addressviewersorter.java

来自「eclipse开发笔记」· Java 代码 · 共 119 行

package com.plugindev.addressbook.views;

import java.util.ArrayList;
import java.util.Comparator;
import java.util.List;

import org.eclipse.jface.viewers.TableViewer;
import org.eclipse.jface.viewers.Viewer;
import org.eclipse.jface.viewers.ViewerSorter;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.widgets.TableColumn;
import org.eclipse.ui.IMemento;

public class AddressViewerSorter extends ViewerSorter {
	private static final String TAG_DESENDING = "descending";

	private static final String TAG_INDEX = "columnIndex";

	private static final String TAG_CATEGORY = "category";

	private static final String TAG_TRUE = "true";

	private class SortInfo {
		int columnIndex;

		Comparator comparator;

		boolean descending;
	}

	private TableViewer viewer;

	private SortInfo[] infos;

	public AddressViewerSorter(TableViewer viewer, TableColumn[] columns,
			Comparator[] comparators) {
		this.viewer = viewer;
		infos = new SortInfo[columns.length];
		for (int i = 0; i < columns.length; i++) {
			infos[i] = new SortInfo();
			infos[i].columnIndex = i;
			infos[i].comparator = comparators[i];
			infos[i].descending = false;
			createSelectionListener(columns[i], infos[i]);
		}
	}

	public int compare(Viewer viewer, Object address1, Object address2) {
		for (int i = 0; i < infos.length; i++) {
			int result = infos[i].comparator.compare(address1, address2);
			if (result != 0) {
				if (infos[i].descending)
					return -result;
				return result;
			}
		}
		return 0;
	}

	private void createSelectionListener(final TableColumn column,
			final SortInfo info) {
		column.addSelectionListener(new SelectionAdapter() {
			public void widgetSelected(SelectionEvent e) {
				sortUsing(info);
			}
		});
	}

	protected void sortUsing(SortInfo info) {
		if (info == infos[0])
			info.descending = !info.descending;
		else {
			for (int i = 0; i < infos.length; i++) {
				if (info == infos[i]) {
					System.arraycopy(infos, 0, infos, 1, i);
					infos[0] = info;
					info.descending = false;
					break;
				}
			}
		}
		viewer.refresh();
	}

	public void saveState(IMemento memento) {
		for (int i = 0; i < infos.length; i++) {
			SortInfo info = infos[i];
			IMemento mem = memento.createChild(TAG_CATEGORY);
			mem.putInteger(TAG_INDEX, info.columnIndex);
			if (info.descending)
				mem.putString(TAG_DESENDING, TAG_TRUE);
		}
	}

	public void init(IMemento memento) {
		List newInfos = new ArrayList(infos.length);
		IMemento[] mems = memento.getChildren(TAG_CATEGORY);
		for (int i = 0; i < mems.length; i++) {
			IMemento mem = mems[i];
			Integer value = mem.getInteger(TAG_INDEX);
			if (value == null)
				continue;
			int index = value.intValue();
			if (index < 0 || index >= infos.length)
				continue;
			SortInfo info = infos[index];
			if (newInfos.contains(info))
				continue;
			info.descending = TAG_TRUE.equals(mem.getString(TAG_DESENDING));
			newInfos.add(info);
		}
		for (int i = 0; i < infos.length; i++)
			if (!newInfos.contains(infos[i]))
				newInfos.add(infos[i]);
		infos = (SortInfo[]) newInfos.toArray(new SortInfo[newInfos.size()]);
	}
}