Saturday, March 16, 2013

JavaFX: Delete row from a table

Previous articles demonstrate how to "embed Button in TableView" and "Get row data from TableView".

To delete a row in the table, or delete a record in ObservableList (data), call the method:

data.remove(selectdIndex);

Delete row from a table
Delete row from a table


In the original approach, the record ID is assigned as the size of ObservableList data. In order to keep track of the id number, variable data_nextId is introduced.

package javafxdyntable;

import java.util.Random;
import javafx.application.Application;
import javafx.beans.property.SimpleBooleanProperty;
import javafx.beans.property.SimpleIntegerProperty;
import javafx.beans.property.SimpleStringProperty;
import javafx.beans.value.ObservableValue;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.chart.XYChart;
import javafx.scene.control.Button;
import javafx.scene.control.ContentDisplay;
import javafx.scene.control.TableCell;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableView;
import javafx.scene.control.TextField;
import javafx.scene.control.cell.PropertyValueFactory;
import javafx.scene.input.KeyCode;
import javafx.scene.input.KeyEvent;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;
import javafx.util.Callback;

/**
* @web http://java-buddy.blogspot.com/
*/
public class JavaFXDynTable extends Application {

private TableView tableView = new TableView();
private Button btnNew = new Button("New Record");

static Random random = new Random();

static final String Day[] = {
"Monday",
"Tuesday",
"Wednesday",
"Thursday",
"Friday"};

public static class Record {
private final SimpleIntegerProperty id;
private final SimpleIntegerProperty value_0;
private final SimpleIntegerProperty value_1;
private final SimpleIntegerProperty value_2;
private final SimpleIntegerProperty value_3;
private final SimpleIntegerProperty value_4;

Record(int i, int v0, int v1, int v2, int v3,
int v4) {
this.id = new SimpleIntegerProperty(i);
this.value_0 = new SimpleIntegerProperty(v0);
this.value_1 = new SimpleIntegerProperty(v1);
this.value_2 = new SimpleIntegerProperty(v2);
this.value_3 = new SimpleIntegerProperty(v3);
this.value_4 = new SimpleIntegerProperty(v4);
}

public int getId() {
return id.get();
}

public void setId(int v) {
id.set(v);
}

public int getValue_0() {
return value_0.get();
}

public void setValue_0(int v) {
value_0.set(v);
}

public int getValue_1() {
return value_1.get();
}

public void setValue_1(int v) {
value_1.set(v);
}

public int getValue_2() {
return value_2.get();
}

public void setValue_2(int v) {
value_2.set(v);
}

public int getValue_3() {
return value_3.get();
}

public void setValue_3(int v) {
value_3.set(v);
}

public int getValue_4() {
return value_4.get();
}

public void setValue_4(int v) {
value_4.set(v);
}

};

ObservableList<Record> data = FXCollections.observableArrayList();
int data_nextId = 0;

@Override
public void start(final Stage primaryStage) {
primaryStage.setTitle("java-buddy.blogspot.com");
tableView.setEditable(true);
Callback<TableColumn, TableCell> cellFactory =
new Callback<TableColumn, TableCell>() {

@Override
public TableCell call(TableColumn p) {
return new EditingCell();
}
};

btnNew.setOnAction(btnNewHandler);

//init table
//Un-editable column of "id"
TableColumn col_id = new TableColumn("ID");
tableView.getColumns().add(col_id);
col_id.setCellValueFactory(
new PropertyValueFactory<Record, String>("id"));

//Editable columns
for(int i=0; i<Day.length; i++){
TableColumn col = new TableColumn(Day[i]);
col.setCellValueFactory(
new PropertyValueFactory<Record, String>(
"value_" + String.valueOf(i)));
tableView.getColumns().add(col);
col.setCellFactory(cellFactory);
}

//Insert Button
TableColumn col_action = new TableColumn<>("Action");
col_action.setSortable(false);

col_action.setCellValueFactory(
new Callback<TableColumn.CellDataFeatures<Record, Boolean>,
ObservableValue<Boolean>>() {

@Override
public ObservableValue<Boolean> call(TableColumn.CellDataFeatures<Record, Boolean> p) {
return new SimpleBooleanProperty(p.getValue() != null);
}
});

col_action.setCellFactory(
new Callback<TableColumn<Record, Boolean>, TableCell<Record, Boolean>>() {

@Override
public TableCell<Record, Boolean> call(TableColumn<Record, Boolean> p) {
return new ButtonCell(tableView);
}

});
tableView.getColumns().add(col_action);

tableView.setItems(data);

Group root = new Group();
VBox vBox = new VBox();
vBox.setSpacing(10);
vBox.getChildren().addAll(btnNew, tableView);
root.getChildren().add(vBox);
primaryStage.setScene(new Scene(root, 600, 400));
primaryStage.show();
}

public static void main(String[] args) {
launch(args);
}

//Define the button cell
private class ButtonCell extends TableCell<Record, Boolean> {
final Button cellButton = new Button("Delete");

ButtonCell(final TableView tblView){

cellButton.setOnAction(new EventHandler<ActionEvent>(){

@Override
public void handle(ActionEvent t) {
int selectdIndex = getTableRow().getIndex();

//delete the selected item in data
data.remove(selectdIndex);
}
});
}

//Display button if the row is not empty
@Override
protected void updateItem(Boolean t, boolean empty) {
super.updateItem(t, empty);
if(!empty){
setGraphic(cellButton);
}
}
}

EventHandler<ActionEvent> btnNewHandler =
new EventHandler<ActionEvent>(){

@Override
public void handle(ActionEvent t) {

//generate new Record with random number
Record newRec = new Record(
data_nextId,
random.nextInt(100),
random.nextInt(100),
random.nextInt(100),
random.nextInt(100),
random.nextInt(100));
data.add(newRec);
data_nextId++;

}
};

class EditingCell extends TableCell<XYChart.Data, Number> {

private TextField textField;

public EditingCell() {}

@Override
public void startEdit() {

super.startEdit();

if (textField == null) {
createTextField();
}

setGraphic(textField);
setContentDisplay(ContentDisplay.GRAPHIC_ONLY);
textField.selectAll();
}

@Override
public void cancelEdit() {
super.cancelEdit();

setText(String.valueOf(getItem()));
setContentDisplay(ContentDisplay.TEXT_ONLY);
}

@Override
public void updateItem(Number item, boolean empty) {
super.updateItem(item, empty);

if (empty) {
setText(null);
setGraphic(null);
} else {
if (isEditing()) {
if (textField != null) {
textField.setText(getString());
}
setGraphic(textField);
setContentDisplay(ContentDisplay.GRAPHIC_ONLY);
} else {
setText(getString());
setContentDisplay(ContentDisplay.TEXT_ONLY);
}
}
}

private void createTextField() {
textField = new TextField(getString());
textField.setMinWidth(this.getWidth() - this.getGraphicTextGap()*2);
textField.setOnKeyPressed(new EventHandler<KeyEvent>() {

@Override
public void handle(KeyEvent t) {
if (t.getCode() == KeyCode.ENTER) {
commitEdit(Integer.parseInt(textField.getText()));
} else if (t.getCode() == KeyCode.ESCAPE) {
cancelEdit();
}
}
});
}

private String getString() {
return getItem() == null ? "" : getItem().toString();
}
}

}


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