Question

I have a big problem with JTable. Here is how it works:

• a user adds a new Shape to Model
• Controller updates Model and sends a notification to View to update
• View gets data from Model and renders them

I use addRow(...) method to add rows of shapes. But it adds the whole List of shapes to the curent data (so I get this: shape1, shape1, shape2, shape1, shape2, shape3 for three shapes). I tried to delete rows somehow or setRowCount(0) but none of it worked correctly.

TableModel

package dpo.mvc.view.table;

import javax.swing.table.DefaultTableModel;

import dpo.mvc.model.Shape;
import dpo.mvc.view.View;
import dpo.mvc.view.ViewListener;

@SuppressWarnings("serial")
public class CustomTableModel extends DefaultTableModel implements ViewListener {

    private View view;

    public CustomTableModel(View view, String ... columns) {
        this.view = view;
        this.setColumnIdentifiers(columns);
        this.addTableModelListener(new TableListener(view));
    }

    @Override
    public boolean isCellEditable(int row, int column) {
        return column != 0;
    }

    private void load() {
        for (Shape shape : view.getModel().getShapesList()) {
            this.addRow(new Object[] {shape.getId(), shape.getPositionX(), shape.getPositionY(), shape.getSize()});
        }
    }

    @Override
    public void render() {
        load();     
    }

}

TableListener

package dpo.mvc.view.table;

import javax.swing.event.TableModelEvent;
import javax.swing.event.TableModelListener;

import dpo.mvc.view.View;

public class TableListener implements TableModelListener {

    private View view;

    public TableListener(View view) {
        this.view = view;
    }

    @Override
    public void tableChanged(TableModelEvent e) {
        int changedRow = e.getFirstRow();
        String[] shapeData = getData();

        if (e.getType() == TableModelEvent.UPDATE) {
            view.getController().shapeChanged(shapeData);
        }
    }

}

Answer 1

If the Shape is meant to appear in another component, register the class containing that component as a TableModelListener using the addTableModelListener() method of your TableModel. If the Shape is meant to appear in the JTable, you’ll probably want to implement TableCellRenderer, as discussed in How to Use Tables: Using Custom Renderers and shown here.