I have looked at the master-detail example. This has some value for me but does not solve my problem. I need to be able to have a gui composite that displays an object. I need to be able to change to different objects and have the gui work properly. Using the default binding from the wizard binds this to a fixed object. There does not seem to be a method that will flush out all the old bindings and allow new ones to be created for a different instance of the object. Keeping all those bindings going is not a good idea. I looked and found the class org.eclipse.core.databinding.observable.value.WritableValue which encapsulates the object so that binding can be done to an object that changes. In particular, the WritableValue object is updated with a new instance of the bound object using the setValue(Object) method. But this means that the binding is different.
Instead of having a standard binding given by the wizard, the following is needed to create the binding to the object encapsulated by WritableValue.
- Code: Select all
IObservableValue personObsNameObserveValue = BeansObservables.observeDetailValue(Realm.getDefault(), wv, "name",
String.class);
This binds the value of the object set in the WritableValue instance wv with the "name" property of that object.
The binding to the text element is the same, and the connection of these two is the same. So the change is in the creation of the IObservableValue. This is different from your example because yours uses ViewersObservables to allow multiple selections to be made.
The full code to duplicate this is shown below. My question is whether the designer will be improved to allow the creation and handling of the WritableValue or will that have to be done by hand? It isn't difficult except that it takes more time to do by hand than through the wizard.
Thanks
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Visual class- Code: Select all
package com.palmer;
import org.eclipse.core.databinding.DataBindingContext;
import org.eclipse.core.databinding.beans.BeansObservables;
import org.eclipse.core.databinding.observable.Realm;
import org.eclipse.core.databinding.observable.value.IObservableValue;
import org.eclipse.core.databinding.observable.value.WritableValue;
import org.eclipse.jface.action.MenuManager;
import org.eclipse.jface.action.StatusLineManager;
import org.eclipse.jface.action.ToolBarManager;
import org.eclipse.jface.databinding.swt.SWTObservables;
import org.eclipse.jface.window.ApplicationWindow;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.MouseAdapter;
import org.eclipse.swt.events.MouseEvent;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.widgets.Group;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.Text;
public class TestBind extends ApplicationWindow {
private Text addressText;
private Text nameText;
private Person[] persons = { new Person("Bill Diddly", "123 SW 18th"),
new Person("Helen Proof", "723 SE Clinton"),
new Person("Sammy Hanker", "4363 NE 33rd") };
private WritableValue wv = new WritableValue();
/**
* Create the application window
*/
public TestBind() {
super(null);
createActions();
addToolBar(SWT.FLAT | SWT.WRAP);
addMenuBar();
addStatusLine();
setPerson(new Person());
}
/**
* Create contents of the application window
*
* @param parent
*/
@Override
protected Control createContents(Composite parent) {
Composite container = new Composite(parent, SWT.NONE);
final GridLayout gridLayout = new GridLayout();
gridLayout.numColumns = 2;
container.setLayout(gridLayout);
final Label nameLabel = new Label(container, SWT.NONE);
nameLabel.setText("Name");
this.nameText = new Text(container, SWT.BORDER);
final GridData gd_nameText = new GridData(SWT.FILL, SWT.CENTER, true,
false);
this.nameText.setLayoutData(gd_nameText);
final Label addressLabel = new Label(container, SWT.NONE);
addressLabel.setText("Address");
this.addressText = new Text(container, SWT.BORDER);
final GridData gd_addressText = new GridData(SWT.FILL, SWT.CENTER,
true, false);
this.addressText.setLayoutData(gd_addressText);
new Label(container, SWT.NONE);
final Button printButton = new Button(container, SWT.NONE);
printButton.addMouseListener(new MouseAdapter() {
public void mouseUp(final MouseEvent e) {
System.out.println(getPerson());
}
});
printButton.setText("Print");
new Label(container, SWT.NONE);
final Button newButton = new Button(container, SWT.NONE);
newButton.addMouseListener(new MouseAdapter() {
public void mouseUp(final MouseEvent e) {
setPerson(new Person());
getPerson().setName("new");
initDataBindings();
}
});
newButton.setText("New");
final Group group = new Group(container, SWT.NONE);
group.setLayoutData(new GridData(SWT.LEFT, SWT.CENTER, false, false, 2,
1));
final GridLayout gridLayout_1 = new GridLayout();
gridLayout_1.numColumns = 3;
group.setLayout(gridLayout_1);
final Button person1Button = new Button(group, SWT.NONE);
person1Button.addSelectionListener(new SelectionAdapter() {
public void widgetSelected(final SelectionEvent e) {
do_person1Button_widgetSelected(e);
}
});
person1Button.setText("Person 1");
final Button person2Button = new Button(group, SWT.NONE);
