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

 import java.util.*;

 import org.kuali.student.common.ui.client.configurable.mvc.FieldDescriptor;

 import org.kuali.student.common.ui.client.configurable.mvc.SectionTitle;

 import org.kuali.student.common.ui.client.configurable.mvc.layouts.BasicLayout;

 import org.kuali.student.common.ui.client.configurable.mvc.views.VerticalSectionView;

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

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

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

 import org.kuali.student.common.ui.client.widgets.buttongroups.ButtonEnumerations;

 import org.kuali.student.common.ui.client.widgets.field.layout.button.ActionCancelGroup;

 import org.kuali.student.common.ui.client.widgets.field.layout.element.MessageKeyInfo;

 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.SelectionChangeEvent;

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

 import org.kuali.student.core.assembly.data.Data;

 import org.kuali.student.core.assembly.data.Metadata;

 import org.kuali.student.core.assembly.data.QueryPath;

 import org.kuali.student.core.dto.RichTextInfo;

 import org.kuali.student.core.statement.dto.ReqCompFieldInfo;

 import org.kuali.student.core.statement.dto.ReqCompFieldTypeInfo;

 import org.kuali.student.core.statement.dto.ReqComponentInfo;

 import org.kuali.student.core.statement.dto.ReqComponentTypeInfo;

 import org.kuali.student.core.validation.dto.ValidationResultInfo;

 import com.google.gwt.core.client.GWT;

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

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

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

 public class ReqCompEditWidget extends FlowPanel {

     //widgets

     private FlowPanel reqCompTypePanel = new FlowPanel();

     private FlowPanel ReqCompEditPanel = new FlowPanel();

     private KSDropDown reqCompTypesList = new KSDropDown();

     private VerticalSectionView reqCompFieldsPanel;

     private ActionCancelGroup actionCancelButtons = new ActionCancelGroup(ButtonEnumerations.AddCancelEnum.ADD, ButtonEnumerations.AddCancelEnum.CANCEL);

     private final String NO_SELECTION_TEXT = "Select rule type";

     //data

     private List<ReqComponentTypeInfo> reqCompTypeInfoList;     //list of all Requirement Component Types based on selected Statement Type

     private ListItems listItemReqCompTypes;                         //list of all Requirement Component Types wrapped in a list for drop down

     private Map<String, String> compositionTemplates = new HashMap<String, String>();

     private ReqComponentInfo editedReqComp;                                                //Req. Component that user is editing or adding

     private ReqComponentTypeInfo selectedReqCompType;           //the type of Req. Component that the user is editing or adding

     private List<String> selectedReqCompFieldTypes;             //types of all fields for given selected req. component type

     private boolean addingNewReqComp;                           //adding (true) or editing (false) req. component

     private DataModel ruleFieldsData;

     private BasicLayout reqCompFieldsLayout;

     private Map<String, Widget> customWidgets = new HashMap<String, Widget>();

     private Map<String, Widget> customWidgetsNew;

     //other

     private Callback reqCompConfirmCallback;

     private Callback newReqCompSelectedCallback;

     private Callback fieldsMetadataTemplateCallback;

     private Callback compositionTemplateCallback;

     private Callback displayCustomWidgetCallback;

     private String newReqCompId;

     private static int tempReqCompInfoID = 999999;

     private static final String REQ_COMP_MODEL_ID = "reqCompModelId";

     private enum ReqCompEditView {VIEW}

     //TODO use app context for text

     public ReqCompEditWidget(String newReqCompId) {

         super();

         ruleFieldsData = new DataModel();

         ruleFieldsData.setRoot(new Data());

         this.newReqCompId = newReqCompId;

    //     this.relatedProgramReqInfoId = relatedProgramReqInfoId;

         //wait until req. comp. types are loaded and user actually selects a type from drop down

         reqCompTypesList.setEnabled(false);

         setEnableAddRuleButtons(false);

         setupReqCompTypesList();

         setupHandlers();

         displayReqCompListPanel();

         add(ReqCompEditPanel);

         displayConfirmButton();

     }

     private void setupHandlers() {

         actionCancelButtons.addCallback(new Callback<ButtonEnumerations.ButtonEnum>(){

                 @Override

                public void exec(ButtonEnumerations.ButtonEnum result) {

                     setEnableAddRuleButtons(false);

                     if (result == ButtonEnumerations.AddCancelEnum.ADD) {

                         //true if we have no fields for this req. component type

                         if (((selectedReqCompFieldTypes == null) || selectedReqCompFieldTypes.size() == 0) && (customWidgets.size() == 0)) {

                             finalizeRuleUpdate();

                             return;

                         }

                         //validate and retrieve fields

                         validateAndRetrieveFields();

                     } else { //user canceled add/edit rule action

                         setupNewReqComp();

                         reqCompConfirmCallback.exec(null);

                     }

                }

         });

         reqCompTypesList.addSelectionChangeHandler(new SelectionChangeHandler() {

                         @Override

             public void onSelectionChange(SelectionChangeEvent event) {

                             if (!event.isUserInitiated()) {

                                 return;

                             }

                 //disable Step 2 section and enable 'Add Rule' and 'cancel' buttons

                  newReqCompSelectedCallback.exec(null);

                  setEnableAddRuleButtons(true);

                  List<String> ids = ((KSSelectItemWidgetAbstract)event.getWidget()).getSelectedItems();

                  selectedReqCompType = reqCompTypeInfoList.get(Integer.valueOf(ids.get(0)));

                  if (addingNewReqComp) {

                      createReqComp(selectedReqCompType);

                  } else {

                          //editedReqComp.setRequiredComponentType(selectedReqCompType);

                      editedReqComp.setType(selectedReqCompType.getId());

                  }

                  displayFieldsSection();

          }});

     }

     private void validateAndRetrieveFields() {

         final List<ReqCompFieldInfo> editedFields = new ArrayList<ReqCompFieldInfo>();

         reqCompFieldsLayout.updateModel();

         //1. validate and retrieve non-custom fields

         if (ruleFieldsData.getRoot().size() > 0) {

             ruleFieldsData.validate(new Callback<List<ValidationResultInfo>>() {

                 @Override

                 public void exec(List<ValidationResultInfo> validationResults) {

                     //do not proceed if the user input is not valid

                     if (!reqCompFieldsLayout.isValid(validationResults, true, true)) {

                         setEnableAddRuleButtons(true);

                         return;

                     }

                     //2. retrieve entered values and set the rule info

                     for (ReqCompFieldTypeInfo fieldTypeInfo : selectedReqCompType.getReqCompFieldTypeInfos()) {

                         //we handle custom widgets elsewhere in order to deal with callbacks

                         if (customWidgets.containsKey(fieldTypeInfo.getId())) {

                             continue;

                         }

                         ReqCompFieldInfo fieldInfo = new ReqCompFieldInfo();

                         fieldInfo.setId(null);

                         fieldInfo.setType(fieldTypeInfo.getId());

                         String fieldValue = ruleFieldsData.getRoot().get(fieldTypeInfo.getId()).toString();

                         fieldInfo.setValue((fieldValue == null ? "" : fieldValue.toString()));

                         editedFields.add(fieldInfo);

                     }

                     //2. retrieve non-custom fields

                     retrieveValuesFromCustomWidgets(editedFields);

                 }

             });

         } else {

             //2. retrieve non-custom fields

             retrieveValuesFromCustomWidgets(editedFields);

         }

     }

     private void retrieveValuesFromCustomWidgets(final List<ReqCompFieldInfo> editedFields) {

         if (customWidgets.size() == 0) {

             editedReqComp.setReqCompFields(editedFields);

             finalizeRuleUpdate();

             return;

         }

         final Iterator iter = customWidgets.entrySet().iterator();

         while (iter.hasNext()) {

             final String fieldType = (String)((Map.Entry)iter.next()).getKey();

             ((AccessWidgetValue)customWidgets.get(fieldType)).getValue(new Callback<String>() {

                 @Override

                 public void exec(String widgetValue) {

                     //clu set validation failed...

                     if (widgetValue == null) {

                         setEnableAddRuleButtons(true);

                         return;

