Graph Layout in Views
In Views, graphs are instances of the class IlvGrapher. We call these instances graphers. The nodes, which are instances of IlvGraphic, and the links, which are instances of IlvLinkImage, “know” how to draw themselves. The nodes can have arbitrary coordinates, or they can be placed interactively or by code. All that needs to be done to lay out the grapher to obtain a readable drawing is to compute and assign appropriate coordinates for the nodes. In some cases, the shape of the links may also need to be modified. The main task of the Graph Layout package is to provide support for the operation of laying out a grapher—that is, drawing the graph.
The Graph Layout package of Views benefits from its integration with the graph visualization and graph manipulation features of the Views 2D Graphics Professional product. This core library provides a wide range of very useful features to build powerful graphic interfaces easily:
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Predefined, extensible types of graphic objects for nodes and links
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A customizable mechanism to choose the contact points between links and nodes
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Grapher interactor classes
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Multiple views of the same grapher
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Management of multiple layers
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Selections management
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Events management
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Listeners on the contents of the grapher and/or on the views
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Printing facilities
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User properties on nodes and links
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Input/output operations
For details on these features, see the Views Foundation and 2D Graphics Professional User’s Manuals.
| Note
The Graph Layout package allows you to add layout capabilities to applications that do not use the Views grapher. For details, see |
