share-updates/src/main/java/org/gcube/portlets/user/shareupdates/client/dialog/PickUsersDialog.java

package org.gcube.portlets.user.shareupdates.client.dialog;

import java.util.ArrayList;
import java.util.Date;

import org.gcube.portal.databook.shared.Like;
import org.gcube.portlets.user.shareupdates.client.events.PickedUserEvent;
import org.gcube.portlets.user.shareupdates.client.form.SingleUserTemplate;
import org.gcube.portlets.user.shareupdates.shared.PickingUser;

import com.google.gwt.core.client.GWT;
import com.google.gwt.event.dom.client.KeyCodes;
import com.google.gwt.event.dom.client.KeyDownEvent;
import com.google.gwt.event.dom.client.KeyDownHandler;
import com.google.gwt.event.dom.client.MouseOutEvent;
import com.google.gwt.event.dom.client.MouseOutHandler;
import com.google.gwt.event.dom.client.MouseOverEvent;
import com.google.gwt.event.dom.client.MouseOverHandler;
import com.google.gwt.event.shared.HandlerManager;
import com.google.gwt.user.client.Event;
import com.google.gwt.user.client.ui.FocusPanel;
import com.google.gwt.user.client.ui.MultiWordSuggestOracle;
import com.google.gwt.user.client.ui.PopupPanel;
import com.google.gwt.user.client.ui.SuggestOracle.Callback;
import com.google.gwt.user.client.ui.SuggestOracle.Request;
import com.google.gwt.user.client.ui.SuggestOracle.Response;
import com.google.gwt.user.client.ui.SuggestOracle.Suggestion;
import com.google.gwt.user.client.ui.VerticalPanel;

public class PickUsersDialog extends PopupPanel {

	public final static int ARROW_UP = 38; 
	public final static int ARROW_DOWN = 40; 

	public final static int DELETE = KeyCodes.KEY_DELETE; 
	public final static int ENTER = KeyCodes.KEY_ENTER; 
	public final static int ESCAPE = KeyCodes.KEY_ESCAPE; 
	public final static int TAB = KeyCodes.KEY_TAB; 

	private HandlerManager eventBus;

	private int limit = 10;

	private final MultiWordSuggestOracle oracle = new MultiWordSuggestOracle();

	private ArrayList<String> users = new ArrayList<String>();
	private int displayIndexSelected;

	private FocusPanel focusPanel = new FocusPanel();
	private VerticalPanel mainPanel = new VerticalPanel();

	//needed because is selected when it popups 
	private SingleUserTemplate first;

	public PickUsersDialog(HandlerManager eventBus) {
		super(true, false);
		this.eventBus = eventBus;
		focusPanel.setWidth("525px");
		mainPanel.setWidth("525px");
		setWidth("525px");
		focusPanel.add(mainPanel);
		setWidget(focusPanel);
		setStyleName("pickDialog");		

		oracle.add("Massimiliano Assante");
		oracle.add("Pasquale Pagano");
		oracle.add("Leonardo Candela");
		oracle.add("Anton Ellenbroek");
		oracle.add("Ward Appeltans");
		oracle.add("Gianpaolo Coro");
		oracle.add("Federico De Faveri");
		oracle.add("Marco Pozzi");
		oracle.add("Marino Marini");
		oracle.add("Franco Zoppi");
		oracle.add("Valentina Marioli");
		oracle.add("Antonio Gioia");

		//remove the first selected when hovering
		focusPanel.addMouseOverHandler(new MouseOverHandler() {			
			@Override
			public void onMouseOver(MouseOverEvent event) {
				if (first != null)
					first.removeStyleName("pickperson-selected");				
			}
		});

		focusPanel.addMouseOutHandler(new MouseOutHandler() {
			@Override
			public void onMouseOut(MouseOutEvent event) {
				select(displayIndexSelected);		
			}
		});	
	}

	/**
	 * called for each keyUp event from the user
	 * @param event
	 * @param x
	 * @param y
	 * @param currText
	 */
	public void onKeyUp(Event event, int x, int y, String currText) {
		if (currText.endsWith("@")) { //the only way i found to intercept @
			setPopupPosition(x, y);
			hide();
		} else if (currText.contains("@")) {
			if (pickingUser(currText)) {
				handleNonCharKeys(event);
			}
		} else if (!currText.contains("@")) 
			hide();		
	}

	/**
	 * split the text and keeps listening for user keyboard events
	 * @param currText the text being typed
	 */
	private boolean pickingUser(String currText) {
		String[] toSplit = currText.split("@"); //get the interesting part
		if (toSplit[1].trim().length() > 0) {
			showSuggestions(toSplit[1]);
			return true;
		}
		hide();
		return false;
	}
	/**
	 * handles the nonchar events (arrows, esc, enter etc)
	 * @param event
	 */
	private void handleNonCharKeys(Event event) {
		switch (event.getKeyCode()) {
		case ARROW_UP:
			if (displayIndexSelected > 0)
				select(--displayIndexSelected);
			break;
		case ARROW_DOWN:
		case TAB:			
			if (displayIndexSelected+1 < mainPanel.getWidgetCount()) 
				select(displayIndexSelected+1);		
			break;
		case ESCAPE:
		case DELETE:
			hide();
		case ENTER: //selectd with keyboard
			SingleUserTemplate ut = null;
			if (mainPanel.getWidgetCount() > 0) {
				if (displayIndexSelected < 0 || displayIndexSelected >= mainPanel.getWidgetCount()) //when there's only one left sometimes here i get -sth, no time to see why :)
					ut = (SingleUserTemplate) mainPanel.getWidget(0);
				else 
					ut = (SingleUserTemplate) mainPanel.getWidget(displayIndexSelected);
				eventBus.fireEvent(new PickedUserEvent(new PickingUser("id", "username", ut.getFullName(), "thumb")));
				hide();
			}
			break;
		default:
			break;
		}
	}

	public void showSuggestions(String query) {
		if (query.length() > 0) {
			oracle.requestSuggestions(new Request(query, limit), new Callback() {
				public void onSuggestionsReady(Request request, Response response) {
					mainPanel.clear();
					int i = 0;
					for (Suggestion s : response.getSuggestions()) {
						if (i == 0) {
							first = getUserTemplate(new PickingUser("", "",  s.getDisplayString(), ""), i);
							first.addStyleName("pickperson-selected");
							mainPanel.add(first);
						}
						else
							mainPanel.add(getUserTemplate(new PickingUser("", "",  s.getDisplayString(), ""), i));
						i++;
					}
					if (i > 0)
						show();
				}
			});
		}
	}

	private SingleUserTemplate getUserTemplate(PickingUser user, int displayIndex) {
		return new SingleUserTemplate(this, user, displayIndex);
	}

	/**
	 * select the user in the model and in the view
	 * @param displayIndex
	 */
	public void select(int displayIndex) {
		for (int i = 0; i < mainPanel.getWidgetCount(); i++) {
			SingleUserTemplate ut = (SingleUserTemplate) mainPanel.getWidget(i);
			if (i == displayIndex) {
				ut.addStyleName("pickperson-selected");
				displayIndexSelected = i;
				//GWT.log("Selected: "+ut.getFullName());
			}
			else
				ut.removeStyleName("pickperson-selected");
		}
	}
}