QT QTableView添加CheckBox

news2024/12/25 8:50:30

需求：QTableView中指定列所有Item均为CheckBox项，要求CheckBox居中显示

显示效果如下：三种表现效果

实现方式：

系统控件QCheckBox
自绘制CheckBox
CheckBox的图片

实现代码：(原理：利用委托自绘的方式)

CheckBoxDelegate

#ifndef CHECKBOXDELETAGE_H
#define CHECKBOXDELETAGE_H

#include <QStyledItemDelegate>

class QPixmap;
class CheckBoxDelegate : public QStyledItemDelegate
{
    Q_OBJECT

public:
    enum class CheckBoxPaintType : quint8
    {
        SysControl  = 0, // 系统控件
        OwnerDraw   = 1, // 自绘CheckBox
        DrawImage   = 2, // 绘制图片
    };

public:
    explicit CheckBoxDelegate(CheckBoxPaintType type = CheckBoxPaintType::SysControl, QWidget *parent = nullptr);
    ~CheckBoxDelegate();

    void initCheckBoxPixmaps(CheckBoxPaintType type);
    void initCheckBoxPixmapBySysControl(const QString& key, bool checked);
    void initCheckBoxPixmapByOwnerDraw(const QString& key, bool checked);
    void initCheckBoxPixmapByDrawImage(const QString& key, bool checked);

    // 虚函数
    void paint(QPainter *painter, const QStyleOptionViewItem &option, const QModelIndex &index) const override;
    bool editorEvent(QEvent *event, QAbstractItemModel *model, const QStyleOptionViewItem &option, const QModelIndex &index) override;

signals:

private:
    QPixmap* mCheckedPix = nullptr;
    QPixmap* mUnCheckedPix = nullptr;
};

#endif // CHECKBOXDELETAGE_H

#include "checkboxdeletage.h"
#include <QCheckBox>
#include <QApplication>
#include <QMouseEvent>
#include <QPixmapCache>
#include <QPainter>

CheckBoxDelegate::CheckBoxDelegate(CheckBoxDelegate::CheckBoxPaintType type, QWidget *parent)
    : QStyledItemDelegate(parent)
{
    initCheckBoxPixmaps(type);
}

CheckBoxDelegate::~CheckBoxDelegate()
{
    delete mCheckedPix;
    delete mUnCheckedPix;
}

void CheckBoxDelegate::initCheckBoxPixmaps(CheckBoxDelegate::CheckBoxPaintType type)
{
    switch (type)
    {
    case CheckBoxPaintType::SysControl:
        initCheckBoxPixmapBySysControl("checked", true);
        initCheckBoxPixmapBySysControl("unchecked", false);
        break;
    case CheckBoxPaintType::OwnerDraw:
        initCheckBoxPixmapByOwnerDraw("checked", true);
        initCheckBoxPixmapByOwnerDraw("unchecked", false);
        break;
    case CheckBoxPaintType::DrawImage:
        initCheckBoxPixmapByDrawImage("checked", true);
        initCheckBoxPixmapByDrawImage("unchecked", false);
        break;
    default:
        break;
    }
}

void CheckBoxDelegate::initCheckBoxPixmapBySysControl(const QString &key, bool checked)
{
    QPixmap* pix = new QPixmap(13,13);
    QPainter painter(pix);

    QStyleOptionToolButton style;
    style.iconSize = QSize(13, 13);
    style.state = checked ? QStyle::State_On : QStyle::State_Off;
    style.state |= QStyle::State_Enabled;
    style.rect = QRect(0,0, 13,13);
    QCheckBox box;
    QApplication::style()->drawPrimitive(QStyle::PE_IndicatorCheckBox, &style, &painter, &box);

    if (checked)
        mCheckedPix = pix;
    else
        mUnCheckedPix = pix;
}

void CheckBoxDelegate::initCheckBoxPixmapByOwnerDraw(const QString &key, bool checked)
{
    QPixmap* pix = new QPixmap(13,13);
    QPainter painter(pix);
    painter.setPen(QColorConstants::Green);

