https://stackoverflow.com/questions/22183175
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RussianIn theory, you can monitor items in an observable list for changes by creating the list with an extractor. The idea is, for a TableView, you specify a Callback which provides an array of Observables for each object in the list. The observables will be observed by the list and any ListChangeListeners registered with the list will be notified (via a change with wasUpdated() returning true) when existing items have changes to the specified properties.
However, this only seems to work in Java 8; there's likely a bug filed somewhere for JavaFX 2.2.
Here's an example, based on the usual TableView sample.
import java.util.Arrays;
import java.util.List;
import javafx.application.Application;
import javafx.beans.Observable;
import javafx.beans.property.SimpleStringProperty;
import javafx.beans.property.StringProperty;
import javafx.beans.value.ChangeListener;
import javafx.beans.value.ObservableValue;
import javafx.collections.FXCollections;
import javafx.collections.ListChangeListener;
import javafx.collections.ObservableList;
import javafx.scene.Scene;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableView;
import javafx.scene.control.cell.PropertyValueFactory;
import javafx.scene.control.cell.TextFieldTableCell;
import javafx.scene.layout.BorderPane;
import javafx.stage.Stage;
import javafx.util.Callback;
public class TableUpdatePropertyExample extends Application {
@Override
public void start(Stage primaryStage) {
final TableView<Person> table = new TableView<>();
table.setEditable(true);
final TableColumn<Person, String> firstNameCol = createTableColumn("First Name");
final TableColumn<Person, String> lastNameCol = createTableColumn("Last Name");
final TableColumn<Person, String> emailCol = createTableColumn("Email");
table.getColumns().addAll(Arrays.asList(firstNameCol, lastNameCol, emailCol));
final List<Person> data = Arrays.asList(
new Person("Jacob", "Smith", "jacob.smith@example.com"),
new Person("Isabella", "Johnson", "isabella.johnson@example.com"),
new Person("Ethan", "Williams", "ethan.williams@example.com"),
new Person("Emma", "Jones", "emma.jones@example.com"),
new Person("Michael", "Brown", "michael.brown@example.com")
);
table.setItems(FXCollections.observableList(data, new Callback<Person, Observable[]>() {
@Override
public Observable[] call(Person person) {
return new Observable[] {person.firstNameProperty(), person.lastNameProperty(), person.emailProperty()};
}
}));
table.getItems().addListener(new ListChangeListener<Person>() {
@Override
public void onChanged(
javafx.collections.ListChangeListener.Change<? extends Person> change) {
while (change.next()) {
if (change.wasUpdated()) {
Person updatedPerson = table.getItems().get(change.getFrom());
System.out.println(updatedPerson+" was updated");
}
}
}
});
final BorderPane root = new BorderPane();
root.setCenter(table);
final Scene scene = new Scene(root, 600, 400);
primaryStage.setScene(scene);
primaryStage.show();
}
private TableColumn<Person, String> createTableColumn(String title) {
TableColumn<Person, String> col = new TableColumn<>(title);
col.setCellValueFactory(new PropertyValueFactory<Person, String>(makePropertyName(title)));
col.setCellFactory(TextFieldTableCell.<Person>forTableColumn());
return col ;
}
private String makePropertyName(String text) {
boolean first = true ;
StringBuilder prop = new StringBuilder();
for (String word : text.split("\\s")) {
if (first) {
prop.append(word.toLowerCase());
} else {
prop.append(Character.toUpperCase(word.charAt(0)));
if (word.length() > 1) {
prop.append(word.substring(1));
}
}
first=false ;
}
return prop.toString();
}
public static class Person {
private final StringProperty firstName ;
private final StringProperty lastName ;
private final StringProperty email ;
public Person(String firstName, String lastName, String email) {
this.firstName = new SimpleStringProperty(this, "firstName", firstName);
this.lastName = new SimpleStringProperty(this, "lastName", lastName);
this.email = new SimpleStringProperty(this, "email", email);
}
public String getFirstName() {
return firstName.get();
}
public void setFirstName(String firstName) {
this.firstName.set(firstName);
}
public StringProperty firstNameProperty() {
return firstName ;
}
public String getLastName() {
return lastName.get();
}
public void setLastName(String lastName) {
this.lastName.set(lastName);
}
public StringProperty lastNameProperty() {
return lastName ;
}
public String getEmail() {
return email.get();
}
public void setEmail(String email) {
this.email.set(email);
}
public StringProperty emailProperty() {
return email ;
}
@Override
public String toString() {
return getFirstName() + " " + getLastName();
}
}
public static void main(String[] args) {
launch(args);
}
}
For validation, you might consider overriding the set and setValue methods in the model class's property. I haven't tried this, and I suspect you may need to mess with the TableCell in order to make it work properly, but something along the lines of:
this.email = new StringPropertyBase(email) {
final Pattern pattern = Pattern.compile("[a-zA-Z_0-9]+@[a-zA-Z0-9.]+");
@Override
public String getName() {
return "email";
}
@Override
public Object getBean() {
return Person.this;
}
@Override
public void set(String email) {
if (pattern.matcher(email).matches()) {
super.set(email);
}
}
@Override
public void setValue(String email) {
if (pattern.matcher(email).matches()) {
super.setValue(email);
}
}
};
in place of the one liner in the Person class above.
UPDATE: To make this work in JavaFX 2.2, you can basically roll your own version of the "extractor". It's a bit of work but not too bad. Something like the following seems to work, for example:
final List<Person> data = Arrays.asList(
new Person("Jacob", "Smith", "jacob.smith@example.com"),
new Person("Isabella", "Johnson", "isabella.johnson@example.com"),
new Person("Ethan", "Williams", "ethan.williams@example.com"),
new Person("Emma", "Jones", "emma.jones@example.com"),
new Person("Michael", "Brown", "michael.brown@example.com")
);
final ChangeListener<String> firstNameListener = new ChangeListener<String>() {
@Override
public void changed(ObservableValue<? extends String> obs,
String oldFirstName, String newFirstName) {
Person person = (Person)((StringProperty)obs).getBean();
System.out.println("First name for "+person+" changed from "+oldFirstName+" to "+newFirstName);
}
};
final ChangeListener<String> lastNameListener = new ChangeListener<String>() {
@Override
public void changed(ObservableValue<? extends String> obs,
String oldLastName, String newLastName) {
Person person = (Person)((StringProperty)obs).getBean();
System.out.println("Last name for "+person+" changed from "+oldLastName+" to "+oldLastName);
}
};
final ChangeListener<String> emailListener = new ChangeListener<String>() {
@Override
public void changed(ObservableValue<? extends String> obs,
String oldEmail, String newEmail) {
Person person = (Person)((StringProperty)obs).getBean();
System.out.println("Email for "+person+" changed from "+oldEmail+" to "+oldEmail);
}
};
table.getItems().addListener(new ListChangeListener<Person>() {
@Override
public void onChanged(
javafx.collections.ListChangeListener.Change<? extends Person> change) {
while (change.next()) {
for (Person person : change.getAddedSubList()) {
person.firstNameProperty().addListener(
firstNameListener);
person.lastNameProperty().addListener(lastNameListener);
person.emailProperty().addListener(emailListener);
}
for (Person person : change.getRemoved()) {
person.firstNameProperty().removeListener(
firstNameListener);
person.lastNameProperty().removeListener(
lastNameListener);
person.emailProperty().removeListener(emailListener);
}
}
}
});
table.getItems().addAll(data);
