OS.bee application front ends have at least one perspective for their user communication. Perspectives are technically spoken the visual containers in which an OS.bee applications deliver their front end visible to the user. Following the E4 model, the application front ends are subdivided into meaningful areas using parts, part stacks, and sash containers.

Application Layout Model

User Interaction

Determine the available actions within an perspective, such as a drop-down menu, context menus or a toolbar.


Equip end users with resize capabilities of perspective parts following the E4 application model, which give them the flexibility to choose their individual size of working areas.

Perspective DSL

Sash containers

Use sash containers to subdivide perspectives into main working areas in which part stacks or parts are organized either vertically or horizontally.

Part stacks

Use part stacks to add areas, where the contained elements are stacked one behind each other and where the foremost shown at a time.


Define parts as a sub-area of a sash container, in which to place your user interface components (views).



Combine sash containers and part stacks which can contain each other to create any kind of subdivision of a perspective.

DSL Grammar