Subversion Repositories eFlore/Archives.cel-v1

/*

Auto-Completion Textbox for GWT

Copyright (C) 2006 Oliver Albers http://gwt.components.googlepages.com/

This library is free software; you can redistribute it and/or

modify it under the terms of the GNU Lesser General Public

License as published by the Free Software Foundation; either

version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,

but WITHOUT ANY WARRANTY; without even the implied warranty of

MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public

License along with this library; if not, write to the Free Software

Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

*/

package org.tela_botanica.client;

// TODO : traiter latence (augmenter en fonction rapidité saisie + texte vide)

// TODO : traiter Tab (selection)

// TODO : revoir traitement keyup, keydown

import com.google.gwt.json.client.JSONArray;

import com.google.gwt.json.client.JSONParser;

import com.google.gwt.json.client.JSONString;

import com.google.gwt.json.client.JSONValue;

import com.google.gwt.user.client.HTTPRequest;

import com.google.gwt.user.client.ResponseTextHandler;

import com.google.gwt.user.client.ui.ChangeListener;

import com.google.gwt.user.client.ui.KeyboardListener;

import com.google.gwt.user.client.ui.ListBox;

import com.google.gwt.user.client.ui.PopupPanel;

import com.google.gwt.user.client.ui.RootPanel;

import com.google.gwt.user.client.ui.TextBox;

import com.google.gwt.user.client.ui.Widget;

import java.util.Vector;

import java.util.HashMap;

public class AutoCompleteAsyncTextBox extends TextBox

    implements KeyboardListener, ChangeListener, SourcesAutoCompleteAsyncTextBoxEvents {

  private String searchUrl = null;

  private AutoCompleteAsyncTextBoxListenerCollection autoCompleteAsyncTextBoxListeners=null;

  private HashMap cache = new HashMap();

  private boolean searching = false;

  protected PopupPanel choicesPopup = new PopupPanel(true);

  protected ListBox choices = new ListBox();

  protected Vector items = new Vector();

  protected boolean popupAdded = false;

  protected boolean visible = false;

  /**

   * Default Constructor

   *

   */

  public AutoCompleteAsyncTextBox()

  {

    super();

    this.addKeyboardListener(this);

    choices.addChangeListener(this);

    this.setStyleName("AutoCompleteAsyncTextBox");

    choicesPopup.add(choices);

    choicesPopup.addStyleName("AutoCompleteChoices");

    choices.setStyleName("list");

  }

  public void addAutoCompleteAsyncTextBoxListener(AutoCompleteAsyncTextBoxListener listener) {

	    if (autoCompleteAsyncTextBoxListeners == null) {

	      autoCompleteAsyncTextBoxListeners = new AutoCompleteAsyncTextBoxListenerCollection();

	    }

	    autoCompleteAsyncTextBoxListeners.addElement(listener);

  }

  public void setSearchUrl(String url) {

	  this.searchUrl=url;

  }

  private void doFetchURL(String match) {

	  /*

	   * Here we fetch the URL and call the handler

	   */

	  if (this.searchUrl!=null && searching==false) {

		  searching=true;

	      HTTPRequest.asyncGet(this.searchUrl + match,

	  		    new ResponseTextHandler(){

	    	  		public void onCompletion(String str) {

	    	  			JSONValue jsonValue= JSONParser.parse(str);

	    	  			JSONArray jsonArray;

	    	  			JSONString jsonString;

	    	  			if ((jsonArray = jsonValue.isArray()) != null) {

	    	  				for (int i = 0; i < jsonArray.size(); ++i) {

	    	  					if ((jsonString = (jsonArray.get(i)).isString()) != null) {

	    	  						addItem(jsonString.stringValue());

	    	  					}

	    	  				}

	    	  			}

	    	  			displayList();

	    		  }

	  		    });

