c++ qtreewidget和qtablewidget支持撤销与恢复功能 代码qundogroup

以下是使用 `QUndoStack` 实现 `QTreeWidget` 和 `QTableWidget` 的撤销与恢复功能的示例代码：

#include <QApplication>
#include <QMainWindow>
#include <QUndoStack>
#include <QTreeWidget>
#include <QTableWidget>
#include <QHeaderView>

class UndoCommand : public QUndoCommand
{
public:
    explicit UndoCommand(QTreeWidgetItem *item, const QString &text, QUndoCommand *parent = nullptr)
        : QUndoCommand(parent), m_item(item), m_oldText(item->text(0)), m_newText(text)
    {
    }

    void undo() override
    {
        m_item->setText(0, m_oldText);
    }

    void redo() override
    {
        m_item->setText(0, m_newText);
    }

private:
    QTreeWidgetItem *m_item;
    QString m_oldText;
    QString m_newText;
};

class TreeWidget : public QTreeWidget
{
    Q_OBJECT
public:
    explicit TreeWidget(QWidget *parent = nullptr) : QTreeWidget(parent)
    {
        m_undoStack = new QUndoStack(this);
    }

protected:
    void keyPressEvent(QKeyEvent *event) override
    {
        if (event->key() == Qt::Key_Z && (event->modifiers() & Qt::ControlModifier)) {
            if (event->modifiers() & Qt::ShiftModifier) {
                m_undoStack->redo();
            } else {
                m_undoStack->undo();
            }
            event->accept();
        } else {
            QTreeWidget::keyPressEvent(event);
        }
    }

    void mousePressEvent(QMouseEvent *event) override
    {
        if (event->button() == Qt::LeftButton) {
            m_lastItem = currentItem();
        }
        QTreeWidget::mousePressEvent(event);
    }

    void mouseReleaseEvent(QMouseEvent *event) override
    {
        if (event->button() == Qt::LeftButton) {
            auto item = currentItem();
            if (item && item == m_lastItem) {
                auto text = item->text(0);
                auto newText = QInputDialog::getText(this, tr("Edit"), tr("Text:"), QLineEdit::Normal, text);
                if (!newText.isEmpty() && newText != text) {
                    auto cmd = new UndoCommand(item, newText);
                    m_undoStack->push(cmd);
                }
            }
        }
        QTreeWidget::mouseReleaseEvent(event);
    }

private:
    QUndoStack *m_undoStack;
    QTreeWidgetItem *m_lastItem;
};

class TableWidget : public QTableWidget
{
    Q_OBJECT
public:
    explicit TableWidget(QWidget *parent = nullptr) : QTableWidget(parent)
    {
        m_undoStack = new QUndoStack(this);
    }

protected:
    void keyPressEvent(QKeyEvent *event) override
    {
        if (event->key() == Qt::Key_Z && (event->modifiers() & Qt::ControlModifier)) {
            if (event->modifiers() & Qt::ShiftModifier) {
                m_undoStack->redo();
            } else {
                m_undoStack->undo();
            }
            event->accept();
        } else {
            QTableWidget::keyPressEvent(event);
        }
    }

    void mousePressEvent(QMouseEvent *event) override
    {
        if (event->button() == Qt::LeftButton) {
            m_lastItem = itemAt(event->pos());
        }
        QTableWidget::mousePressEvent(event);
    }

    void mouseReleaseEvent(QMouseEvent *event) override
    {
        if (event->button() == Qt::LeftButton) {
            auto item = itemAt(event->pos());
            if (item && item == m_lastItem) {
                auto text = item->text();
                auto newText = QInputDialog::getText(this, tr("Edit"), tr("Text:"), QLineEdit::Normal, text);
                if (!newText.isEmpty() && newText != text) {
                    auto cmd = new UndoCommand(item, newText);
                    m_undoStack->push(cmd);
                }
            }
        }
        QTableWidget::mouseReleaseEvent(event);
    }

private:
    QUndoStack *m_undoStack;
    QTableWidgetItem *m_lastItem;
};

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);

    QMainWindow mainWindow;
    auto treeWidget = new TreeWidget(&mainWindow);
    auto tableWidget = new TableWidget(&mainWindow);

    treeWidget->setHeaderLabel("Tree Widget");
    tableWidget->horizontalHeader()->setStretchLastSection(true);
    tableWidget->setRowCount(3);
    tableWidget->setColumnCount(2);
    tableWidget->setHorizontalHeaderLabels({"Column 1", "Column 2"});
    tableWidget->setItem(0, 0, new QTableWidgetItem("Item 1-1"));
    tableWidget->setItem(0, 1, new QTableWidgetItem("Item 1-2"));
    tableWidget->setItem(1, 0, new QTableWidgetItem("Item 2-1"));
    tableWidget->setItem(1, 1, new QTableWidgetItem("Item 2-2"));
    tableWidget->setItem(2, 0, new QTableWidgetItem("Item 3-1"));
    tableWidget->setItem(2, 1, new QTableWidgetItem("Item 3-2"));

    mainWindow.setCentralWidget(treeWidget);
    mainWindow.addDockWidget(Qt::RightDockWidgetArea, new QDockWidget("Table Widget", &mainWindow));
    mainWindow.centralWidget()->setMinimumSize(400, 300);
    mainWindow.dockWidgetAreaChanged(Qt::RightDockWidgetArea);

    auto tableWidgetContainer = new QWidget(&mainWindow);
    auto tableWidgetLayout = new QVBoxLayout(tableWidgetContainer);
    tableWidgetLayout->setMargin(0);
    tableWidgetLayout->addWidget(tableWidget);
    mainWindow.findChild<QDockWidget*>("Table Widget")->setWidget(tableWidgetContainer);

    mainWindow.show();

    return a.exec();
}

#include "main.moc"

在这个示例中，我们继承了 `QTreeWidget` 和 `QTableWidget` 类，重写了 `keyPressEvent` 和 `mousePressEvent` 方法，以便在用户按下 `Ctrl+Z` 或单击一个单元格时执行撤销和恢复操作。我们还创建了一个 `UndoCommand` 类，以便保存撤销和恢复所需的数据。最后，我们将 `QTreeWidget` 和 `QTableWidget` 放在一个 `QMainWindow` 中，以便测试这些小部件。