                     }

                     ReqCompFieldInfo fieldInfo = new ReqCompFieldInfo();

                     fieldInfo.setId(null);

                     fieldInfo.setType(fieldType);

                     fieldInfo.setValue(widgetValue);

                     editedFields.add(fieldInfo);

                     //TODO not sure if this will work all the time due to parallel nature of this code but running out of time

                     iter.remove();

                     if (customWidgets.size() == 0) {

                         //3. update req. component being edited

                         editedReqComp.setReqCompFields(editedFields);

                         finalizeRuleUpdate();

                     }

                 }

             });

         }

     }

     private void finalizeRuleUpdate() {

         editedReqComp.setType(selectedReqCompType.getId());

         //callback needs to update NL for given req. component and the rule

         reqCompConfirmCallback.exec(editedReqComp);

     }

     public void setupNewReqComp() {

         addingNewReqComp = true;

         selectedReqCompType = null;

         createReqComp(null);

         ReqCompEditPanel.clear();

         redraw();

     }

     /* create a new Req. Component Type based on user selection or empty at first */

     private void createReqComp(ReqComponentTypeInfo reqCompTypeInfo) {

         RichTextInfo desc = new RichTextInfo();

         desc.setPlain("");

         desc.setFormatted("");

         editedReqComp = new ReqComponentInfoUi();

         editedReqComp.setDesc(desc);

         editedReqComp.setId(newReqCompId + Integer.toString(tempReqCompInfoID++));

         editedReqComp.setReqCompFields(null);

         //editedReqComp.setRequiredComponentType(reqCompTypeInfo);

         if (reqCompTypeInfo != null) {

             editedReqComp.setType(reqCompTypeInfo.getId());

         }

     }

     //call when user wants to edit an existing req. component

     public void setupExistingReqComp(ReqComponentInfo existingReqComp) {

         if (!actionCancelButtons.getButton(ButtonEnumerations.AddCancelEnum.ADD).isEnabled()) {

             return;

         }

         addingNewReqComp = false;

         editedReqComp = existingReqComp;

         //originalReqType = editedReqComp.getRequiredComponentType();

         selectedReqCompType = null;

         for (ReqComponentTypeInfo aReqCompTypeInfoList : reqCompTypeInfoList) {

             if (editedReqComp.getType().equals(aReqCompTypeInfoList.getId())) {

                 selectedReqCompType = aReqCompTypeInfoList;

                 break;

             }

         }

         if (selectedReqCompType == null) {

             GWT.log("Unknown Requirement Component Type found: " + existingReqComp.getType(), null);

             Window.alert("Unknown Requirement Component Type found: " + existingReqComp.getType());

         }

         redraw();

     }

     private void redraw() {

         selectReqCompTypeInList();

         displayFieldsSection();

         if (addingNewReqComp) {

             actionCancelButtons.getButton(ButtonEnumerations.AddCancelEnum.ADD).setText("Add Rule");

             setEnableAddRuleButtons(false);

         } else {

             actionCancelButtons.getButton(ButtonEnumerations.AddCancelEnum.ADD).setText("Update Rule");

             setEnableAddRuleButtons(false);

             if (selectedReqCompType != null) {

                 setEnableAddRuleButtons(true);

             }

         }

     }

     public void displayFieldsSection() {

         //if no req. comp. type is selected then don't display anything

         if (selectedReqCompType == null) {

             return;

         }

         //no display if the req. comp. type has no fields

         if ((selectedReqCompType.getReqCompFieldTypeInfos() == null) || selectedReqCompType.getReqCompFieldTypeInfos().isEmpty()) {

             ReqCompEditPanel.clear();

             selectedReqCompFieldTypes = new ArrayList<String>();

             return;

         }

         //get composition template either from local cache or from service through user of this widget

         String compositionTemplate = compositionTemplates.get(selectedReqCompType.getId());

         if (compositionTemplate == null) {

             compositionTemplateCallback.exec(editedReqComp);

             return;

         }

         displayFieldsStart(compositionTemplate);

     }

     public void displayFieldsStart(String compositionTemplate) {

         compositionTemplates.put(selectedReqCompType.getId(), compositionTemplate);

         setEnableAddRuleButtons(true);

         selectedReqCompFieldTypes = new ArrayList<String>();

         for (ReqCompFieldTypeInfo fieldTypeInfo : selectedReqCompType.getReqCompFieldTypeInfos()) {

             selectedReqCompFieldTypes.add(fieldTypeInfo.getId());

