feat: warn for OSM URLs (#2074)

Author: JaffaKetchup

.github/workflows/branch.yml

@@ -82,7 +82,7 @@ jobs:
           channel: "stable"
           cache: true
       - name: Build Android Application
-        run: flutter build apk
+        run: flutter build apk --dart-define=flutter.flutter_map.unblockOSM="${{ secrets.UNBLOCK_OSM }}"
       - name: Archive Artifact
         uses: actions/upload-artifact@v4
         with:
@@ -105,7 +105,7 @@ jobs:
           channel: "stable"
           cache: true
       - name: Build Windows Application
-        run: flutter build windows
+        run: flutter build windows --dart-define=flutter.flutter_map.unblockOSM="${{ secrets.UNBLOCK_OSM }}"
       - name: Create Windows Application Installer
         run: iscc "windowsApplicationInstallerSetup.iss"
         working-directory: .
@@ -131,7 +131,7 @@ jobs:
           channel: "stable"
           cache: true
       - name: Build Web Application
-        run: flutter build web --wasm
+        run: flutter build web --wasm --dart-define=flutter.flutter_map.unblockOSM="${{ secrets.UNBLOCK_OSM }}"
       - name: Archive Artifact
         uses: actions/upload-artifact@v4
         with:

.github/workflows/master.yml

@@ -51,7 +51,7 @@ jobs:
           channel: "stable"
           cache: true
       - name: Build Android Application
-        run: flutter build apk
+        run: flutter build apk --dart-define=flutter.flutter_map.unblockOSM="${{ secrets.UNBLOCK_OSM }}"
       - name: Archive Artifact
         uses: actions/upload-artifact@v4
         with:
@@ -76,7 +76,7 @@ jobs:
           channel: "stable"
           cache: true
       - name: Build Windows Application
-        run: flutter build windows
+        run: flutter build windows --dart-define=flutter.flutter_map.unblockOSM="${{ secrets.UNBLOCK_OSM }}"
       - name: Create Windows Application Installer
         run: iscc "windowsApplicationInstallerSetup.iss"
         working-directory: .
@@ -104,7 +104,7 @@ jobs:
           channel: "stable"
           cache: true
       - name: Build Web Application
-        run: flutter build web --wasm
+        run: flutter build web --wasm --dart-define=flutter.flutter_map.unblockOSM="${{ secrets.UNBLOCK_OSM }}"
       - name: Archive Artifact
         uses: actions/upload-artifact@v4
         with:

lib/src/layer/tile_layer/tile_layer.dart

@@ -1,7 +1,7 @@
 import 'dart:async';
 import 'dart:math';
 
-import 'package:collection/collection.dart' show MapEquality;
+import 'package:collection/collection.dart' show MapEquality, ListEquality;
 import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_map/flutter_map.dart';
@@ -12,6 +12,7 @@ import 'package:flutter_map/src/layer/tile_layer/tile_image_manager.dart';
 import 'package:flutter_map/src/layer/tile_layer/tile_range.dart';
 import 'package:flutter_map/src/layer/tile_layer/tile_range_calculator.dart';
 import 'package:flutter_map/src/layer/tile_layer/tile_scale_calculator.dart';
+import 'package:flutter_map/src/layer/tile_layer/unblock_osm.dart';
 import 'package:flutter_map/src/misc/extensions.dart';
 import 'package:http/http.dart';
 import 'package:http/retry.dart';
@@ -343,6 +344,41 @@ class TileLayer extends StatefulWidget {
 }
 
