connectionwidget.cpp Example File

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#include "connectionwidget.h"
#include <QtWidgets>
#include <QtSql>
ConnectionWidget::ConnectionWidget(QWidget *parent)
    : QWidget(parent)
{
    QVBoxLayout *layout = new QVBoxLayout(this);
    tree = new QTreeWidget(this);
    tree->setObjectName(QLatin1String("tree"));
    tree->setHeaderLabels(QStringList(tr("database")));
    tree->header()->setSectionResizeMode(QHeaderView::Stretch);
    QAction *refreshAction = new QAction(tr("Refresh"), tree);
    metaDataAction = new QAction(tr("Show Schema"), tree);
    connect(refreshAction, &QAction::triggered, this, &ConnectionWidget::refresh);
    connect(metaDataAction, &QAction::triggered, this, &ConnectionWidget::showMetaData);
    tree->addAction(refreshAction);
    tree->addAction(metaDataAction);
    tree->setContextMenuPolicy(Qt::ActionsContextMenu);
    layout->addWidget(tree);
    QMetaObject::connectSlotsByName(this);
}
ConnectionWidget::~ConnectionWidget()
{
}
static QString qDBCaption(const QSqlDatabase &db)
{
    QString nm = db.driverName();
    nm.append(QLatin1Char(':'));
    if (!db.userName().isEmpty())
        nm.append(db.userName()).append(QLatin1Char('@'));
    nm.append(db.databaseName());
    return nm;
}
void ConnectionWidget::refresh()
{
    tree->clear();
    QStringList connectionNames = QSqlDatabase::connectionNames();
    bool gotActiveDb = false;
    for (int i = 0; i < connectionNames.count(); ++i) {
        QTreeWidgetItem *root = new QTreeWidgetItem(tree);
        QSqlDatabase db = QSqlDatabase::database(connectionNames.at(i), false);
        root->setText(0, qDBCaption(db));
        if (connectionNames.at(i) == activeDb) {
            gotActiveDb = true;
            setActive(root);
        }
        if (db.isOpen()) {
            QStringList tables = db.tables();
            for (int t = 0; t < tables.count(); ++t) {
                QTreeWidgetItem *table = new QTreeWidgetItem(root);
                table->setText(0, tables.at(t));
            }
        }
    }
    if (!gotActiveDb) {
        activeDb = connectionNames.value(0);
        setActive(tree->topLevelItem(0));
    }
    tree->doItemsLayout(); // HACK
}
QSqlDatabase ConnectionWidget::currentDatabase() const
{
    return QSqlDatabase::database(activeDb);
}
static void qSetBold(QTreeWidgetItem *item, bool bold)
{
    QFont font = item->font(0);
    font.setBold(bold);
    item->setFont(0, font);
}
void ConnectionWidget::setActive(QTreeWidgetItem *item)
{
    for (int i = 0; i < tree->topLevelItemCount(); ++i) {
        if (tree->topLevelItem(i)->font(0).bold())
            qSetBold(tree->topLevelItem(i), false);
    }
    if (!item)
        return;
    qSetBold(item, true);
    activeDb = QSqlDatabase::connectionNames().value(tree->indexOfTopLevelItem(item));
}
void ConnectionWidget::on_tree_itemActivated(QTreeWidgetItem *item, int /* column */)
{
    if (!item)
        return;
    if (!item->parent()) {
        setActive(item);
    } else {
        setActive(item->parent());
        emit tableActivated(item->text(0));
    }
}
void ConnectionWidget::showMetaData()
{
    QTreeWidgetItem *cItem = tree->currentItem();
    if (!cItem || !cItem->parent())
        return;
    setActive(cItem->parent());
    emit metaDataRequested(cItem->text(0));
}
void ConnectionWidget::on_tree_currentItemChanged(QTreeWidgetItem *current, QTreeWidgetItem *)
{
    metaDataAction->setEnabled(current && current->parent());
}