	  }

  }

  /**

   * Not used at all

   */

  public void onKeyDown(Widget arg0, char arg1, int arg2) {

  }

  /**

   * Not used at all

   */

  public void onKeyPress(Widget arg0, char arg1, int arg2) {

	    if(arg1 == KEY_DOWN)

	    {

	      int selectedIndex = choices.getSelectedIndex();

	      selectedIndex++;

	      if(selectedIndex >= choices.getItemCount())

	      {

	        selectedIndex = 0;

	      }

	      choices.setSelectedIndex(selectedIndex);

	      return;

	    }

	    if(arg1 == KEY_UP)

	    {

	      int selectedIndex = choices.getSelectedIndex();

	      selectedIndex--;

	      if(selectedIndex < 0)

	      {

	        selectedIndex = choices.getItemCount() - 1 ;

	      }

	      choices.setSelectedIndex(selectedIndex);

	      return;

	    }

  }

  /**

   * A key was released, start autocompletion

   */

  public void onKeyUp(Widget arg0, char arg1, int arg2) {

	 if(arg1 == KEY_DOWN)

	 {

		 return;

	 }

	 if(arg1 == KEY_UP)

	 {

		 return;

	 }

    if(arg1 == KEY_ENTER)

    {

      if(visible)

      {

        complete();

      }

      else {

    	 // Validation de l'entree :

          if (autoCompleteAsyncTextBoxListeners!= null) {

              autoCompleteAsyncTextBoxListeners.fireTextBoxEnter(this, this.getText());

          }

    	  this.setText("");

      }

      return;

    }

    if(arg1 == KEY_ESCAPE)

    {

      choices.clear();

      items.clear();

      choicesPopup.hide();

      visible = false;

      return;

    }

 // Lancement appel

    String text = this.getText();

    if(text.length() > 0)

    {

      items.clear();

      if (getFromCache(text)!=null) {

    	  items=getFromCache(text);

    	  displayList();

      }

      else {

    	  this.doFetchURL(text);

      }

    }

  }

  // Display assistant

    public void displayList() {

    	searching=false;

	    if(this.items.size() > 0)

	    {

	      addToCache(this.getText(),(Vector) items.clone());

	      choices.clear();

	      for(int i = 0; i < items.size(); i++)

	      {

	        choices.addItem((String) items.get(i));

	      }

	      // if there is only one match and it is what is in the

	      // text field anyways there is no need to show autocompletion

	      if(items.size() == 1 && ((String) items.get(0)).compareTo(this.getText()) == 0)

	      {

	        choicesPopup.hide();

	      } else {

	        choices.setSelectedIndex(0);

	        choices.setVisibleItemCount(items.size());

	        if(!popupAdded)

	        {

	          RootPanel.get().add(choicesPopup);

	          popupAdded = true;

	        }

	        choicesPopup.show();

	        visible = true;

	        choicesPopup.setPopupPosition(this.getAbsoluteLeft(),

	        this.getAbsoluteTop() + this.getOffsetHeight());

	        //choicesPopup.setWidth(this.getOffsetWidth() + "px");

	        choices.setWidth(this.getOffsetWidth() + "px");

	      }

	    } else {

	      visible = false;

	      choicesPopup.hide();

	    }

	  }

  /**

   * A mouseclick in the list of items

   */

  public void onChange(Widget arg0) {

    complete();

  }

  public void onClick(Widget arg0) {

    complete();

  }

  // add selected item to textbox

  protected void complete()

  {

    if(choices.getItemCount() > 0)

    {

      this.setText(choices.getItemText(choices.getSelectedIndex()));

    }

    visible=false;

    items.clear();

    choices.clear();

    choicesPopup.hide();

  }

  public void addItem(String item) {

	  items.add(item);

  }

  private void addToCache (String query, Vector result)

  {

	cache.put(query.toLowerCase(),result);

  }

  private Vector getFromCache (String query)

  {

	return (Vector) cache.get(query.toLowerCase());

  }

}