更新zest 2中节点的标签/图标

Question

我正在使用带有SpaceTreeLayoutAlgorithm的GraphViewer，并尝试在创建图形后更新节点的标签/图标。

已经测试过的变体

viewer.refresh(node, true);

和

viewer.refresh(viewer.getGraphModelNode(node), true);

与查看器或其图形控件的各种刷新/重画方法相结合，但没有成功。

有关查看器用法的更多详细信息：

GraphViewer viewer = new GraphViewer(parent, SWT.BORDER);
ArrayContentProvider content = new MyArrayContentProvider(..);

viewer.setContentProvider(content);
LabelProvider glp = new MyGraphLabelProvider(..);
viewer.setLabelProvider(glp);

List<MyNodeClass> nodes = .. //list of all node elements
viewer.setInput(nodes);

TriangleSubgraphFactory subGraphFactory = new TriangleSubgraphFactory();
SpaceTreeLayoutAlgorithm spaceTreeAlg = new SpaceTreeLayoutAlgorithm();

viewer.getGraphControl().setSubgraphFactory(subGraphFactory);
viewer.getGraphControl().setExpandCollapseManager(
    spaceTreeAlg.getExpandCollapseManager());
viewer.setLayoutAlgorithm(spaceTreeAlg, true);

如Fabian所建议的那样会导致错误。我也没有设法将SpaceTreeLayoutAlgorithm(int方向)与TOP_DOWN以外的任何方向一起使用，否则我会得到一个NPE。

稍后调用viewer.setInput会导致以下结果：

Caused by: java.util.NoSuchElementException
at java.util.HashMap$HashIterator.nextEntry(HashMap.java:813)
at java.util.HashMap$KeyIterator.next(HashMap.java:845)
at org.eclipse.zest.core.widgets.custom.TriangleSubgraph.updateFigure(TriangleSubgraph.java:169)
at org.eclipse.zest.core.widgets.custom.TriangleSubgraph$1.defaultHandle(TriangleSubgraph.java:147)
at org.eclipse.zest.layouts.algorithms.TreeLayoutObserver$TreeListener.nodeRemoved(TreeLayoutObserver.java:308)
at org.eclipse.zest.layouts.algorithms.TreeLayoutObserver$1.nodeRemoved(TreeLayoutObserver.java:344)
at org.eclipse.zest.core.widgets.InternalLayoutContext.fireNodeRemovedEvent(InternalLayoutContext.java:399)
at org.eclipse.zest.core.widgets.InternalNodeLayout.dispose(InternalNodeLayout.java:327)
at org.eclipse.zest.core.widgets.Graph.removeNode(Graph.java:977)
at org.eclipse.zest.core.widgets.GraphNode.dispose(GraphNode.java:188)
at org.eclipse.zest.core.viewers.AbstractStructuredGraphViewer.inputChanged(AbstractStructuredGraphViewer.java:494)
at org.eclipse.zest.core.viewers.GraphViewer.inputChanged(GraphViewer.java:136)
at org.eclipse.jface.viewers.ContentViewer.setInput(ContentViewer.java:280)
at org.eclipse.jface.viewers.StructuredViewer.setInput(StructuredViewer.java:1690)

以下代码可用于刷新，但这不可能是预期的用途：

GraphLabelProvider glp
GraphNode n = viewer.getGraphModelNode(node);
n.setText(glp.getText(node));
n.setImage(glp.getImage(node));

Answer 1

我不确定您到底是如何使用查看器的，但最简单的方法可能是将查看器的输入重置为您想要可视化的新数据(您在内容和标签提供商中处理这些数据)。当您设置输入时，图形会自动更新：

viewer.setInput(myChangedDataToBeVisualized);