pos)
         sendPassData(pos)
     }
 
@@ -342,8 +342,8 @@ class RadarViewModel(
         }
     }
 
-    private suspend fun processRadios(radios: List<SatRadio>, orbitalObject: OrbitalObject, time: Long) {
+    private suspend fun processRadios(radios: List<SatRadio>, satPos: OrbitalPos) {
-        val transmitters = satelliteRepo.getRadios(orbitalObject, stationPos, radios, time)
+        val transmitters = satelliteRepo.getRadios(satPos, radios)
         _uiState.update { state ->
             val freq = if (state.transceivers.selectedUuid != null) {
                 val selectedRadio = transmitters.firstOrNull { it.uuid == state.transceivers.selectedUuid }

feature/roaming/build.gradle.kts

@@ -0,0 +1,11 @@
+plugins {
+    alias(libs.plugins.convention.featurePlugin)
+}
+
+android {
+    namespace = "com.rtbishop.look4sat.feature.roaming"
+}
+
+dependencies {
+    implementation(project(":core:data"))
+}

feature/roaming/src/main/java/com/rtbishop/look4sat/feature/roaming/RoamingScreen.kt

@@ -0,0 +1,791 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.rtbishop.look4sat.feature.roaming
+
+import android.Manifest
+import android.annotation.SuppressLint
+import android.content.Context
+import android.content.Intent
+import android.content.pm.PackageManager
+import android.location.Location
+import android.location.LocationListener
+import android.location.LocationManager
+import android.os.Bundle
+import android.provider.Settings
+import androidx.activity.compose.rememberLauncherForActivityResult
+import androidx.activity.result.contract.ActivityResultContracts
+import androidx.compose.foundation.Image
+import androidx.compose.foundation.background
+import androidx.compose.foundation.shape.CircleShape
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxHeight
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.offset
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.layout.width
+import androidx.compose.material3.CircularProgressIndicator
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.foundation.layout.WindowInsets
+import androidx.compose.foundation.layout.windowInsetsPadding
+import androidx.compose.foundation.layout.systemBars
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.DisposableEffect
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.res.painterResource
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.text.style.TextAlign
+import androidx.compose.ui.unit.dp
+import androidx.compose.ui.unit.sp
+import androidx.core.content.ContextCompat
+import java.text.SimpleDateFormat
+import java.util.Date
+import java.util.Locale
+
+/**
+ * 漫游页 —— 原样照搬自 QTH定位器 2.0 (com.us1pm.gridsquarelocator)。
+ * UI: res/layout/main.xml (结构/尺寸/颜色逐项照搬, 不做任何更改)
+ * 逻辑: MainActivity.showLocation() / checkEnabled() / GPS 实时监听
+ * 红线: UI 与逻辑均不更改, 与成品截图逐像素对齐。
+ */
+@Composable
+fun RoamingScreen() {
+    val context = LocalContext.current
+    var state by remember { mutableStateOf(RoamingState()) }
+    // 照搬 onCreate: 日期固定文本 + 小时前缀(定位时拼接分钟)
+    val dateText = remember { SimpleDateFormat("dd MMM yyyy", Locale.getDefault()).format(Date()) }
+    var hourPrefix by remember { mutableStateOf("") }
+    // 照搬 onCreate: 初始 checkEnabled() -> 红点+设置按钮, 日期隐藏
+    var hasPermission by remember { mutableStateOf(false) }
+    val permissionLauncher = rememberLauncherForActivityResult(
+        ActivityResultContracts.RequestMultiplePermissions()
+    ) { }
+    LaunchedEffect(Unit) {
+        hourPrefix = SimpleDateFormat("HH:mm", Locale.getDefault()).format(Date()).substring(0, 3)
+        val fine = ContextCompat.checkSelfPermission(context, Manifest.permission.ACCESS_FINE_LOCATION) ==
+            PackageManager.PERMISSION_GRANTED
+        val coarse = ContextCompat.checkSelfPermission(context, Manifest.permission.ACCESS_COARSE_LOCATION) ==
+            PackageManager.PERMISSION_GRANTED
+        hasPermission = fine || coarse
+        if (!hasPermission) {
+            permissionLauncher.launch(
+                arrayOf(Manifest.permission.ACCESS_FINE_LOCATION, Manifest.permission.ACCESS_COARSE_LOCATION)
+            )
+        } else {
+            // 照搬 onResume: 绿点+进度条+提示+日期显示, 红点/按钮隐藏
+            state = state.copy(gpsOn = true, gpsOff = false, showSettings = false, showProgress = true, showNotice = true, showDate = true)
+        }
+    }
+    // 照搬 onResume/onPause: GPS + network 监听, 10 秒 / 10 米
+    val locationManager = remember { context.getSystemService(Context.LOCATION_SERVICE) as LocationManager }
+    DisposableEffect(locationManager, hasPermission) {
+        if (hasPermission) {
+            @SuppressLint("MissingPermission")
+            val listener = object : LocationListener {
+                override fun onLocationChanged(location: Location) {
+                    // 照搬 showLocation 开头: 只接受 gps / network provider
+                    if (location.provider != "gps" && location.provider != "network") return
+                    state = roamingStateFromLocation(location.latitude, location.longitude, location.time, hourPrefix)
+                        .copy(date = dateText)
+                }
+
+                override fun onProviderDisabled(provider: String) {
+                    // 照搬 checkEnabled: 红点+按钮, 日期隐藏
+                    state = state.copy(gpsOn = false, gpsOff = true, showSettings = true, showProgress = false, showNotice = false, showDate = false)
+                }
+
+                override fun onProviderEnabled(provider: String) {
+                    state = state.copy(gpsOn = true, gpsOff = false, showSettings = false, showProgress = true, showNotice = true, showDate = true)
+                }
+
+                @Deprecated("Deprecated in Java")
+                override fun onStatusChanged(provider: String?, status: Int, extras: Bundle?) = Unit
+            }
+            try {
+                locationManager.requestLocationUpdates("gps", 10_000L, 10f, listener)
+                locationManager.requestLocationUpdates("network", 10_000L, 10f, listener)
+            } catch (_: SecurityException) {
+            }
+            onDispose { locationManager.removeUpdates(listener) }
+        } else {
+            onDispose { }
+        }
+    }
+    // 照搬 res/layout/main.xml: 浅色页面, 蓝色信息区, 43sp 定位码, 3x3 九宫格, 底部版权
+    // 按用户要求: 上下往内缩进系统栏安全区, 避免内容被状态栏/导航栏遮挡
+    Column(
+        modifier = Modifier
+            .fillMaxSize()
+            .background(MaterialTheme.colorScheme.background)
+            .windowInsetsPadding(WindowInsets.systemBars)
+    ) {
+        // relativeLayout7: 顶部 GPS 状态条, 25dp 高, holo_blue_bright
+        Box(
+            modifier = Modifier
+                .fillMaxWidth()
+                .padding(2.dp)
+                .height(25.dp)
+                .background(MaterialTheme.colorScheme.surfaceVariant)
+        ) {
+            Row(modifier = Modifier.fillMaxSize(), verticalAlignment = Alignment.CenterVertically) {
+                // tvTitleGPS: "GPS" 14sp 黑, 左 8dp
+                Text(
+                    text = "GPS",
+                    fontSize = 14.sp,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                    modifier = Modifier.padding(start = 8.dp)
+                )
+                // imGps: toRightOf tvTitleGPS + marginLeft 15dp (成品 main.xml)
+                Spacer(modifier = Modifier.width(15.dp))
+                // imGps: 绿点 (15dp, 主题色 primary -> 夜间滤镜下可见)
+                if (state.gpsOn) {
+                    Box(
+                        modifier = Modifier
+                            .size(15.dp)
+                            .background(MaterialTheme.colorScheme.primary, CircleShape)
+                    )
+                }
+                // imGpsOff: 红点叠层 (15dp, 主题色 error)
+                if (state.gpsOff) {
+                    Box(
+                        modifier = Modifier
+                            .size(15.dp)
+                            .background(MaterialTheme.colorScheme.error, CircleShape)
+                    )
+                }
+                Spacer(modifier = Modifier.weight(1f))
