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/*******************************************************************************
* 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
* Matthew Hall - bug 260329
******************************************************************************/
package org.eclipse.jface.examples.databinding.snippets;
import java.beans.PropertyChangeListener;
import java.beans.PropertyChangeSupport;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import org.eclipse.core.databinding.DataBindingContext;
import org.eclipse.core.databinding.beans.BeansObservables;
import org.eclipse.core.databinding.observable.IObservable;
import org.eclipse.core.databinding.observable.Realm;
import org.eclipse.core.databinding.observable.list.IObservableList;
import org.eclipse.core.databinding.observable.list.WritableList;
import org.eclipse.core.databinding.observable.masterdetail.IObservableFactory;
import org.eclipse.core.databinding.observable.masterdetail.MasterDetailObservables;
import org.eclipse.jface.databinding.swt.SWTObservables;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.layout.RowLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Combo;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Shell;
/**
* Shows how to bind a Combo so that when update its items, the selection is
* retained if at all possible.
*
* @since 3.2
*/
public class Snippet002UpdateComboRetainSelection {
public static void main(String[] args) {
final Display display = new Display();
Realm.runWithDefault(SWTObservables.getRealm(display), new Runnable() {
public void run() {
ViewModel viewModel = new ViewModel();
Shell shell = new View(viewModel).createShell();
// The SWT event loop
while (!shell.isDisposed()) {
if (!display.readAndDispatch()) {
display.sleep();
}
}
// Print the results
System.out.println(viewModel.getText());
}
});
display.dispose();
}
// 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 View's model--the root of our Model graph for this particular GUI.
public static class ViewModel extends AbstractModelObject {
private String text = "beef";
private List choices = new ArrayList();
{
choices.add("pork");
choices.add("beef");
choices.add("poultry");
choices.add("vegatables");
}
public List getChoices() {
return choices;
}
public void setChoices(List choices) {
List old = this.choices;
this.choices = choices;
firePropertyChange("choices", old, choices);
}
public String getText() {
return text;
}
public void setText(String text) {
String oldValue = this.text;
this.text = text;
firePropertyChange("text", oldValue, text);
}
}
// The GUI view
static class View {
private ViewModel viewModel;
/**
* used to make a new choices array unique
*/
static int count;
public View(ViewModel viewModel) {
this.viewModel = viewModel;
}
public Shell createShell() {
// Build a UI
Shell shell = new Shell(Display.getCurrent());
shell.setLayout(new RowLayout(SWT.VERTICAL));
Combo combo = new Combo(shell, SWT.BORDER | SWT.READ_ONLY);
Button reset = new Button(shell, SWT.NULL);
reset.setText("reset collection");
reset.addSelectionListener(new SelectionAdapter() {
public void widgetSelected(SelectionEvent e) {
List newList = new ArrayList();
newList.add("Chocolate");
newList.add("Vanilla");
newList.add("Mango Parfait");
newList.add("beef");
newList.add("Cheesecake");
newList.add(Integer.toString(++count));
viewModel.setChoices(newList);
}
});
// Print value out first
System.out.println(viewModel.getText());
DataBindingContext dbc = new DataBindingContext();
IObservableList list = MasterDetailObservables.detailList(BeansObservables.observeValue(viewModel, "choices"),
getListDetailFactory(),
String.class);
dbc.bindList(SWTObservables.observeItems(combo), list);
dbc.bindValue(SWTObservables.observeText(combo), BeansObservables.observeValue(viewModel, "text"));
// Open and return the Shell
shell.pack();
shell.open();
return shell;
}
}
private static IObservableFactory getListDetailFactory() {
return new IObservableFactory() {
public IObservable createObservable(Object target) {
WritableList list = WritableList.withElementType(String.class);
list.addAll((Collection) target);
return list;
}
};
}
}
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