feat: mobile, virtual mouse (#12911)

* feat: mobile, virtual mouse

Signed-off-by: fufesou <linlong1266@gmail.com>

* feat: mobile, virtual mouse, mouse mode

Signed-off-by: fufesou <linlong1266@gmail.com>

* refact: mobile, virtual mouse, mouse mode

Signed-off-by: fufesou <linlong1266@gmail.com>

* feat: mobile, virtual mouse mode

Signed-off-by: fufesou <linlong1266@gmail.com>

* feat: mobile virtual mouse, options

Signed-off-by: fufesou <linlong1266@gmail.com>

---------

Signed-off-by: fufesou <linlong1266@gmail.com>
Co-authored-by: RustDesk <71636191+rustdesk@users.noreply.github.com>

flutter/lib/common/widgets/gestures.dart

@@ -1,6 +1,7 @@
 import 'dart:async';
 import 'package:flutter/gestures.dart';
 import 'package:flutter/widgets.dart';
+import 'package:flutter_hbb/common/widgets/remote_input.dart';
 
 enum GestureState {
   none,
@@ -96,6 +97,12 @@ class CustomTouchGestureRecognizer extends ScaleGestureRecognizer {
           if (onTwoFingerScaleEnd != null) {
             onTwoFingerScaleEnd!(d);
           }
+          if (isSpecialHoldDragActive) {
+            // If we are in special drag mode, we need to reset the state.
+            // Otherwise, the next `onTwoFingerScaleUpdate()` will handle a wrong `focalPoint`.
+            _currentState = GestureState.none;
+            return;
+          }
           break;
         case GestureState.threeFingerVerticalDrag:
           debugPrint("ThreeFingerState.vertical onEnd");