How can I get the ordered elements of a JFace's TableViewer?
I have implemented the JFace's TableViewer sorting according to Vogella's instructions (reproduced below). It happens that the sorting is made in the graphical interface only (it is not reflected in the original data structure) and I need o get the elements in the order they are displayed in the GUI.
Alternatively, an implementation which reflects the sorting in the original data structure would fit too.
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
EDITED:
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();
}
The second approach (which wasn't required):
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);
or use getFilters() and getComparator() and filter and sort using them.