+                // tvDate: 14sp 黑, 居中
+                if (state.showDate) {
+                    Text(text = state.date.ifEmpty { dateText }, fontSize = 14.sp, color = MaterialTheme.colorScheme.onSurfaceVariant)
+                }
+                Spacer(modifier = Modifier.weight(1f))
+                // tvTime: 14sp 黑, 右对齐
+                Text(
+                    text = state.time,
+                    fontSize = 14.sp,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                    modifier = Modifier.padding(end = 8.dp)
+                )
+            }
+            // btnLocationSettings: 黄色按钮, 居中
+            // btnLocationSettings: 成品 #faf8f54a 半透明黄, 14sp 黑字, 居中
+            if (state.showSettings) {
+                Box(
+                    modifier = Modifier
+                        .align(Alignment.Center)
+                        .background(MaterialTheme.colorScheme.primary)
+                        .clickable { context.startActivity(Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS)) }
+                        .padding(horizontal = 5.dp),
+                    contentAlignment = Alignment.Center
+                ) {
+                    Text(text = "设置启用GPS", fontSize = 14.sp, color = MaterialTheme.colorScheme.onPrimary)
+                }
+            }
+        }
+        // linearLayout4: 经纬度区, holo_blue_bright
+        Column(
+            modifier = Modifier
+                .fillMaxWidth()
+                .padding(horizontal = 2.dp)
+                .background(MaterialTheme.colorScheme.surfaceVariant)
+        ) {
+            // 纬度行: tvLati 16sp 黑 左 8dp | tvLat 右对齐 3dp
+            Row(modifier = Modifier.fillMaxWidth().padding(vertical = 2.dp), verticalAlignment = Alignment.CenterVertically) {
+                Text(text = state.latLabel, fontSize = 16.sp, color = MaterialTheme.colorScheme.onSurfaceVariant, modifier = Modifier.padding(start = 8.dp))
+                Spacer(modifier = Modifier.weight(1f))
+                Text(text = state.latValue, fontSize = 14.sp, color = MaterialTheme.colorScheme.onSurfaceVariant, modifier = Modifier.padding(end = 3.dp))
+            }
+            // 经度行
+            Row(modifier = Modifier.fillMaxWidth().padding(vertical = 2.dp), verticalAlignment = Alignment.CenterVertically) {
+                Text(text = state.lonLabel, fontSize = 16.sp, color = MaterialTheme.colorScheme.onSurfaceVariant, modifier = Modifier.padding(start = 8.dp))
+                Spacer(modifier = Modifier.weight(1f))
+                Text(text = state.lonValue, fontSize = 14.sp, color = MaterialTheme.colorScheme.onSurfaceVariant, modifier = Modifier.padding(end = 3.dp))
+            }
+        }
+        // relativeLayout6: 定位码区, 43sp bold 黑居中
+        Box(
+            modifier = Modifier
+                .fillMaxWidth()
+                .padding(2.dp)
+                .background(MaterialTheme.colorScheme.surfaceVariant)
+        ) {
+            Text(
+                text = state.loc,
+                fontSize = 43.sp,
+                fontWeight = FontWeight.Bold,
+                color = MaterialTheme.colorScheme.onSurfaceVariant,
+                textAlign = TextAlign.Center,
+                modifier = Modifier.fillMaxWidth()
+            )
+            // progressBar: 加载中, 居中
+            if (state.showProgress) {
+                CircularProgressIndicator(
+                    modifier = Modifier.size(24.dp).align(Alignment.Center),
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                    strokeWidth = 2.dp
+                )
+            }
+            // tvNotice: 提示文字, 居中顶部
+            if (state.showNotice) {
+                Text(
+                    text = "请稍等，加载可能需要几分钟的时间。",
+                    fontSize = 16.sp,
+                    fontStyle = androidx.compose.ui.text.font.FontStyle.Italic,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                    modifier = Modifier.align(Alignment.TopCenter).padding(top = 2.dp)
+                )
+            }
+        }
+        // relativeLayout: 九宫格, 占满剩余, 底部 15dp
+        // 用 Box 等价 RelativeLayout 布局: 左格贴左 / 中格水平居中 / 右格贴右 (成品 main.xml)
+        Column(modifier = Modifier.fillMaxWidth().weight(1f).padding(bottom = 15.dp)) {
+            // 行1: relativeLayout5 (上排: 纬度 +1)
+            Box(modifier = Modifier.fillMaxWidth().weight(1f)) {
+                GridCell(text = state.grids[0], modifier = Modifier.width(80.dp).fillMaxHeight().align(Alignment.CenterStart))
+                GridCell(text = state.grids[1], modifier = Modifier.width(200.dp).fillMaxHeight().align(Alignment.Center))
+                GridCell(text = state.grids[2], modifier = Modifier.width(80.dp).fillMaxHeight().align(Alignment.CenterEnd))
+            }
+            // 行2: relativeLayout4, 205dp 高 (中排: 中央)
+            Box(modifier = Modifier.fillMaxWidth().height(205.dp)) {
+                GridCell(text = state.grids[3], modifier = Modifier.width(80.dp).fillMaxHeight().align(Alignment.CenterStart))
+                // 中央列: tv22 (100x80dp centerInParent) 叠在 linearLayout3 (200x200dp) 之上
+                Box(modifier = Modifier.width(200.dp).fillMaxHeight().align(Alignment.Center)) {
+                    // linearLayout3: 200x200dp, marginTop 2dp, holo_blue_bright
+                    Box(
+                        modifier = Modifier
+                            .align(Alignment.TopCenter)
+                            .offset(y = 2.dp)
+                            .size(width = 200.dp, height = 200.dp)
+                            .background(MaterialTheme.colorScheme.surfaceVariant)
+                    ) {
+                        // iv: 红点 10x10dp, top|left, leftMargin/topMargin 查表绝对定位
+                        Image(
+                            painter = painterResource(R.drawable.roam_pnt),
+                            contentDescription = null,
+                            modifier = Modifier
+                                .size(10.dp)
+                                .offset(x = state.markerLeft.dp, y = state.markerTop.dp)
+                        )
+                    }
+                    // tv22: 100x80dp centerInParent, 30sp bold, textColorHighlight(白)
+                    Text(
+                        text = state.grids[4],
+                        fontSize = 30.sp,
+                        fontWeight = FontWeight.Bold,
+                        color = MaterialTheme.colorScheme.onSurfaceVariant,
+                        textAlign = TextAlign.Center,
+                        modifier = Modifier
+                            .size(width = 100.dp, height = 80.dp)
+                            .align(Alignment.Center)
+                    )
+                }
+                GridCell(text = state.grids[5], modifier = Modifier.width(80.dp).fillMaxHeight().align(Alignment.CenterEnd))
+            }
+            // 行3: relativeLayout3 (下排: 纬度 -1)
+            Box(modifier = Modifier.fillMaxWidth().weight(1f)) {
+                GridCell(text = state.grids[6], modifier = Modifier.width(80.dp).fillMaxHeight().align(Alignment.CenterStart))
+                GridCell(text = state.grids[7], modifier = Modifier.width(200.dp).fillMaxHeight().align(Alignment.Center))
+                GridCell(text = state.grids[8], modifier = Modifier.width(80.dp).fillMaxHeight().align(Alignment.CenterEnd))
+            }
+        }
+        // tv4: 底部版权, 10sp 黑 (往上拉, 底部预留空间避免被导航栏遮挡)
+        Text(
+            text = "制作：US1PM  汉化：BA7LCE",
+            fontSize = 10.sp,
+            color = MaterialTheme.colorScheme.onSurfaceVariant,
+            textAlign = TextAlign.Center,
+            modifier = Modifier.fillMaxWidth().padding(bottom = 10.dp)
+        )
+    }
+}
+
+// 周边格: 60/200/60dp, #0BACF1, bold 居中, 2dp margin (照搬 tv11/tv13/tv21/tv23/tv31/tv33)
+@Composable
+private fun GridCell(text: String, modifier: Modifier) {
+    Box(
+        modifier = modifier
+            .padding(2.dp)
+            .background(MaterialTheme.colorScheme.surface),
+        contentAlignment = Alignment.Center
+    ) {
+        Text(
+            text = text,
