Draggables weren't using the new coordinate system (#777)

* refactoring drag start events

* Fixing joystick, adding tests and examples

* format fixes

examples/lib/stories/controls/controls.dart

@@ -52,7 +52,17 @@ void addControlsStories(Dashbook dashbook) {
     )
     ..add(
       'Draggables',
-      (_) => GameWidget(game: DraggablesGame()),
+      (context) {
+        return GameWidget(
+          game: DraggablesGame(
+            zoom: context.listProperty(
+              'zoom',
+              1,
+              [0.5, 1, 1.5],
+            ),
+          ),
+        );
+      },
       codeLink: baseLink('gestures/draggables.dart'),
     )
     ..add(

examples/lib/stories/controls/draggables.dart

@@ -27,8 +27,8 @@ class DraggableSquare extends PositionComponent
   }
 
   @override
-  bool onDragStart(int pointerId, Vector2 startPosition) {
-    dragDeltaPosition = startPosition - position;
+  bool onDragStart(int pointerId, DragStartInfo info) {
+    dragDeltaPosition = info.eventPosition.game - position;
     return false;
   }
 
@@ -57,8 +57,13 @@ class DraggableSquare extends PositionComponent
 }
 
 class DraggablesGame extends BaseGame with HasDraggableComponents {
+  final double zoom;
+
+  DraggablesGame({required this.zoom});
+
   @override
   Future<void> onLoad() async {
+    camera.zoom = zoom;
     add(DraggableSquare());
     add(DraggableSquare()..y = 350);
   }

examples/lib/stories/controls/multitap_advanced.dart

@@ -39,9 +39,9 @@ class MultitapAdvancedGame extends BaseGame
   }
 
   @override
-  void onDragStart(int pointerId, Vector2 position) {
+  void onDragStart(int pointerId, DragStartInfo info) {
     end = null;
-    start = position;
+    start = info.eventPosition.game;
   }
 
   @override

packages/flame/lib/src/components/joystick/joystick_action.dart

@@ -163,13 +163,13 @@ class JoystickAction extends BaseComponent with Draggable, HasGameRef {
   }
 
   @override
-  bool onDragStart(int pointerId, Vector2 startPosition) {
+  bool onDragStart(int pointerId, DragStartInfo info) {
     if (_dragging) {
       return true;
     }
 
     if (enableDirection) {
-      _dragPosition = startPosition;
+      _dragPosition = info.eventPosition.widget;
       _dragging = true;
     }
     _sendEvent(ActionEvent.down);

packages/flame/lib/src/components/joystick/joystick_directional.dart

@@ -130,11 +130,11 @@ class JoystickDirectional extends BaseComponent with Draggable, HasGameRef {
   }
 
   @override
-  bool onDragStart(int pointerId, Vector2 startPosition) {
-    _updateDirectionalRect(startPosition);
+  bool onDragStart(int pointerId, DragStartInfo info) {
+    _updateDirectionalRect(info.eventPosition.widget);
     if (!_dragging) {
       _dragging = true;
-      _dragPosition = startPosition;
+      _dragPosition = info.eventPosition.widget;
       return true;
     }
     return false;

packages/flame/lib/src/components/mixins/draggable.dart

@@ -1,20 +1,19 @@
 import 'package:flutter/material.dart';
 
-import '../../../extensions.dart';
 import '../../game/base_game.dart';
 import '../../gestures/events.dart';
 import '../base_component.dart';
 
 mixin Draggable on BaseComponent {
-  bool onDragStart(int pointerId, Vector2 startPosition) {
+  bool onDragStart(int pointerId, DragStartInfo info) {
     return true;
   }
 
-  bool onDragUpdate(int pointerId, DragUpdateInfo details) {
+  bool onDragUpdate(int pointerId, DragUpdateInfo info) {
     return true;
   }
 
-  bool onDragEnd(int pointerId, DragEndInfo details) {
+  bool onDragEnd(int pointerId, DragEndInfo info) {
     return true;
   }
 
