JavaFX TableView Sort Policy - javafx

Question

I have a tableview which has an observable list of custom class objects attached to it (Class type: SalesInvoiceNetSale). The data all displays fine within the table. The last item in the observable list is a totals row (Class type: SalesInvoiceNetSaleTotal which extends the SalesInvoiceNetSale class). I simply wish to make my table not sort the last record within the array if the user tries to sort the table by column. I have found another post pretty much asking how to do the same thing but can't seem to figure this out, I suspect it's my non understanding of Java 8's Lambda Expressions. TableView exclude bottom row (total) from sorting
public ObservableList<SalesInvoiceNetSale> applyTableTotalsToSalesInvoiceNetSaleList(ObservableList<SalesInvoiceNetSale> data, TableView table) {
// Adds A Total Row To The Table View & Disables The Sort Policy
double netValueTotal = 0;
double netDelivery = 0.0;
double netOversize = 0.0;
double netDeposit = 0.0;
for (SalesInvoiceNetSale i : data) {
netValueTotal += i.getNetValue();
netDelivery += i.getNetShipping();
netOversize += i.getNetOversize();
netDeposit += i.getNetDeposit();
}
SalesInvoiceNetSaleTotal rowTotal = new SalesInvoiceNetSaleTotal();
rowTotal.setNetValue(netValueTotal);
rowTotal.setNetShipping(netDelivery);
rowTotal.setNetDeposit(netDeposit);
rowTotal.setNetOversize(netOversize);
rowTotal.setLabel("Totals");
data.add(rowTotal);
table.sortPolicyProperty().set(t -> {
Comparator<Row> comparator = (r1, r2)
-> r1 == TOTAL ? 1 //TOTAL at the bottom
: r2 == TOTAL ? -1 //TOTAL at the bottom
: t.getComparator() == null ? 0 //no column sorted: don't change order
: t.getComparator().compare(r1, r2); //columns are sorted: sort accordingly
FXCollections.sort(table.getItems(), comparator);
return true;
});
return data;
}
Am very new to JavaFX and can't seem to find by way of example of a sort policy...

Answer 1

You can try something like this, for your case :
table.sortPolicyProperty().set(t -> {
Comparator<SalesInvoiceNetSale> comparator = (r1, r2)
-> r1 == rowTotal ? 1 //rowTotal at the bottom
: r2 == rowTotal ? -1 //rowTotal at the bottom
: t.getComparator() == null ? 0 //no column sorted: don't change order
: t.getComparator().compare(r1, r2); //columns are sorted: sort accordingly
FXCollections.sort(table.getItems(), comparator);
return true;
});
Incase you don't understand what is happening here, a snapshot without lambda expression :
table.sortPolicyProperty().set( new Callback<TableView<SalesInvoiceNetSale>, Boolean>() {
#Override
public Boolean call(TableView<SalesInvoiceNetSale> param) {
Comparator<SalesInvoiceNetSale> comparator = new Comparator<SalesInvoiceNetSale>() {
#Override
public int compare(SalesInvoiceNetSale r1, SalesInvoiceNetSale r2) {
if (r1 == rowTotal) {
return 1;
} else if (r2 == rowTotal) {
return -1;
} else if (param.getComparator() == null) {
return 0;
} else {
return param.getComparator().compare(r1, r2);
}
}
};
FXCollections.sort(table.getItems(), comparator);
return true;
}
});
Working Example
If you still have doubts, please find a working example, with a scenario similar to yours, I have created a class ExtraPerson which extends Person and made the new object of ExtraPerson as the footer
import java.util.Comparator;
import javafx.application.Application;
import javafx.beans.property.SimpleStringProperty;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.geometry.Insets;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.control.Label;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableView;
import javafx.scene.control.cell.PropertyValueFactory;
import javafx.scene.layout.VBox;
import javafx.scene.text.Font;
import javafx.stage.Stage;
import javafx.util.Callback;
public class TableViewSampleWithoutEdit extends Application {
private TableView<Person> table = new TableView<Person>();
private ExtraPerson extraPerson = new ExtraPerson("Ninja Village");
private final ObservableList<Person> data = FXCollections
.observableArrayList(
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"),
extraPerson);
public static void main(String[] args) {
launch(args);
}
#Override
public void start(Stage stage) {
Scene scene = new Scene(new Group());
stage.setTitle("Table View Sample");
stage.setWidth(450);
stage.setHeight(500);
final Label label = new Label("Address Book");
label.setFont(new Font("Arial", 20));
table.setEditable(true);
TableColumn firstNameCol = new TableColumn("First Name");
firstNameCol.setMinWidth(100);
firstNameCol
.setCellValueFactory(new PropertyValueFactory<Person, String>(
"firstName"));
TableColumn lastNameCol = new TableColumn("Last Name");
lastNameCol.setMinWidth(100);
lastNameCol
.setCellValueFactory(new PropertyValueFactory<Person, String>(
"lastName"));
TableColumn emailCol = new TableColumn("Email");
emailCol.setMinWidth(200);
emailCol.setCellValueFactory(new PropertyValueFactory<Person, String>(
"email"));
/**
* Adding comparator to extraPerson
*/
table.sortPolicyProperty().set(
new Callback<TableView<Person>, Boolean>() {
#Override
public Boolean call(TableView<Person> param) {
Comparator<Person> comparator = new Comparator<Person>() {
#Override
public int compare(Person r1, Person r2) {
if (r1 == extraPerson) {
return 1;
} else if (r2 == extraPerson) {
return -1;
} else if (param.getComparator() == null) {
return 0;
} else {
return param.getComparator()
.compare(r1, r2);
}
}
};
FXCollections.sort(table.getItems(), comparator);
return true;
}
});
table.setItems(data);
table.getColumns().addAll(firstNameCol, lastNameCol, emailCol);
final VBox vbox = new VBox();
vbox.setSpacing(5);
vbox.setPadding(new Insets(10, 0, 0, 10));
vbox.getChildren().addAll(label, table);
((Group) scene.getRoot()).getChildren().addAll(vbox);
stage.setScene(scene);
stage.show();
}
public static class Person {
private final SimpleStringProperty firstName;
private final SimpleStringProperty lastName;
private final SimpleStringProperty email;
private Person(String fName, String lName, String email) {
this.firstName = new SimpleStringProperty(fName);
this.lastName = new SimpleStringProperty(lName);
this.email = new SimpleStringProperty(email);
}
public String getFirstName() {
return firstName.get();
}
public void setFirstName(String fName) {
firstName.set(fName);
}
public String getLastName() {
return lastName.get();
}
public void setLastName(String fName) {
lastName.set(fName);
}
public String getEmail() {
return email.get();
}
public void setEmail(String fName) {
email.set(fName);
}
}
public static class ExtraPerson extends Person {
private final SimpleStringProperty address;
private ExtraPerson(String address) {
super("Itachi", "Uchiha", "leaf#village.ninja");
this.address = new SimpleStringProperty(address);
}
public String getAddress() {
return address.get();
}
public void setAddress(String address) {
this.address.set(address);
}
}
}

Answer 2

Here is the code to do the same thing with a TreeTableView in Java8 and lambda expressions.
treeTable.sortPolicyProperty().set(treeTableView -> {
Comparator<? super TreeItem<YOURMODEL>> comparator = (model1, model2) -> {
if(model1.isTotalRow()) {
return 1;
} else if(model2.isTotalRow()) {
return -1;
} else if (treeTableView.getComparator() == null) {
return 0;
} else {
return treeTableView.getComparator().compare(model1, model2);
}
};
treeTable.getRoot().getChildren().sort(comparator);
return true;
});