/**

  * Copyright 2010 The Kuali Foundation Licensed under the

  * Educational Community License, Version 2.0 (the "License"); you may

  * not use this file except in compliance with the License. You may

  * obtain a copy of the License at

  *

  * http://www.osedu.org/licenses/ECL-2.0

  *

  * Unless required by applicable law or agreed to in writing,

  * software distributed under the License is distributed on an "AS IS"

  * BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express

  * or implied. See the License for the specific language governing

  * permissions and limitations under the License.

  */

 package org.kuali.student.common.ui.client.widgets.impl;

 import java.util.ArrayList;

 import java.util.List;

 import org.kuali.student.common.dto.Idable;

 import org.kuali.student.common.ui.client.mvc.Callback;

 import org.kuali.student.common.ui.client.widgets.list.KSSelectItemWidgetAbstract;

 import org.kuali.student.common.ui.client.widgets.list.ListItems;

 import org.kuali.student.common.ui.client.widgets.list.ModelListItems;

 import com.google.gwt.event.dom.client.BlurEvent;

 import com.google.gwt.event.dom.client.BlurHandler;

 import com.google.gwt.event.dom.client.ChangeEvent;

 import com.google.gwt.event.dom.client.ChangeHandler;

 import com.google.gwt.event.dom.client.ClickEvent;

 import com.google.gwt.event.dom.client.ClickHandler;

 import com.google.gwt.event.dom.client.FocusEvent;

 import com.google.gwt.event.dom.client.FocusHandler;

 import com.google.gwt.event.dom.client.HasBlurHandlers;

 import com.google.gwt.event.dom.client.HasFocusHandlers;

 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.HandlerRegistration;

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

 public class KSDropDownImpl extends KSSelectItemWidgetAbstract implements HasFocusHandlers, HasBlurHandlers{

         private ListBox listBox;

         private boolean blankFirstItem = true;

         private final String EMPTY_ITEM = "";

         public KSDropDownImpl() {

             init();

         }

         public void redraw(){

             String selectedItem = getSelectedItem();

         listBox.clear();

         if(blankFirstItem){

             listBox.addItem(EMPTY_ITEM);

         }

         for (String id: super.getListItems().getItemIds()){

             listBox.addItem(super.getListItems().getItemText(id),id);

         }

         selectItem(selectedItem);

         setInitialized(true);

         }

     protected void init() {

                 listBox = new ListBox(false);

         this.initWidget(listBox);

                 setupDefaultStyle();

                 listBox.addChangeHandler(new ChangeHandler(){

             public void onChange(ChangeEvent event) {

                 fireChangeEvent(true);

             }

                 });

         }

         private void setupDefaultStyle() {

             listBox.addStyleName("KS-Dropdown");

                 listBox.addBlurHandler(new BlurHandler(){

                         public void onBlur(BlurEvent event) {

                             listBox.removeStyleName("KS-Dropdown-Focus");

                         }

                 });

                 listBox.addFocusHandler(new FocusHandler(){

                         public void onFocus(FocusEvent event) {

                             listBox.addStyleName("KS-Dropdown-Focus");

                         }

                 });

                 listBox.addMouseOverHandler(new MouseOverHandler(){

                         public void onMouseOver(MouseOverEvent event) {

                             listBox.addStyleName("KS-Dropdown-Hover");

                         }

                 });

                 listBox.addMouseOutHandler(new MouseOutHandler(){

                         public void onMouseOut(MouseOutEvent event) {

                             listBox.removeStyleName("KS-Dropdown-Hover");

                         }

                 });

                 listBox.addClickHandler(new ClickHandler(){

                         public void onClick(ClickEvent event) {

                                 if(listBox.getSelectedIndex() != -1){

                                     listBox.addStyleName("KS-Dropdown-Selected");

                                 }

                                 else{

                                     listBox.removeStyleName("KS-Dropdown-Selected");

                                 }

                         }

                 });

         }

         public void selectItem(String id){

             if (id != null){

                     boolean matched = false;

                     for(int i = 0; i < listBox.getItemCount(); i++){

                             if(id.equals(listBox.getValue(i))){

                                     matched = true;

                                     listBox.setSelectedIndex(i);

                                     fireChangeEvent(false);

                                     break;

                             }

                     }

                     if(!matched){

                             //Default to select the first item if the id does not match and make it a user event

                                 if(blankFirstItem && listBox.getSelectedIndex() != 0){

                                         listBox.setSelectedIndex(0);

                                         fireChangeEvent(false);

                                 }

                     }

             }

         }

     /**

      * @see org.kuali.student.common.ui.client.widgets.list.KSSelectItemWidgetAbstract#deSelectItem(java.lang.String)

      */

     @Override

     public void deSelectItem(String id) {

         int i = listBox.getSelectedIndex();

         if (i >= 0 && listBox.getValue(i).equals(id)){

             listBox.setItemSelected(i, false);

             listBox.setItemSelected(0, true);

             fireChangeEvent(false);

         }

     }

     @Override

     public <T extends Idable> void setListItems(ListItems listItems) {

         if(listItems instanceof ModelListItems){

             Callback<T> redrawCallback = new Callback<T>(){

                 @Override

                 public void exec(T result){

                     KSDropDownImpl.this.redraw();

                 }

             };

             ((ModelListItems<T>)listItems).addOnAddCallback(redrawCallback);

             ((ModelListItems<T>)listItems).addOnRemoveCallback(redrawCallback);

             ((ModelListItems<T>)listItems).addOnUpdateCallback(redrawCallback);

             ((ModelListItems<T>)listItems).addOnBulkUpdateCallback(redrawCallback);

         }

         super.setListItems(listItems);

         this.redraw();

     }

     /**

      * @see org.kuali.student.common.ui.client.widgets.list.KSSelectItemWidgetAbstract#getSelectedItems()

      */

     @Override

     public List<String> getSelectedItems() {

         List<String> result = new ArrayList<String>();

         int selectedIdx = listBox.getSelectedIndex();

         if((blankFirstItem && selectedIdx > 0) || (!blankFirstItem && selectedIdx >= 0)){

             String id = listBox.getValue(selectedIdx);

             result.add(id);

         }

         return result;

     }

     /**

      * @see org.kuali.student.common.ui.client.widgets.list.KSSelectItemWidgetAbstract#onLoad()

      */

     @Override

     public void onLoad() {

     }

     @Override

     public void setEnabled(boolean b) {

         listBox.setEnabled(b);

     }

     @Override

     public boolean isEnabled() {

         return listBox.isEnabled();

     }

     public boolean isBlankFirstItem() {

         return blankFirstItem;

     }

     public void setBlankFirstItem(boolean blankFirstItem) {

         this.blankFirstItem = blankFirstItem;

     }

         @Override

         public HandlerRegistration addFocusHandler(FocusHandler handler) {

                 return listBox.addFocusHandler(handler);

         }

         @Override

         public HandlerRegistration addBlurHandler(BlurHandler handler) {

                 return listBox.addBlurHandler(handler);

         }

     @Override

     public void clear() {

         //need to select the default item

         if (super.getListItems() != null) {

             listBox.clear();

             if(blankFirstItem){

                 listBox.addItem(EMPTY_ITEM);

             }

             for (String id: super.getListItems().getItemIds()){

                 listBox.addItem(super.getListItems().getItemText(id),id);

             }

             fireChangeEvent(false);

         }

     }

 }