         }

         fieldsMetadataTemplateCallback.exec(selectedReqCompFieldTypes);

     }

     public void displayFieldsEnd(List<Metadata> fieldsMetadataList) {

         customWidgets = new HashMap<String, Widget>();

         List<ReqCompFieldInfo> reqCompFields = (editedReqComp == null ? null : editedReqComp.getReqCompFields());

         reqCompFieldsPanel = new VerticalSectionView(ReqCompEditView.VIEW, "", REQ_COMP_MODEL_ID, false);

         reqCompFieldsPanel.addStyleName("KS-Rule-FieldsList");

         Map<String, FieldDescriptor> fields = new HashMap<String, FieldDescriptor>();

         int ix = 0;

         Metadata fieldGradeTypeMetadata = null;

         Metadata fieldGradeMetadata = null;

         ReqCompEditPanel.clear();

         Map<String, Metadata> fieldDefinitionMetadata = new HashMap<String,Metadata>();

         for (Metadata oneFieldMetadata : fieldsMetadataList) {

             Metadata fieldMetadata = oneFieldMetadata.getProperties().get("value");

             String fieldType = selectedReqCompFieldTypes.get(ix++);

             //add clusets separately

             if (RulesUtil.isCluSetWidget(fieldType)) {

                 displayCustomWidgetCallback.exec(fieldType);

                 continue;

             }

             String fieldLabel = getFieldLabel(fieldType);

             FieldDescriptor fd;

             if (RulesUtil.isGradeWidget(fieldType)) {

                 if (fieldType.equals("kuali.reqComponent.field.type.gradeType.id")) {

                     fieldGradeTypeMetadata = fieldMetadata;

                 }

                 if (fieldType.equals("kuali.reqComponent.field.type.grade.id")) {

                     fieldGradeMetadata = fieldMetadata;

                 }

                 if ((fieldGradeTypeMetadata != null) && (fieldGradeMetadata != null)) {

                     fieldType = "kuali.reqComponent.field.type.grade.id";

                     Widget gradeWidget = customWidgetsNew.get(fieldType);

                     List<Metadata> fieldsMetadata = new ArrayList<Metadata>();

                     fieldsMetadata.add(fieldGradeTypeMetadata);

                     fieldsMetadata.add(fieldGradeMetadata);

                     ((AccessWidgetValue)gradeWidget).initWidget(fieldsMetadata);

                     fieldLabel = getFieldLabel(fieldType);

                     fieldMetadata = fieldGradeMetadata;

                     fd = new FieldDescriptor(fieldType, new MessageKeyInfo(fieldLabel), fieldMetadata, gradeWidget);

                 } else {

                     continue;

                 }

             } else if (RulesUtil.isCluWidget(fieldType)) {

                 Widget customWidget = customWidgetsNew.get(fieldType);

                 ((AccessWidgetValue)customWidget).initWidget(null);

                 fd = new FieldDescriptor(fieldType, new MessageKeyInfo(fieldLabel), fieldMetadata, customWidget);

             } else {

                 fd = new FieldDescriptor(fieldType, new MessageKeyInfo(fieldLabel), fieldMetadata);

             }

             //reqCompFieldsPanel.addField(fd);

             fields.put(fieldType, fd);

             //add field to the data model metadata

             fieldDefinitionMetadata.put(fieldType, fieldMetadata);

         }

         //now we add fields to the panel in proper order based on composition template

         for (String type : getFieldSequence()) {

             if (RulesUtil.isCluSetWidget(type) || type.equals("kuali.reqComponent.field.type.gradeType.id")) {

                 continue;

             }

             reqCompFieldsPanel.addField(fields.get(type));

