JComboBox作为JTable列编辑器

Question

   public class Model extends AbstractTableModel {

protected String[] colNames;
protected Vector data;

Model(String[] col) {
    this.colNames = col;
    this.data = new Vector();
}

@Override
public int getRowCount() {
    return this.data.size();
}

@Override
public String getColumnName(int col) {
    return this.colNames[col];
}

@Override
public int getColumnCount() {
    return this.colNames.length;
}

@Override
public Object getValueAt(int rowIndex, int columnIndex) {
    Product record = (Product) data.get(rowIndex);
    switch (columnIndex) {
        case qi:
            return record.getQuantity();
        case di:
            return record.getDecsription();
        case ui:
            return record.getPrice();
        case ti:
            return record.getTprice();
        default:
            return new Object();
    }

}

@Override
public boolean isCellEditable(int row, int col) {
   return col<=3;

}

@Override
public void setValueAt(Object value, int row, int column) {
    Product record = (Product) data.get(row);
    switch (column) {
        case qi:
            record.setQuantity((Integer) value);
            break;
        case di:
            record.setDecsription((String) value);
            break;
        case ui:
            record.setPrice((Double) value);
            break;
        case ti:
            record.setTprice((Double) value);
            break;
        default:
            System.out.println("invalid index");
    }
    fireTableCellUpdated(row, column);//this is for updating the cell
}

@Override
public Class getColumnClass(int column) {// returns a class representing the datatype of the data stored in that column
    switch (column) {
        case qi:
            return Integer.class;
        case di:
            return String.class;
        case ui:
        case ti:
            return Double.class;
        default:
            return Object.class;
    }
}

public void addEmptyRow() {
    data.add(new Product());
    fireTableRowsInserted(
            data.size() - 1,
            data.size() - 1);

}

public boolean hasEmptyRow() {
    if (data.isEmpty()) {
        return false;
    }
    Product productRecord = (Product) data.get(data.size() - 1);
    if (productRecord.getDecsription().trim().equals("")
            && productRecord.getPrice() == 0.0
            && productRecord.getQuantity() == 0
            && productRecord.getTprice() == 0) {
        return true;
    } else {
        return false;
    }}

public final class Table {

JTable table;
JScrollPane sp;
static final String[] columNames = {"Quantity", "Description", "Unity Price", "Total Price", ""};
Model model = new Model(columNames);
String[] values = {"1", "2", "3"};

public Table() {

    createTable();
}

public void createTable() {

    JFrame f = new JFrame();
    f.setSize(300, 300);
    f.setVisible(true);

    //information regarding the table here
    table = new JTable();
    table.setModel(model);
    table.setSurrendersFocusOnKeystroke(true);
    table.setPreferredScrollableViewportSize(new java.awt.Dimension(300, 300));
    TableColumn col = table.getColumnModel().getColumn(1);
    col.setCellEditor(new myComboBoxEditor(values));
    col.setCellRenderer(new MyComboBoxRenderer(values));

    sp = new javax.swing.JScrollPane(table);

    //information on table model
    model.addTableModelListener(new Table.InteractiveTableModelListener());
    if (!model.hasEmptyRow()) {
        model.addEmptyRow();
    }

    //
    f.add(sp);
    TableColumn hidden = table.getColumnModel().getColumn(Model.hi);
    hidden.setMinWidth(2);
    hidden.setPreferredWidth(2);
    hidden.setMaxWidth(2);
    hidden.setCellRenderer(new InteractiveRenderer(Model.hi));
}

public void highlightLastRow(int row) {
    int lastrow = model.getRowCount();//return the number of rows - last row
    if (row == lastrow - 1) {
        table.setRowSelectionInterval(lastrow - 1, lastrow - 1);
    } else {
        table.setRowSelectionInterval(row + 1, row + 1);
    }

    table.setColumnSelectionInterval(0, 0);//setting it to the first column
}

class InteractiveRenderer extends DefaultTableCellRenderer {

    protected int interactiveColumn;

    public InteractiveRenderer(int interactiveColumn) {
        this.interactiveColumn = interactiveColumn;
    }

    @Override
    public Component getTableCellRendererComponent(JTable table,
            Object value, boolean isSelected, boolean hasFocus, int row,
            int column) {
        Component c = super.getTableCellRendererComponent(table, value, isSelected, hasFocus, row, column);
        if (column == interactiveColumn && hasFocus) {
            if ((Table.this.model.getRowCount() - 1) == row
                    && !Table.this.model.hasEmptyRow()) {
                Table.this.model.addEmptyRow();//this is where we append a new row
            }

            highlightLastRow(row);//making it get focus and highlighted
        }

        return c;//returning the component
    }
}

public class InteractiveTableModelListener implements TableModelListener {

    @Override
    public void tableChanged(TableModelEvent evt) {
        if (evt.getType() == TableModelEvent.UPDATE) {
            int column = evt.getColumn();
            int row = evt.getFirstRow();
            System.out.println("row: " + row + " column: " + column);
            table.setColumnSelectionInterval(column + 1, column + 1);
            table.setRowSelectionInterval(row, row);
        }
    }
}

private class myComboBoxEditor extends DefaultCellEditor {

    myComboBoxEditor(String[] items) {
        super(new JComboBox(items));

    }
}

private class MyComboBoxRenderer extends JComboBox implements TableCellRenderer {

    public MyComboBoxRenderer(String[] items) {
        super(items);
    }

    @Override
    public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected,
            boolean hasFocus, int row, int column) {
        if (isSelected) {
            setForeground(table.getSelectionForeground());
            super.setBackground(table.getSelectionBackground());
        } else {
            setForeground(table.getForeground());
            setBackground(table.getBackground());
        }
        setSelectedItem(value);
        return this;
    }

}

public static void main(String[] args) {

    Table tab = new Table();
}}

Answer 1

现在我知道问题出在哪里了。您的TableColumnRenderer应该将您想要的效果绑定到您创建的组合框上的侦听器。

当您获得呈现器（或者更确切地说是您的InteractiveRenderer）时，不应该调用它

    if (column == interactiveColumn && hasFocus) {
        if ((Table.this.model.getRowCount() - 1) == row
                && !Table.this.model.hasEmptyRow()) {
            Table.this.model.addEmptyRow();//this is where we append a new row
        }

        highlightLastRow(row);//making it get focus and highlighted
    }

这部分才是罪魁祸首。您实际上想要做的是将其移到JComboBox上的侦听器中：

public MyComboBoxRenderer(String[] items) {
    super(items);
    // Java 8. Should be easy to convert to anonymous class
    setActionListener(e -> { 
        Table.this.model.addEmptyRow(); 
        this.highlightLastRow(); 
    });
}