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Event-driven lists for dynamically filtered and sorted tables
/* Glazed Lists (c) 2003-2006 */
/* http://publicobject.com/glazedlists/ publicobject.com,*/
/* O'Dell Engineering Ltd.*/
package ca.odell.glazedlists.swt;
// the core Glazed Lists packages
import ca.odell.glazedlists.EventList;
import ca.odell.glazedlists.SortedList;
import ca.odell.glazedlists.gui.AbstractTableComparatorChooser;
import ca.odell.glazedlists.impl.gui.MouseOnlySortingStrategy;
import ca.odell.glazedlists.impl.gui.SortingStrategy;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.Table;
import org.eclipse.swt.widgets.TableColumn;
/**
* A TableComparatorChooser is a tool that allows the user to sort a ListTable by clicking
* on the table's headers. It requires that the ListTable has a SortedList as
* a source as the sorting on that list is used.
*
* @see Snippet 2
*
* @author Jesse Wilson
*/
public final class TableComparatorChooser extends AbstractTableComparatorChooser {
private final SortingStrategy sortingStrategy;
/** the table being sorted */
private Table table;
/** listeners to sort change events */
private List sortListeners = new ArrayList();
/** listeners for column headers */
private ColumnListener columnListener = new ColumnListener();
/**
* Creates and installs a TableComparatorChooser.
*
* @deprecated replaced with {@link #install}, which is functionally
* identical but uses a more fitting name to convey the action that is
* performed.
*/
public TableComparatorChooser(DefaultEventTableViewer eventTableViewer, SortedList sortedList, boolean multipleColumnSort) {
super(sortedList, eventTableViewer.getTableFormat());
// save the SWT-specific state
this.table = eventTableViewer.getTable();
// listen for events on the specified table
for(int c = 0; c < table.getColumnCount(); c++) {
table.getColumn(c).addSelectionListener(columnListener);
}
// sort using the specified approach
sortingStrategy = new MouseOnlySortingStrategy(multipleColumnSort);
}
/**
* Installs a new TableComparatorChooser that responds to clicks
* on the specified table and uses them to sort the specified list.
*
* @param eventTableViewer the table viewer for the table to be sorted
* @param sortedList the sorted list to update.
* @param multipleColumnSort true to sort by multiple columns
* at a time, or false to sort by a single column. Although
* sorting by multiple columns is more powerful, the user interface is
* not as simple and this strategy should only be used where necessary.
*/
public static TableComparatorChooser install(DefaultEventTableViewer eventTableViewer, SortedList sortedList, boolean multipleColumnSort) {
return new TableComparatorChooser(eventTableViewer, sortedList, multipleColumnSort);
}
/**
* Registers the specified {@link Listener} to receive notification whenever
* the {@link Table} is sorted by this {@link TableComparatorChooser}.
*/
public void addSortListener(final Listener sortListener) {
sortListeners.add(sortListener);
}
/**
* Deregisters the specified {@link Listener} to no longer receive events.
*/
public void removeSortActionListener(final Listener sortListener) {
for(Iterator i = sortListeners.iterator(); i.hasNext(); ) {
if(sortListener == i.next()) {
i.remove();
return;
}
}
throw new IllegalArgumentException("Cannot remove nonexistent listener " + sortListener);
}
/**
* Handles column clicks.
*/
class ColumnListener implements org.eclipse.swt.events.SelectionListener {
public void widgetSelected(SelectionEvent e) {
TableColumn column = (TableColumn)e.widget;
Table table = column.getParent();
int columnIndex = table.indexOf(column);
sortingStrategy.columnClicked(sortingState, columnIndex, 1, false, false);
}
public void widgetDefaultSelected(SelectionEvent e) {
// Do Nothing
}
}
/**
* Updates the SWT table to indicate sorting icon on the primary sort column.
*/
protected final void updateTableSortColumn() {
final List sortedColumns = getSortingColumns();
if (sortedColumns.isEmpty()) {
// no columns sorted
table.setSortColumn(null);
table.setSortDirection(SWT.NONE);
} else {
// make GL primary sort column the SWT table sort column
final int primaryColumnIndex = sortedColumns.get(0).intValue();
final int sortDirection = isColumnReverse(primaryColumnIndex) ? SWT.DOWN : SWT.UP;
table.setSortColumn(table.getColumn(primaryColumnIndex));
table.setSortDirection(sortDirection);
}
}
/**
* Updates the comparator in use and applies it to the table.
*
* This method is called when the sorting state changed.
*/
@Override
protected final void rebuildComparator() {
super.rebuildComparator();
// update sorting icon in SWT table
updateTableSortColumn();
// notify interested listeners that the sorting has changed
Event sortEvent = new Event();
sortEvent.widget = table;
for(Iterator i = sortListeners.iterator(); i.hasNext(); ) {
i.next().handleEvent(sortEvent);
}
}
/**
* Releases the resources consumed by this {@link TableComparatorChooser} so that it
* may eventually be garbage collected.
*
* A {@link TableComparatorChooser} will be garbage collected without a call to
* {@link #dispose()}, but not before its source {@link EventList} is garbage
* collected. By calling {@link #dispose()}, you allow the {@link TableComparatorChooser}
* to be garbage collected before its source {@link EventList}. This is
* necessary for situations where an {@link TableComparatorChooser} is short-lived but
* its source {@link EventList} is long-lived.
*
*
Warning: It is an error
* to call any method on a {@link TableComparatorChooser} after it has been disposed.
*/
@Override
public void dispose() {
// stop listening for events on the specified table
for(int c = 0; c < table.getColumnCount(); c++) {
table.getColumn(c).removeSelectionListener(columnListener);
}
}
}