As the 1st phase of my GSoC project - "Refactoring: Designer/schema integration", I've started the task 1, which is "Providing a single GUI editor for schema". 

As the "Designer" and "Edit relational schema" pages share overlapping functionalities, the idea is to bring these two pages and have a more improved page alone.Under this, functionalities of  the "Designer" will be improved in such a way, by combining features of the "Edit relational schema" page. 

For that I've created some mockups, and already published in my blog.

 

As shown in the above figure, I've introduced two new buttons into the "Designer" page, and followings are the functionalities:

Edit page: A user can edit/delete an existing page.

Save as: coordinates of the table layout can be saved to an existing page or to a new page.

Apart from these two, while the user is loading the designer page, 

• if there are previously saved pages exist, the the first page will be loaded into the designer by default.
• if there are no such saved pages, then the default table layout will be loaded.

Best Regards

Bimal.