How do I achieve the docking behavior to a window instead of to a content.

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WPF

MVVM

My requirement is :
I have a parent window mainwindow.xaml
When I click a button in mainwindow.xaml another windows sample.xaml opens.
Now,the window sample.xaml should be dockable.i.e along with the minimize ,maximize,close buttons i need an icon for docking the sample.xaml to the parent window mainwindow.xaml.
Now,when i mouseover the docked panel it should show me the window with only undock icon and close button on its header.
When i click on undock icon,then the normal window should be opened with all the four buttons(minimize,maximize,close and dockicon.).Kindly suggest how can I implement this one in wpf.