Added a new callback ValueTree::Listener::valueTreeRedirected()

modules/juce_data_structures/values/juce_ValueTree.cpp

@@ -663,6 +663,8 @@ ValueTree& ValueTree::operator= (const ValueTree& other)
     }
 
     object = other.object;
+
+    listeners.call (&ValueTree::Listener::valueTreeRedirected, *this);
     return *this;
 }
 
@@ -671,12 +673,6 @@ ValueTree::ValueTree (ValueTree&& other) noexcept
     : object (static_cast <SharedObject::Ptr&&> (other.object))
 {
 }
-
-ValueTree& ValueTree::operator= (ValueTree&& other) noexcept
-{
-    object = static_cast <SharedObject::Ptr&&> (other.object);
-    return *this;
-}
 #endif
 
 ValueTree::~ValueTree()

modules/juce_data_structures/values/juce_ValueTree.h

@@ -93,7 +93,6 @@ public:
 
    #if JUCE_COMPILER_SUPPORTS_MOVE_SEMANTICS
     ValueTree (ValueTree&& other) noexcept;
-    ValueTree& operator= (ValueTree&& other) noexcept;
    #endif
 
     /** Destructor. */
@@ -412,6 +411,12 @@ public:
             the listener is registered, and not to any of its children.
         */
         virtual void valueTreeParentChanged (ValueTree& treeWhoseParentHasChanged) = 0;
+
+        /** This method is called when a tree is made to point to a different internal shared object.
+            When operator= is used to make a ValueTree refer to a different object, this callback
+            will be made.
+        */
+        virtual void valueTreeRedirected (ValueTree& treeWhichHasBeenChanged) {}
     };
 
     /** Adds a listener to receive callbacks when this node is changed.