+            fontSize = 14.sp,
+            fontWeight = FontWeight.Bold,
+            color = MaterialTheme.colorScheme.onSurface,
+            textAlign = TextAlign.Center
+        )
+    }
+}
+
+/**
+ * 照搬 MainActivity.showLocation() 的状态。
+ * 网格/九宫格/红点查表与成品逐行一致。
+ */
+data class RoamingState(
+    val date: String = "",
+    val time: String = "",
+    val latLabel: String = "纬度",
+    val latValue: String = "",
+    val lonLabel: String = "经度",
+    val lonValue: String = "",
+    val loc: String = "",
+    val grids: List<String> = List(9) { "" },
+    /** 红点 leftMargin(dp), 经度第 3 对字符查表 */
+    val markerLeft: Int = 0,
+    /** 红点 topMargin(dp), 纬度第 3 对字符查表(屏幕 Y 反转) */
+    val markerTop: Int = 0,
+    val gpsOn: Boolean = false,
+    val gpsOff: Boolean = true,
+    val showSettings: Boolean = true,
+    val showProgress: Boolean = false,
+    val showNotice: Boolean = false,
+    val showDate: Boolean = false
+)
+
+/**
+ * 照搬 showLocation() 的完整计算: 时间/经纬度 DMS/8 位网格/九宫格/红点查表。
+ */
+fun roamingStateFromLocation(lat: Double, lon: Double, fixTime: Long, hourPrefix: String): RoamingState {
+    // 照搬: tvTime = 缓存小时前缀 + 定位时间分钟
+    val minute = SimpleDateFormat("mm", Locale.getDefault()).format(Date(fixTime))
+    val time = hourPrefix + minute
+    // 方向字符
+    val ew = if (lon >= 0.0) "E" else "W"
+    val ns = if (lat >= 0.0) "N" else "S"
+    // 照搬: 纬度 DMS (String.valueOf 无补零)
+    val latAbs = if (lat < 0.0) -lat else lat
+    val latDeg = latAbs.toInt()
+    val latMinFull = (latAbs - latDeg) * 60.0
+    val latMin = latMinFull.toInt()
+    val latSec = ((latMinFull - latMin) * 60.0).toInt()
+    val latLabel = "纬度  $latDeg° $latMin' $latSec\" $ns"
+    val latValue = "$lat° "
+    // 照搬: 经度 DMS
+    val lonAbs = if (lon < 0.0) -lon else lon
+    val lonDeg = lonAbs.toInt()
+    val lonMinFull = (lonAbs - lonDeg) * 60.0
+    val lonMin = lonMinFull.toInt()
+    val lonSec = ((lonMinFull - lonMin) * 60.0).toInt()
+    val lonLabel = "经度 $lonDeg° $lonMin' $lonSec\" $ew"
+    val lonValue = "$lon° "
+    // 照搬: 8 位网格编码 (区间查表)
+    val (str, str2, str3, str4) = encodeLon(lon)
+    val (str5, str6, str38, str9) = encodeLat(lat)
+    val loc = str + str5 + str2 + str6 + str3 + str38 + str4 + str9
+    // 照搬: 九宫格 parseInt3 五分支
+    val grids = buildGrids(str, str5, str2, str6, str3, str38)
+    // 照搬: 红点查表 (第 3 对字符)
+    val markerLeft = lonMargin[str3.firstOrNull()] ?: 0
+    val markerTop = latMargin[str38.firstOrNull()] ?: 0
+    return RoamingState(
+        time = time,
+        latLabel = latLabel,
+        latValue = latValue,
+        lonLabel = lonLabel,
+        lonValue = lonValue,
+        loc = loc,
+        grids = grids,
+        markerLeft = markerLeft,
+        markerTop = markerTop,
+        gpsOn = true,
+        gpsOff = false,
+        showSettings = false,
+        showProgress = false,
+        showNotice = false,
+        showDate = true
+    )
+}
+
+// 红点 leftMargin 查表 (MainActivity 1286-1386 行): 经度第 3 对 a..x -> -2..190 dp
+private val lonMargin = mapOf(
+    'a' to -2, 'b' to 8, 'c' to 16, 'd' to 24, 'e' to 32, 'f' to 40, 'g' to 48, 'h' to 56,
+    'i' to 65, 'j' to 74, 'k' to 83, 'l' to 92, 'm' to 101, 'n' to 110, 'o' to 119, 'p' to 128,
+    'q' to 137, 'r' to 146, 's' to 155, 't' to 163, 'u' to 171, 'v' to 179, 'w' to 184, 'x' to 190
+)
+
+// 红点 topMargin 查表 (MainActivity 1315-1363 行): 纬度第 3 对 a..x -> 190..-2 dp (屏幕 Y 反转)
+private val latMargin = mapOf(
+    'a' to 190, 'b' to 182, 'c' to 174, 'd' to 169, 'e' to 163, 'f' to 155, 'g' to 146, 'h' to 137,
+    'i' to 128, 'j' to 119, 'k' to 110, 'l' to 101, 'm' to 92, 'n' to 83, 'o' to 74, 'p' to 65,
+    'q' to 56, 'r' to 48, 's' to 40, 't' to 32, 'u' to 24, 'v' to 16, 'w' to 8, 'x' to -2
+)
+
+// 照搬 311-611 行: 经度 -> (20°区字母, 2°数字, 2'字母, 30"数字)
+private fun encodeLon(inputLon: Double): List<String> {
+    var longitude = inputLon
+    var d = 0.0
+    val str = when {
+        (longitude >= -180.0) && (longitude <= -160.0) -> { longitude += 180.0; "A" }
+        (longitude >= -160.0) && (longitude <= -140.0) -> { longitude += 160.0; "B" }
+        (longitude >= -140.0) && (longitude <= -120.0) -> { longitude += 140.0; "C" }
+        (longitude >= -120.0) && (longitude <= -100.0) -> { longitude += 120.0; "D" }
+        (longitude >= -100.0) && (longitude <= -80.0) -> { longitude += 100.0; "E" }
+        (longitude >= -80.0) && (longitude <= -60.0) -> { longitude += 80.0; "F" }
+        (longitude >= -60.0) && (longitude <= -40.0) -> { longitude += 60.0; "G" }
+        (longitude >= -40.0) && (longitude <= -20.0) -> { longitude += 40.0; "H" }
+        (longitude >= -20.0) && (longitude <= 0.0) -> { longitude += 20.0; "I" }
+        (longitude >= 0.0) && (longitude <= 20.0) -> "J"
+        (longitude >= 20.0) && (longitude <= 40.0) -> { longitude -= 20.0; "K" }
+        (longitude >= 40.0) && (longitude <= 60.0) -> { longitude -= 40.0; "L" }
+        (longitude >= 60.0) && (longitude <= 80.0) -> { longitude -= 60.0; "M" }
+        (longitude >= 80.0) && (longitude <= 100.0) -> { longitude -= 80.0; "N" }
+        (longitude >= 100.0) && (longitude <= 120.0) -> { longitude -= 100.0; "O" }
+        (longitude >= 120.0) && (longitude <= 140.0) -> { longitude -= 120.0; "P" }
+        (longitude >= 140.0) && (longitude <= 160.0) -> { longitude -= 140.0; "Q" }
+        (longitude >= 160.0) && (longitude <= 180.0) -> { longitude -= 160.0; "R" }
+        else -> { longitude = 0.0; " " }
+    }
+    val str2 = when {
+        ((longitude >= 0.0) && (longitude <= 2.0)) || ((longitude >= -20.0) && (longitude <= -18.0)) -> { d = longitude * 60.0; "0" }
+        ((longitude >= 2.0) && (longitude <= 4.0)) || ((longitude >= -18.0) && (longitude <= -16.0)) -> { d = (longitude - 2.0) * 60.0; "1" }
+        ((longitude >= 4.0) && (longitude <= 6.0)) || ((longitude >= -16.0) && (longitude <= -14.0)) -> { d = (longitude - 4.0) * 60.0; "2" }
+        ((longitude >= 6.0) && (longitude <= 8.0)) || ((longitude >= -14.0) && (longitude <= -12.0)) -> { d = (longitude - 6.0) * 60.0; "3" }
+        ((longitude >= 8.0) && (longitude <= 10.0)) || ((longitude >= -12.0) && (longitude <= -10.0)) -> { d = (longitude - 8.0) * 60.0; "4" }
+        ((longitude >= 10.0) && (longitude <= 12.0)) || ((longitude >= -10.0) && (longitude <= -8.0)) -> { d = (longitude - 10.0) * 60.0; "5" }
+        ((longitude >= 12.0) && (longitude <= 14.0)) || ((longitude >= -8.0) && (longitude <= -6.0)) -> { d = (longitude - 12.0) * 60.0; "6" }
+        ((longitude >= 14.0) && (longitude <= 16.0)) || ((longitude >= -6.0) && (longitude <= -4.0)) -> { d = (longitude - 14.0) * 60.0; "7" }
+        ((longitude >= 16.0) && (longitude <= 18.0)) || ((longitude >= -4.0) && (longitude <= -2.0)) -> { d = (longitude - 16.0) * 60.0; "8" }
+        ((longitude >= 18.0) && (longitude <= 20.0)) || ((longitude >= -2.0) && (longitude <= 0.0)) -> { d = (longitude - 18.0) * 60.0; "9" }
+        else -> { d = 0.0; " " }
+    }
+    val str3 = when {
+        ((d >= 0.0) && (d <= 5.0)) || ((d >= -120.0) && (d <= -115.0)) -> { longitude = d * 60.0; "a" }
+        ((d >= 5.0) && (d <= 10.0)) || ((d >= -115.0) && (d <= -110.0)) -> { longitude = (d - 5.0) * 60.0; "b" }
+        ((d >= 10.0) && (d <= 15.0)) || ((d >= -110.0) && (d <= -105.0)) -> { longitude = (d - 10.0) * 60.0; "c" }
+        ((d >= 15.0) && (d <= 20.0)) || ((d >= -105.0) && (d <= -100.0)) -> { longitude = (d - 15.0) * 60.0; "d" }
+        ((d >= 20.0) && (d <= 25.0)) || ((d >= -100.0) && (d <= -95.0)) -> { longitude = (d - 20.0) * 60.0; "e" }
+        ((d >= 25.0) && (d <= 30.0)) || ((d >= -95.0) && (d <= -90.0)) -> { longitude = (d - 25.0) * 60.0; "f" }
+        ((d >= 30.0) && (d <= 35.0)) || ((d >= -90.0) && (d <= -85.0)) -> { longitude = (d - 30.0) * 60.0; "g" }
+        ((d >= 35.0) && (d <= 40.0)) || ((d >= -85.0) && (d <= -80.0)) -> { longitude = (d - 35.0) * 60.0; "h" }
+        ((d >= 40.0) && (d <= 45.0)) || ((d >= -80.0) && (d <= -75.0)) -> { longitude = (d - 40.0) * 60.0; "i" }
+        ((d >= 45.0) && (d <= 50.0)) || ((d >= -75.0) && (d <= -70.0)) -> { longitude = (d - 45.0) * 60.0; "j" }
