InstanceComparator.java

/*
 * Copyright 2009-2012 Amazon Technologies, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *    http://aws.amazon.com/apache2.0
 *
 * This file is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES
 * OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and
 * limitations under the License.
 */
package com.amazonaws.eclipse.ec2.ui.views.instances;

import java.util.List;

import org.eclipse.jface.viewers.Viewer;

import com.amazonaws.eclipse.ec2.TagFormatter;
import com.amazonaws.eclipse.ec2.ui.SelectionTableComparator;
import com.amazonaws.services.ec2.model.Instance;

/**
 * Comparator for sorting the instances by any column.
 */
class InstanceComparator extends SelectionTableComparator {

	/**
     * 
     */
    private final InstanceSelectionTable instanceSelectionTable;

    /**
	 * @param defaultColumn
	 * @param instanceSelectionTable TODO
	 */
	public InstanceComparator(InstanceSelectionTable instanceSelectionTable, int defaultColumn) {
		super(defaultColumn);
        this.instanceSelectionTable = instanceSelectionTable;
	}

	/* (non-Javadoc)
	 * @see com.amazonaws.eclipse.ec2.ui.views.instances.SelectionTableComparator#compareIgnoringDirection(org.eclipse.jface.viewers.Viewer, java.lang.Object, java.lang.Object)
	 */
	@Override
	protected int compareIgnoringDirection(Viewer viewer, Object e1, Object e2) {
		if (!(e1 instanceof Instance && e2 instanceof Instance)) {
			return 0;
		}

		Instance i1 = (Instance)e1;
		Instance i2 = (Instance)e2;

		switch (this.sortColumn) {
		case ViewContentAndLabelProvider.INSTANCE_ID_COLUMN:
			return (i1.getInstanceId().compareTo(i2.getInstanceId()));
		case ViewContentAndLabelProvider.PUBLIC_DNS_COLUMN:
			return (i1.getPublicDnsName().compareTo(i2.getPublicDnsName()));
		case ViewContentAndLabelProvider.ROOT_DEVICE_COLUMN:
            return (i1.getRootDeviceType().compareTo(i2.getRootDeviceType()));		    
		case ViewContentAndLabelProvider.STATE_COLUMN:
			return (i1.getState().getName().compareTo(i2.getState().getName()));
		case ViewContentAndLabelProvider.INSTANCE_TYPE_COLUMN:
			return (i1.getInstanceType().compareTo(i2.getInstanceType()));
		case ViewContentAndLabelProvider.AVAILABILITY_ZONE_COLUMN:
			return (i1.getPlacement().getAvailabilityZone().compareTo(i2.getPlacement().getAvailabilityZone()));
		case ViewContentAndLabelProvider.IMAGE_ID_COLUMN:
			return (i1.getImageId().compareTo(i2.getImageId()));
		case ViewContentAndLabelProvider.KEY_NAME_COLUMN:
		    String k1 = i1.getKeyName();
		    String k2 = i2.getKeyName();
		    if (k1 == null)
		        k1 = "";
		    if (k2 == null)
		        k2 = "";
		    return k1.compareTo(k2);
		case ViewContentAndLabelProvider.LAUNCH_TIME_COLUMN:
			return (i1.getLaunchTime().compareTo(i2.getLaunchTime()));
		case ViewContentAndLabelProvider.SECURITY_GROUPS_COLUMN:
			return compareSecurityGroups(i1, i2);
		case ViewContentAndLabelProvider.TAGS_COLUMN:
            return TagFormatter.formatTags(i1.getTags()).compareTo(
                    TagFormatter.formatTags(i2.getTags()));
		default:
			return 0;
		}
	}

	/**
	 * Compares the security groups for the specified instances and returns
	 * a -1, 0, or 1 depending on the comparison. See compareTo() for more
	 * details on the returned value.
	 *
	 * @param i1
	 *            The first instance to compare.
	 * @param i2
	 *            The second instance to compare.
	 *
	 * @return -1, 0, or 1 depending on the comparison of the security
	 *         groups in the specified instances.
	 */
	private int compareSecurityGroups(Instance i1, Instance i2) {
		List<String> groups1 = this.instanceSelectionTable.contentAndLabelProvider.getSecurityGroupsForInstance(i1.getInstanceId());
		List<String> groups2 = this.instanceSelectionTable.contentAndLabelProvider.getSecurityGroupsForInstance(i2.getInstanceId());

		String formattedList1 = formatSecurityGroups(groups1);
		String formattedList2 = formatSecurityGroups(groups2);

		return formattedList1.compareTo(formattedList2);
	}

	/**
	 * Formats a list of security groups as a string for easy comparison.
	 * It's assumed that the list of security groups is already sorted.
	 *
	 * @param securityGroupList
	 *            The list to format as a single string.
	 *
	 * @return A single string containing the specified list of security
	 *         groups.
	 */
	private String formatSecurityGroups(List<String> securityGroupList) {
	    if (securityGroupList == null) return "";

		String formattedList = "";
		for (String group : securityGroupList) {
			if (formattedList.length() > 0) {
				formattedList += ", ";
			}

			formattedList += group;
		}

		return formattedList;
	}

}