Example 5.20. Setting a component arrangement style

// 'graph' is of type y.layout.LayoutGraph. 

SmartOrganicLayouter sol = new SmartOrganicLayouter();
ComponentLayouter cl = (ComponentLayouter)sol.getComponentLayouter();

// Set another arrangement style instead of the default 
// ComponentLayouter.STYLE_ROWS. 
cl.setStyle(ComponentLayouter.STYLE_PACKED_COMPACT_RECTANGLE);

// Buffered layout with component arrangement. 
new BufferedLayouter(sol).doLayout(graph);

Example 5.21. Excluding components from layout calculation

// 'graph' is of type y.layout.LayoutGraph. 

NodeList[] components = GraphConnectivity.connectedComponents(graph);

// Create a node map that will be used as a data provider to hold boolean 
// values indicating whether a component should be considered for layout 
// calculation. 
NodeMap nm = graph.createNodeMap();

// Every second component of the graph is marked so that a layout is calculated 
// for it. The other components, while being arranged nevertheless, are not 
// considered for layout calculation. 
for (int i = 0; i < components.length; i += 2) {
  nm.setBool(components[i].firstNode(), true);
}

// Register the node map with the graph using the special look-up key defined
// by class ComponentLayouter.
graph.addDataProvider(ComponentLayouter.LAYOUT_NODE_DPKEY, nm);

// The default ComponentLayouter stage of SmartOrganicLayouter arranges all 
// components. 
new BufferedLayouter(new SmartOrganicLayouter()).doLayout(graph);

// Remove the data provider from the graph. 
graph.removeDataProvider(nm);

Example 5.22. Using different layout algorithms for components

// 'graph' is of type y.layout.LayoutGraph. 

NodeList[] components = GraphConnectivity.connectedComponents(graph);

// Create a node map that will be used as a data provider to hold a Layouter 
// implementation for each of the components. This layouter will be used for 
// layout calculation.
NodeMap nm = graph.createNodeMap();
// Register the node map with the graph using the special look-up key defined 
// by class LayoutMultiplexer.
graph.addDataProvider(LayoutMultiplexer.LAYOUTER_DPKEY, nm);

// For each component one of the layouters is set. (Actually, a layouter is set 
// for the component's first node only. Nevertheless, this layouter is used for 
// the entire component, since LayoutMultiplexer takes the first non-null 
// Layouter it can retrieve from the data provider.)
Layouter[] coreLayouter = { new IncrementalHierarchicLayouter(), 
                            new SmartOrganicLayouter(), 
                            new OrthogonalLayouter() };
for (int i = 0; i < components.length; i++) {
  nm.set(components[i].firstNode(), coreLayouter[i % 3]);
}

// ComponentLayouter uses LayoutMultiplexer as its core layouter, which, for 
// each component, invokes the layouter retrieved from the data provider 
// registered with the graph.
// Afterwards, the ComponentLayouter nicely arranges the components.
ComponentLayouter cl = new ComponentLayouter();
cl.setCoreLayouter(new LayoutMultiplexer());
new BufferedLayouter(cl).doLayout(graph);

// Remove the data provider from the graph. 
graph.removeDataProvider(nm);