+        ((d >= 50.0) && (d <= 55.0)) || ((d >= -70.0) && (d <= -65.0)) -> { longitude = (d - 50.0) * 60.0; "k" }
+        ((d >= 55.0) && (d <= 60.0)) || ((d >= -65.0) && (d <= -60.0)) -> { longitude = (d - 55.0) * 60.0; "l" }
+        ((d >= 60.0) && (d <= 65.0)) || ((d >= -60.0) && (d <= -55.0)) -> { longitude = (d - 60.0) * 60.0; "m" }
+        ((d >= 65.0) && (d <= 70.0)) || ((d >= -55.0) && (d <= -50.0)) -> { longitude = (d - 65.0) * 60.0; "n" }
+        ((d >= 70.0) && (d <= 75.0)) || ((d >= -50.0) && (d <= -45.0)) -> { longitude = (d - 70.0) * 60.0; "o" }
+        ((d >= 75.0) && (d <= 80.0)) || ((d >= -45.0) && (d <= -40.0)) -> { longitude = (d - 75.0) * 60.0; "p" }
+        ((d >= 80.0) && (d <= 85.0)) || ((d >= -40.0) && (d <= -35.0)) -> { longitude = (d - 80.0) * 60.0; "q" }
+        ((d >= 85.0) && (d <= 90.0)) || ((d >= -35.0) && (d <= -30.0)) -> { longitude = (d - 85.0) * 60.0; "r" }
+        ((d >= 90.0) && (d <= 95.0)) || ((d >= -30.0) && (d <= -25.0)) -> { longitude = (d - 90.0) * 60.0; "s" }
+        ((d >= 95.0) && (d <= 100.0)) || ((d >= -25.0) && (d <= -20.0)) -> { longitude = (d - 95.0) * 60.0; "t" }
+        ((d >= 100.0) && (d <= 105.0)) || ((d >= -20.0) && (d <= -15.0)) -> { longitude = (d - 100.0) * 60.0; "u" }
+        ((d >= 105.0) && (d <= 110.0)) || ((d >= -15.0) && (d <= -10.0)) -> { longitude = (d - 105.0) * 60.0; "v" }
+        ((d >= 110.0) && (d <= 115.0)) || ((d >= -10.0) && (d <= -5.0)) -> { longitude = (d - 110.0) * 60.0; "w" }
+        ((d >= 115.0) && (d <= 120.0)) || ((d >= -5.0) && (d <= 0.0)) -> { longitude = (d - 115.0) * 60.0; "x" }
+        else -> { longitude = 0.0; " " }
+    }
+    val str4 = when {
+        ((longitude >= 0.0) && (longitude <= 30.0)) || ((longitude >= -300.0) && (longitude <= -270.0)) -> "0"
+        ((longitude >= 30.0) && (longitude <= 60.0)) || ((longitude >= -270.0) && (longitude <= -240.0)) -> "1"
+        ((longitude >= 60.0) && (longitude <= 90.0)) || ((longitude >= -240.0) && (longitude <= -210.0)) -> "2"
+        ((longitude >= 90.0) && (longitude <= 120.0)) || ((longitude >= -210.0) && (longitude <= -180.0)) -> "3"
+        ((longitude >= 120.0) && (longitude <= 150.0)) || ((longitude >= -180.0) && (longitude <= -150.0)) -> "4"
+        ((longitude >= 150.0) && (longitude <= 180.0)) || ((longitude >= -150.0) && (longitude <= -120.0)) -> "5"
+        ((longitude >= 180.0) && (longitude <= 210.0)) || ((longitude >= -120.0) && (longitude <= -90.0)) -> "6"
+        ((longitude >= 210.0) && (longitude <= 240.0)) || ((longitude >= -90.0) && (longitude <= -60.0)) -> "7"
+        ((longitude >= 240.0) && (longitude <= 270.0)) || ((longitude >= -60.0) && (longitude <= -30.0)) -> "8"
+        ((longitude >= 270.0) && (longitude <= 300.0)) || ((longitude >= -30.0) && (longitude <= 0.0)) -> "9"
+        else -> " "
+    }
+    return listOf(str, str2, str3, str4)
+}
+
+// 照搬 612-914 行: 纬度 -> (10°区字母, 1°数字, 1'字母, 15"数字)
+private fun encodeLat(inputLat: Double): List<String> {
+    var latitude = inputLat
+    var d2 = 0.0
+    var d3 = 0.0
+    val str5 = when {
+        (latitude >= -90.0) && (latitude <= -80.0) -> { d2 = latitude + 90.0; "A" }
+        (latitude >= -80.0) && (latitude <= -70.0) -> { d2 = latitude + 80.0; "B" }
+        (latitude >= -70.0) && (latitude <= -60.0) -> { d2 = latitude + 70.0; "C" }
+        (latitude >= -60.0) && (latitude <= -50.0) -> { d2 = latitude + 60.0; "D" }
+        (latitude >= -50.0) && (latitude <= -40.0) -> { d2 = latitude + 50.0; "E" }
+        (latitude >= -40.0) && (latitude <= -30.0) -> { d2 = latitude + 40.0; "F" }
+        (latitude >= -30.0) && (latitude <= -20.0) -> { d2 = latitude + 30.0; "G" }
+        (latitude >= -20.0) && (latitude <= -10.0) -> { d2 = latitude + 20.0; "H" }
+        (latitude >= -10.0) && (latitude <= 0.0) -> { d2 = latitude + 10.0; "I" }
+        (latitude >= 0.0) && (latitude <= 10.0) -> { d2 = latitude; "J" }
+        (latitude >= 10.0) && (latitude <= 20.0) -> { d2 = latitude - 10.0; "K" }
+        (latitude >= 20.0) && (latitude <= 30.0) -> { d2 = latitude - 20.0; "L" }
+        (latitude >= 30.0) && (latitude <= 40.0) -> { d2 = latitude - 30.0; "M" }
+        (latitude >= 40.0) && (latitude <= 50.0) -> { d2 = latitude - 40.0; "N" }
+        (latitude >= 50.0) && (latitude <= 60.0) -> { d2 = latitude - 50.0; "O" }
+        (latitude >= 60.0) && (latitude <= 70.0) -> { d2 = latitude - 60.0; "P" }
+        (latitude >= 70.0) && (latitude <= 80.0) -> { d2 = latitude - 70.0; "Q" }
+        (latitude >= 80.0) && (latitude <= 90.0) -> { d2 = latitude - 80.0; "R" }
+        else -> { d2 = 0.0; " " }
+    }
+    var str6 = " "
+    when {
+        ((d2 >= 0.0) && (d2 <= 1.0)) || ((d2 >= -10.0) && (d2 <= -9.0)) -> { d3 = d2 * 60.0; str6 = "0" }
+        ((d2 >= 1.0) && (d2 <= 2.0)) || ((d2 >= -9.0) && (d2 <= -8.0)) -> { d3 = (d2 - 1.0) * 60.0; str6 = "1" }
+        ((d2 >= 2.0) && (d2 <= 3.0)) || ((d2 >= -8.0) && (d2 <= -7.0)) -> { d3 = (d2 - 2.0) * 60.0; str6 = "2" }
+        ((d2 >= 3.0) && (d2 <= 4.0)) || ((d2 >= -7.0) && (d2 <= -6.0)) -> { d3 = (d2 - 3.0) * 60.0; str6 = "3" }
+        ((d2 >= 4.0) && (d2 <= 5.0)) || ((d2 >= -6.0) && (d2 <= -5.0)) -> { d3 = (d2 - 4.0) * 60.0; str6 = "4" }
+        ((d2 >= 5.0) && (d2 <= 6.0)) || ((d2 >= -5.0) && (d2 <= -4.0)) -> { d3 = (d2 - 5.0) * 60.0; str6 = "5" }
+        ((d2 >= 6.0) && (d2 <= 7.0)) || ((d2 >= -4.0) && (d2 <= -3.0)) -> { d3 = (d2 - 6.0) * 60.0; str6 = "6" }
+        ((d2 >= 7.0) && (d2 <= 8.0)) || ((d2 >= -3.0) && (d2 <= -2.0)) -> { d3 = (d2 - 7.0) * 60.0; str6 = "7" }
+        ((d2 >= 8.0) && (d2 <= 9.0)) || ((d2 >= -2.0) && (d2 <= -1.0)) -> { d3 = (d2 - 8.0) * 60.0; str6 = "8" }
+        ((d2 >= 9.0) && (d2 <= 10.0)) || ((d2 >= -1.0) && (d2 <= 0.0)) -> { d3 = (d2 - 9.0) * 60.0; str6 = "9" }
+    }
+    val str38 = when {
+        ((d3 >= 0.0) && (d3 <= 2.5)) || ((d3 >= -60.0) && (d3 <= -57.5)) -> { d2 = d3 * 60.0; "a" }
+        ((d3 >= 2.5) && (d3 <= 5.0)) || ((d3 >= -57.5) && (d3 <= -55.0)) -> { d2 = (d3 - 2.5) * 60.0; "b" }
+        ((d3 >= 5.0) && (d3 <= 7.5)) || ((d3 >= -55.0) && (d3 <= -52.5)) -> { d2 = (d3 - 5.0) * 60.0; "c" }
+        ((d3 >= 7.5) && (d3 <= 10.0)) || ((d3 >= -52.5) && (d3 <= -50.0)) -> { d2 = (d3 - 7.5) * 60.0; "d" }
+        ((d3 >= 10.0) && (d3 <= 12.5)) || ((d3 >= -50.0) && (d3 <= -47.5)) -> { d2 = (d3 - 10.0) * 60.0; "e" }
+        ((d3 >= 12.5) && (d3 <= 15.0)) || ((d3 >= -47.5) && (d3 <= -45.0)) -> { d2 = (d3 - 12.5) * 60.0; "f" }
+        ((d3 >= 15.0) && (d3 <= 17.5)) || ((d3 >= -45.0) && (d3 <= -42.5)) -> { d2 = (d3 - 15.0) * 60.0; "g" }
+        ((d3 >= 17.5) && (d3 <= 20.0)) || ((d3 >= -42.5) && (d3 <= -40.0)) -> { d2 = (d3 - 17.5) * 60.0; "h" }
+        ((d3 >= 20.0) && (d3 <= 22.5)) || ((d3 >= -40.0) && (d3 <= -37.5)) -> { d2 = (d3 - 20.0) * 60.0; "i" }
+        ((d3 >= 22.5) && (d3 <= 25.0)) || ((d3 >= -37.5) && (d3 <= -35.0)) -> { d2 = (d3 - 22.5) * 60.0; "j" }
+        ((d3 >= 25.0) && (d3 <= 27.5)) || ((d3 >= -35.0) && (d3 <= -32.5)) -> { d2 = (d3 - 25.0) * 60.0; "k" }
+        ((d3 >= 27.5) && (d3 <= 30.0)) || ((d3 >= -32.5) && (d3 <= -30.0)) -> { d2 = (d3 - 27.5) * 60.0; "l" }
+        ((d3 >= 30.0) && (d3 <= 32.5)) || ((d3 >= -30.0) && (d3 <= -27.5)) -> { d2 = (d3 - 30.0) * 60.0; "m" }
+        ((d3 >= 32.5) && (d3 <= 35.0)) || ((d3 >= -27.5) && (d3 <= -25.0)) -> { d2 = (d3 - 32.5) * 60.0; "n" }
+        ((d3 >= 35.0) && (d3 <= 37.5)) || ((d3 >= -25.0) && (d3 <= -22.5)) -> { d2 = (d3 - 35.0) * 60.0; "o" }
+        ((d3 >= 37.5) && (d3 <= 40.0)) || ((d3 >= -22.5) && (d3 <= -20.0)) -> { d2 = (d3 - 37.5) * 60.0; "p" }
+        ((d3 >= 40.0) && (d3 <= 42.5)) || ((d3 >= -20.0) && (d3 <= -17.5)) -> { d2 = (d3 - 40.0) * 60.0; "q" }
+        ((d3 >= 42.5) && (d3 <= 45.0)) || ((d3 >= -17.5) && (d3 <= -15.0)) -> { d2 = (d3 - 42.5) * 60.0; "r" }
+        ((d3 >= 45.0) && (d3 <= 47.5)) || ((d3 >= -15.0) && (d3 <= -12.5)) -> { d2 = (d3 - 45.0) * 60.0; "s" }
+        ((d3 >= 47.5) && (d3 <= 50.0)) || ((d3 >= -12.5) && (d3 <= -10.0)) -> { d2 = (d3 - 47.5) * 60.0; "t" }
