- Qt 5.5
- Qt SQL
- SQL Browser
- connectionwidget.cpp Example File
- Qt 5.5.1 Reference Documentation

# connectionwidget.cpp Example File

sqlbrowser/connectionwidget.cpp

    /****************************************************************************
    **
    ** Copyright (C) 2015 The Qt Company Ltd.
    ** Contact: http://www.qt.io/licensing/
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    ** This file is part of the demonstration applications of the Qt Toolkit.
    **
    ** $QT_BEGIN_LICENSE:LGPL21$
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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, SIGNAL(triggered()), SLOT(refresh()));
        connect(metaDataAction, SIGNAL(triggered()), SLOT(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());
    }