Qt 5.11 | Qt SQL | Drill Down Example | view.cpp Example File

Qt 5.11.3 Reference Documentation

# view.cpp Example File

drilldown/view.cpp

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      #include "informationwindow.h"
      #include "imageitem.h"
      #include "view.h"

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

          scene = new QGraphicsScene(this);
          scene->setSceneRect(0, 0, 465, 365);
          setScene(scene);

          addItems();

          setMinimumSize(470, 370);
          setMaximumSize(470, 370);

          QLinearGradient gradient(QPointF(0, 0), QPointF(0, 370));
          gradient.setColorAt(0, QColor("#868482"));
          gradient.setColorAt(1, QColor("#5d5b59"));
          setBackgroundBrush(gradient);
      }

      void View::addItems()
      {
          int itemCount = itemTable->rowCount();

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

          for (int i = 0; i < itemCount; i++) {
              QSqlRecord record = itemTable->record(i);

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

              int columnOffset = ((i % 2) * 37);
              int x = ((i % 2) * imageOffset) + leftMargin + columnOffset;
              int y = ((i / 2) * imageOffset) + topMargin;

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

              QGraphicsTextItem *label = scene->addText(item);
              label->setDefaultTextColor(QColor("#d7d6d5"));
              QPointF labelOffset((120 - 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 >= itemTable->rowCount())
              return;

          InformationWindow *window = findWindow(id);
          if (!window) {
              window = new InformationWindow(id, itemTable, this);

              connect(window, QOverload<int,const QString &>::of(&InformationWindow::imageChanged),
                      this, QOverload<int,const QString &>::of(&View::updateImage));

              window->move(pos() + QPoint(20, 40));
              window->show();
              informationWindows.append(window);
          }

          if (window->isVisible()) {
              window->raise();
              window->activateWindow();
          } else
              window->show();
      }

      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) const
      {
          for (auto window : informationWindows) {
              if (window && (window->id() == id))
                  return window;
          }
          return nullptr;
      }