如何获取 JFace 的 TableViewer 的有序元素？

Question

我已经根据Vogella的说明(复制如下)实现了JFace的TableViewer排序。碰巧排序只在图形界面中进行(它没有反映在原始数据结构中)，并且我需要按照它们在GUI中显示的顺序获得元素。

或者，在原始数据结构中反映排序的实现也会适合。

---

package de.vogella.jface.tableviewer.sorter;
import org.eclipse.jface.viewers.Viewer;
import org.eclipse.jface.viewers.ViewerComparator;
import org.eclipse.swt.SWT;
import de.vogella.jface.tableviewer.model.Person;
public class MyViewerComparator extends ViewerComparator {
  private int propertyIndex;
  private static final int DESCENDING = 1;
  private int direction = DESCENDING;
  public MyViewerComparator() {
    this.propertyIndex = 0;
    direction = DESCENDING;
  }
  public int getDirection() {
    return direction == 1 ? SWT.DOWN : SWT.UP;
  }
  public void setColumn(int column) {
    if (column == this.propertyIndex) {
      // Same column as last sort; toggle the direction
      direction = 1 - direction;
    } else {
      // New column; do an ascending sort
      this.propertyIndex = column;
      direction = DESCENDING;
    }
  }
  @Override
  public int compare(Viewer viewer, Object e1, Object e2) {
    Person p1 = (Person) e1;
    Person p2 = (Person) e2;
    int rc = 0;
    switch (propertyIndex) {
    case 0:
      rc = p1.getFirstName().compareTo(p2.getFirstName());
      break;
    case 1:
      rc = p1.getLastName().compareTo(p2.getLastName());
      break;
    case 2:
      rc = p1.getGender().compareTo(p2.getGender());
      break;
    case 3:
      if (p1.isMarried() == p2.isMarried()) {
        rc = 0;
      } else
        rc = (p1.isMarried() ? 1 : -1);
      break;
    default:
      rc = 0;
    }
    // If descending order, flip the direction
    if (direction == DESCENDING) {
      rc = -rc;
    }
    return rc;
  }
}

