Relationship b/w different classes

Hi all,
before making any question i will first tell you about my class heirarchy..starting from down i have two widget classes ,these two widget classes are included in a scene class which is included in a view class and the view is controlled by a widget ....so when the main is executed a widget is called which turns on the view which has a scene and that scene has two widget parts to it..
Now my problem is at the scene and one of the widget...
i want to include a tab bar/widget in that widget and have tried to written a few lines of code in scene class...the output always has been nothing ....but the code for tab seems ok as if i show() it just there it is visible in a separte widget of its own..
now i am certain here that i am missing something of a setParent /child thing here....i cannt set a tabs parent to be scene or even a proxy widget ,so i have no idea how to over come this problem

below is my code ,if it helps any of you to understand the problem..Thanks already!

Code:

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Scene::Scene()
{
	proxy = new QGraphicsProxyWidget;
	inItem = new InputItems(); //this is my QWidget class which should be displayed when a particular Tab is ON
	tabBar = new QTabBar();
 
	tabBar->setTabButton(1,QTabBar::LeftSide,new QPushButton);
	tabBar->addTab("first");
	proxy = addWidget(inItem);
 
 
}

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