From Jeremy Moles, updates to osgwidget examples.

Merged by Robert Osfield from OpenSceneGraph-osgWidget-dev

examples/osgwidgetaddremove/osgwidgetaddremove.cpp

@@ -65,13 +65,13 @@ public:
         // Take special note here! Not only do the Button objects have their
         // own overridden methods for changing the color, but they have attached
         // callbacks for doing the work with local data.
-        getByName("Widget_1")->addCallback(osgWidget::Callback(
+        getByName("Widget_1")->addCallback(new osgWidget::Callback(
             &AddRemove::handlePressAdd,
             this,
             osgWidget::EVENT_MOUSE_PUSH
         ));
 
-        getByName("Widget_2")->addCallback(osgWidget::Callback(
+        getByName("Widget_2")->addCallback(new osgWidget::Callback(
             &AddRemove::handlePressRemove,
             this,
             osgWidget::EVENT_MOUSE_PUSH
@@ -94,7 +94,6 @@ public:
         ss << "a random widget " << num;
 
         _win1->addWidget(new ABCWidget(ss.str()));
-        _win1->resize();
 
         num++;
 
@@ -110,7 +109,6 @@ public:
         osgWidget::Widget* w = _win1->getObjects()[v.size() - 1].get();
 
         _win1->removeWidget(w);
-        _win1->resize();
 
         return true;
     }