+        ((d3 >= 50.0) && (d3 <= 52.5)) || ((d3 >= -10.0) && (d3 <= -7.5)) -> { d2 = (d3 - 50.0) * 60.0; "u" }
+        ((d3 >= 52.5) && (d3 <= 55.0)) || ((d3 >= -7.5) && (d3 <= -5.0)) -> { d2 = (d3 - 52.5) * 60.0; "v" }
+        ((d3 >= 55.0) && (d3 <= 57.5)) || ((d3 >= -5.0) && (d3 <= -2.5)) -> { d2 = (d3 - 55.0) * 60.0; "w" }
+        ((d3 >= 57.5) && (d3 <= 60.0)) || ((d3 >= -2.5) && (d3 <= 0.0)) -> { d2 = (d3 - 57.5) * 60.0; "x" }
+        else -> { d2 = 0.0; " " }
+    }
+    val str9 = when {
+        ((d2 >= 0.0) && (d2 <= 15.0)) || ((d2 >= -150.0) && (d2 <= -135.0)) -> "0"
+        ((d2 >= 15.0) && (d2 <= 30.0)) || ((d2 >= -135.0) && (d2 <= -120.0)) -> "1"
+        ((d2 >= 30.0) && (d2 <= 45.0)) || ((d2 >= -120.0) && (d2 <= -105.0)) -> "2"
+        ((d2 >= 45.0) && (d2 <= 60.0)) || ((d2 >= -105.0) && (d2 <= -90.0)) -> "3"
+        ((d2 >= 60.0) && (d2 <= 75.0)) || ((d2 >= -90.0) && (d2 <= -75.0)) -> "4"
+        ((d2 >= 75.0) && (d2 <= 90.0)) || ((d2 >= -75.0) && (d2 <= -60.0)) -> "5"
+        ((d2 >= 90.0) && (d2 <= 105.0)) || ((d2 >= -60.0) && (d2 <= -45.0)) -> "6"
+        ((d2 >= 105.0) && (d2 <= 120.0)) || ((d2 >= -45.0) && (d2 <= -30.0)) -> "7"
+        ((d2 >= 120.0) && (d2 <= 135.0)) || ((d2 >= -30.0) && (d2 <= -15.0)) -> "8"
+        ((d2 >= 135.0) && (d2 <= 150.0)) || ((d2 >= -15.0) && (d2 <= 0.0)) -> "9"
+        else -> " "
+    }
+    return listOf(str5, str6, str38, str9)
+}
+
+/**
+ * 照搬 917-1283 行: 九宫格 parseInt3 五分支(内部/西界/东界/北界/南界 + 四角)。
+ * 返回 9 格文本: [上左, 上中, 上右, 左中, 中央, 右中, 下左, 下中, 下右]。
+ */
+private fun buildGrids(str: String, str5: String, str2: String, str6: String, str3: String, str38: String): List<String> {
+    val parseInt = str2.toInt()
+    val parseInt2 = str6.toInt()
+    val str39 = str + str5
+    val str40 = str2 + str6
+    val parseInt3 = str40.toInt()
+    val str41 = str39 + str40
+    val g = MutableList(9) { "" }
+    fun fmt2(n: Int) = if (n <= 9) "0$n" else n.toString()
+    if ((parseInt > 0) && (parseInt < 9) && (parseInt2 > 0) && (parseInt2 < 9)) {
+        // 内部: 数字对 ±1
+        val i7 = parseInt3 + 1
+        val i8 = i7 - 10
+        val valueOf9 = fmt2(i8)
+        val str11 = i7.toString()
+        val valueOf18 = (i7 + 10).toString()
+        val i9 = parseInt3 - 10
+        val valueOf10 = fmt2(i9)
+        val valueOf19 = (parseInt3 + 10).toString()
+        val i10 = parseInt3 - 1
+        val i11 = i10 - 10
+        val valueOf11 = fmt2(i11)
+        val str14 = i10.toString()
+        val str15 = (i10 + 10).toString()
+        g[0] = str39 + valueOf9
+        g[1] = str39 + str11
+        g[2] = str39 + valueOf18
+        g[3] = str39 + valueOf10
+        g[4] = str41
+        g[5] = str39 + valueOf19
+        g[6] = str39 + valueOf11
+        g[7] = str39 + str14
+        g[8] = str39 + str15
+    } else if ((parseInt == 0) && (parseInt2 > 0) && (parseInt2 < 9)) {
+        // 西边界: 经度 0 -> 9, 经度字母 -1
+        val str43 = (str[0] - 1).toString() + str5
+        val str44 = "9" + (parseInt2 + 1)
+        val i12 = parseInt3 + 1
+        val valueOf7 = fmt2(i12)
+        val str12 = (i12 + 10).toString()
+        val sb4 = "9" + parseInt2
+        val valueOf20 = (parseInt3 + 10).toString()
+        val str46 = "9" + (parseInt2 - 1)
+        val i13 = parseInt3 - 1
+        val valueOf8 = fmt2(i13)
+        val str15 = (i13 + 10).toString()
+        g[0] = str43 + str44
+        g[1] = str39 + valueOf7
+        g[2] = str39 + str12
+        g[3] = str43 + sb4
+        g[4] = str41
+        g[5] = str39 + valueOf20
+        g[6] = str43 + str46
+        g[7] = str39 + valueOf8
+        g[8] = str39 + str15
+    } else if ((parseInt == 9) && (parseInt2 > 0) && (parseInt2 < 9)) {
+        // 东边界: 经度 9 -> 0, 经度字母 +1
+        val str47 = (str[0] + 1).toString() + str5
+        val i14 = parseInt3 + 1
+        val valueOf21 = (i14 - 10).toString()
+        val valueOf22 = i14.toString()
+        val str48 = "0" + (parseInt2 + 1)
+        val valueOf23 = (parseInt3 - 10).toString()
+        val str49 = "0" + parseInt2
+        val i15 = parseInt3 - 1
+        val valueOf24 = (i15 - 10).toString()
+        val valueOf25 = i15.toString()
+        val str15 = "0" + (parseInt2 - 1)
+        g[0] = str39 + valueOf21
+        g[1] = str39 + valueOf22
+        g[2] = str47 + str48
+        g[3] = str39 + valueOf23
+        g[4] = str41
+        g[5] = str47 + str49
+        g[6] = str39 + valueOf24
+        g[7] = str39 + valueOf25
+        g[8] = str47 + str15
+    } else if ((parseInt < 9) && (parseInt > 0) && (parseInt2 == 9)) {
+        // 北边界: 纬度 9 -> 0, 纬度字母 +1
+        val str50 = str + (str5[0] + 1).toString()
+        val i16 = parseInt3 - 9
+        val i17 = i16 - 10
+        val valueOf4 = fmt2(i17)
+        val valueOf26 = i16.toString()
+        val valueOf27 = (i16 + 10).toString()
+        val i18 = parseInt3 - 10
+        val valueOf5 = fmt2(i18)
+        val valueOf28 = (parseInt3 + 10).toString()
+        val i19 = parseInt3 - 1
+        val i20 = i19 - 10
+        val valueOf6 = fmt2(i20)
+        val str14 = i19.toString()
+        val str15 = (i19 + 10).toString()
+        g[0] = str39 + valueOf4
+        g[1] = str50 + valueOf26
+        g[2] = str39 + valueOf27
+        g[3] = str39 + valueOf5
+        g[4] = str41
+        g[5] = str39 + valueOf28
+        g[6] = str39 + valueOf6
+        g[7] = str39 + str14
+        g[8] = str39 + str15
+    } else if ((parseInt < 9) && (parseInt > 0) && (parseInt2 == 0)) {
+        // 南边界: 纬度 0 -> 9, 纬度字母 -1
+        val str52 = str + (str5[0] - 1).toString()
+        val i21 = parseInt3 + 1
+        val i22 = i21 - 10
+        val valueOf = fmt2(i22)
+        val valueOf29 = i21.toString()
+        val valueOf30 = (i21 + 10).toString()
+        val i23 = parseInt3 - 10
+        val valueOf2 = fmt2(i23)
+        val valueOf31 = (parseInt3 + 10).toString()
+        val i24 = parseInt3 - 1
+        val valueOf3 = fmt2(i24)
+        val str14 = (i24 + 10).toString()
+        val str15 = (i24 + 20).toString()
+        g[0] = str39 + valueOf
+        g[1] = str39 + valueOf29
+        g[2] = str39 + valueOf30
+        g[3] = str39 + valueOf2
+        g[4] = str41
+        g[5] = str39 + valueOf31
+        g[6] = str52 + valueOf3
+        g[7] = str52 + str14
+        g[8] = str52 + str15
+    } else if (parseInt3 == 0) {
+        // 四角 00: 经纬度数字均 -1 进位
+        val v32 = (str[0] - 1).toString()
+        val v33 = (str5[0] - 1).toString()
+        g[0] = v32 + str5 + "91"
+        g[1] = str39 + "01"
+        g[2] = str39 + "11"
+        g[3] = v32 + str5 + "90"
+        g[4] = str41
+        g[5] = v32 + str5 + "10"
+        g[6] = v32 + v33 + "99"
+        g[7] = str + v33 + "09"
+        g[8] = str + v33 + "19"
+    } else if (parseInt3 == 9) {
+        // 四角 09: 经度 -1, 纬度 +1
+        val v34 = (str[0] - 1).toString()
+        val v35 = (str5[0] + 1).toString()
+        g[0] = v34 + v35 + "90"
+        g[1] = str + v35 + "00"
+        g[2] = str + v35 + "10"
+        g[3] = v34 + str5 + "99"
+        g[4] = str41
+        g[5] = v34 + str5 + "19"
+        g[6] = v34 + str5 + "98"
+        g[7] = v34 + str5 + "08"
+        g[8] = v34 + str5 + "18"
+    } else if (parseInt3 == 99) {
+        // 四角 99: 经纬度数字均 +1 进位
+        val v36 = (str[0] + 1).toString()
+        val v37 = (str5[0] + 1).toString()
+        g[0] = str + v37 + "80"
+        g[1] = str + v37 + "90"
+        g[2] = v36 + v37 + "00"
+        g[3] = str39 + "89"
+        g[4] = str41
+        g[5] = v36 + str5 + "09"
+        g[6] = str39 + "88"
+        g[7] = str39 + "98"
+        g[8] = v36 + str5 + "08"
+    } else if (parseInt3 == 90) {
+        // 四角 90: 经度 +1, 纬度 -1
+        val v38 = (str[0] + 1).toString()
+        val v39 = (str5[0] - 1).toString()
+        g[0] = str39 + "81"
+        g[1] = str39 + "91"
+        g[2] = v38 + str5 + "01"
+        g[3] = str39 + "80"
+        g[4] = str41
+        g[5] = v38 + str5 + "00"
+        g[6] = str + v39 + "89"
+        g[7] = str + v39 + "99"
+        g[8] = v38 + v39 + "09"
+    }
+    return g
+}

