Improve tile handling

lib/src/layer/tile_layer/tile.dart

@@ -16,7 +16,7 @@ class Tile {
   DateTime? loaded;
   late DateTime loadStarted;
 
-  AnimationController? animationController;
+  final AnimationController? animationController;
 
   double get opacity => animationController == null
       ? (active ? 1.0 : 0.0)
@@ -33,12 +33,18 @@ class Tile {
     required this.coords,
     required this.tilePos,
     required this.imageProvider,
+    required final TickerProvider vsync,
     this.tileReady,
     this.current = false,
     this.active = false,
     this.retain = false,
     this.loadError = false,
-  });
+    final Duration? duration,
+  }) : animationController = duration != null
+            ? AnimationController(duration: duration, vsync: vsync)
+            : null {
+    animationController?.addStatusListener(_onAnimateEnd);
+  }
 
   void loadTileImage() {
     loadStarted = DateTime.now();
@@ -78,15 +84,9 @@ class Tile {
     _imageStream?.removeListener(_listener);
   }
 
-  void startFadeInAnimation(Duration duration, TickerProvider vsync,
-      {double? from}) {
-    animationController?.removeStatusListener(_onAnimateEnd);
-    animationController?.dispose();
-
-    animationController = AnimationController(duration: duration, vsync: vsync)
-      ..addStatusListener(_onAnimateEnd);
-
-    animationController!.forward(from: from);
+  void startFadeInAnimation({double? from}) {
+    animationController?.reset();
+    animationController?.forward(from: from);
   }
 
   void _onAnimateEnd(AnimationStatus status) {
@@ -96,14 +96,14 @@ class Tile {
   }
 
   void _tileOnLoad(ImageInfo imageInfo, bool synchronousCall) {
-    if (null != tileReady) {
+    if (tileReady != null) {
       this.imageInfo = imageInfo;
       tileReady!(coords, null, this);
     }
   }
 
   void _tileOnError(dynamic exception, StackTrace? stackTrace) {
-    if (null != tileReady) {
+    if (tileReady != null) {
       tileReady!(
           coords, exception ?? 'Unknown exception during loadTileImage', this);
     }

lib/src/layer/tile_layer/tile_layer.dart

@@ -432,7 +432,7 @@ class _TileLayerState extends State<TileLayer> with TickerProviderStateMixin {
 
     final tileWidgets = <Widget>[
       for (var tile in tilesToRender)
-        TileWidget(
+        AnimatedTile(
           tile: tile,
           size: _tileSize,
           tileTransformation: zoomToTransformation[tile.coords.z] ??
@@ -633,6 +633,8 @@ class _TileLayerState extends State<TileLayer> with TickerProviderStateMixin {
         imageProvider:
             widget.tileProvider.getImage(coords.wrap(_wrapX, _wrapY), widget),
         tileReady: _tileReady,
+        vsync: this,
+        duration: widget.tileFadeInDuration,
       );
 
       _tileManager.add(coords, newTile);
@@ -712,11 +714,7 @@ class _TileLayerState extends State<TileLayer> with TickerProviderStateMixin {
         (tile.loadError && null == widget.errorImage)) {
       tile.active = true;
     } else {
-      tile.startFadeInAnimation(
-        widget.tileFadeInDuration!,
-        this,
-        from: fadeInStart,
-      );
+      tile.startFadeInAnimation(from: fadeInStart);
     }
 
     if (mounted) {

lib/src/layer/tile_layer/tile_widget.dart

@@ -1,16 +1,15 @@
 import 'package:flutter/widgets.dart';
 import 'package:flutter_map/flutter_map.dart';
-import 'package:flutter_map/src/layer/tile_layer/animated_tile.dart';
 import 'package:flutter_map/src/layer/tile_layer/tile_transformation.dart';
 
-class TileWidget extends StatelessWidget {
+class AnimatedTile extends StatelessWidget {
   final Tile tile;
   final CustomPoint size;
   final TileTransformation tileTransformation;
   final ImageProvider? errorImage;
   final TileBuilder? tileBuilder;
 
-  const TileWidget({
+  const AnimatedTile({
     required this.tile,
     required this.size,
     required this.tileTransformation,
@@ -26,16 +25,27 @@ class TileWidget extends StatelessWidget {
     final num width = size.x * tileTransformation.scale;
     final num height = size.y * tileTransformation.scale;
 
+    Widget tileWidget;
+    if (tile.loadError && errorImage != null) {
+      tileWidget = Image(image: errorImage!);
+    } else if (tile.animationController == null) {
+      tileWidget = RawImage(image: tile.imageInfo?.image, fit: BoxFit.fill);
+    } else {
+      tileWidget = AnimatedBuilder(
+        animation: tile.animationController!,
+        builder: (context, child) => RawImage(
+            image: tile.imageInfo?.image,
+            fit: BoxFit.fill,
+            opacity: tile.animationController!),
+      );
+    }
+
     return Positioned(
       left: pos.x.toDouble(),
       top: pos.y.toDouble(),
       width: width.toDouble(),
       height: height.toDouble(),
-      child: AnimatedTile(
-        tile: tile,
-        errorImage: errorImage,
-        tileBuilder: tileBuilder,
-      ),
+      child: tileBuilder?.call(context, tileWidget, tile) ?? tileWidget,
     );
   }
 }