@@ -25,10 +24,10 @@ mixin Draggable on BaseComponent {
   final List<int> _currentPointerIds = [];
   bool _checkPointerId(int pointerId) => _currentPointerIds.contains(pointerId);
 
-  bool handleDragStart(int pointerId, Vector2 startPosition) {
-    if (containsPoint(startPosition)) {
+  bool handleDragStart(int pointerId, DragStartInfo info) {
+    if (containsPoint(info.eventPosition.game)) {
       _currentPointerIds.add(pointerId);
-      return onDragStart(pointerId, startPosition);
+      return onDragStart(pointerId, info);
     }
     return true;
   }
@@ -59,8 +58,8 @@ mixin Draggable on BaseComponent {
 
 mixin HasDraggableComponents on BaseGame {
   @mustCallSuper
-  void onDragStart(int pointerId, Vector2 startPosition) {
-    _onGenericEventReceived((c) => c.handleDragStart(pointerId, startPosition));
+  void onDragStart(int pointerId, DragStartInfo info) {
+    _onGenericEventReceived((c) => c.handleDragStart(pointerId, info));
   }
 
   @mustCallSuper

packages/flame/lib/src/game/game_widget/gestures.dart

@@ -192,14 +192,28 @@ Widget applyAdvancedGesturesDetectors(Game game, Widget child) {
     );
   }
 
-  void addDragRecognizer(Drag Function(int, Vector2) config) {
+  void addDragRecognizer(Game game, Drag Function(int, DragStartInfo) config) {
     addAndConfigureRecognizer(
       () => ImmediateMultiDragGestureRecognizer(),
       (ImmediateMultiDragGestureRecognizer instance) {
         instance.onStart = (Offset o) {
           final pointerId = lastGeneratedDragId++;
-          final position = game.convertGlobalToLocalCoordinate(o.toVector2());
-          return config(pointerId, position);
+
+          final global = o;
+          final local = game
+              .convertGlobalToLocalCoordinate(
+                global.toVector2(),
+              )
+              .toOffset();
+
+          final details = DragStartDetails(
+            localPosition: local,
+            globalPosition: global,
+          );
+          return config(
+            pointerId,
+            DragStartInfo.fromDetails(game, details),
+          );
         };
       },
     );
@@ -228,15 +242,15 @@ Widget applyAdvancedGesturesDetectors(Game game, Widget child) {
   }
 
   if (game is MultiTouchDragDetector) {
-    addDragRecognizer((int pointerId, Vector2 position) {
-      game.onDragStart(pointerId, position);
+    addDragRecognizer(game, (int pointerId, DragStartInfo info) {
+      game.onDragStart(pointerId, info);
       return _DragEvent(game)
         ..onUpdate = ((details) => game.onDragUpdate(pointerId, details))
         ..onEnd = ((details) => game.onDragEnd(pointerId, details))
         ..onCancel = (() => game.onDragCancel(pointerId));
     });
   } else if (game is HasDraggableComponents) {
-    addDragRecognizer((int pointerId, Vector2 position) {
+    addDragRecognizer(game, (int pointerId, DragStartInfo position) {
       game.onDragStart(pointerId, position);
       return _DragEvent(game)
         ..onUpdate = ((details) => game.onDragUpdate(pointerId, details))

packages/flame/lib/src/gestures/detectors.dart

@@ -1,4 +1,3 @@
-import '../../extensions.dart';
 import '../game/game.dart';
 import 'events.dart';
 
@@ -11,7 +10,7 @@ mixin MultiTouchTapDetector on Game {
 }
 
 mixin MultiTouchDragDetector on Game {
-  void onDragStart(int pointerId, Vector2 startPosition) {}
+  void onDragStart(int pointerId, DragStartInfo info) {}
   void onDragUpdate(int pointerId, DragUpdateInfo info) {}
   void onDragEnd(int pointerId, DragEndInfo info) {}
   void onDragCancel(int pointerId) {}

