我正在开发一个 RCP 应用程序，并为此使用 Nebula 的 NatTable。说到选择，我不明白我应该如何使用它。
我想要的是：
- 我想选择整行。我可以使用
RowOnlySelectionConfiguration和来做到这一点RowOnlySelectionBindings。 - 如果我选择一行，我希望选择保留在那里，并且当该行中的某些数据更新时不会被清除。我怎么做？
- 如果选择了一行，并且该行中元素的位置发生了变化（例如，删除了先前的元素之一，并且位置更改为 index - 1），我希望选择与元素一起更改位置，以便更改后选择相同的元素。我怎么做？
我已经看到文档讨论了一个PreserveSelectionModel可以用于的：
如果您使用
PreserveSelectionStructuralChangeEventHandler以前版本中的解决方法不清除对结构更改的选择，您会注意到此解决方法将不再有效。如果您仍然需要该行为，您现在可以通过配置和设置这样的SelectionModel实例来实现相同的目的：SelectionModel model = new SelectionModel(selectionLayer); // configure to not clear the selection on structural changes model.setClearSelectionOnChange(false); selectionLayer.setSelectionModel(model);如果您希望选择应该随着结构变化（例如排序）而更新和移动，请尝试使用
PreserveSelectionModel.
https://www.eclipse.org/nattable/nandn/nandn_120.php
所以我想我必须使用PreserveSelectionModel? 但那里我不能打电话setClearSelectionOnChange(false)。默认情况下会这样做吗？
我该如何使用PreserveSelectionModel？我在构造函数中传递了什么？
我在一个名为 的类中实现了我自己的 BodyLayerStack，TableBodyLayerStack我在构造函数中尝试了这个：
public TableBodyLayerStack(IUniqueIndexLayer underlyingLayer) {
super(underlyingLayer);
columnReorderLayer = new ColumnReorderLayer(underlyingLayer);
columnHideShowLayer = new ColumnHideShowLayer(columnReorderLayer);
selectionLayer = new SelectionLayer(columnHideShowLayer, null, true, false);
PreserveSelectionModel<?> selectionModel = new PreserveSelectionModel<>(
selectionLayer, null, null);
selectionLayer.setSelectionModel(selectionModel);
selectionLayer.registerEventHandler(new SelectEventHandler(selectionLayer));
viewportLayer = new ViewportLayer(selectionLayer);
setUnderlyingLayer(viewportLayer);
registerCommandHandler(new CopyDataCommandHandler(selectionLayer));
}
然后，在我的实现的构造器中GridLayer，我这样做：
// ...
bodyLayer = new TableBodyLayerStack(eventLayer);
// register different selection move command handler that always moves by row
bodyLayer.getSelectionLayer().addConfiguration(new RowOnlySelectionConfiguration<T>());
// register selection bindings that will perform row selections instead of cell selections
// registering the bindings on a layer that is above the SelectionLayer will consume the
// commands before they are handled by the SelectionLayer
bodyLayer.addConfiguration(new RowOnlySelectionBindings());
// ...
但这给了我 NullPointerExceptions 在PreserveSelectionModel.
Error while painting table: null
java.lang.NullPointerException
at org.eclipse.nebula.widgets.nattable.selection.preserve.PreserveSelectionModel.getRowPositionByRowObject(PreserveSelectionModel.java:520)
at org.eclipse.nebula.widgets.nattable.selection.preserve.PreserveSelectionModel.createMarkerPoint(PreserveSelectionModel.java:559)
at org.eclipse.nebula.widgets.nattable.selection.preserve.PreserveSelectionModel.getSelectionAnchor(PreserveSelectionModel.java:531)
at org.eclipse.nebula.widgets.nattable.selection.SelectionLayer.getSelectionAnchor(SelectionLayer.java:276)
at org.eclipse.nebula.widgets.nattable.selection.SelectionLayer.getConfigLabelsByPosition(SelectionLayer.java:415)
at org.eclipse.nebula.widgets.nattable.layer.AbstractLayerTransform.getConfigLabelsByPosition(AbstractLayerTransform.java:316)
at org.eclipse.nebula.widgets.nattable.layer.AbstractIndexLayerTransform.getConfigLabelsByPosition(AbstractIndexLayerTransform.java:318)
at org.eclipse.nebula.widgets.nattable.layer.CompositeLayer.getConfigLabelsByPosition(CompositeLayer.java:553)
at org.eclipse.nebula.widgets.nattable.layer.cell.AbstractLayerCell.getConfigLabels(AbstractLayerCell.java:48)
at org.eclipse.nebula.widgets.nattable.layer.AbstractLayer.getCellPainter(AbstractLayer.java:354)
at org.eclipse.nebula.widgets.nattable.layer.AbstractLayerTransform.getCellPainter(AbstractLayerTransform.java:336)
at org.eclipse.nebula.widgets.nattable.layer.AbstractLayerTransform.getCellPainter(AbstractLayerTransform.java:336)
at org.eclipse.nebula.widgets.nattable.layer.AbstractLayerTransform.getCellPainter(AbstractLayerTransform.java:336)
at org.eclipse.nebula.widgets.nattable.layer.AbstractIndexLayerTransform.getCellPainter(AbstractIndexLayerTransform.java:340)
at org.eclipse.nebula.widgets.nattable.layer.AbstractLayerTransform.getCellPainter(AbstractLayerTransform.java:336)
at org.eclipse.nebula.widgets.nattable.layer.AbstractIndexLayerTransform.getCellPainter(AbstractIndexLayerTransform.java:340)
at org.eclipse.nebula.widgets.nattable.layer.CompositeLayer.getCellPainter(CompositeLayer.java:586)
at org.eclipse.nebula.widgets.nattable.painter.layer.CellLayerPainter.paintCell(CellLayerPainter.java:171)
at org.eclipse.nebula.widgets.nattable.painter.layer.CellLayerPainter.paintLayer(CellLayerPainter.java:81)
at org.eclipse.nebula.widgets.nattable.painter.layer.GridLineCellLayerPainter.paintLayer(GridLineCellLayerPainter.java:106)
at org.eclipse.nebula.widgets.nattable.selection.SelectionLayerPainter.paintLayer(SelectionLayerPainter.java:95)
at org.eclipse.nebula.widgets.nattable.layer.CompositeLayer$CompositeLayerPainter.paintLayer(CompositeLayer.java:913)
at org.eclipse.nebula.widgets.nattable.painter.layer.NatLayerPainter.paintLayer(NatLayerPainter.java:43)
at org.eclipse.nebula.widgets.nattable.NatTable.paintNatTable(NatTable.java:408)
at org.eclipse.nebula.widgets.nattable.NatTable.paintControl(NatTable.java:403)
...
我猜这是因为我在我的构造函数中传递了空值PreserveSelectionModel。但是我该如何使用它呢？我必须传递什么作为构造函数的参数？我从哪里获得价值？
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