Add swipedown exit fullscreen feature

lib/src/chewie_player.dart

@@ -104,11 +104,26 @@ class ChewieState extends State<Chewie> {
   ) {
     return Scaffold(
       resizeToAvoidBottomInset: false,
-      body: Container(
-        alignment: Alignment.center,
-        color: Colors.black,
-        child: controllerProvider,
-      ),
+      body: widget.controller.swipeToExitFullscreen
+          ? GestureDetector(
+              onVerticalDragEnd: (DragEndDetails details) {
+                // A positive dy indicates a downward swipe. Use a threshold to avoid accidental triggers.
+                final double dy = details.primaryVelocity ?? 0;
+                if (dy > widget.controller.swipeThreshold) {
+                  widget.controller.exitFullScreen();
+                }
+              },
+              child: Container(
+                alignment: Alignment.center,
+                color: Colors.black,
+                child: controllerProvider,
+              ),
+            )
+          : Container(
+              alignment: Alignment.center,
+              color: Colors.black,
+              child: controllerProvider,
+            ),
     );
   }
 
@@ -335,6 +350,8 @@ class ChewieController extends ChangeNotifier {
     this.hideControlsTimer = defaultHideControlsTimer,
     this.controlsSafeAreaMinimum = EdgeInsets.zero,
     this.pauseOnBackgroundTap = false,
+    this.swipeToExitFullscreen = true,
+    this.swipeThreshold = 300,
   }) : assert(
          playbackSpeeds.every((speed) => speed > 0),
          'The playbackSpeeds values must all be greater than 0',
@@ -394,6 +411,8 @@ class ChewieController extends ChangeNotifier {
     )?
     routePageBuilder,
     bool? pauseOnBackgroundTap,
+    bool? swipeToExitFullscreen,
+    double? swipeThreshold,
   }) {
     return ChewieController(
       draggableProgressBar: draggableProgressBar ?? this.draggableProgressBar,
@@ -458,6 +477,9 @@ class ChewieController extends ChangeNotifier {
       progressIndicatorDelay:
           progressIndicatorDelay ?? this.progressIndicatorDelay,
       pauseOnBackgroundTap: pauseOnBackgroundTap ?? this.pauseOnBackgroundTap,
+      swipeToExitFullscreen:
+          swipeToExitFullscreen ?? this.swipeToExitFullscreen,
+      swipeThreshold: swipeThreshold ?? this.swipeThreshold,
     );
   }
 
@@ -630,6 +652,13 @@ class ChewieController extends ChangeNotifier {
   /// Defines if the player should pause when the background is tapped
   final bool pauseOnBackgroundTap;
 
+  /// Defines if the player allows swipe to exit fullscreen
+  final bool swipeToExitFullscreen;
+
+  /// Defines the minimum velocity threshold for swipe to exit fullscreen gesture
+  /// The velocity is measured in pixels per second
+  final double swipeThreshold;
+
   static ChewieController of(BuildContext context) {
     final chewieControllerProvider = context
         .dependOnInheritedWidgetOfExactType<ChewieControllerProvider>()!;