person2Button.addSelectionListener(new SelectionAdapter() {
public void widgetSelected(final SelectionEvent e) {
do_person2Button_widgetSelected(e);
}
});
person2Button.setText("Person 2");
final Button person3Button = new Button(group, SWT.NONE);
person3Button.addSelectionListener(new SelectionAdapter() {
public void widgetSelected(final SelectionEvent e) {
do_person3Button_widgetSelected(e);
}
});
person3Button.setText("Person 3");
initDataBindings();
return container;
}
/**
* Create the actions
*/
private void createActions() {
// Create the actions
}
/**
* Create the menu manager
*
* @return the menu manager
*/
@Override
protected MenuManager createMenuManager() {
MenuManager menuManager = new MenuManager("menu");
return menuManager;
}
/**
* Create the toolbar manager
*
* @return the toolbar manager
*/
@Override
protected ToolBarManager createToolBarManager(int style) {
ToolBarManager toolBarManager = new ToolBarManager(style);
return toolBarManager;
}
/**
* Create the status line manager
*
* @return the status line manager
*/
@Override
protected StatusLineManager createStatusLineManager() {
StatusLineManager statusLineManager = new StatusLineManager();
statusLineManager.setMessage(null, "");
return statusLineManager;
}
/**
* Launch the application
*
* @param args
*/
public static void main(String args[]) {
Display display = Display.getDefault();
Realm.runWithDefault(SWTObservables.getRealm(display), new Runnable() {
public void run() {
try {
TestBind window = new TestBind();
window.setBlockOnOpen(true);
window.open();
Display.getCurrent().dispose();
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
/**
* Configure the shell
*
* @param newShell
*/
@Override
protected void configureShell(Shell newShell) {
super.configureShell(newShell);
newShell.setText("New Application");
}
/**
* Return the initial size of the window
*/
@Override
protected Point getInitialSize() {
return new Point(500, 375);
}
/**
* @param person
* the person to set
*/
public void setPerson(Person person) {
wv.setValue(person);
}
/**
* @return the person
*/
public Person getPerson() {
return (Person) wv.getValue();
}
protected void do_person1Button_widgetSelected(final SelectionEvent e) {
System.out.println("set person 0");
setPerson(persons[0]);
}
protected void do_person2Button_widgetSelected(final SelectionEvent e) {
System.out.println("set person 1");
setPerson(persons[1]);
}
protected void do_person3Button_widgetSelected(final SelectionEvent e) {
System.out.println("set person 2");
setPerson(persons[2]);
}
protected DataBindingContext initDataBindings() {
IObservableValue personObsNameObserveValue = BeansObservables
.observeDetailValue(Realm.getDefault(), wv, "name",
String.class);
IObservableValue addressTextTextObserveWidget = SWTObservables
.observeText(addressText, SWT.Modify);
IObservableValue nameTextTextObserveWidget = SWTObservables
.observeText(nameText, SWT.Modify);
IObservableValue addressNameObserveValue = BeansObservables
.observeDetailValue(Realm.getDefault(), wv, "address",
String.class);
//
//
DataBindingContext bindingContext = new DataBindingContext();
//
bindingContext.bindValue(nameTextTextObserveWidget,
personObsNameObserveValue, null, null);
bindingContext.bindValue(addressTextTextObserveWidget,
addressNameObserveValue, null, null);
//
return bindingContext;
}
}
Person class- Code: Select all
/**
*
*/
package com.palmer;
import java.beans.PropertyChangeListener;
import java.beans.PropertyChangeSupport;
/**
* @author byron
*
*/
public class Person {
private String name;
private String address;
public Person() {
super();
setName("");
setAddress("");
}
/**
* @param name
* @param address
*/
public Person(String name, String address) {
super();
setName(name);
setAddress(address);
}
public String getName() {
return name;
}
public void setName(String name) {
firePropertyChange("name", this.name, name);
this.name = name;
}
public String getAddress() {
return address;
}
public void setAddress(String address) {
firePropertyChange("address", this.address, address);
this.address = address;
}
@Override
public String toString() {
StringBuffer buf = new StringBuffer();
buf.append("Person [ Name:").append(name);
buf.append(" Address:").append(address).append(" ]");
return buf.toString();
}
//-------------------------------------------------
transient private PropertyChangeSupport propertyChangeSupport =
new PropertyChangeSupport(this);
public void addPropertyChangeListener(String propertyName,
PropertyChangeListener listener) {
System.out.println("addPropertyChangeListener" + propertyName);
propertyChangeSupport.addPropertyChangeListener(propertyName,
listener);
}
public void removePropertyChangeListener(String propertyName,
PropertyChangeListener listener) {
System.out.println("removePropertyChangeListener "+propertyName);
propertyChangeSupport.removePropertyChangeListener(propertyName,
listener);
}
protected void firePropertyChange(String propertyName, Object oldValue,
Object newValue) {
System.out.println("firePropertyChange " + propertyName + " "
+ oldValue + " -> " + newValue);
propertyChangeSupport.firePropertyChange(propertyName, oldValue,
newValue);
}
}
