Fall back to OpenStreetMap when the build has no Google Maps key

app/src/main/java/dev/wander/android/opentagviewer/HistoryViewActivity.java

@@ -216,7 +216,7 @@ protected void onCreate(Bundle savedInstanceState) {
         // Obtain the SupportMapFragment and get notified when the map is ready to be used.
         // 根据用户设置创建地图提供商
         String mapProviderType = this.userSettings.getMapProvider();
-        this.mapProvider = MapProviderFactory.create(mapProviderType);
+        this.mapProvider = MapProviderFactory.create(MapProviderFactory.effectiveProvider(this, mapProviderType));
 
         // 初始化地图
         this.mapProvider.initialize(this, R.id.history_map, this);

app/src/main/java/dev/wander/android/opentagviewer/MapsActivity.java

@@ -21,9 +21,7 @@
 
 import android.bluetooth.le.ScanSettings;
 import android.content.Intent;
-import android.content.pm.ApplicationInfo;
 import android.app.Dialog;
-import android.content.pm.PackageManager;
 import android.content.res.ColorStateList;
 import android.location.Address;
 import android.location.Geocoder;
@@ -502,7 +500,6 @@ protected void onCreate(Bundle savedInstanceState) {
         app.setupTheme();
 
         WindowCompat.setDecorFitsSystemWindows(getWindow(), false);
-        this.checkApiKey();
 
         this.binding = ActivityMapsBinding.inflate(getLayoutInflater());
         setContentView(this.binding.getRoot());
@@ -560,6 +557,9 @@ protected void onCreate(Bundle savedInstanceState) {
 
         // 根据用户设置创建地图提供商
         String mapProviderType = this.userSettings.getMapProvider();
+        // A build without a Google Maps key (secrets.properties) still has a map: OpenStreetMap
+        // needs no key, so it stands in for Google rather than the app refusing to start.
+        mapProviderType = MapProviderFactory.effectiveProvider(this, mapProviderType);
 
         // **Before the new provider touches it.** Changing provider calls recreate(), and the
         // FragmentManager restores Google's map fragment into this container while a plain view
@@ -1751,26 +1751,6 @@ public void onClickMoreForDevice(View view) {
         deviceInfoActivityLauncher.launch(deviceInfoIntent);
     }
 
-    private void checkApiKey() {
-        try {
-            ApplicationInfo appInfo = getPackageManager().getApplicationInfo(getPackageName(), PackageManager.GET_META_DATA);
-            Bundle bundle = Objects.requireNonNull(appInfo.metaData);
-
-            String apiKey = bundle.getString("com.google.android.geo.API_KEY");
-
-            if (apiKey == null || apiKey.isBlank() || apiKey.equals("DEFAULT_API_KEY")) {
-                Toast.makeText(this, "API Key was not set in secrets.properties", LENGTH_SHORT).show();
-                throw new RuntimeException("API Key was not set in secrets.properties");
-            }
-        } catch (PackageManager.NameNotFoundException e) {
-            Log.e(TAG, "Package name not found.", e);
-            throw new RuntimeException("Error getting package info", e);
-        } catch (NullPointerException e) {
-            Log.e(TAG, "Error accessing meta-data.", e); // Handle the case where meta-data is completely missing
-            throw new RuntimeException("Error accessing meta-data in manifest", e);
-        }
-    }
-
     private void handleAuthAndShowDevices() {
         var async = userAuthRepo.getUserAuth()
             .subscribe(this::getAppleUser,

app/src/main/java/dev/wander/android/opentagviewer/ui/maps/MapProviderFactory.java

@@ -1,9 +1,13 @@
 package dev.wander.android.opentagviewer.ui.maps;
 
+import android.content.Context;
+import android.content.pm.PackageManager;
+import android.os.Bundle;
 import android.util.Log;
 
 import androidx.annotation.VisibleForTesting;
 
+import java.util.Set;
 import java.util.function.Supplier;
 
 /**
@@ -47,6 +51,43 @@ public static void reset() {
         replacement = null;
     }
 
