请将上述代码分成.h和.cpp文件来写

好的，下面是将上述代码分成.h和.cpp文件的示例：

MainWindow.h：

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QPushButton>
#include <QGridLayout>
#include <QTimer>

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    MainWindow(QWidget *parent = nullptr);
    ~MainWindow();

private slots:
    void onButtonPressed();
    void onButtonReleased();
    void onLongPressTimeout();
    void onButtonDoubleClicked();

private:
    void setupUI();
    void setBackground();
    void createButtons();

    QWidget *centralWidget;
    QGridLayout *gridLayout;
    QTimer *longPressTimer;
};

#endif // MAINWINDOW_H

MainWindow.cpp：

#include "mainwindow.h"
#include <QPalette>

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
{
    setupUI();
    setBackground();
    createButtons();
}

MainWindow::~MainWindow()
{
}

void MainWindow::setupUI()
{
    centralWidget = new QWidget(this);
    gridLayout = new QGridLayout(centralWidget);
    setCentralWidget(centralWidget);
}

void MainWindow::setBackground()
{
    QPalette palette;
    palette.setBrush(this->backgroundRole(), QBrush(QImage("background.jpg")));
    this->setPalette(palette);
}

void MainWindow::createButtons()
{
    for (int i = 0; i < 7; i++) {
        QPushButton *button = new QPushButton(centralWidget);
        button->setIcon(QIcon("icon.png"));
        button->setIconSize(QSize(100, 100));
        button->setStyleSheet("background-color: transparent; border: none;");
        gridLayout->addWidget(button, i / 3, i % 3);

        connect(button, &QPushButton::pressed, this, &MainWindow::onButtonPressed);
        connect(button, &QPushButton::released, this, &MainWindow::onButtonReleased);
        connect(button, &QPushButton::doubleClicked, this, &MainWindow::onButtonDoubleClicked);
    }
}

void MainWindow::onButtonPressed()
{
    longPressTimer->start(1000);
}

void MainWindow::onButtonReleased()
{
    longPressTimer->stop();
}

void MainWindow::onLongPressTimeout()
{
    QPushButton *button = qobject_cast<QPushButton*>(sender());
    // 移动按钮的逻辑处理
}

void MainWindow::onButtonDoubleClicked()
{
    QPushButton *button = qobject_cast<QPushButton*>(sender());
    // 进入其他界面的逻辑处理
}

请确保在.h文件中包含所需的头文件，并在.cpp文件中实现相应的函数。同时，将"background.jpg"和"icon.png"替换为您自己的图片路径。希望对您有所帮助！如果还有其他问题，请随时提问。