allow clearing all signal handlers; allow clearing all menu item subitems

src/dlangui/core/signals.d

@@ -164,6 +164,10 @@ struct Listener(RETURN_T, T1...)
     final slot_t get() {
         return _listener;
     }
+    /// disconnect all listeners
+    final void clear() {
+        _listener = null;
+    }
     alias get this;
 }
 
@@ -235,6 +239,10 @@ struct Signal(T1) if (is(T1 == interface) && __traits(allMembers, T1).length ==
     final void disconnect(T1 listener) {
         disconnect(&__traits(getMember, listener, __traits(allMembers, T1)[0]));
     }
+    /// disconnect all listeners
+    final void clear() {
+        _listeners.clear();
+    }
 }
 
 /// Multiple listeners; implicitly specified return and parameter types
@@ -287,4 +295,8 @@ struct Signal(RETURN_T, T1...)
     final void disconnect(slot_t listener) {
         _listeners -= listener;
     }
+    /// disconnect all listeners
+    final void clear() {
+        _listeners.clear();
+    }
 }

src/dlangui/widgets/menu.d

@@ -232,6 +232,12 @@ class MenuItem {
         }
         return res;
     }
+    /// removes all subitems
+    void clear() {
+        foreach(ref item; _subitems)
+            item = null;
+        _subitems.length = 0;
+    }
     /// returns text description for first accelerator of action; null if no accelerators
     @property dstring acceleratorText() {
         if (!_action)

views/DLANGUI_VERSION

@@ -1 +1 @@
-v0.9.145
+v0.9.146