         }

         //setup data model

         Metadata modelDefinitionMetadata = new Metadata();

         modelDefinitionMetadata.setCanView(true);

         modelDefinitionMetadata.setDataType(Data.DataType.DATA);

         modelDefinitionMetadata.setProperties(fieldDefinitionMetadata);

         ruleFieldsData = new DataModel();

         ruleFieldsData.setRoot(new Data());

         ruleFieldsData.setDefinition(new DataModelDefinition(modelDefinitionMetadata));

         if (selectedReqCompFieldTypes.contains("kuali.reqComponent.field.type.grade.id")) {

             selectedReqCompFieldTypes.remove("kuali.reqComponent.field.type.gradeType.id");

         }

         //initialize fields with values if user is editing an existing rule

         if (!addingNewReqComp) {

             for (String fieldType : selectedReqCompFieldTypes) {

                 String fieldValue = getFieldValue(reqCompFields, fieldType);

                 if (fieldValue != null) {

                     if (RulesUtil.isCluSetWidget(fieldType)) {

                         ((AccessWidgetValue)customWidgets.get(fieldType)).setValue(fieldValue);

                     } else if (RulesUtil.isCluWidget(fieldType)) {

                         ((AccessWidgetValue)customWidgetsNew.get(fieldType)).setValue(fieldValue);

                         ruleFieldsData.set(QueryPath.parse(fieldType), fieldValue);

                     } else {

                         ruleFieldsData.set(QueryPath.parse(fieldType), fieldValue);

                     }

                 }

             }

         }

         //setup controller

         reqCompFieldsLayout = new BasicLayout(null);

         reqCompFieldsLayout.addView(reqCompFieldsPanel);

         reqCompFieldsLayout.setDefaultModelId(REQ_COMP_MODEL_ID);

         reqCompFieldsLayout.registerModel(REQ_COMP_MODEL_ID, new ModelProvider<DataModel>() {

             @Override

             public void requestModel(final ModelRequestCallback<DataModel> callback) {

                 callback.onModelReady(ruleFieldsData);

             }

         });

         //show fields

         ReqCompEditPanel.add(reqCompFieldsLayout);

         reqCompFieldsLayout.showView(ReqCompEditView.VIEW);

         //TODO save history

     }

     //TODO we should mix the custom widgets with regular widgets

     public void displayCustomWidget(String fieldType, Widget customWidget) {

         KSLabel label = new KSLabel(getFieldLabel(fieldType));

         label.addStyleName("KS-Rule-ReqComp-Custom-Widget-label");

         ReqCompEditPanel.add(label);

         customWidgets.put(fieldType, customWidget);

         ReqCompEditPanel.add(customWidget);

     }

     private String getFieldLabel(String fieldType) {

         String compositionTemplate = compositionTemplates.get(selectedReqCompType.getId());

         String label = compositionTemplate.substring(compositionTemplate.indexOf(fieldType) + fieldType.length());

         int ix = label.indexOf("reqCompFieldLabel") + "reqCompFieldLabel".length();

         int ix2 = label.indexOf(">", ix);

         return label.substring(ix, ix2).replace("=", "").trim();

     }

     private List<String> getFieldSequence() {

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

         String compositionTemplate = compositionTemplates.get(selectedReqCompType.getId());

         int stIx = 0;

         while (compositionTemplate.indexOf("reqCompFieldType", stIx) > 0) {

             stIx = compositionTemplate.indexOf("reqCompFieldType") + "reqCompFieldType".length();

             compositionTemplate = compositionTemplate.substring(stIx);

             stIx = 0;

             int ix = compositionTemplate.indexOf(";");

             String type = compositionTemplate.substring(0, ix).replace("=", "").replace(" ", "");

             fieldTypes.add(type);

         }

         return fieldTypes;

     }

     private String getFieldValue(List<ReqCompFieldInfo> fields, String key) {

         if (fields == null) {

             return null;

         }

         for (ReqCompFieldInfo fieldInfo : fields) {

             if (fieldInfo.getType().equals(key)) {

                 return (fieldInfo.getValue() == null ? "" : fieldInfo.getValue());

             }

         }

         return "";

     }

     private void displayConfirmButton() {

         actionCancelButtons.addStyleName("KS-Rule-ReqComp-btn");

         actionCancelButtons.getButton(ButtonEnumerations.AddCancelEnum.ADD).setText("Add Rule");

         add(actionCancelButtons);

