In my Eclipse RCP application I have a view that should never be closed. For remove "Close" button from view title and not allow to detach view (after this user can close detached window) I have added lines
layout.getViewLayout("my_view_id").setCloseable(false);
layout.getViewLayout("my_view_id").setMoveable(false);
in
createInitialLayout(IPageLayout layout) { ... }
method of perspective class.
But one more way to close view remains: user can minimize view and after this close it via context menu of minimized icon:

How can I remove "Close" menu item from context menu or not allow to show context menu on minimized view?