PopupDropDownEditCell.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.Arrays;
import java.util.List;

import com.google.gwt.core.client.GWT;
import com.google.gwt.core.client.Scheduler;
import com.google.gwt.core.client.Scheduler.ScheduledCommand;
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.user.client.ui.PopupPanel.PositionCallback;
import org.drools.workbench.models.datamodel.oracle.DropDownData;
import org.gwtbootstrap3.client.ui.ListBox;
import org.kie.workbench.common.widgets.client.datamodel.AsyncPackageDataModelOracle;
import org.kie.workbench.common.widgets.client.widget.EnumDropDownUtilities;
import org.kie.workbench.common.widgets.decoratedgrid.client.widget.CellTableDropDownDataValueMapProvider;

/**
 * A Popup drop-down Editor ;-)
 */
public class PopupDropDownEditCell extends
                                   AbstractPopupEditCell<String, String> {

    private final ListBox listBox = GWT.create( ListBox.class );
    private final boolean isMultipleSelect;

    private final String factType;
    private final String factField;

    private final AsyncPackageDataModelOracle dmo;
    private final CellTableDropDownDataValueMapProvider dropDownManager;

    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 PopupDropDownEditCell( final String factType,
                                  final String factField,
                                  final AsyncPackageDataModelOracle dmo,
                                  final CellTableDropDownDataValueMapProvider dropDownManager,
                                  final boolean isReadOnly ) {
        this( factType,
              factField,
              dmo,
              dropDownManager,
              false,
              isReadOnly );
    }

    public PopupDropDownEditCell( final String factType,
                                  final String factField,
                                  final AsyncPackageDataModelOracle dmo,
                                  final CellTableDropDownDataValueMapProvider dropDownManager,
                                  final boolean isMultipleSelect,
                                  final boolean isReadOnly ) {
        super( isReadOnly );
        this.factType = factType;
        this.factField = factField;
        this.isMultipleSelect = isMultipleSelect;
        this.dropDownManager = dropDownManager;
        this.dmo = dmo;

        this.listBox.setMultipleSelect( isMultipleSelect );

        // 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 ) {
                    commit();
                }
            }

        } );

        vPanel.add( listBox );
    }

    @Override
    public void render( Context context,
                        String value,
                        SafeHtmlBuilder sb ) {

        //We need to get the list of potential values to lookup the "Display" value from the "Stored" value.
        //Since the content of the list may be different for each cell (dependent enumerations) the list
        //has to be populated "on demand". 
        DropDownData dd = dmo.getEnums( this.factType,
                                        this.factField,
                                        this.dropDownManager.getCurrentValueMap( context ) );
        if ( dd == null ) {
            return;
        }

        utilities.setDropDownData( value,
                                   dd,
                                   isMultipleSelect,
                                   dmo.getResourcePath(),
                                   listBox );

        //Render value
        if ( value != null ) {
            String label = getLabel( value );
            sb.append( renderer.render( label ) );
        }
    }

    // Lookup the display text based on the value
    String getLabel( String value ) {
        for ( int i = 0; i < this.listBox.getItemCount(); i++ ) {
            if ( this.listBox.getValue( i ).equals( value ) ) {
                return this.listBox.getItemText( i );
            }
        }
        return value;
    }

    // Commit the change
    @Override
    protected void commit() {

        // 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 );
            }
        }

        setValue( lastContext,
                  lastParent,
                  value );
        if ( valueUpdater != null ) {
            valueUpdater.update( value );
        }
        panel.hide();
    }

    // Start editing the cell
    @Override
    protected void startEditing( final Context context,
                                 final Element parent,
                                 final String value ) {

        //We need to get the list of potential values for the enumeration. Since the content 
        //of the list may be different for each cell (dependent enumerations) the list
        //has to be populated "on demand". 
        DropDownData dd = dmo.getEnums( this.factType,
                                        this.factField,
                                        this.dropDownManager.getCurrentValueMap( context ) );
        if ( dd == null ) {
            return;
        }

        utilities.setDropDownData( value,
                                   dd,
                                   isMultipleSelect,
                                   dmo.getResourcePath(),
                                   listBox );

        // Select the appropriate item
        boolean emptyValue = ( value == null );
        if ( emptyValue ) {
            listBox.setSelectedIndex( 0 );
        } else {
            if ( listBox.isMultipleSelect() ) {
                final List<String> values = Arrays.asList( value.split( "," ) );
                for ( int i = 0; i < listBox.getItemCount(); i++ ) {
                    listBox.setItemSelected( i,
                                             values.contains( listBox.getValue( i ) ) );
                }

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

        panel.setPopupPositionAndShow( new PositionCallback() {
            public void setPosition( int offsetWidth,
                                     int offsetHeight ) {
                panel.setPopupPosition( parent.getAbsoluteLeft()
                                                + offsetX,
                                        parent.getAbsoluteTop()
                                                + offsetY );

                // Focus the first enabled control
                Scheduler.get().scheduleDeferred( new ScheduledCommand() {

                    public void execute() {
                        listBox.setFocus( true );
                    }

                } );
            }
        } );

    }

}