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TableCellRenderer 以及如何在不使用 JTable.repaint() 的情况下刷新单元格背景

更新时间:2023-12-04 19:21:22

当您更改所选项目时会出现此问题.您的组合框和表格之间存在一些隐式交互(组合框的选定项目会影响表格的绘制方式).

The issue occurs when you change the selected item. You have some implicit interaction between your combobox and you table (the selected item of the combo box influences the way the table is painted).

当comboboxpopup隐藏时,它会自动触发悬停区域的重绘(RepaintManager只会重绘悬停区域,而不是整个表格).但与此同时,您更改了表格单元格的绘制方式(第一个单元格不再绘制为红色,因为它们不再与选择匹配).但是,重绘管理器强制只重绘表格的一小部分区域,该区域没有完全覆盖红色单元格,因此您会看到这些视觉故障.

When the comboboxpopup is hidden, it automatically triggers a repaint of the hovered area (the RepaintManager will only repaint the hovered area, not the complete table). But in the meantime, you have changed the way the cells of the table are painted (the first cells are no longer painted in red because they don't match the selection anymore). However, the repaint manager forces to repaint only a small area of the table which does not cover completely the red cells, hence you see those visual glitches.

这里有两个我能想到的解决方案:

Here are 2 solutions I can come up with:

  • 向组合框添加一个 ActionListener 并调用 table.repaint()(容易做到)
  • 更改您的表格模型并为相关单元格调用 fireTableCellUpdated(row, column).
  • Add an ActionListener to the combobox and invoke table.repaint() (easy to do)
  • Change your table model and call fireTableCellUpdated(row, column) for the relevant cells.

SSCCE 用于第二个解决方案:

SSCCE for the second solution:

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.ArrayList;
import java.util.List;

import javax.swing.DefaultComboBoxModel;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.SwingUtilities;
import javax.swing.border.EmptyBorder;
import javax.swing.table.DefaultTableCellRenderer;
import javax.swing.table.DefaultTableModel;

public class MyTableAndRenderer {

    private final class DefaultTableModelExtension extends DefaultTableModel {
        private static final long serialVersionUID = 1L;

        private String selected;

        private DefaultTableModelExtension(Object[][] data, Object[] columnNames) {
            super(data, columnNames);
        }

        @Override
        public Class getColumnClass(int column) {
            return getValueAt(0, column).getClass();
        }

        public String getSelected() {
            return selected;
        }

        public void setSelected(String selected) {
            if (this.selected == null && selected == null || this.selected != null && this.selected.equalsIgnoreCase(selected)) {
                return;
            }
            class Cell {
                public final int row;
                public final int column;

                public Cell(int row, int column) {
                    super();
                    this.row = row;
                    this.column = column;
                }
            }
            List<Cell> updatedCells = new ArrayList<Cell>();
            if (this.selected != null) {
                for (int i = 0; i < data.length; i++) {
                    Object[] o = data[i];
                    for (int j = 0; j < o.length; j++) {
                        Object object = o[j];
                        if (this.selected.toString().equalsIgnoreCase(object.toString())) {
                            updatedCells.add(new Cell(i, j));
                        }
                    }
                }
            }
            this.selected = selected;
            if (this.selected != null) {
                for (int i = 0; i < data.length; i++) {
                    Object[] o = data[i];
                    for (int j = 0; j < o.length; j++) {
                        Object object = o[j];
                        if (this.selected.toString().equalsIgnoreCase(object.toString())) {
                            updatedCells.add(new Cell(i, j));
                        }
                    }
                }
            }
            for (Cell pair : updatedCells) {
                fireTableCellUpdated(pair.row, pair.column);
            }
        }
    }

    private JFrame frame = new JFrame();
    private JPanel panel = new JPanel();
    private String[] items = { "Item 1", "Item 2", "Item 3", "Item 4" };
    private DefaultComboBoxModel comboBoxModel = new DefaultComboBoxModel(items);
    private JComboBox combo = new JComboBox(comboBoxModel);
    private JPanel panel1 = new JPanel();
    private String[] columnNames = { "First Name", "Last Name", "Sport", "# of Years", "Vegetarian" };
    private Object[][] data = { { "Kathy", "Smith", "Item 1", new Integer(5), false }, { "John", "Doe", "Item 1", new Integer(3), true },
            { "Sue", "Black", "Item 3", new Integer(2), false }, { "Jane", "White", "Item 3", new Integer(20), true },
            { "Joe", "Brown", "Item 3", new Integer(10), false } };
    private DefaultTableModelExtension model = new DefaultTableModelExtension(data, columnNames);
    private JTable table = new JTable(model);

    public MyTableAndRenderer() {
        panel.setBorder(new EmptyBorder(10, 0, 2, 0));
        panel.add(combo);
        combo.addActionListener(new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {
                updateSelected();
            }

        });
        // Need first synch
        updateSelected();
        table.setDefaultRenderer(Object.class, new DefaultTableCellRenderer() {
            @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);
                String str = combo.getSelectedItem().toString();
                if (value.toString().equalsIgnoreCase(str)) {
                    c.setBackground(Color.RED);
                } else {
                    c.setBackground(null);
                }
                return this;
            }
        });
        table.getTableHeader().setReorderingAllowed(false);
        table.setAutoCreateRowSorter(true);
        table.setPreferredScrollableViewportSize(table.getPreferredSize());
        panel1.setLayout(new GridLayout(1, 1, 10, 10));
        panel1.add(new JScrollPane(table));
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.add(panel, BorderLayout.NORTH);
        frame.add(panel1);
        frame.pack();
        frame.setVisible(true);
    }

    private void updateSelected() {
        model.setSelected((String) combo.getSelectedItem());
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                MyTableAndRenderer fs = new MyTableAndRenderer();
            }
        });
    }
}