AbstractProxyPopupDropDownListBox.java

/*
 * Copyright 2014 Red Hat, Inc. and/or its affiliates.
 *
 * Licensed under the Apache 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.apache.org/licenses/LICENSE-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.kie.workbench.common.widgets.decoratedgrid.client.widget.cells;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

import com.google.gwt.cell.client.Cell;
import com.google.gwt.dom.client.Element;
import com.google.gwt.event.dom.client.KeyCodes;
import com.google.gwt.event.dom.client.KeyDownEvent;
import com.google.gwt.event.dom.client.KeyDownHandler;
import com.google.gwt.safehtml.shared.SafeHtmlBuilder;
import com.google.gwt.text.shared.SafeHtmlRenderer;
import com.google.gwt.user.client.ui.Widget;
import org.drools.workbench.models.datamodel.oracle.DropDownData;
import org.gwtbootstrap3.client.ui.ListBox;
import org.kie.workbench.common.widgets.client.widget.EnumDropDownUtilities;

/**
 * A Popup drop-down Editor for use within AbstractProxyPopupDropDownEditCell
 */
public abstract class AbstractProxyPopupDropDownListBox<C> implements ProxyPopupDropDown<C> {

    private String[][] items;
    private final ListBox listBox;
    private final AbstractProxyPopupDropDownEditCell proxy;

    final EnumDropDownUtilities utilities = new EnumDropDownUtilities() {
        @Override
        protected int addItems( final ListBox listBox ) {
            return 0;
        }

        @Override
        protected void selectItem( final ListBox listBox ) {
            //Nothing needed by default
        }
    };

    public AbstractProxyPopupDropDownListBox( final AbstractProxyPopupDropDownEditCell proxy ) {

        this.listBox = new ListBox();
        this.proxy = proxy;

        // Tabbing out of the ListBox commits changes
        listBox.addKeyDownHandler( new KeyDownHandler() {

            public void onKeyDown( KeyDownEvent event ) {
                boolean keyTab = event.getNativeKeyCode() == KeyCodes.KEY_TAB;
                boolean keyEnter = event.getNativeKeyCode() == KeyCodes.KEY_ENTER;
                if ( keyEnter || keyTab ) {
                    proxy.commit();
                }
            }

        } );
    }

    @Override
    public void render( final Cell.Context context,
                        final C value,
                        final SafeHtmlBuilder sb,
                        final SafeHtmlRenderer<String> renderer ) {
        //Render value
        if ( value != null ) {
            String label = getLabel( convertToString( value ) );
            sb.append( renderer.render( label ) );
        }
    }

    @Override
    public void setValue( final C value ) {
        final List<String> convertedValues = new ArrayList<String>();
        convertedValues.add( convertToString( value ) );
        setDropDownData( DropDownData.create( (String[]) convertedValues.toArray() ) );
    }

    @Override
    public void setDropDownData( final DropDownData dd ) {
        utilities.setDropDownData( "",
                                   dd,
                                   false,
                                   proxy.getDataModelOracle().getResourcePath(),
                                   listBox );

        //Scrape values from ListBox as they may have been populated from a server-side call
        final int itemCount = listBox.getItemCount();
        this.items = new String[ itemCount ][ 2 ];
        for ( int i = 0; i < itemCount; i++ ) {
            String value = listBox.getValue( i ).trim();
            String text = listBox.getItemText( i ).trim();
            this.items[ i ][ 0 ] = value;
            this.items[ i ][ 1 ] = text;
        }
    }

    // Lookup the display text based on the value
    private String getLabel( final String value ) {
        for ( int i = 0; i < this.items.length; i++ ) {
            if ( this.items[ i ][ 0 ].equals( value ) ) {
                return items[ i ][ 1 ];
            }
        }
        return value;
    }

    // Commit the change
    @Override
    public C getValue() {

        // Update value
        String value = null;
        if ( listBox.isMultipleSelect() ) {
            for ( int i = 0; i < listBox.getItemCount(); i++ ) {
                if ( listBox.isItemSelected( i ) ) {
                    if ( value == null ) {
                        value = listBox.getValue( i );
                    } else {
                        value = value + "," + listBox.getValue( i );
                    }
                }
            }

        } else {
            int selectedIndex = listBox.getSelectedIndex();
            if ( selectedIndex >= 0 ) {
                value = listBox.getValue( selectedIndex );
            }
        }

        return convertFromString( value );
    }

    // Start editing the cell
    @Override
    public void startEditing( final Cell.Context context,
                              final Element parent,
                              final C value ) {
        // Select the appropriate item
        boolean emptyValue = ( value == null );
        if ( emptyValue ) {
            listBox.setSelectedIndex( 0 );
        } else {
            final String convertedValue = convertToString( value );
            if ( listBox.isMultipleSelect() ) {
                final List<String> convertedValues = Arrays.asList( convertedValue.split( "," ) );
                for ( int i = 0; i < listBox.getItemCount(); i++ ) {
                    listBox.setItemSelected( i,
                                             convertedValues.contains( listBox.getValue( i ) ) );
                }

            } else {
                for ( int i = 0; i < listBox.getItemCount(); i++ ) {
                    if ( listBox.getValue( i ).equals( convertedValue ) ) {
                        listBox.setSelectedIndex( i );
                        break;
                    }
                }
            }
        }
    }

    @Override
    public void setFocus( final boolean focused ) {
        listBox.setFocus( focused );
    }

    @Override
    public Widget asWidget() {
        return listBox;
    }

}