释放鼠标时对JTable进行排序

Question

我有一个JTable，其属性AutoCreateRowSorter设置为true。单击时效果很好，但如果单击时仅将鼠标移动1px，则不会出现排序，这在某些情况下不舒服。如何解决这个问题？

UPD我只想在释放鼠标时显示排序。

Answer 1

肮脏的方法（请阅读： 如果您不是绝对地绝望，请确切地知道自己在做什么！请不要这样做
），方法是挂接到uiDelegate安装的MouseListener并将排序触发器移到已发布的方法中。这涉及

• 一个自定义的MouseListener，它将除clicked之外的所有事件委托给原始安装的对象，并在传递发布的对象之前进行排序
• 用自定义替换原件
• 更改LAF时更新替换项（因为原始文件由ui控制）。这需要JTableHeader的子类化，并在updateUI中进行接线

自定义监听器：

public static class EventHook implements MouseListener {

    private JTableHeader header;
    private MouseListener delegate;

    public EventHook(JTableHeader header) {
        this.header = header;
        installHook();
    }

    protected void installHook() {
        MouseListener[] listeners = header.getMouseListeners();
        for (int i = 0; i < listeners.length; i++) {
            MouseListener l = listeners[i];
            if (l.getClass().getName().contains("TableHeaderUI")) {
                this.delegate = l;
                listeners[i] = this;
            }
            header.removeMouseListener(l);
        }
        for (MouseListener l : listeners) {
            header.addMouseListener(l);
        }
    }

    public void uninstallHook() {
        MouseListener[] listeners = header.getMouseListeners();
        for (int i = 0; i < listeners.length; i++) {
            MouseListener l = listeners[i];
            if (l == this) {
                listeners[i] = delegate;
            }
            header.removeMouseListener(l);
        }
        for (MouseListener l : listeners) {
            header.addMouseListener(l);
        }
    }

    @Override
    public void mouseReleased(MouseEvent e) {
        // sort before calling super
        sort(e);
        delegate.mouseReleased(e);
    }

    private void sort(MouseEvent e) {
        if (!header.isEnabled()) {
            return;
        }
        // do nothing if dragged
        if (header.getDraggedDistance() != 0) {
            return;
        }
        if (e.getClickCount() % 2 == 1 &&
                SwingUtilities.isLeftMouseButton(e)) {
            JTable table = header.getTable();
            RowSorter sorter;
            if (table != null && (sorter = table.getRowSorter()) != null) {
                int columnIndex = header.columnAtPoint(e.getPoint());
                if (columnIndex != -1) {
                    columnIndex = table.convertColumnIndexToModel(
                            columnIndex);
                    sorter.toggleSortOrder(columnIndex);
                }
            }
        }
    }

    @Override
    public void mouseClicked(MouseEvent e) {
        // swallow the clicked - want to trigger sort on released
    }

    @Override
    public void mousePressed(MouseEvent e) {
        delegate.mousePressed(e);
    }

    @Override
    public void mouseEntered(MouseEvent e) {
        delegate.mouseEntered(e);
    }

    @Override
    public void mouseExited(MouseEvent e) {
        delegate.mouseExited(e);
    }

}

子类化JTableHeader

public static class MyTableHeader extends JTableHeader {
    private EventHook hook;
    public MyTableHeader(TableColumnModel model) {
        super(model);
    }
    @Override
    public void updateUI() {
        if (hook != null) {
            hook.uninstallHook();
            hook = null;
        }
        super.updateUI();
        hook = new EventHook(this);
    }

}

用法，可以是JTable的子类并重写createDefaultTableHeader或手动设置标头：

// either subclass
JTable table = new JTable(new AncientSwingTeam()) {

    @Override
    protected JTableHeader createDefaultTableHeader() {
        return new MyTableHeader(getColumnModel());
    }

};
table.setAutoCreateRowSorter(true);