Fix GestureDetector long press callback handling (#62897)

* Allow GestureDetector to use long press and secondary long press at the same time.

packages/flutter/lib/src/widgets/gesture_detector.dart

@@ -702,8 +702,7 @@ class GestureDetector extends StatelessWidget {
   Widget build(BuildContext context) {
     final Map<Type, GestureRecognizerFactory> gestures = <Type, GestureRecognizerFactory>{};
 
-    if (
-      onTapDown != null ||
+    if (onTapDown != null ||
         onTapUp != null ||
         onTap != null ||
         onTapCancel != null ||
@@ -741,21 +740,8 @@ class GestureDetector extends StatelessWidget {
         onLongPressUp != null ||
         onLongPressStart != null ||
         onLongPressMoveUpdate != null ||
-        onLongPressEnd != null) {
-      gestures[LongPressGestureRecognizer] = GestureRecognizerFactoryWithHandlers<LongPressGestureRecognizer>(
-        () => LongPressGestureRecognizer(debugOwner: this),
-        (LongPressGestureRecognizer instance) {
-          instance
-            ..onLongPress = onLongPress
-            ..onLongPressStart = onLongPressStart
-            ..onLongPressMoveUpdate = onLongPressMoveUpdate
-            ..onLongPressEnd =onLongPressEnd
-            ..onLongPressUp = onLongPressUp;
-        },
-      );
-    }
-
-    if (onSecondaryLongPress != null ||
+        onLongPressEnd != null ||
+        onSecondaryLongPress != null ||
         onSecondaryLongPressUp != null ||
         onSecondaryLongPressStart != null ||
         onSecondaryLongPressMoveUpdate != null ||
@@ -764,10 +750,15 @@ class GestureDetector extends StatelessWidget {
         () => LongPressGestureRecognizer(debugOwner: this),
         (LongPressGestureRecognizer instance) {
           instance
+            ..onLongPress = onLongPress
+            ..onLongPressStart = onLongPressStart
+            ..onLongPressMoveUpdate = onLongPressMoveUpdate
+            ..onLongPressEnd = onLongPressEnd
+            ..onLongPressUp = onLongPressUp
             ..onSecondaryLongPress = onSecondaryLongPress
             ..onSecondaryLongPressStart = onSecondaryLongPressStart
             ..onSecondaryLongPressMoveUpdate = onSecondaryLongPressMoveUpdate
-            ..onSecondaryLongPressEnd =onSecondaryLongPressEnd
+            ..onSecondaryLongPressEnd = onSecondaryLongPressEnd
             ..onSecondaryLongPressUp = onSecondaryLongPressUp;
         },
       );
@@ -865,6 +856,7 @@ class GestureDetector extends StatelessWidget {
       child: child,
     );
   }
+
   @override
   void debugFillProperties(DiagnosticPropertiesBuilder properties) {
     super.debugFillProperties(properties);

packages/flutter/test/widgets/gesture_detector_test.dart

@@ -381,6 +381,42 @@ void main() {
     }, variant: buttonVariant);
   });
 
+  testWidgets('Primary and secondary long press callbacks should work together in GestureDetector', (WidgetTester tester) async {
+    bool primaryLongPress = false, secondaryLongPress = false;
+
+    await tester.pumpWidget(
+      Container(
+        alignment: Alignment.topLeft,
+        child: Container(
+          alignment: Alignment.center,
+          height: 100.0,
+          color: const Color(0xFF00FF00),
+          child: GestureDetector(
+            onLongPress: () {
+              primaryLongPress = true;
+            },
+            onSecondaryLongPress: () {
+              secondaryLongPress = true;
+            },
+          ),
+        ),
+      ),
+    );
+
+    Future<void> longPress(Duration timeout, int buttons) async {
+      final TestGesture gesture = await tester.startGesture(const Offset(400.0, 50.0), buttons: buttons);
+      await tester.pump(timeout);
+      await gesture.up();
+    }
+
+    // Adding a second to make sure the time for long press has occurred.
+    await longPress(kLongPressTimeout + const Duration(seconds: 1), kPrimaryButton);
+    expect(primaryLongPress, isTrue);
+
+    await longPress(kLongPressTimeout + const Duration(seconds: 1), kSecondaryButton);
+    expect(secondaryLongPress, isTrue);
+  });
+
   testWidgets('Force Press Callback called after force press', (WidgetTester tester) async {
     int forcePressStart = 0;
     int forcePressPeaked = 0;