jforum example source code file (PollChanges.java)

This example jforum source code file (PollChanges.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - jforum tags/keywords

arraylist, iterator, iterator, list, list, poll, poll, pollchanges, polloption, polloption, util

The jforum PollChanges.java source code

package net.jforum.entities;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import net.jforum.view.forum.common.PostCommon;

/**
 * An helper class that holds changes made to the pool.
 * 
 * @author Rafael Steil
 * @version $Id: PollChanges.java,v 1.4 2007/04/24 02:19:46 rafaelsteil Exp $
 */
public class PollChanges {
	private List deletedOptions = new ArrayList();
	private List newOptions = new ArrayList();
	private List changedOptions = new ArrayList();
	
	private boolean hasChanges;
	
	private Poll first;
	private Poll second;
	
	/**
	 * @param first The "complete", most recent poll version. Usually the one
	 * that's in the database. 
	 * @param second The poll to compare with. It usually will be a poll filled
	 * by {@link PostCommon#fillPostFromRequest()}, so matches will be done againts the 
	 * existing poll and the data comming from the server. 
	 */
	public PollChanges(Poll first, Poll second) {
		this.first = first;
		this.second = second;
	}
	
	public void addChangedOption(PollOption option) {
		this.changedOptions.add(option);
		this.hasChanges = true;
	}
	
	public List getChangedOptions() {
		return this.changedOptions;
	}
	
	public void addDeletedOption(PollOption option) {
		this.deletedOptions.add(option);
		this.hasChanges = true;
	}

	public List getDeletedOptions() {
		return this.deletedOptions;
	}
	
	public void addNewOption(PollOption option) {
		this.newOptions.add(option);
		this.hasChanges = true;
	}

	public List getNewOptions() {
		return this.newOptions;
	}
	
	public boolean hasChanges() {
		this.searchForChanges();
		return this.hasChanges;
	}
	
	private void searchForChanges() {
		if (first == null || second == null) {
			return;
		}
		
		boolean isSame = first.getLabel().equals(second.getLabel());
		isSame &= first.getLength() == second.getLength();
		
		this.hasChanges = !isSame;
		
		List firstOptions = first.getOptions();
		List secondOptions = second.getOptions();
		
		// Search for changes in existing options
		for (Iterator iter = firstOptions.iterator(); iter.hasNext(); ) {
			PollOption option = (PollOption)iter.next();
			PollOption changed = this.findOptionById(option.getId(), secondOptions);
			
			if (changed != null && !option.getText().equals(changed.getText())) {
				this.addChangedOption(changed);
			}
			else if (changed == null) {
				this.addDeletedOption(option);
			}
		}

		// Check if the incoming poll added options
		for (Iterator iter = secondOptions.iterator(); iter.hasNext(); ) {
			PollOption option = (PollOption)iter.next();
			
			if (this.findOptionById(option.getId(), firstOptions) == null) {
				this.addNewOption(option);
			}
		}
	}
	
	private PollOption findOptionById(int id, List options) {
		for (Iterator iter = options.iterator(); iter.hasNext(); ) {
			PollOption o = (PollOption)iter.next();
			
			if (o.getId() == id) {
				return o;
			}
		}
		
		return null;
	}
}