feature/roaming/src/test/java/com/rtbishop/look4sat/feature/roaming/RoamingStateTest.kt

@@ -0,0 +1,124 @@
+/*
+ * Look4Sat. Amateur radio satellite tracker and pass predictor.
+ * Copyright (C) 2019-2026 Arty Bishop and contributors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.rtbishop.look4sat.feature.roaming
+
+import org.junit.Assert.assertEquals
+import org.junit.Test
+
+class RoamingStateTest {
+
+    // 用户实测坐标 (QTH定位器 2.0 成品截图): 22.314066 / 108.706575
+    private fun stateOf(lat: Double, lon: Double) =
+        roamingStateFromLocation(lat, lon, System.currentTimeMillis(), "21:")
+
+    @Test
+    fun `user coordinates produce OL42ih45`() {
+        val state = stateOf(22.314066, 108.706575)
+        assertEquals("OL42ih45", state.loc)
+    }
+
+    @Test
+    fun `red marker from ih pair matches reference lookup`() {
+        val state = stateOf(22.314066, 108.706575)
+        // 成品查表: 经度第3对 'i' -> leftMargin 65dp, 纬度第3对 'h' -> topMargin 137dp
+        assertEquals(65, state.markerLeft)
+        assertEquals(137, state.markerTop)
+    }
+
+    @Test
+    fun `grid nine from OL42 matches reference`() {
+        val state = stateOf(22.314066, 108.706575)
+        val expected = listOf(
+            "OL33", "OL43", "OL53",
+            "OL32", "OL42", "OL52",
+            "OL31", "OL41", "OL51"
+        )
+        assertEquals(expected, state.grids)
+    }
+
+    @Test
+    fun `latitude dms formatting matches reference`() {
+        val state = stateOf(22.314066, 108.706575)
+        assertEquals("纬度  22° 18' 50\" N", state.latLabel)
+        assertEquals("22.314066° ", state.latValue)
+        assertEquals("经度 108° 42' 23\" E", state.lonLabel)
+        assertEquals("108.706575° ", state.lonValue)
+    }
+
+    @Test
+    fun `time is hour prefix plus fix minutes`() {
+        // fixTime = 2026-08-03 21:12:13 UTC+8 -> minutes 12
+        val fix = 1785820333000L // 2026-08-03 21:12:13 +0800
+        val state = roamingStateFromLocation(22.314066, 108.706575, fix, "21:")
+        assertEquals("21:12", state.time)
+    }
+
+    @Test
+    fun `west edge borrows lon letter`() {
+        // 经度 0.5 纬度 22.314066: 数字对 02, 西边界 parseInt==0
+        val state = stateOf(22.314066, 0.5)
+        assertEquals(8, state.loc.length)
+        // 左列经度 0->9, 经度字母 J-1=I: IL92
+        assertEquals("IL92", state.grids[3])
+    }
+
+    @Test
+    fun `north edge carries lat letter`() {
+        // 纬度 29.5 经度 108.706575: 数字对 49? -> 纬度数字 9 -> 北边界
+        val state = stateOf(29.5, 108.706575)
+        assertEquals(8, state.loc.length)
+        // 上排纬度 +1 -> 0, 纬度字母 +1 (M)
+        assertEquals("OM40", state.grids[1])
+    }
+
+    @Test
+    fun `east edge carries lon letter`() {
+        // 经度 119.5 纬度 22.314066: 经度数字 9 -> 东边界
+        val state = stateOf(22.314066, 119.5)
+        assertEquals(8, state.loc.length)
+        // 右上 经度 9->0, 经度字母 O+1=P, 纬度 2+1=3: PL03
+        assertEquals("PL03", state.grids[2])
+    }
+
+    @Test
+    fun `south edge borrows lat letter`() {
+        // 纬度 0.5 经度 108.706575: 纬度数字 0 -> 南边界
+        val state = stateOf(0.5, 108.706575)
+        assertEquals(8, state.loc.length)
+        // 下中 纬度 0->9, 纬度字母 J-1=I: OI49
+        assertEquals("OI49", state.grids[7])
+    }
+
+    @Test
+    fun `boundary values wrap like reference`() {
+        // (90, 180) -> RR99xx99 (成品区间查表行为)
+        val state = stateOf(90.0, 180.0)
+        assertEquals("RR99xx99", state.loc)
+    }
+
+    @Test
+    fun `gps state after fix matches showLocation`() {
+        val state = stateOf(22.314066, 108.706575)
+        assertEquals(true, state.gpsOn)
+        assertEquals(false, state.gpsOff)
+        assertEquals(false, state.showSettings)
+        assertEquals(false, state.showProgress)
+        assertEquals(false, state.showNotice)
+        assertEquals(true, state.showDate)
+    }
+}

