AbstractProxyPopupDropDownEditCell.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 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.safehtml.shared.SafeHtmlBuilder;
import com.google.gwt.user.client.ui.PopupPanel.PositionCallback;
import org.drools.workbench.models.datamodel.oracle.DropDownData;
import org.kie.workbench.common.widgets.client.datamodel.AsyncPackageDataModelOracle;
import org.kie.workbench.common.widgets.decoratedgrid.client.widget.CellTableDropDownDataValueMapProvider;

/**
 * A Popup drop-down Editor proxy that delegates operation to different implementations depending on whether
 * the cell should represent a list of values or single value. The need arose from incomplete dependent enumeration
 * definitions; e.g. Fact.field1=['A', 'B'] Fact.field2[field1=A]=['A1', 'A2']; where no dependent enumeration has
 * been defined for Fact.field2[field1=B]. In this scenario a TextBox for field2 should be shown when field1=B
 */
public abstract class AbstractProxyPopupDropDownEditCell<C, V> extends
                                                               AbstractPopupEditCell<C, V> {

    private final String factType;
    private final String factField;

    private final AsyncPackageDataModelOracle dmo;
    private final CellTableDropDownDataValueMapProvider dropDownManager;

    private final ProxyPopupDropDown<C> singleValueEditor;
    private final ProxyPopupDropDown<C> multipleValueEditor;
    private ProxyPopupDropDown<C> delegate;

    public AbstractProxyPopupDropDownEditCell( final String factType,
                                               final String factField,
                                               final AsyncPackageDataModelOracle dmo,
                                               final CellTableDropDownDataValueMapProvider dropDownManager,
                                               final boolean isReadOnly ) {
        super( isReadOnly );
        this.factType = factType;
        this.factField = factField;
        this.dropDownManager = dropDownManager;
        this.singleValueEditor = getSingleValueEditor();
        this.multipleValueEditor = getMultipleValueEditor();
        this.dmo = dmo;
    }

    @Override
    public void render( final Context context,
                        final C value,
                        final 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 ) {
            //If no enumeration exists show a TextBox
            delegate = singleValueEditor;
            delegate.setValue( value );
            vPanel.clear();
            vPanel.add( delegate.asWidget() );

        } else {
            //Otherwise show a drop-down list box
            delegate = multipleValueEditor;
            delegate.setDropDownData( dd );
            vPanel.clear();
            vPanel.add( delegate.asWidget() );
        }

        delegate.render( context,
                         value,
                         sb,
                         renderer );
    }

    @Override
    protected void commit() {
        final C value = delegate.getValue();

        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 C 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 ) {
            //If no enumeration exists show a TextBox
            delegate = singleValueEditor;
            delegate.setValue( value );
            vPanel.clear();
            vPanel.add( delegate.asWidget() );

        } else {
            //Otherwise show a drop-down list box
            delegate = multipleValueEditor;
            delegate.setDropDownData( dd );
            vPanel.clear();
            vPanel.add( delegate.asWidget() );
        }
        delegate.startEditing( context,
                               parent,
                               value );

        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() {
                        delegate.setFocus( true );
                    }

                } );
            }
        } );

    }

    AsyncPackageDataModelOracle getDataModelOracle() {
        return this.dmo;
    }

    protected abstract ProxyPopupDropDown<C> getSingleValueEditor();

    protected abstract ProxyPopupDropDown<C> getMultipleValueEditor();

}