Qt 4.8: view.cpp Example File (sql/drilldown/view.cpp)

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# view.cpp Example File

sql/drilldown/view.cpp

     /****************************************************************************
     **
     ** Copyright (C) 2015 The Qt Company Ltd.
     ** Contact: http://www.qt.io/licensing/
     **
     ** This file is part of the examples of the Qt Toolkit.
     **
     ** $QT_BEGIN_LICENSE:BSD$
     ** 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 "informationwindow.h"
     #include "imageitem.h"
     #include "view.h"

     View::View(const QString &offices, const QString &images, QWidget *parent)
         : QGraphicsView(parent)
     {
         officeTable = new QSqlRelationalTableModel(this);
         officeTable->setTable(offices);
         officeTable->setRelation(1, QSqlRelation(images, "locationid", "file"));
         officeTable->select();

         scene = new QGraphicsScene(this);
         scene->setSceneRect(0, 0, 465, 615);
         setScene(scene);

         addItems();

         QGraphicsPixmapItem *logo = scene->addPixmap(QPixmap(":/logo.png"));
         logo->setPos(30, 515);

     #if !defined(Q_OS_SYMBIAN) && !defined(Q_WS_MAEMO_5)
         setMinimumSize(470, 620);
         setMaximumSize(470, 620);
     #else
         setDragMode(QGraphicsView::ScrollHandDrag);
     #endif

        setWindowTitle(tr("Offices World Wide"));
     }

     void View::addItems()
     {
         int officeCount = officeTable->rowCount();

         int imageOffset = 150;
         int leftMargin = 70;
         int topMargin = 40;

         for (int i = 0; i < officeCount; i++) {
             ImageItem *image;
             QGraphicsTextItem *label;
             QSqlRecord record = officeTable->record(i);

             int id = record.value("id").toInt();
             QString file = record.value("file").toString();
             QString location = record.value("location").toString();

             int columnOffset = ((i / 3) * 37);
             int x = ((i / 3) * imageOffset) + leftMargin + columnOffset;
             int y = ((i % 3) * imageOffset) + topMargin;

             image = new ImageItem(id, QPixmap(":/" + file));
             image->setData(0, i);
             image->setPos(x, y);
             scene->addItem(image);

             label = scene->addText(location);
             QPointF labelOffset((150 - label->boundingRect().width()) / 2, 120.0);
             label->setPos(QPointF(x, y) + labelOffset);
         }
     }

     void View::mouseReleaseEvent(QMouseEvent *event)
     {
         if (QGraphicsItem *item = itemAt(event->pos())) {
             if (ImageItem *image = qgraphicsitem_cast<ImageItem *>(item))
                 showInformation(image);
         }
         QGraphicsView::mouseReleaseEvent(event);
     }

     void View::showInformation(ImageItem *image)
     {
         int id = image->id();
         if (id < 0 || id >= officeTable->rowCount())
             return;

         InformationWindow *window = findWindow(id);
         if (window && window->isVisible()) {
             window->raise();
             window->activateWindow();
         } else if (window && !window->isVisible()) {
     #ifndef Q_OS_SYMBIAN
             window->show();
     #else
             window->showMaximized();
     #endif
         } else {
             InformationWindow *window;
             window = new InformationWindow(id, officeTable, this);

             connect(window, SIGNAL(imageChanged(int,QString)),
                     this, SLOT(updateImage(int,QString)));

     #ifndef Q_OS_SYMBIAN
             window->move(pos() + QPoint(20, 40));
             window->show();
     #else
             window->showMaximized();
     #endif
             informationWindows.append(window);
         }
     }

     void View::updateImage(int id, const QString &fileName)
     {
         QList<QGraphicsItem *> items = scene->items();

         while(!items.empty()) {
             QGraphicsItem *item = items.takeFirst();

             if (ImageItem *image = qgraphicsitem_cast<ImageItem *>(item)) {
                 if (image->id() == id){
                     image->setPixmap(QPixmap(":/" +fileName));
                     image->adjust();
                     break;
                 }
             }
         }
     }

     InformationWindow* View::findWindow(int id)
     {
         QList<InformationWindow*>::iterator i, beginning, end;

         beginning = informationWindows.begin();
         end = informationWindows.end();

         for (i = beginning; i != end; ++i) {
             InformationWindow *window = (*i);
             if (window && (window->id() == id))
                 return window;
         }
         return 0;
     }