+    /**
+     * Values the Maps key takes in a build that has no real one, so Google would draw an empty
+     * grey map. {@code DEFAULT_API_KEY} comes from {@code local.defaults.properties} when there is
+     * no {@code secrets.properties}; {@code maps_key_default_value} is what
+     * {@code build-debug.yml} writes when the repository secret is unavailable, as on fork PRs.
+     */
+    private static final Set<String> PLACEHOLDER_KEYS = Set.of("DEFAULT_API_KEY", "maps_key_default_value");
+
+    /**
+     * The provider to actually use. A build without a usable Google Maps key gets OpenStreetMap,
+     * which needs none, instead of a map that cannot load.
+     */
+    public static String effectiveProvider(final Context context, final String providerType) {
+        String key = null;
+        try {
+            final Bundle meta = context.getPackageManager().getApplicationInfo(
+                    context.getPackageName(), PackageManager.GET_META_DATA).metaData;
+            key = meta == null ? null : meta.getString("com.google.android.geo.API_KEY");
+        } catch (final Exception e) {
+            Log.w(TAG, "Could not read the Maps API key; treating it as absent", e);
+        }
+        return providerFor(providerType, key);
+    }
+
+    /** {@link #effectiveProvider(Context, String)} once the key has been read. */
+    static String providerFor(final String providerType, final String googleMapsKey) {
+        if (PROVIDER_AMAP.equals(providerType) || PROVIDER_OSM.equals(providerType)) {
+            return providerType;
+        }
+        // Google, unset or unknown - all of which create() turns into Google Maps.
+        if (googleMapsKey == null || googleMapsKey.isBlank() || PLACEHOLDER_KEYS.contains(googleMapsKey)) {
+            Log.w(TAG, "No usable Google Maps key in this build; using OpenStreetMap");
+            return PROVIDER_OSM;
+        }
+        return providerType;
+    }
+
     public static IMapProvider create(String providerType) {
         if (replacement != null) {
             Log.d(TAG, "Creating a substituted map provider");

app/src/test/java/dev/wander/android/opentagviewer/ui/maps/MapProviderFactoryTest.java

@@ -0,0 +1,42 @@
+package dev.wander.android.opentagviewer.ui.maps;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+
+public class MapProviderFactoryTest {
+
+    private static final String A_REAL_KEY = "AIzaSyExampleExampleExampleExample123";
+
+    @Test
+    public void googleWithARealKeyStaysGoogle() {
+        assertEquals(MapProviderFactory.PROVIDER_GOOGLE,
+                MapProviderFactory.providerFor(MapProviderFactory.PROVIDER_GOOGLE, A_REAL_KEY));
+    }
+
+    @Test
+    public void googleWithoutAUsableKeyFallsBackToOpenStreetMap() {
+        for (final String key : new String[]{null, "", "  ", "DEFAULT_API_KEY", "maps_key_default_value"}) {
+            assertEquals("key: " + key, MapProviderFactory.PROVIDER_OSM,
+                    MapProviderFactory.providerFor(MapProviderFactory.PROVIDER_GOOGLE, key));
+        }
+    }
+
+    /** create() turns an unset or unknown provider into Google, so those need the key too. */
+    @Test
+    public void anUnsetOrUnknownProviderIsTreatedAsGoogle() {
+        assertEquals(MapProviderFactory.PROVIDER_OSM,
+                MapProviderFactory.providerFor(null, "DEFAULT_API_KEY"));
+        assertEquals(MapProviderFactory.PROVIDER_OSM,
+                MapProviderFactory.providerFor("bing", null));
+        assertEquals("bing", MapProviderFactory.providerFor("bing", A_REAL_KEY));
+    }
+
+    @Test
+    public void otherProvidersNeverDependOnTheGoogleKey() {
+        assertEquals(MapProviderFactory.PROVIDER_AMAP,
+                MapProviderFactory.providerFor(MapProviderFactory.PROVIDER_AMAP, null));
+        assertEquals(MapProviderFactory.PROVIDER_OSM,
+                MapProviderFactory.providerFor(MapProviderFactory.PROVIDER_OSM, null));
+    }
+}