feature/settings/src/main/java/com/rtbishop/look4sat/feature/settings/SettingsDialog.kt

@@ -30,6 +30,8 @@ import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.padding
 import androidx.compose.material3.FilterChip
+import androidx.compose.material3.Icon
+import androidx.compose.material3.IconButton
 import androidx.compose.material3.OutlinedTextField
 import androidx.compose.material3.Switch
 import androidx.compose.material3.Text
@@ -41,11 +43,13 @@ import androidx.compose.runtime.saveable.rememberSaveable
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.res.painterResource
 import androidx.compose.ui.text.font.FontWeight
 import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.unit.dp
 import androidx.compose.ui.unit.sp
 import com.rtbishop.look4sat.core.domain.model.RCSettings
+import com.rtbishop.look4sat.core.domain.source.Sources
 import com.rtbishop.look4sat.core.domain.model.RadioControlSettings
 import com.rtbishop.look4sat.core.presentation.CardButton
 import com.rtbishop.look4sat.core.presentation.LocalSpacing
@@ -203,6 +207,17 @@ fun DataSourcesDialog(
                 singleLine = true,
                 modifier = Modifier.fillMaxWidth(),
                 enabled = isEnabledCustomTle.value,
+                trailingIcon = {
+                    IconButton(
+                        onClick = { urlTle.value = Sources.defaultTleUrl },
+                        enabled = isEnabledCustomTle.value
+                    ) {
+                        Icon(
+                            painter = painterResource(id = R.drawable.ic_reset),
+                            contentDescription = stringResource(id = R.string.prefs_data_reset_url)
+                        )
+                    }
+                },
             )
             Spacer(modifier = Modifier.height(6.dp))
             Row(
@@ -232,6 +247,17 @@ fun DataSourcesDialog(
                 singleLine = true,
                 modifier = Modifier.fillMaxWidth(),
                 enabled = isEnabledCustomTransceivers.value,
+                trailingIcon = {
+                    IconButton(
+                        onClick = { urlTransceivers.value = Sources.defaultTransceiversUrl },
+                        enabled = isEnabledCustomTransceivers.value
+                    ) {
+                        Icon(
+                            painter = painterResource(id = R.drawable.ic_reset),
+                            contentDescription = stringResource(id = R.string.prefs_data_reset_url)
+                        )
+                    }
+                },
             )
             Spacer(modifier = Modifier.height(12.dp))
         }

