fix: multiple external tilesets (#37)

Author: lfraker

lib/src/tile_map_parser.dart

@@ -6,12 +6,16 @@ class TileMapParser {
     return TiledMap.parse(parser);
   }
 
-  static TiledMap parseTmx(String xml, {TsxProvider? tsx}) {
+  /// Parses the provided map xml.
+  ///
+  /// Accepts an optional list of external TsxProviders for external tilesets
+  /// referenced in the map file.
+  static TiledMap parseTmx(String xml, {List<TsxProvider>? tsxList}) {
     final xmlElement = XmlDocument.parse(xml).rootElement;
     if (xmlElement.name.local != 'map') {
       throw 'XML is not in TMX format';
     }
     final parser = XmlParser(xmlElement);
-    return TiledMap.parse(parser, tsx: tsx);
+    return TiledMap.parse(parser, tsxList: tsxList);
   }
 }

lib/src/tiled_map.dart

@@ -196,7 +196,7 @@ class TiledMap {
     );
   }
 
-  static TiledMap parse(Parser parser, {TsxProvider? tsx}) {
+  static TiledMap parse(Parser parser, {List<TsxProvider>? tsxList}) {
     final backgroundColor = parser.getStringOrNull('backgroundcolor');
     final compressionLevel = parser.getInt('compressionlevel', defaults: -1);
     final height = parser.getInt('height');
@@ -220,7 +220,20 @@ class TiledMap {
 
     final tilesets = parser.getChildrenAs(
       'tileset',
-      (e) => Tileset.parse(e, tsx: tsx),
+      (tilesetData) {
+        final tilesetSource = tilesetData.getStringOrNull('source');
+        if (tilesetSource == null || tsxList == null) {
+          return Tileset.parse(tilesetData);
+        }
+        final matchingTsx = tsxList.where(
+          (tsx) => tsx.filename == tilesetSource,
+        );
+
+        return Tileset.parse(
+          tilesetData,
+          tsx: matchingTsx.isNotEmpty ? matchingTsx.first : null,
+        );
+      },
     );
     final layers = Layer.parseLayers(parser);
     final properties = parser.getProperties();

lib/src/tileset/tileset.dart

@@ -168,7 +168,9 @@ class Tileset {
 
   void _checkIfExtenalTsx(String? source, TsxProvider? tsx) {
     if (tsx != null && source != null) {
-      final tileset = Tileset.parse(tsx.getSource(source));
+      final tileset = Tileset.parse(
+        tsx.getChachedSource() ?? tsx.getSource(source),
+      );
       // Copy attributes if not null
       backgroundColor = tileset.backgroundColor ?? backgroundColor;
       columns = tileset.columns ?? columns;

lib/src/tsx_provider.dart

@@ -1,5 +1,15 @@
 part of tiled;
 
+/// abstract class to be implemented for an external tileset data provider.
 abstract class TsxProvider {
+  /// Unique filename for the tileset to be loaded. This should match the
+  /// 'source' property in the map.tmx file.
+  String get filename;
+
+  /// Retrieves the external tileset data given the tileset filename.
   Parser getSource(String filename);
+
+  /// Used when provider implementations cache the data. Returns the cached
+  /// data for the exernal tileset.
+  Parser? getChachedSource();
 }

test/fixtures/external_tileset_1.tsx

@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<tileset version="1.2" tiledversion="2018.11.29" name="level1" tilewidth="16" tileheight="16" tilecount="136" columns="17">
+<image source="../images/map-level1.png" width="272" height="128"/>
+  <tile id="64">
+   <properties>
+    <property name="type" value="sky"/>
+   </properties>
+  </tile>
+  <tile id="65">
+   <properties>
+    <property name="type" value="xpto"/>
+   </properties>
+  </tile>
+</tileset>

test/fixtures/external_tileset_2.tsx

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="UTF-8"?>
+    <tileset version="1.2" tiledversion="2018.11.29" name="level2" tilewidth="16" tileheight="16" tilecount="288" columns="24">
+        <image source="../images/map-level2.png" width="384" height="192" />
+    </tileset>

test/fixtures/map_with_multiple_tilesets.tmx

@@ -166,7 +166,10 @@ void main() {
   group('Parser.parse fills Map with tileset & different img configs', () {
     setUp(() {
       return File('./test/fixtures/map_images.tmx').readAsString().then((xml) {
-        map = TileMapParser.parseTmx(xml, tsx: CustomTsxProvider());
+        map = TileMapParser.parseTmx(
+          xml,
+          tsxList: [CustomTsxProvider.parse('tileset.tsx')],
+        );
       });
     });
 
