AutoCompleteTextField.java

package au.com.vaadinutils.ui;

import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Map.Entry;

import org.vaadin.peter.contextmenu.ContextMenu;
import org.vaadin.peter.contextmenu.ContextMenu.ContextMenuClosedEvent;
import org.vaadin.peter.contextmenu.ContextMenu.ContextMenuClosedListener;
import org.vaadin.peter.contextmenu.ContextMenu.ContextMenuItem;
import org.vaadin.peter.contextmenu.ContextMenu.ContextMenuItemClickEvent;
import org.vaadin.peter.contextmenu.ContextMenu.ContextMenuItemClickListener;

import com.vaadin.event.FieldEvents.TextChangeEvent;
import com.vaadin.event.FieldEvents.TextChangeListener;
import com.vaadin.ui.TextField;

public class AutoCompleteTextField<E> extends TextField
{

	private static final long serialVersionUID = 1L;

	private AutoCompeleteQueryListener<E> listener;
	private Map<E, String> options = new LinkedHashMap<>();
	private AutoCompleteOptionSelected<E> optionListener;
	private ContextMenu contextMenu;
	private boolean isContextMenuOpen = false;

	/**
	 * <pre>
	 * {@code
	 * sample usage
	 * 
	 * 	AutoCompleteTextFieldV2<PostCode> suburb = new AutoCompleteTextFieldV2<>();
	 * 
	 * suburb.setQueryListener(new AutoCompeleteQueryListener<PostCode>()
	 * {
	 * 
	 * 	    @Override
	 * 	    public void handleQuery(AutoCompleteTextFieldV2<PostCode> field,String queryText)
	 * 	    {
	 * 		    field.addOption(new PostCode(3241),"Title");
	 * 	    }
	 * 	});
	 * 
	 * 	suburb.setOptionSelectionListener(new AutoCompleteOptionSelected<PostCode>()
	 * 	{
	 * 	    
	 * 	    @Override
	 * 	    public void optionSelected(AutoCompleteTextFieldV2<PostCode> field, PostCode option)
	 * 	    {
	 * 		field.setValue(option.getSuburb());
	 * 	    }
	 * 	});
	 * }
	 * </pre>
	 * 
	 * The ContextMenu is removed from the parent after each interaction to
	 * allow the default context menu to still work for copy/paste. However
	 * there is an issue with the ContextMenuClosedEvent firing before the
	 * ContextMenuItemClickEvent. This means that the ContextMenu can't be
	 * removed from the parent in onContextMenuClosed, otherwise
	 * contextMenuItemClicked is never entered. The effect of this is that the
	 * default context menu stops working if the user clicks out of the auto
	 * complete context menu without selecting anything.
	 */

	public AutoCompleteTextField(final String caption)
	{
		this();
		setCaption(caption);
	}

	public AutoCompleteTextField()
	{
		setTextChangeEventMode(TextChangeEventMode.LAZY);
		setImmediate(true);
		addTextChangeListener(new TextChangeListener()
		{
			private static final long serialVersionUID = 1L;

			@Override
			public void textChange(final TextChangeEvent event)
			{
				options.clear();

				if (listener != null)
				{
					listener.handleQuery(AutoCompleteTextField.this, event.getText());
				}

				if (!options.isEmpty())
				{
					createContextMenu();
					showOptionMenu();
				}
			}
		});
	}

	private void createContextMenu()
	{
		// Don't create a new context menu if the existing one is still open
		if (isContextMenuOpen)
		{
			return;
		}

		// Create a new ContextMenu as each instance can only be added and
		// removed from a parent once
		contextMenu = new ContextMenu();
		contextMenu.setAsContextMenuOf(this);
		contextMenu.setOpenAutomatically(false);

		contextMenu.addContextMenuCloseListener(new ContextMenuClosedListener()
		{

			@Override
			public void onContextMenuClosed(ContextMenuClosedEvent event)
			{
				isContextMenuOpen = false;
			}
		});
	}

	private void showOptionMenu()
	{
		contextMenu.removeAllItems();
		contextMenu.open(this);
		isContextMenuOpen = true;

		for (final Entry<E, String> option : options.entrySet())
		{
			ContextMenuItem menuItem = contextMenu.addItem(option.getValue());
			menuItem.addItemClickListener(new ContextMenuItemClickListener()
			{

				@Override
				public void contextMenuItemClicked(ContextMenuItemClickEvent event)
				{
					optionListener.optionSelected(AutoCompleteTextField.this, option.getKey());

					// Remove the context menu when it gets closed to allow the
					// default context menu to still be available
					contextMenu.remove();
				}
			});
		}
	}

	public void setOptionSelectionListener(AutoCompleteOptionSelected<E> listener)
	{
		this.optionListener = listener;
	}

	public void removeOptionSelectionListener()
	{
		optionListener = null;
	}

	public void setQueryListener(AutoCompeleteQueryListener<E> listener)
	{
		this.listener = listener;
	}

	public void removeQueryListener()
	{
		listener = null;
	}

	public void addOption(E option, String optionLabel)
	{
		options.put(option, optionLabel);
	}

	public void hideAutoComplete()
	{
		if (contextMenu != null)
		{
			contextMenu.hide();
		}
	}
}