 class _TileLayerState extends State<TileLayer> with TickerProviderStateMixin {
+  static const _openStreetMapUrls = {
+    'tile.openstreetmap.org',
+    'tile.osm.org',
+  };
+  bool get _isOpenStreetMapUrl =>
+      widget.urlTemplate != null &&
+      _openStreetMapUrls.any((target) => widget.urlTemplate!.contains(target));
+
+  static const _unblockOpenStreetMapUrlEnv =
+      String.fromEnvironment('flutter.flutter_map.unblockOSM');
+  static bool get _unblockOpenStreetMapUrl => const ListEquality<int>()
+      .equals(_unblockOpenStreetMapUrlEnv.codeUnits, unblockOSM);
+
+  static final _blockOpenStreetMapUrl =
+      // ignore: dead_code
+      false && (kReleaseMode || kProfileMode) && !_unblockOpenStreetMapUrl;
+  void _warnOpenStreetMapUrl() {
+    if (!_isOpenStreetMapUrl || !kDebugMode || _unblockOpenStreetMapUrl) return;
+    Logger(printer: PrettyPrinter(methodCount: 0)).e(
+      '''\x1B[1m\x1B[3mflutter_map\x1B[0m
+flutter_map wants to help keep map data available for everyone.
+We use the public OpenStreetMap tile servers in our code examples & demo app,
+but they are NOT free to use by everyone.
+In an upcoming non-major release, requests to 'tile.openstreetmap.org' or
+'tile.osm.org' will be blocked by default in release mode.
+Please review https://operations.osmfoundation.org/policies/tiles/ to see if
+your project is compliant with their Tile Usage Policy.
+For more information, see https://docs.fleaflet.dev/tile-servers/using-openstreetmap-direct.
+It describes in additional detail why we feel it is important to do this, how
+you can unblock the tile servers if your use-case is acceptable, the timeframes
+for this new policy, and how we're working to reduce requests without any extra
+work from you.''',
+    );
+  }
+
   bool _initializedFromMapCamera = false;
 
   final _tileImageManager = TileImageManager();
@@ -371,6 +407,7 @@ class _TileLayerState extends State<TileLayer> with TickerProviderStateMixin {
     super.initState();
     _resetSub = widget.reset?.listen(_resetStreamHandler);
     _tileRangeCalculator = TileRangeCalculator(tileDimension: _tileDimension);
+    _warnOpenStreetMapUrl();
   }
 
   // This is called on every map movement so we should avoid expensive logic
@@ -428,6 +465,8 @@ class _TileLayerState extends State<TileLayer> with TickerProviderStateMixin {
     super.didUpdateWidget(oldWidget);
     var reloadTiles = false;
 
+    _warnOpenStreetMapUrl();
+
     // There is no caching in TileRangeCalculator so we can just replace it.
     _tileRangeCalculator = TileRangeCalculator(tileDimension: _tileDimension);
 
@@ -505,6 +544,10 @@ class _TileLayerState extends State<TileLayer> with TickerProviderStateMixin {
 
     if (_outsideZoomLimits(map.zoom.round())) return const SizedBox.shrink();
 
+    if (_isOpenStreetMapUrl && _blockOpenStreetMapUrl) {
+      return const SizedBox.shrink();
+    }
+
     final tileZoom = _clampToNativeZoom(map.zoom);
     final tileBoundsAtZoom = _tileBounds.atZoom(tileZoom);
     final visibleTileRange = _tileRangeCalculator.calculate(
@@ -667,6 +710,10 @@ class _TileLayerState extends State<TileLayer> with TickerProviderStateMixin {
     DiscreteTileRange tileLoadRange, {
     required bool pruneAfterLoad,
   }) {
+    if (_isOpenStreetMapUrl && _blockOpenStreetMapUrl) {
+      return;
+    }
+
     final tileZoom = tileLoadRange.zoom;
     final expandedTileLoadRange = tileLoadRange.expand(widget.panBuffer);
 

lib/src/layer/tile_layer/unblock_osm.dart

@@ -0,0 +1,28 @@
+/// @nodoc
+final unblockOSM = [
+  79,
+  117,
+  114,
+  32,
+  116,
+  105,
+  108,
+  101,
+  32,
+  115,
+  101,
+  114,
+  118,
+  101,
+  114,
+  115,
+  32,
+  97,
+  114,
+  101,
+  32,
+  110,
+  111,
+  116,
+  46,
+];