@@ -222,7 +225,10 @@ void main() {
   group('Parser.parse with tsx provider', () {
     test('it loads external tsx', () {
       return File('./test/fixtures/map_images.tmx').readAsString().then((xml) {
-        map = TileMapParser.parseTmx(xml, tsx: CustomTsxProvider());
+        map = TileMapParser.parseTmx(
+          xml,
+          tsxList: [CustomTsxProvider.parse('tileset.tsx')],
+        );
         expect(
           map.tilesetByName('external').image!.source,
           equals('level1.png'),
@@ -234,18 +240,110 @@ void main() {
   group('Parser.parse with multiple layers', () {
     test('it has 2 layers', () {
       return File('./test/fixtures/map_images.tmx').readAsString().then((xml) {
-        map = TileMapParser.parseTmx(xml, tsx: CustomTsxProvider());
+        map = TileMapParser.parseTmx(
+          xml,
+          tsxList: [CustomTsxProvider.parse('tileset.tsx')],
+        );
         expect(map.layers.length, equals(2));
       });
     });
   });
+
+  group('Map Parses Multiple Tilesets', () {
+    late TiledMap map;
+    setUp(() {
+      return File('./test/fixtures/map_with_multiple_tilesets.tmx')
+          .readAsString()
+          .then((xml) {
+        final tilemapXml = XmlDocument.parse(xml).rootElement;
+        final tsxSourcePaths = tilemapXml.children
+            .whereType<XmlElement>()
+            .where((element) => element.name.local == 'tileset')
+            .map((tsx) => tsx.getAttribute('source'));
+
+        final tsxProviders = tsxSourcePaths
+            .where((key) => key != null)
+            .map((key) => CustomTsxProvider.parse(key!));
+
+        map = TileMapParser.parseTmx(
+          xml,
+          tsxList: tsxProviders.isEmpty ? null : tsxProviders.toList(),
+        );
+        return;
+      });
+    });
+    test(
+      'correct number of tilests',
+      () => expect(
+        map.tilesets.length == 3,
+        true,
+      ),
+    );
+
+    test('tilesets firstgid correct', () {
+      expect(
+        map.tilesets.first.firstGid == 1,
+        true,
+      );
+
+      expect(
+        map.tilesets.last.firstGid == 273,
+        true,
+      );
+    });
+    test('first tileset details correct', () {
+      expect(
+        map.tilesets.first.name == 'level1',
+        true,
+      );
+
+      expect(
+        map.tilesets.first.tileCount == 136,
+        true,
+      );
+    });
+    test('embedded tileset details correct', () {
+      expect(
+        map.tilesets[1].name == 'level_embed',
+        true,
+      );
+    });
+    test('third tileset details correct', () {
+      expect(
+        map.tilesets.last.name == 'level2',
+        true,
+      );
+
+      expect(
+        map.tilesets.last.tileCount == 288,
+        true,
+      );
+    });
+  });
 }
 
 class CustomTsxProvider extends TsxProvider {
+  final String _filename;
+  final String data;
+
+  CustomTsxProvider._(this.data, this._filename);
+
+  @override
+  String get filename => _filename;
+
   @override
   Parser getSource(String key) {
-    final xml = File('./test/fixtures/tileset.tsx').readAsStringSync();
-    final node = XmlDocument.parse(xml).rootElement;
+    final node = XmlDocument.parse(data).rootElement;
     return XmlParser(node);
   }
+
+  @override
+  Parser? getChachedSource() {
+    return getSource('');
+  }
+
+  static CustomTsxProvider parse(String filename) {
+    final xml = File('./test/fixtures/$filename').readAsStringSync();
+    return CustomTsxProvider._(xml, filename);
+  }
 }