Question

我发现this forum thread建议覆盖ListSelectionModel以防止选择行。

我希望在当前所选项目未保存的更改（表格外部）时防止选择更改，直到用户确认丢弃。类似的东西：

public class confirmSelectionChange extends DefaultListSelectionModel {
    public void setSelectionInterval(int index0, int index1) {
        if (unsavedChanges()) {
            super.setSelectionInterval(int index0, int index1);
        }
    }

    private boolean unsavedChanges() {
        if (noUnsavedChangesExist) {
            return true;
        }

        // Present modal dialog: save, discard cancel
        if (dialogAnswer == SAVE) {
            // save changes
            return true;
        } else if (dialogAnswer == DISCARD) {
            return true;
        } else {
            return false;
        }
    }
}

是否可以在ListSelectionModel更改中插入阻止代码？是否有更好的方法来拦截选择变更事件？

我已经在听他们了，但到那时候已经发生了变化。

Answer 1

我的最终解决方案（部分归功于this code guru）是创建一个扩展JTable并覆盖changeSelection()的匿名内部类。我读了一个单独的课，因为我读到有些人不认为匿名内部类是好的OO设计，但我需要知道编辑状态加上我必须调用save / discard方法。无论如何，谁需要封装才是你自己的代码？ ; - ）

jTableMemberList = new JTable() {
    public void changeSelection(int rowIndex, int columnIndex, boolean toggle,
                                boolean extend) {
        // Member is being edited and they've clicked on a DIFFERENT row (this
        // method gets called even when the selection isn't actually changing)
        if (editModeIsActive && getSelectedRow() != rowIndex) {
            // User was editing, now they're trying to move away without saving
            Object[] options = {"Save", "Discard", "Cancel"};
            int n = JOptionPane.showOptionDialog(this,
                                            "There are unsaved changes for the "
                                            + "currently selected member.\n\n"
                                            + "Would you like to save them?",
                                            "Save changes?",
                                            JOptionPane.YES_NO_CANCEL_OPTION,
                                            JOptionPane.WARNING_MESSAGE,
                                            null,
                                            options,
                                            options[0]);

            if (n == JOptionPane.YES_OPTION) {
                saveChanges();
            } else if (n == JOptionPane.NO_OPTION) {
                discardChanges();
            } else {
                // Exit without passing call on to super
                return;
            }
        }

        // make the selection change
        super.changeSelection(rowIndex, columnIndex, toggle, extend);
    }
};

这个解决方案到目前为止似乎有效，但我还没有对它进行过广泛的测试。在这段代码的一个黑暗角落里可能存在漏洞或陷阱......

希望它可以帮助别人！

拦截jTable选择更改事件

1 个答案: