client side view mode

Signed-off-by: 21pages <pages21@163.com>

flutter/lib/models/model.dart

@@ -47,6 +47,7 @@ class FfiModel with ChangeNotifier {
   bool _touchMode = false;
   Timer? _timer;
   var _reconnects = 1;
+  bool _viewOnly = false;
   WeakReference<FFI> parent;
 
   Map<String, bool> get permissions => _permissions;
@@ -65,6 +66,8 @@ class FfiModel with ChangeNotifier {
 
   bool get isPeerAndroid => _pi.platform == kPeerPlatformAndroid;
 
+  bool get viewOnly => _viewOnly;
+
   set inputBlocked(v) {
     _inputBlocked = v;
   }
@@ -373,7 +376,8 @@ class FfiModel with ChangeNotifier {
   _updateSessionWidthHeight(String id) {
     parent.target?.canvasModel.updateViewStyle();
     if (display.width <= 0 || display.height <= 0) {
-      debugPrintStack(label: 'invalid display size (${display.width},${display.height})');
+      debugPrintStack(
+          label: 'invalid display size (${display.width},${display.height})');
     } else {
       bind.sessionSetSize(id: id, width: display.width, height: display.height);
     }
@@ -516,6 +520,19 @@ class FfiModel with ChangeNotifier {
       //
     }
   }
+
+  void setViewOnly(String id, bool value) {
+    if (value) {
+      ShowRemoteCursorState.find(id).value = value;
+    } else {
+      ShowRemoteCursorState.find(id).value =
+          bind.sessionGetToggleOptionSync(id: id, arg: 'show-remote-cursor');
+    }
+    if (_viewOnly != value) {
+      _viewOnly = value;
+      notifyListeners();
+    }
+  }
 }
 
 class ImageModel with ChangeNotifier {