/**

  * 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.pagetable;

 import java.util.ArrayList;

 import java.util.List;

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

 import org.kuali.student.common.ui.client.widgets.searchtable.ResultRow;

 import com.google.gwt.gen2.table.client.AbstractColumnDefinition;

 import com.google.gwt.gen2.table.client.CellRenderer;

 import com.google.gwt.gen2.table.client.ColumnDefinition;

 import com.google.gwt.gen2.table.client.DefaultTableDefinition;

 import com.google.gwt.gen2.table.client.PagingScrollTable;

 import com.google.gwt.gen2.table.client.SelectionGrid.SelectionPolicy;

 import com.google.gwt.gen2.table.client.TableDefinition.AbstractCellView;

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

 /**

  * Constructing a PagingScrollTable from GWT's Incubator is complicated. This class uses the Builder

  * Pattern to simplify it. All public methods, except build() return a reference to the builder

  * so methods can be chained; these methods can be called in any order.

  * Calling build() at the end of the chain returns the constructed PagingScrollTable

  * {@code

  *   pagingScrollTable = new PagingScrollTableBuilder<Person>().tablePixelSize(220, 200).cacheTable(10, 10).

  *     columnDefinitions(createColumnDefinitions()).build(new PersonDTOs().getPersons());

  * }

  * Parameterized type is the Data Transfer Object type which contains a row's data

  *

  * Column Definitions map a table column to a dto's field and set column header

  *

  * PagingOptions are the paging widget. It is created after the builder creates the table and

  * may be positioned anywhere.

  * @see com.google.gwt.gen2.table.client.PagingOptions

  *

  * RowSelectionHandler is added after the builder creates the table.

  * @see com.google.gwt.gen2.table.event.client.RowSelectionHandler

  * @see com.google.gwt.gen2.table.event.client.FixedWidthGrid

  * @see org.kuali.student.common.ui.client.widgets.pagetable.TableSelectionToLabelHandler

  * @author Kuali Student Team (gstruthers@berkeley.edu)

  *

  */

 public class PagingScrollTableBuilder<RowType extends Idable> {

     private PagingScrollTable<RowType> pagingScrollTable;

     private int tablePixelWidth = 0;

     private int tablePixelHeight = 0;

     private boolean isPagable = false;

     private int numPageRows = 0;

     private int numPages = 0;

     private SelectionPolicy selectionPolicy = SelectionPolicy.MULTI_ROW;

     private List<AbstractColumnDefinition<RowType, ?>> columnDefs;

     private List<Integer> columnPixelWidths = new ArrayList<Integer>();

     /**

      * This constructs the builder

      *

      */

     public PagingScrollTableBuilder() {

         super();

     }

     /**

      * This method defines the table's display size in pixels

      * Required

      *

      * @param tablePixelWidth

      * @param tablePixelHeight

      * @return builder

      */

     public PagingScrollTableBuilder<RowType> tablePixelSize(int tablePixelWidth,int tablePixelHeight) {

         this.tablePixelWidth = tablePixelWidth;

         this.tablePixelHeight = tablePixelHeight;

         return this;

     }

     /**

      * This method defines the table's cache

      * Optional, use for paging table only. If not called, table displays all rows.

      *

      * @param numPageRows to display on a page

      * @param numPages in the table

      * @return builder

      */

     public PagingScrollTableBuilder<RowType> cacheTable(int numPageRows,int numPages) {

         this.numPageRows = numPageRows;

         this.numPages = numPages;

         this.isPagable = true;

         return this;

     }

     /**

      * This method adds the table's column definitions

      * Required

      *

      * @see com.google.gwt.gen2.table.client.AbstractColumnDefinition

      * Set a column definitions preferredWidth in pixels, and the builder will use that to

      * set the column width in the table. This works around setPreferredWidth not setting it itself.

      * ColumnDefinitions may be reused in other PagingScrollTables for the same dto. They are

      * passed to the builder as a

      * {@code List<AbstractColumnDefinition<RowType, ?>>}

      * Where rowType is the dto and '?' is the column type. The column definition's index in the list

      * is its column index in the table.

      *

      * @param columnDefs table display column index equals columnDefs index

      * @return builder

      */

     public PagingScrollTableBuilder<RowType> columnDefinitions(List<AbstractColumnDefinition<RowType, ?>> columnDefs) {

         this.columnDefs = columnDefs;

         return this;

     }

     /**

      * This method sets row selection policy. Get this setting from the search definition when it is available.

      * Default is MULTI_ROW

      * Optional

      * @since M5

      * @param selectionPolicy

      * @return builder

      */

     public PagingScrollTableBuilder<RowType> setSelectionPolicy(SelectionPolicy selectionPolicy){

         this.selectionPolicy = selectionPolicy;

         return this;

     }

     /**

      * This method builds the table model. Call at the end of the builder method chain.

      * Required

      *

      *

      * @return the built pagingScrollTable

      */

     @SuppressWarnings("unchecked")//columnDef cast

     public PagingScrollTable<RowType> build(GenericTableModel tableModel) {

         DefaultTableDefinition<RowType> tableDefinition = new DefaultTableDefinition<RowType>();

         if(columnDefs!=null){

                 for (AbstractColumnDefinition columnDef: columnDefs) {

                     columnPixelWidths.add(columnDef.getPreferredColumnWidth());

                     CellRenderer renderer = new CellRenderer(){

                                         @Override

                                         public void renderRowValue(Object rowValue,

                                                         ColumnDefinition columnDef, AbstractCellView view) {

                                                 if(rowValue!=null&& rowValue instanceof ResultRow){

                                                         view.setHTML((String)columnDef.getCellValue(rowValue));

                                                 }

                                         }

                     };

                     columnDef.setCellRenderer(renderer);

                     tableDefinition.addColumnDefinition(columnDef);

                 }

         }

         if(isPagable){

             pagingScrollTable = new PagingScrollTable<RowType>(tableModel.createCachedTableModel(numPageRows,numPages),tableDefinition);

             pagingScrollTable.setPageSize(numPageRows);

         }else {

             pagingScrollTable = new PagingScrollTable<RowType>(tableModel,tableDefinition);

             pagingScrollTable.setPageSize(tableModel.getRowCount());

         }

         pagingScrollTable.setPixelSize(tablePixelWidth,tablePixelHeight);//FIXME workaround for incubator bug   [KSCOR-225] This table to be replaced in M6

         pagingScrollTable.setEmptyTableWidget(new HTML("There is no data to display"));

         pagingScrollTable.getDataTable().setSelectionPolicy(selectionPolicy);

         return this.pagingScrollTable;

     }

 }