connectionwidget.cpp Example File

  /****************************************************************************
  **
  ** Copyright (C) 2016 The Qt Company Ltd.
  ** Contact: https://www.qt.io/licensing/
  **
  ** This file is part of the demonstration applications of the Qt Toolkit.
  **
  ** $QT_BEGIN_LICENSE:BSD$
  ** Commercial License Usage
  ** Licensees holding valid commercial Qt licenses may use this file in
  ** accordance with the commercial license agreement provided with the
  ** Software or, alternatively, in accordance with the terms contained in
  ** a written agreement between you and The Qt Company. For licensing terms
  ** and conditions see https://www.qt.io/terms-conditions. For further
  ** information use the contact form at https://www.qt.io/contact-us.
  **
  ** BSD License Usage
  ** Alternatively, you may use this file under the terms of the BSD license
  ** as follows:
  **
  ** "Redistribution and use in source and binary forms, with or without
  ** modification, are permitted provided that the following conditions are
  ** met:
  **   * Redistributions of source code must retain the above copyright
  **     notice, this list of conditions and the following disclaimer.
  **   * Redistributions in binary form must reproduce the above copyright
  **     notice, this list of conditions and the following disclaimer in
  **     the documentation and/or other materials provided with the
  **     distribution.
  **   * Neither the name of The Qt Company Ltd nor the names of its
  **     contributors may be used to endorse or promote products derived
  **     from this software without specific prior written permission.
  **
  **
  ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
  **
  ** $QT_END_LICENSE$
  **
  ****************************************************************************/

  #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());
  }