view.cpp Example File
sql/drilldown/view.cpp

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 #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);

 #ifndef Q_OS_SYMBIAN
     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;
 }