examples/org.eclipse.jface.examples.databinding/src/org/eclipse/jface/examples/databinding/snippets/Snippet001NestedSelectionWithCombo.java

/*******************************************************************************
 * Copyright (c) 2006 The Pampered Chef, Inc. and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     The Pampered Chef, Inc. - initial API and implementation
 *     Brad Reynolds - bug 116920
 ******************************************************************************/

package org.eclipse.jface.examples.databinding.snippets;

import java.beans.PropertyChangeListener;
import java.beans.PropertyChangeSupport;
import java.util.ArrayList;
import java.util.HashSet;

import org.eclipse.core.databinding.DataBindingContext;
import org.eclipse.core.databinding.beans.BeansObservables;
import org.eclipse.core.databinding.observable.Observables;
import org.eclipse.core.databinding.observable.Realm;
import org.eclipse.core.databinding.observable.map.IObservableMap;
import org.eclipse.core.databinding.observable.value.IObservableValue;
import org.eclipse.jface.databinding.swt.SWTObservables;
import org.eclipse.jface.databinding.viewers.ObservableMapLabelProvider;
import org.eclipse.jface.databinding.viewers.ViewersObservables;
import org.eclipse.jface.layout.GridLayoutFactory;
import org.eclipse.jface.viewers.ArrayContentProvider;
import org.eclipse.jface.viewers.ComboViewer;
import org.eclipse.jface.viewers.ListViewer;
import org.eclipse.swt.SWT;
import org.eclipse.swt.widgets.Combo;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.List;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.Text;

/**
 * Demonstrates nested selection.<br>
 * At the first level, user may select a person.<br>
 * At the second level, user may select a city to associate with the selected<br>
 * person or edit the person's name.
 */
public class Snippet001NestedSelectionWithCombo {
	public static void main(String[] args) {
		ViewModel viewModel = new ViewModel();
		Shell shell = new View(viewModel).createShell();

		// The SWT event loop
		Display display = Display.getCurrent();
		while (!shell.isDisposed()) {
			if (!display.readAndDispatch()) {
				display.sleep();
			}
		}
	}

	// Minimal JavaBeans support
	public static abstract class AbstractModelObject {
		private PropertyChangeSupport propertyChangeSupport = new PropertyChangeSupport(
				this);

		public void addPropertyChangeListener(PropertyChangeListener listener) {
			propertyChangeSupport.addPropertyChangeListener(listener);
		}

		public void addPropertyChangeListener(String propertyName,
				PropertyChangeListener listener) {
			propertyChangeSupport.addPropertyChangeListener(propertyName,
					listener);
		}

		public void removePropertyChangeListener(PropertyChangeListener listener) {
			propertyChangeSupport.removePropertyChangeListener(listener);
		}

		public void removePropertyChangeListener(String propertyName,
				PropertyChangeListener listener) {
			propertyChangeSupport.removePropertyChangeListener(propertyName,
					listener);
		}

		protected void firePropertyChange(String propertyName, Object oldValue,
				Object newValue) {
			propertyChangeSupport.firePropertyChange(propertyName, oldValue,
					newValue);
		}
	}

	// The data model class. This is normally a persistent class of some sort.
	// 
	// This example implements full JavaBeans bound properties so that changes
	// to instances of this class will automatically be propogated to the UI.
	public static class Person extends AbstractModelObject {
		// Constructor
		public Person(String name, String city) {
			this.name = name;
			this.city = city;
		}

		// Some JavaBean bound properties...
		String name;

		String city;

		public String getName() {
			return name;
		}

		public void setName(String name) {
			String oldValue = this.name;
			this.name = name;
			firePropertyChange("name", oldValue, name);
		}

		public String getCity() {
			return city;
		}

		public void setCity(String city) {
			String oldValue = this.city;
			this.city = city;
			firePropertyChange("city", oldValue, city);
		}
	}

	// The View's model--the root of our GUI's Model graph
	//
	// Typically each View class has a corresponding ViewModel class.
	// The ViewModel is responsible for getting the objects to edit from the
	// DAO. Since this snippet doesn't have any persistent objects to
	// retrieve, this ViewModel just instantiates some objects to edit.
	// 
	// This ViewModel also implements JavaBean bound properties.
	static class ViewModel extends AbstractModelObject {
		// The model to bind
		private ArrayList people = new ArrayList();
		{
			people.add(new Person("Wile E. Coyote", "Tucson"));
			people.add(new Person("Road Runner", "Lost Horse"));
			people.add(new Person("Bugs Bunny", "Forrest"));
		}

		// Choice of cities for the Combo
		private ArrayList cities = new ArrayList();
		{
			cities.add("Tucson");
			cities.add("AcmeTown");
			cities.add("Lost Horse");
			cities.add("Forrest");
			cities.add("Lost Mine");
		}

		public ArrayList getPeople() {
			return people;
		}

		public ArrayList getCities() {
			return cities;
		}
	}

	// The GUI view
	static class View {
		private ViewModel viewModel;

		public View(ViewModel viewModel) {
			this.viewModel = viewModel;
		}

		public Shell createShell() {
			// Build a UI
			Shell shell = new Shell(Display.getCurrent());
			Realm realm = SWTObservables.getRealm(shell.getDisplay());

			List peopleList = new List(shell, SWT.BORDER);
			Text name = new Text(shell, SWT.BORDER);
			Combo city = new Combo(shell, SWT.BORDER | SWT.READ_ONLY);

			ListViewer peopleListViewer = new ListViewer(peopleList);
			IObservableMap attributeMap = BeansObservables.observeMap(
					Observables.staticObservableSet(realm, new HashSet(
							viewModel.getPeople())), Person.class, "name");
			peopleListViewer.setLabelProvider(new ObservableMapLabelProvider(
					attributeMap));
			peopleListViewer.setContentProvider(new ArrayContentProvider());
			peopleListViewer.setInput(viewModel.getPeople());

			DataBindingContext dbc = new DataBindingContext(realm);
			IObservableValue selectedPerson = ViewersObservables
					.observeSingleSelection(peopleListViewer);
			dbc.bindValue(SWTObservables.observeText(name, SWT.Modify),
					BeansObservables.observeDetailValue(realm, selectedPerson,
							"name", String.class), null, null);

			ComboViewer cityViewer = new ComboViewer(city);
			cityViewer.setContentProvider(new ArrayContentProvider());
			cityViewer.setInput(viewModel.getCities());

			IObservableValue citySelection = ViewersObservables
					.observeSingleSelection(cityViewer);
			dbc.bindValue(citySelection, BeansObservables.observeDetailValue(
					realm, selectedPerson, "city", String.class), null, null);

			GridLayoutFactory.swtDefaults().applyTo(shell);
			// Open and return the Shell
			shell.pack();
			shell.open();
			return shell;
		}
	}

}