org.drools.guvnor.client.decisiontable.cells.PopupDropDownEditCell.java Source code

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Here is the source code for org.drools.guvnor.client.decisiontable.cells.PopupDropDownEditCell.java

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/*
 * Copyright 2011 JBoss Inc
 * 
 * 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.drools.guvnor.client.decisiontable.cells;

import org.drools.guvnor.client.widgets.drools.decoratedgrid.CellTableDropDownDataValueMapProvider;
import org.drools.ide.common.client.modeldriven.DropDownData;
import org.drools.ide.common.client.modeldriven.SuggestionCompletionEngine;
import org.drools.ide.common.client.modeldriven.ui.ConstraintValueEditorHelper;

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.ListBox;
import com.google.gwt.user.client.ui.PopupPanel.PositionCallback;

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

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

    private final String factType;
    private final String factField;

    private final SuggestionCompletionEngine sce;
    private final CellTableDropDownDataValueMapProvider dropDownManager;

    public PopupDropDownEditCell(final String factType, final String factField,
            final SuggestionCompletionEngine sce, final CellTableDropDownDataValueMapProvider dropDownManager,
            final boolean isReadOnly) {
        super(isReadOnly);
        this.factType = factType;
        this.factField = factField;
        this.dropDownManager = dropDownManager;
        this.sce = sce;

        this.listBox = new ListBox();

        // 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 = sce.getEnums(this.factType, this.factField,
                this.dropDownManager.getCurrentValueMap(context));
        if (dd == null) {
            return;
        }
        setItems(dd.fixedList);

        //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 = ConstraintValueEditorHelper.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;
        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 = sce.getEnums(this.factType, this.factField,
                this.dropDownManager.getCurrentValueMap(context));
        if (dd == null) {
            return;
        }
        setItems(dd.fixedList);

        // Select the appropriate item
        boolean emptyValue = (value == null);
        if (emptyValue) {
            listBox.setSelectedIndex(0);
        } 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);
                    }

                });
            }
        });

    }

}