How to populate TableView with rows of List<Object>?
In my model I have Row and Cell objects that represent tabular data read from a file. Each Row can return a list of cells. I want to populate TableView with Cell.toString() values, something like:
for (Row row : rows) {
// Add row to TableView.
for (Cell cell : row.getCells()) {
// Add cell.toString() in a current TableView row.
}
}
Most tutorials I found deal with columns that are associated with fields of some object, but I just want to display data without knowing what columns represent.
Essentially, your issue boils down to the fact that you need a dynamic amount of columns, which is not what TableView was initially made for: It does not render object relations - it was designed to display properties, which are fixed for the objects of the TableView (the keys/properties are the same for every object - eg a person's name, age, etc...)
Below I implemented a simple approach which is a fully runnable example of how this can be achieved.
import javafx.application.Application;
import javafx.beans.property.SimpleStringProperty;
import javafx.scene.Scene;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableView;
import javafx.stage.Stage;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;
public class DynamicTableViewColumnCount extends Application
{
public static void main(String[] args)
{
launch(args);
}
@Override
public void start(Stage primaryStage) throws Exception
{
TableView<Row> tableView = new TableView<>();
// make sample data
List<Row> rows = makeSampleData();
int max = getMaxCells(rows);
makeColumns(max, tableView);
tableView.getItems().addAll(rows);
// Boilerplate code for showing the TableView
Scene scene = new Scene(tableView, 1000, 1000);
primaryStage.setScene(scene);
primaryStage.show();
}
public void makeColumns(int count, TableView<Row> tableView)
{
for (int m = 0; m < count; m++)
{
TableColumn<Row, String> column = new TableColumn<>(Integer.toString(m));
column.setCellValueFactory(param -> {
// int index = Integer.parseInt(param.getTableColumn().getText());
int index = param.getTableView().getColumns().indexOf(param.getTableColumn());
List<Cell> cells = param.getValue().getCells();
return new SimpleStringProperty(cells.size() > index ? cells.get(index).toString() : null);
});
tableView.getColumns().add(column);
}
}
public int getMaxCells(List<Row> rows)
{
int max = 0;
for (Row row : rows)
max = Math.max(max, row.getCells().size());
return max;
}
public List<Row> makeSampleData()
{
Random random = new Random();
List<Row> rows = new ArrayList<>();
for (int i = 0; i < 16; i++)
{
Row e = new Row();
int jMax = random.nextInt(6); // from 0 to 5
for (int j = 0; j <= jMax; j++)
{
e.getCells().add(new Cell(Long.toHexString(random.nextLong())));
}
rows.add(e);
}
return rows;
}
static class Row
{
private final List<Cell> list = new ArrayList<>();
public List<Cell> getCells()
{
return list;
}
}
static class Cell
{
private final String value;
public Cell(String value)
{
this.value = value;
}
@Override
public String toString()
{
return value;
}
}
}