    QRect rect(0,0,13,13);
    // 抗锯齿
    painter.setRenderHint(QPainter::Antialiasing);
    painter.setBrush(QBrush(QColorConstants::White));
    painter.drawRect(rect);

    if (checked)
    {
        QPointF points[3] = {
            QPointF(rect.x() + rect.width() * 2 / 11, rect.y() + rect.height() * 6 / 11),
            QPointF(rect.x() + rect.width() * 4 / 11, rect.y() + rect.height() * 8 / 11),
            QPointF(rect.x() + rect.width() * 9 / 11, rect.y() + rect.height() * 3 / 11),
        };

        painter.setPen(QPen(QBrush(QColorConstants::Green),2));
        painter.drawPolyline(points, 3);
    }

    if (checked)
        mCheckedPix = pix;
    else
        mUnCheckedPix = pix;
    // 也可直接放入QPixmapCache中去，此处就简单处理更高效些
    //QPixmapCache::insert(key, pix);
}

void CheckBoxDelegate::initCheckBoxPixmapByDrawImage(const QString &key, bool checked)
{
    QPixmap* pix = new QPixmap(checked ? ":/image/checked.png" : ":/image/unchecked.png");

    if (checked)
        mCheckedPix = pix;
    else
        mUnCheckedPix = pix;
}


void CheckBoxDelegate::paint(QPainter *painter, const QStyleOptionViewItem &option, const QModelIndex &index) const
{
    QStyleOptionViewItem viewOption(option);
    initStyleOption(&viewOption, index);
    if (viewOption.state.testFlag(QStyle::State_HasFocus))
        viewOption.state ^= QStyle::State_HasFocus;

    QStyledItemDelegate::paint(painter, option, index);

    bool checked = index.data(Qt::UserRole).toBool();

    QPixmap* pix = checked? mCheckedPix : mUnCheckedPix;
    if (pix)
    {
        // 居中显示
        QRect rect = pix->rect();
        int offsetX = option.rect.width() / 2 - rect.width() / 2;
        int offsetY = option.rect.height() / 2 - rect.height() / 2;
        rect.translate(option.rect.x() + offsetX, option.rect.y() + offsetY);
        painter->drawPixmap(rect, *pix);
    }
}

bool CheckBoxDelegate::editorEvent(QEvent *event, QAbstractItemModel *model, const QStyleOptionViewItem &option, const QModelIndex &index)
{
    if (event->type() == QEvent::MouseButtonPress || event->type() == QEvent::MouseButtonDblClick)
    {
        // 鼠标单双击切换选中状态
        QMouseEvent* mouseEvent = static_cast<QMouseEvent*>(event);
        if (option.rect.contains(mouseEvent->pos()))
        {
            model->setData(index, !model->data(index, Qt::UserRole).toBool(), Qt::UserRole);
        }
    }
    return QStyledItemDelegate::editorEvent(event, model, option, index);
}

使用：

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QTabWidget>
#include <QSplitter>
#include <QTableView>
#include <QStandardItemModel>
#include "checkboxdeletage.h"

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
    , ui(new Ui::MainWindow)
{
    ui->setupUi(this);

    QTabWidget* tabWidget = new QTabWidget(this);
    QSplitter* splitter = new QSplitter(Qt::Orientation::Horizontal, this);

    QTableView* tableView = new QTableView(this);

    QStandardItemModel* model = new QStandardItemModel(2,3,this);
    tableView->setModel(model);

    tableView->setItemDelegateForColumn(0, new CheckBoxDelegate(CheckBoxDelegate::CheckBoxPaintType::SysControl, this));
    tableView->setItemDelegateForColumn(1, new CheckBoxDelegate(CheckBoxDelegate::CheckBoxPaintType::OwnerDraw, this));
    tableView->setItemDelegateForColumn(2, new CheckBoxDelegate(CheckBoxDelegate::CheckBoxPaintType::DrawImage, this));
    // 不可编辑
    tableView->setEditTriggers(QAbstractItemView::EditTrigger::NoEditTriggers);
    // 整行选中
    tableView->setSelectionBehavior(QAbstractItemView::SelectRows);
    // 多行可选
    tableView->setSelectionMode(QAbstractItemView::SelectionMode::ExtendedSelection);

    splitter->addWidget(tableView);
    tabWidget->addTab(splitter, "CheckBox");

    setCentralWidget(tabWidget);
}

MainWindow::~MainWindow()
{
    delete ui;
}