Diagram Concepts

A diagram is a partial (exhaustive in some cases) view of the model content with a graphical representation of nodes and links.

Common Diagram Properties

The following properties are common to all diagrams. They can be edited in the Properties View by selecting the diagram in the project explorer. The Properties View can be opened by selecting Window->Show View->Properties from the menu bar.

Name

The Name property allows to change the name of the diagram.

Package

The Package property allows to show the diagram in a subfolder under the diagram's semantic element in the capella project explorer. By default, the is property is empty, and the capella project explorer shows the diagram as a direct child of the model element targeted by the diagram:

Setting the package property to 'sample', will show the Diagram in a folder with that label under the target element:

Note that there is only one level of depth for diagram packages, and a Diagram can belong to only one package.

Elements of Interest

The Elements of Interest property allows to associate a Diagram with an arbitrary list of model elements that are of special interest to the diagram. The Semantic Browser view displays the relation between a Diagram and its Elements of Interest.

Diagram Refreshing Strategies

Diagrams may no represent the latest state the model they represent. For instance, if the model is modified directly in the Capella Project Explorer, the related diagrams may not represent the model anymore (because of addition, deletion, renaming, …).

There are several refresh strategies:

• At opening (i.e. the diagrams are systematically refreshed when being opened).
• Automatic Refresh (i.e. the diagrams are refreshed automatically if they are open, they always represent the latest state of the model).
• Manual Refresh (i.e. refreshing a diagram is an explicit action performed by the user when necessary.)

To manually refresh diagrams, two methods are available:

• The button in the diagram toolbar to refresh the currently displayed diagram.
• The contextual menu command of the Project Explorer to refresh all diagrams in the model or a subset of diagrams below a model element:

To change the refreshing strategy, see the diagram-related Preferences.

Blank and Contextual Diagrams, Contextual Diagram Elements

Blank Diagrams

Blank diagrams are the most common diagrams in Capella. Blank means the user decides which elements should appear on the diagram. This allows him to build focused diagrams, with specific purposes.

Contextual Diagrams

Contextual diagram are focused on one specific element. These diagrams have specific refresh rues. Examples:

• A contextual dataflow diagram is centered on one specific Function (which label appears in bold). The refresh strategy is to automatically display all the other Functions exchanging information with the current Function.
• A contextual external interface diagram is centered on one specific Component. The refresh strategy is to automatically display all Interfaces provided by the current Component, and all the Components providing / requiring these Interfaces.

Contextual Diagram Elements

The idea of diagrams with contextual elements is to unify Blank and Contextual diagrams. All diagrams are blank, but the user can decide that a given diagram is going to be contextual to a selected subset of elements.

Example of elements in Physical Architecture: A Functional Chain goes through three sets of Functions / Behaviour Components / Nodes.

Using the Properties View of the diagram, the Functional Chain FC1 is set as a contextual element for the current diagram (several elements could be set as contextual). At this stage, the new diagram only contains two pieces of the Functional Chain and does not even display the Functional Chain.

The result is seen in the Properties View.

The next refresh on the diagram automatically creates the missing pieces of the Functional Chain. Any semantic change of the Functional Chain (addition of steps, etc.) will automatically be taken into account in this diagram.

Below is another example. The Behaviour Component BC2 is set as contextual: the other Components it is communicating with are automatically displayed.

Layout Management

Pin / Unpin Diagram Elements

Diagram element pinning allows marking specific elements in a diagram as having a fixed location so that they are not moved by the Arrange All action. Once the end user has performed a first layout effort, the Arrange All action can still be called for new elements without risking harming the positioning of existing elements.

When diagram elements are selected the diagram toolbar contains two dedicated buttons to pin / unpin selected elements.

When no diagram element is selected, the diagram toolbar contains a button for displaying a dialog showing the pin / unpin status of all elements.

Arrange All Bordered Nodes

In addition to the standard automatic layout, this specific action allows to arrange the edges so that they are as short as possible. This action moves the ports of a node / container when necessary. It is useful when the position of the nodes and containers has already been defined and edges still need a better layout.