feature/settings/src/main/java/com/rtbishop/look4sat/feature/settings/SettingsScreen.kt

@@ -29,6 +29,7 @@ import androidx.compose.foundation.layout.Spacer
 import androidx.compose.foundation.layout.fillMaxHeight
 import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.heightIn
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.width
 import androidx.compose.foundation.lazy.grid.GridCells
@@ -339,6 +340,8 @@ private fun LocationCard(
             Row(horizontalArrangement = Arrangement.SpaceBetween, modifier = Modifier.fillMaxWidth()) {
                 Text(text = "Lat: ${settings.stationPos.latitude}°")
                 Text(text = "Lon: ${settings.stationPos.longitude}°")
+            }
+            Row(horizontalArrangement = Arrangement.SpaceBetween, modifier = Modifier.fillMaxWidth()) {
                 Text(text = "Qth: ${settings.stationPos.qthLocator}")
             }
             Spacer(modifier = Modifier.height(1.dp))
@@ -484,11 +487,12 @@ private fun OtherCardPreview() = MainTheme {
 @Composable
 private fun OtherCard(settings: OtherSettings, onAction: (SettingsAction) -> Unit) {
     ElevatedCard(
-        modifier = Modifier
+        modifier = Modifier.fillMaxWidth()
-            .fillMaxWidth()
-            .height(268.dp)
     ) {
-        Column(modifier = Modifier.padding(horizontal = 8.dp, vertical = 4.dp)) {
+        Column(
+            modifier = Modifier.padding(horizontal = 8.dp, vertical = 4.dp),
+            verticalArrangement = Arrangement.spacedBy(4.dp)
+        ) {
             Text(
                 text = stringResource(id = R.string.prefs_other_title),
                 color = MaterialTheme.colorScheme.primary
@@ -556,15 +560,11 @@ private fun CardCreditsPreview() = MainTheme { CardCredits() }
 @Composable
 private fun CardCredits(modifier: Modifier = Modifier) {
     ElevatedCard(
-        modifier = modifier
+        modifier = modifier.fillMaxWidth()
-            .fillMaxWidth()
-            .height(268.dp)
     ) {
         Column(
-            verticalArrangement = Arrangement.SpaceBetween,
+            verticalArrangement = Arrangement.spacedBy(8.dp),
-            modifier = Modifier
+            modifier = Modifier.padding(horizontal = 8.dp, vertical = 4.dp)
-                .padding(horizontal = 8.dp, vertical = 4.dp)
-                .fillMaxHeight()
         ) {
             Text(
                 text = stringResource(id = R.string.prefs_outro_title),
@@ -573,6 +573,8 @@ private fun CardCredits(modifier: Modifier = Modifier) {
             Text(
                 text = stringResource(id = R.string.prefs_outro_thanks)
             )
+            // 感谢列表与保修声明之间保留约两行间距 (用户要求)
+            Spacer(modifier = Modifier.height(24.dp))
             Text(
                 text = stringResource(id = R.string.prefs_outro_license),
                 color = MaterialTheme.colorScheme.primary
@@ -588,7 +590,7 @@ private fun TopCard(onClick: () -> Unit, modifier: Modifier = Modifier, version:
             horizontalArrangement = Arrangement.spacedBy(12.dp),
             verticalAlignment = Alignment.CenterVertically,
             modifier = Modifier
-                .height(48.dp)
+                .heightIn(min = 48.dp)
                 .clickable { onClick() }) {
             Spacer(Modifier)
             Icon(
@@ -603,7 +605,6 @@ private fun TopCard(onClick: () -> Unit, modifier: Modifier = Modifier, version:
                 modifier = Modifier
                     .weight(1f)
                     .padding(end = 6.dp)
-                    .infiniteMarquee()
             )
         }
     }

gradle/libs.versions.toml

@@ -1,8 +1,8 @@
 [versions]
 #noinspection UnusedVersionCatalogEntry
-appVersionCode = "443"
+appVersionCode = "448"
 #noinspection UnusedVersionCatalogEntry
-appVersionName = "4.4.3"
+appVersionName = "4.4.8"
 #noinspection UnusedVersionCatalogEntry
 compileSdk = "37"
 #noinspection UnusedVersionCatalogEntry
@@ -11,6 +11,11 @@ minSdk = "24"
 jdkVersion = "21"
 #noinspection UnusedVersionCatalogEntry
 packageName = "com.rtbishop.look4sat"
+# Fork application ID: official app uses com.rtbishop.look4sat with a different
+# signing cert. Installing a fork with the same applicationId would conflict
+# with the official build (signature mismatch / cannot overwrite), so the fork
+# ships under its own applicationId suffix.
+applicationId = "com.rtbishop.look4sat.bg7nta"
 
 android-gradle-plugin = "9.3.1"
 

settings.gradle.kts

@@ -25,6 +25,7 @@ include(
     ":feature:mutual",
     ":feature:passes",
     ":feature:radar",
+    ":feature:roaming",
     ":feature:satellites",
     ":feature:settings"
 )