lib/motion/accessors.rb in rm-extensions-0.4.5 vs lib/motion/accessors.rb in rm-extensions-0.5.0

@@ -17,9 +17,29 @@
             val
           end
         end
       end
 
+      # creates an +attr_accessor+ like behavior, but the objects are
+      # stored in an NSMapTable with strong keys (the attrs) and
+      # weak values.  If the value deallocates, it becomes nil, unlike
+      # a traditional WeakRef.
+      # does not conform to KVO like attr_accessor does.
+      def rmext_zeroing_weak_attr_accessor(*attrs)
+        attrs.each do |attr|
+          define_method(attr) do
+            if @__zeroing_weak_holders
+              @__zeroing_weak_holders.objectForKey(attr)
+            end
+          end
+          define_method("#{attr}=") do |val|
+            @__zeroing_weak_holders ||= NSMapTable.strongToWeakObjectsMapTable
+            @__zeroing_weak_holders.setObject(val, forKey:attr)
+            val
+          end
+        end
+      end
+
     end
 
   end
 
 end