packages/flame/test/components/draggable.dart

@@ -1,25 +0,0 @@
-import 'package:flame/components.dart';
-import 'package:flame/game.dart';
-import 'package:test/test.dart';
-
-class _GameWithDraggables extends BaseGame with HasDraggableComponents {}
-
-class _GameWithoutDraggables extends BaseGame {}
-
-class DraggableComponent extends PositionComponent with Draggable {}
-
-void main() {
-  group('draggables test', () {
-    test('make sure they cannot be added to invalid games', () async {
-      final game1 = _GameWithDraggables();
-      // should be ok
-      await game1.add(DraggableComponent());
-
-      final game2 = _GameWithoutDraggables();
-      expect(
-        () => game2.add(DraggableComponent()),
-        isA<AssertionError>(),
-      );
-    });
-  });
-}

packages/flame/test/components/draggable_test.dart

@@ -0,0 +1,93 @@
+import 'package:flame/components.dart';
+import 'package:flame/game.dart';
+import 'package:flame/gestures.dart';
+import 'package:flutter/gestures.dart';
+import 'package:test/test.dart';
+
+class _GameWithDraggables extends BaseGame with HasDraggableComponents {}
+
+class _GameWithoutDraggables extends BaseGame {}
+
+class DraggableComponent extends PositionComponent with Draggable {
+  bool hasStartedDragging = false;
+
+  @override
+  bool onDragStart(int pointerId, DragStartInfo event) {
+    hasStartedDragging = true;
+    return true;
+  }
+}
+
+void main() {
+  group('draggables test', () {
+    test('make sure they cannot be added to invalid games', () async {
+      final game1 = _GameWithDraggables();
+      game1.onResize(Vector2.all(100));
+      // should be ok
+      await game1.add(DraggableComponent());
+
+      final game2 = _GameWithoutDraggables();
+      game2.onResize(Vector2.all(100));
+      var hasError = false;
+
+      try {
+        await game2.add(DraggableComponent());
+      } catch (e) {
+        hasError = true;
+      }
+
+      expect(hasError, true);
+    });
+
+    test('can be dragged', () async {
+      final game = _GameWithDraggables();
+      game.onResize(Vector2.all(100));
+      final component = DraggableComponent()
+        ..x = 10
+        ..y = 10
+        ..width = 10
+        ..height = 10;
+
+      await game.add(component);
+      // So component is added
+      game.update(0.01);
+      game.onDragStart(
+        1,
+        DragStartInfo.fromDetails(
+          game,
+          DragStartDetails(
+            localPosition: const Offset(12, 12),
+            globalPosition: const Offset(12, 12),
+          ),
+        ),
+      );
+      expect(component.hasStartedDragging, true);
+    });
+
+    test('when the game has camera zoom, can be dragged', () async {
+      final game = _GameWithDraggables();
+      game.onResize(Vector2.all(100));
+      final component = DraggableComponent()
+        ..x = 10
+        ..y = 10
+        ..width = 10
+        ..height = 10;
+
+      await game.add(component);
+      game.camera.zoom = 1.5;
+      // So component is added
+      game.update(0.01);
+      game.onDragStart(
+        1,
+        DragStartInfo.fromDetails(
+          game,
+          DragStartDetails(
+            localPosition: const Offset(12, 12),
+            globalPosition: const Offset(12, 12),
+          ),
+        ),
+      );
+      expect(component.hasStartedDragging, true);
+    });
+  });
+}

packages/flame/test/components/tapables_test.dart

@@ -12,14 +12,22 @@ void main() {
   group('tapables test', () {
     test('make sure they cannot be added to invalid games', () async {
       final game1 = _GameWithTapables();
+      game1.onResize(Vector2.all(100));
       // should be ok
       await game1.add(TapableComponent());
 
       final game2 = _GameWithoutTapables();
-      expect(
-        () => game2.add(TapableComponent()),
-        isA<AssertionError>(),
-      );
+      game2.onResize(Vector2.all(100));
+
+      var hasError = false;
+
+      try {
+        await game2.add(TapableComponent());
+      } catch (e) {
+        hasError = true;
+      }
+
+      expect(hasError, true);
     });
   });
 }