     }

     private void displayReqCompListPanel() {

         reqCompTypePanel.setStyleName("KS-Rule-ReqCompList-box");

         SectionTitle subHeader = SectionTitle.generateH5Title("Select rule type");

         subHeader.setStyleName("KS-Rule-ReqComp-header");

         reqCompTypePanel.add(subHeader);

         KSLabel instructions = new KSLabel("Use the list below to select the type of rule you would like to add to this requirement");

         reqCompTypePanel.add(instructions);

         reqCompTypesList.addStyleName("KS-Rule-ReqCompList");

         reqCompTypePanel.add(reqCompTypesList);

         add(reqCompTypePanel);

     }

     private void selectReqCompTypeInList() {

         if (selectedReqCompType == null) {

             if (reqCompTypesList.getSelectedItem() != null) {

                 reqCompTypesList.deSelectItem(reqCompTypesList.getSelectedItem());

             }

             return;

         }

         int i = 0;

         for (ReqComponentTypeInfo comp : reqCompTypeInfoList) {

             if (comp.getId().equals(selectedReqCompType.getId())) {

                 reqCompTypesList.selectItem(Integer.toString(i));

                 break;

             }

             i++;

         }

     }

     private void setupReqCompTypesList() {

             listItemReqCompTypes = new ListItems() {

                 @Override

                 public List<String> getAttrKeys() {

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

                     attributes.add("Key");

                     return attributes;

                 }

                 @Override

                 public String getItemAttribute(String id, String attrkey) {

                     String value = null;

                     Integer index;

                     try{

                         index = Integer.valueOf(id);

                         value = reqCompTypeInfoList.get(index).getDescr();

                     } catch (Exception e) {

                     }

                     return value;

                 }

                 @Override

                 public int getItemCount() {

                     return reqCompTypeInfoList.size();

                 }

                 @Override

                 public List<String> getItemIds() {

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

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

                         ids.add(String.valueOf(i));

                     }

                     return ids;

                 }

                 @Override

                 public String getItemText(String id) {

                     return getItemAttribute(id, "?");

                 }

             };

     }

     private void setEnableAddRuleButtons(boolean enable) {

         actionCancelButtons.getButton(ButtonEnumerations.AddCancelEnum.ADD).setEnabled(enable);

         actionCancelButtons.getButton(ButtonEnumerations.AddCancelEnum.CANCEL).setEnabled(enable);

         if (!enable) {

             reqCompFieldsPanel = null;

         }

     }

     //called by view that manages this widget, passing list of req. component types

     public void setReqCompList(List<ReqComponentTypeInfo> reqComponentTypeInfoList) {

         if (reqComponentTypeInfoList == null || reqComponentTypeInfoList.size() == 0) {

             GWT.log("Missing Requirement Component Types", null);

             Window.alert("Missing Requirement Component Types");

             return;

         }

         //store all requirement components locally

         reqCompTypeInfoList = reqComponentTypeInfoList;

         reqCompTypesList.setListItems(listItemReqCompTypes);

         if (reqCompTypesList.getSelectedItem() != null) {

             reqCompTypesList.deSelectItem(reqCompTypesList.getSelectedItem());

         }

         reqCompTypesList.setEnabled(true);

         setEnableAddRuleButtons(false);

     }

     public void setCustomWidgets(Map<String, Widget> customWidgets) {

         customWidgetsNew = customWidgets;

     }

     public void setReqCompConfirmButtonClickCallback(Callback<ReqComponentInfoUi> actionButtonClickedReqCompCallback) {

         reqCompConfirmCallback = actionButtonClickedReqCompCallback;

     }

     public void setRetrieveCompositionTemplateCallback(Callback<ReqComponentInfo> callback) {

         compositionTemplateCallback = callback;

     }

     public void setRetrieveFieldsMetadataCallback(Callback<List<String>> callback) {

         fieldsMetadataTemplateCallback = callback;

     }

     public void setNewReqCompSelectedCallbackCallback(Callback<ReqComponentInfo> callback) {

         newReqCompSelectedCallback = callback;

     }

     public void setRetrieveCustomWidgetCallback(Callback<String> callback) {

         displayCustomWidgetCallback = callback;

     }

 }