PopupValueListDropDownEditCell.java

/*
 * Copyright 2015 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.gwtbootstrap3.client.ui.ListBox;
import org.kie.workbench.common.widgets.client.util.ConstraintValueHelper;

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

    // Using GWT.create so we can test this class with GwtMockito
    protected final ListBox listBox = GWT.create(ListBox.class);
    protected String[][] items;
    protected V value;

    public PopupValueListDropDownEditCell( final String[] items,
                                           final boolean isReadOnly ) {
        this( items,
              false,
              isReadOnly );
    }

    public PopupValueListDropDownEditCell( final String[] items,
                                           final boolean isMultipleSelect,
                                           final boolean isReadOnly ) {
        super( isReadOnly );

        this.listBox.setMultipleSelect( isMultipleSelect );
        setItems( items );

        // 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 ) {

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

    // Set content of drop-down
    private void setItems( String[] items ) {
        this.listBox.clear();
        this.items = new String[items.length][2];
        for (int i = 0; i < items.length; i++) {
            String item = items[i].trim();
            if ( item.indexOf( '=' ) > 0 ) {
                String[] splut = ConstraintValueHelper.splitValue( item );
                this.items[i][0] = splut[0];
                this.items[i][1] = splut[1];
                this.listBox.addItem( splut[1],
                                      splut[0] );
            } else {
                this.items[i][0] = item;
                this.items[i][1] = item;
                this.listBox.addItem( item,
                                      item );
            }
        }
    }

    // Lookup the display text based on the value
    private String getLabel( 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
    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 ) {

        // 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 );
                    }

                } );
            }
        } );

    }

}