The workspace shows a context menu when the user right-clicks a page tab
header. Various options are presented such as the ability to close the page or
create new cells via splitting. Here the user is about to split horizontally.
Below is the result of the horizontal split with Page1 moved into a separate
cell on the right hand side. Right-clicking a page header now shows additional
options that have become relevant because there are now two cells inside
Splitting vertically has resulted in this final image below. You can customize the
presented context menu by intercepting an event and then adding extra menu
items specific to your application.