The main window of our WPF application consists of 4 regions, arranged as 2x2 tiles. The user must be able to resize these regions. This is not a problem when using a Grid control with GridSplitter elements.
But there is an additional requirement. In the center of window where all the regions meet there has to be a button which can be used to resize the regions too. The user can drag the button around. As a result all regions resize. E.g. if the user drags the button to the left the width of both regions on the left decreases. If the button is dragged to the bottom the height of the top regions increase while the height of the bottom regions decrease.
How can I do this using the WPF technology?