Selector.java

package com.drawbridge.utils;

import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.util.ArrayList;
import java.util.LinkedList;

import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JComponent;

import com.drawbridge.Activity;

/**
 * A class to allow people to select carousel position using circles
 * 
 * @author Alistair Stead
 * 
 */
public class Selector extends JComponent
{

	private static final long	serialVersionUID	= -1445599836911520390L;
	private int					mSelected			= 0;
	private final int			mSelectorSize;
	private Long				mSelectorChangeTimestamp;

	private LinkedList<JButton>	selectorButtons;

	/**
	 * @param numberOfSelectors
	 *            - how many selectors are needed
	 * @throws Exception
	 */
	public Selector(Activity activity, int numberOfSelectors) throws Exception {
		if (!validateSelectorNumber(numberOfSelectors))
		{
			throw new Exception("Number of selectors is incorrect");
		}
		mSelectorSize = numberOfSelectors;
		this.setLayout(new BoxLayout(this, BoxLayout.X_AXIS));

		// Load all images
		JButton left = new JButton();

		// Add Left Buttons
		left.setText("< Left");
		this.add(left);
		left.addMouseListener(new MouseAdapter()
		{
			@Override
			public void mousePressed(MouseEvent me)
			{
				if(Activity.getInstance().scrollThread == null || (Activity.getInstance().scrollThread != null && !Activity.getInstance().scrollThread.isAlive())){
					int newSelector = Math.max(0, mSelected - 1);
					logSelectorChange(mSelected, newSelector);
					mSelected = newSelector;
					notifyListenersSelectorChange(newSelector);
					for (int i = 0; i < selectorButtons.size(); i++) {
						if (i == newSelector)
							selectorButtons.get(i).setEnabled(false);
						else
							selectorButtons.get(i).setEnabled(true);
					}
				Selector.this.repaint();
				}
			}

		});

		// Add button for each Segment
		selectorButtons = new LinkedList<JButton>();
		for (int i = 0; i < numberOfSelectors; i++) {
			JButton segmentButton = new JButton();
			final int index = i;
			segmentButton.setText("" + (i + 1));
			segmentButton.addMouseListener(new MouseAdapter()
			{
				@Override
				public void mousePressed(MouseEvent me)
				{
					if(Activity.getInstance().scrollThread == null || (Activity.getInstance().scrollThread != null && !Activity.getInstance().scrollThread.isAlive())){
						Selector.this.notifyListenersSelectorChange(index);
						logSelectorChange(mSelected, index);
						mSelected = index;
						for (int i = 0; i < selectorButtons.size(); i++) {
							if (i == index)
								selectorButtons.get(i).setEnabled(false);
							else
								selectorButtons.get(i).setEnabled(true);
						}
					}
				}
			});
			this.add(segmentButton);
			selectorButtons.add(segmentButton);
		}

		// Add Right Buttons
		JButton right = new JButton();
		right.setText("Right >");
		this.add(right);
		right.addMouseListener(new MouseAdapter()
		{
			@Override
			public void mousePressed(MouseEvent me)
			{
				if(Activity.getInstance().scrollThread == null || (Activity.getInstance().scrollThread != null && !Activity.getInstance().scrollThread.isAlive())){
					int newSelector = Math.min(mSelectorSize - 1, mSelected + 1);
					logSelectorChange(mSelected, newSelector);
					mSelected = newSelector;
					notifyListenersSelectorChange(newSelector);
					for (int i = 0; i < selectorButtons.size(); i++) {
						if (i == newSelector)
							selectorButtons.get(i).setEnabled(false);
						else
							selectorButtons.get(i).setEnabled(true);
					}
				}
			}
		});

		selectorButtons.get(0).setEnabled(false);
		mSelectorChangeTimestamp = System.currentTimeMillis();
	}
	
	public int getSelected(){
		return mSelected;
	}

	public interface SelectorListener
	{
		public void onSelectorChange(int selectorID);
	}

	private ArrayList<SelectorListener>	selectorListeners	= new ArrayList<SelectorListener>();

	public void addSelectorListener(SelectorListener selectorListener)
	{
		selectorListeners.add(selectorListener);
	}

	private void notifyListenersSelectorChange(int index)
	{
		for (int i = 0; i < selectorListeners.size(); i++)
		{
			selectorListeners.get(i).onSelectorChange(index);
		}
	}

	private boolean validateSelectorNumber(int number)
	{
		if (number <= 0)
			return false;
		return true;
	}
	
	public void resetTimestamp(){
		mSelectorChangeTimestamp = System.currentTimeMillis();
	}

	/**
	 * Check if any selector change is a view change, and log time differences in analytics
	 * 
	 * @param mSelected
	 * @param newSelector
	 */
	private void logSelectorChange(int oldIndex, int newIndex)
	{
		if (oldIndex != newIndex) {
			long timeNow = System.currentTimeMillis();
			long timeDifference = timeNow - mSelectorChangeTimestamp;
			mSelectorChangeTimestamp = timeNow;
			AnalyticUtils.recordTimeOnRepresentation(oldIndex, timeDifference);
		}
	}

	public long getTimestamp()
	{
		return mSelectorChangeTimestamp;
	}
}