---

package de.vogella.jface.tableviewer;
import org.eclipse.jface.viewers.ArrayContentProvider;
import org.eclipse.jface.viewers.ColumnLabelProvider;
import org.eclipse.jface.viewers.TableViewer;
import org.eclipse.jface.viewers.TableViewerColumn;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.Table;
import org.eclipse.swt.widgets.TableColumn;
import org.eclipse.swt.widgets.Text;
import org.eclipse.ui.part.ViewPart;
import de.vogella.jface.tableviewer.model.ModelProvider;
import de.vogella.jface.tableviewer.model.Person;
import de.vogella.jface.tableviewer.sorter.MyViewerComparator;
public class View extends ViewPart {
  public static final String ID = "de.vogella.jface.tableviewer.view";
  private MyViewerComparator comparator;
  private TableViewer viewer;
  // We use icons
  private static final Image CHECKED = Activator.getImageDescriptor("icons/checked.gif").createImage();
  private static final Image UNCHECKED = Activator.getImageDescriptor("icons/unchecked.gif").createImage();
  public void createPartControl(Composite parent) {
    GridLayout layout = new GridLayout(2, false);
    parent.setLayout(layout);
    Label searchLabel = new Label(parent, SWT.NONE);
    searchLabel.setText("Search: ");
    final Text searchText = new Text(parent, SWT.BORDER | SWT.SEARCH);
    searchText.setLayoutData(new GridData(GridData.GRAB_HORIZONTAL
        | GridData.HORIZONTAL_ALIGN_FILL));
    createViewer(parent);
    // Set the sorter for the table
    comparator = new MyViewerComparator();
    viewer.setComparator(comparator);
  }
  private void createViewer(Composite parent) {
    viewer = new TableViewer(parent, SWT.MULTI | SWT.H_SCROLL
        | SWT.V_SCROLL | SWT.FULL_SELECTION | SWT.BORDER);
    createColumns(parent, viewer);
    final Table table = viewer.getTable();
    table.setHeaderVisible(true);
    table.setLinesVisible(true);
    viewer.setContentProvider(new ArrayContentProvider());
    // Get the content for the viewer, setInput will call getElements in the
    // contentProvider
    viewer.setInput(ModelProvider.INSTANCE.getPersons());
    // Make the selection available to other views
    getSite().setSelectionProvider(viewer);
    // Layout the viewer
    GridData gridData = new GridData();
    gridData.verticalAlignment = GridData.FILL;
    gridData.horizontalSpan = 2;
    gridData.grabExcessHorizontalSpace = true;
    gridData.grabExcessVerticalSpace = true;
    gridData.horizontalAlignment = GridData.FILL;
    viewer.getControl().setLayoutData(gridData);
  }
  public TableViewer getViewer() {
    return viewer;
  }
  // This will create the columns for the table
  private void createColumns(final Composite parent, final TableViewer viewer) {
    String[] titles = { "First name", "Last name", "Gender", "Married" };
    int[] bounds = { 100, 100, 100, 100 };
    // First column is for the first name
    TableViewerColumn col = createTableViewerColumn(titles[0], bounds[0], 0);
    col.setLabelProvider(new ColumnLabelProvider() {
      @Override
      public String getText(Object element) {
        Person p = (Person) element;
        return p.getFirstName();
      }
    });
    // Second column is for the last name
    col = createTableViewerColumn(titles[1], bounds[1], 1);
    col.setLabelProvider(new ColumnLabelProvider() {
      @Override
      public String getText(Object element) {
        Person p = (Person) element;
        return p.getLastName();
      }
    });
    // Now the gender
    col = createTableViewerColumn(titles[2], bounds[2], 2);
    col.setLabelProvider(new ColumnLabelProvider() {
      @Override
      public String getText(Object element) {
        Person p = (Person) element;
        return p.getGender();
      }
    });
    // // Now the status married
    col = createTableViewerColumn(titles[3], bounds[3], 3);
    col.setLabelProvider(new ColumnLabelProvider() {
      @Override
      public String getText(Object element) {
        return null;
      }
      @Override
      public Image getImage(Object element) {
        if (((Person) element).isMarried()) {
          return CHECKED;
        } else {
          return UNCHECKED;
        }
      }
    });
  }
  private TableViewerColumn createTableViewerColumn(String title, int bound,
      final int colNumber) {
    final TableViewerColumn viewerColumn = new TableViewerColumn(viewer,
        SWT.NONE);
    final TableColumn column = viewerColumn.getColumn();
    column.setText(title);
    column.setWidth(bound);
    column.setResizable(true);
    column.setMoveable(true);
    column.addSelectionListener(getSelectionAdapter(column, colNumber));
    return viewerColumn;
  }
  private SelectionAdapter getSelectionAdapter(final TableColumn column,
      final int index) {
    SelectionAdapter selectionAdapter = new SelectionAdapter() {
      @Override
      public void widgetSelected(SelectionEvent e) {
        comparator.setColumn(index);
        int dir = comparator.getDirection();
        viewer.getTable().setSortDirection(dir);
        viewer.getTable().setSortColumn(column);
        viewer.refresh();
      }
    };
    return selectionAdapter;
  }

/** * Passing the focus request to the viewer's control. */
  public void setFocus() {
    viewer.getControl().setFocus();
  }
}

Answer 1

edit:

TableItem[] items = viewer.getTable().getItems();
MyObject[] objectsInGui = new MyObject[items.length];
for (int i = 0; i < items.length; i++) {
    objectsInGui[i] = (MyObject) items[i].getData();
}

第二种方法(不是必需的):

Method getRoot = StructuredViewer.getMethod("getRoot");
getRoot.setAccessible(true);
Method getSortedChildren = StructuredViewer.getMethod("getSortedChildren", Object.class);
getSortedChildren.setAccessible(true);
Object root = getRoot.invoke(viewer);
Object[] objectsInGui = getSortedChildren.invoke(viewer, root);

或使用getFilters()和getComparator()，并使用它们进行筛选和排序。