PropertyPageComboField.java

/*******************************************************************************
 * Copyright 2015 Software Evolution and Architecture Lab, University of Zurich
 * 
 * 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 eu.cloudwave.wp5.feedback.eclipse.base.ui.properties;

import org.eclipse.core.runtime.preferences.IEclipsePreferences;
import org.eclipse.swt.SWT;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.widgets.Combo;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Label;

import eu.cloudwave.wp5.feedback.eclipse.base.ui.factories.ControlFactory;
import eu.cloudwave.wp5.feedback.eclipse.base.ui.factories.ControlFactoryImpl;

/**
 * Implementation of {@link PropertyPageField} for date type properties.
 */
public class PropertyPageComboField extends AbstractPropertyPageField implements PropertyPageField {

  private static final String EMPTY = ""; //$NON-NLS-1$

  /**
   * The width of the property field.
   */
  private static final int FIELD_WIDTH = 200;

  private Combo comboField;
  private String key;
  private String labelText;
  private String[] items;

  private ControlFactory controlFactory;

  public PropertyPageComboField(final String key, final String labelText, final String[] items) {
    this.controlFactory = new ControlFactoryImpl();
    this.key = key;
    this.labelText = labelText;
    this.items = items;
  }

  /**
   * {@inheritDoc}
   */
  @Override
  public void display(final Composite parent) {
    createLabel(parent);
    createToggle(parent);
  }

  private void createLabel(final Composite parent) {
    final GridData labelLayoutData = new GridData();
    labelLayoutData.grabExcessHorizontalSpace = true;
    labelLayoutData.horizontalAlignment = SWT.FILL;
    labelLayoutData.widthHint = LABELS_MIN_WIDTH;
    final Label label = controlFactory.createLabel(parent, labelText);
    label.setLayoutData(labelLayoutData);
  }

  public void createToggle(final Composite parent) {
    GridData grid = new GridData();
    grid.widthHint = FIELD_WIDTH;

    comboField = new Combo(parent, SWT.READ_ONLY);
    comboField.setItems(this.items);
    comboField.setLayoutData(grid);
  }

  /**
   * {@inheritDoc}
   */
  @Override
  public void loadValue(final IEclipsePreferences propertyStore) {
    String interval = propertyStore.get(key, EMPTY);
    for (int i = 0; i < this.items.length; i++) {
      if (this.items[i].equals(interval)) {
        comboField.select(i);
      }
    }
  }

  /**
   * Stores the current aggregation interval
   */
  @Override
  public void storeValue(final IEclipsePreferences propertyStore) {
    int selectedIndex = comboField.getSelectionIndex();
    if (selectedIndex != -1) {
      propertyStore.put(key, comboField.getItem(selectedIndex));
    }
    else {
      propertyStore.remove(key);
    }
  }
}