/**

  * 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.list.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.KSCheckBox;

 import org.kuali.student.common.ui.client.widgets.KSLabel;

 import org.kuali.student.common.ui.client.widgets.focus.FocusGroup;

 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.BlurHandler;

 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.logical.shared.ValueChangeEvent;

 import com.google.gwt.event.logical.shared.ValueChangeHandler;

 import com.google.gwt.event.shared.HandlerRegistration;

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

 /**

  *  This class will generate a checkbox list from a ListItems instance.

  *  For a ListItems instance with just one attribute it will be a list of checkboxes which

  *  may be horizontal or vertical as controlled by the maxCols attribute 

  *  If maxCols <=2 checkboxes will be vertical, otherwise horizontal.

  * 

  *  For ListItems with > 1 attribute a table with a header row will be generated 

  *  with each column being a ListItems attribute. This can be turned off using setIgnoreMultipleAttributes

  * 

  * @author Kuali Student Team 

  *

  */

 public class KSCheckBoxListImpl extends KSSelectItemWidgetAbstract implements ValueChangeHandler<Boolean>, HasBlurHandlers, HasFocusHandlers {

     private final FocusGroup focus = new FocusGroup(this);

     private FlexTable layout = new FlexTable();

     private List<String> selectedItems = new ArrayList<String>();

     private int maxCols = 1; //default max columns

     private boolean enabled = true;

     private boolean ignoreMultipleAttributes = false;

     public KSCheckBoxListImpl() {

         initWidget(layout);

     }

     /**

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

      */

     public void deSelectItem(String id) {

         for (int i=0; i < layout.getRowCount(); i++){

             for (int j=0; j < layout.getCellCount(i); j++){

                 KSCheckBox checkbox = (KSCheckBox)layout.getWidget(i, j);

                 if (checkbox.getFormValue().equals(id)){

                     this.selectedItems.remove(id);

                     checkbox.setValue(false);

                     fireChangeEvent(false);

                     break;

                 }

             }

         }                

     }

     /**

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

      */

     public List<String> getSelectedItems() {

         return selectedItems;

     }

     /**

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

      */

     public void selectItem(String id) {

         if (!selectedItems.contains(id)){

             for (int i=0; i < layout.getRowCount(); i++){

                 for (int j=0; j < layout.getCellCount(i); j++){

                     KSCheckBox checkbox = (KSCheckBox)layout.getWidget(i, j);

                     if (checkbox.getFormValue().equals(id)){

                         this.selectedItems.add(id);

                         checkbox.setValue(true);

                         fireChangeEvent(false);

                         break;

                     }

                 }

             }

         }

     }

     public void redraw(){

         layout.clear();

         int itemCount = super.getListItems().getItemCount();

         int currCount = 0;

         int row = 0;

         int col = 0;

         // If ListItems has more than one attribute create a table with each attribute in its own column

         if (!ignoreMultipleAttributes && super.getListItems().getAttrKeys() != null && super.getListItems().getAttrKeys().size() > 1) {

             layout.addStyleName("KS-Checkbox-Table");

             layout.setWidget(row, col++, new KSLabel("Select"));

             for (String attr:super.getListItems().getAttrKeys()){

                 layout.setWidget(row, col++, new KSLabel(attr));

             }

             row++;

             col=0;

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

                 layout.setWidget(row, col, createCheckbox(id));

                 for (String attr:super.getListItems().getAttrKeys()){

                     String value = super.getListItems().getItemAttribute(id, attr);

                     layout.setWidget(row, ++col, new KSLabel(value));

                 }                    

                 row++;

                 col = 0;

             }

         }

         else if (maxCols <= 2){

             //Row flow - increment row faster than column

             int maxRows = (itemCount / maxCols) + (itemCount % 2);

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

                 currCount++;

                 row = (currCount % maxRows);

                 row = ((row == 0) ? maxRows:row) - 1;

                 layout.setWidget(row, col, createCheckboxWithLabel(id));                    

                 col += ((row + 1)/ maxRows) * 1;

             }

         } else {

             //Column flow - increment column faster than row

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

                 currCount++;

                 col = currCount % maxCols;

                 col = ((col == 0) ? maxCols:col) - 1;

                 layout.setWidget(row, col, createCheckboxWithLabel(id));

                 row += ((col + 1 )/ maxCols) * 1;

             }

         }

         setInitialized(true);

     }

     @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){

                     KSCheckBoxListImpl.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);

         redraw();

     }

     private KSCheckBox createCheckbox(String id){

         KSCheckBox checkbox = new KSCheckBox();

         checkbox.setFormValue(id);

         checkbox.addValueChangeHandler(this);

         focus.addWidget(checkbox);

         return checkbox;

     }

     private KSCheckBox createCheckboxWithLabel(String id){

         KSCheckBox checkbox = new KSCheckBox(getListItems().getItemText(id));

         checkbox.setFormValue(id);

         checkbox.addValueChangeHandler(this);

         focus.addWidget(checkbox);

         return checkbox;

     }

     public void onLoad() {}

     /**

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

      */

     @Override

     public void setColumnSize(int col) {

         maxCols = col;

     }

     @Override

     public void setEnabled(boolean b) {

         enabled = b;

         for (int i=0; i < layout.getRowCount(); i++){

             for (int j=0; j < layout.getCellCount(i); j++){

                 ((KSCheckBox)layout.getWidget(i, j)).setEnabled(b);

             }

         }

     }

     @Override

     public boolean isEnabled() {

         return enabled;

     }

     @Override

     public boolean isMultipleSelect(){

         return true;

     }

     public void setIgnoreMultipleAttributes(boolean ignoreMultiple){

             this.ignoreMultipleAttributes = ignoreMultiple;

     }

     @Override

     public void clear(){

         selectedItems.clear();

         fireChangeEvent(false);

         redraw();

     }

     @Override

     public HandlerRegistration addBlurHandler(BlurHandler handler) {

         return focus.addBlurHandler(handler);

     }

     @Override

     public HandlerRegistration addFocusHandler(FocusHandler handler) {

         return focus.addFocusHandler(handler);

     }

         @Override

         public void onValueChange(ValueChangeEvent<Boolean> event) {

         KSCheckBox checkbox = (KSCheckBox)(event.getSource());   

         String value = checkbox.getFormValue();

         if (event.getValue()){

             if (!selectedItems.contains(value)){

                 selectedItems.add(value);

             }

         } else {

             selectedItems.remove(value);

         }

         fireChangeEvent(true);

         }

 }