Qt 5.9 | Qt Widgets | Weather Anchor Layout Example | main.cpp Example File

Qt 5.9.9 Reference Documentation

# main.cpp Example File

graphicsview/weatheranchorlayout/main.cpp

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      #include <QApplication>
      #include <QLabel>
      #include <QPainter>
      #include <QPushButton>

      #include <QGraphicsAnchorLayout>
      #include <QGraphicsProxyWidget>
      #include <QGraphicsScene>
      #include <QGraphicsSceneResizeEvent>
      #include <QGraphicsView>
      #include <QGraphicsWidget>

      class GraphicsView : public QGraphicsView
      {
      public:
          GraphicsView(QGraphicsScene *scene, QGraphicsWidget *widget)
              : QGraphicsView(scene), w(widget)
          {
          }

          void resizeEvent(QResizeEvent *event) override
          {
              w->setGeometry(0, 0, event->size().width(), event->size().height());
          }

          QGraphicsWidget *w;
      };

      class PixmapWidget : public QGraphicsLayoutItem
      {

      public:
          PixmapWidget(const QPixmap &pix)
              : QGraphicsLayoutItem()
          {
              original = new QGraphicsPixmapItem(pix);
              setGraphicsItem(original);
              original->show();
              r = QRectF(QPointF(0, 0), pix.size());
          }

          ~PixmapWidget()
          {
              setGraphicsItem(0);
              delete original;
          }

          void setZValue(qreal z)
          {
              original->setZValue(z);
          }

          void setGeometry (const QRectF &rect) override
          {
              original->setTransform(QTransform::fromScale(rect.width() / r.width(),
                                                           rect.height() / r.height()), true);
              original->setPos(rect.x(), rect.y());
              r = rect;
          }

      protected:
          QSizeF sizeHint(Qt::SizeHint which, const QSizeF &constraint = QSizeF()) const override
          {
              Q_UNUSED(constraint);
              QSizeF sh;
              switch (which) {
                  case Qt::MinimumSize:
                      sh = QSizeF(0, 0);
                      break;
                  case Qt::PreferredSize:
                      sh = QSizeF(50, 50);
                      break;
                  case Qt::MaximumSize:
                      sh = QSizeF(QWIDGETSIZE_MAX, QWIDGETSIZE_MAX);
                      break;
                  default:
                      break;
              }
              return sh;
          }

      private:
          QGraphicsPixmapItem *original;
          QRectF r;
      };

      class PlaceWidget : public QGraphicsWidget
      {
          Q_OBJECT

      public:
          PlaceWidget(const QPixmap &pix)
              : QGraphicsWidget()
              , original(pix)
              , scaled(pix)
          {
          }

          void paint(QPainter *painter, const QStyleOptionGraphicsItem *, QWidget *) override
          {
              QPointF reflection = QPointF();
              reflection.setY(scaled.height() + 2);

              painter->drawPixmap(QPointF(), scaled);

              QPixmap tmp(scaled.size());
              tmp.fill(Qt::transparent);
              QPainter p(&tmp);

              // create gradient
              QPoint p1(scaled.width() / 2, 0);
              QPoint p2(scaled.width() / 2, scaled.height());
              QLinearGradient linearGrad(p1, p2);
              linearGrad.setColorAt(0, QColor(0, 0, 0, 0));
              linearGrad.setColorAt(0.65, QColor(0, 0, 0, 127));
              linearGrad.setColorAt(1, QColor(0, 0, 0, 255));

              // apply 'mask'
              p.setBrush(linearGrad);
              p.fillRect(0, 0, tmp.width(), tmp.height(), QBrush(linearGrad));
              p.fillRect(0, 0, tmp.width(), tmp.height(), QBrush(linearGrad));

              // paint the image flipped
              p.setCompositionMode(QPainter::CompositionMode_DestinationOver);
              p.drawPixmap(0, 0, QPixmap::fromImage(scaled.toImage().mirrored(false, true)));
              p.end();

              painter->drawPixmap(reflection, tmp);
          }

          void resizeEvent(QGraphicsSceneResizeEvent *event) override
          {
              QSize newSize = event->newSize().toSize();
              newSize.setHeight(newSize.height() / 2);
              scaled = original.scaled(newSize);
          }

          QRectF boundingRect() const override
          {
              QSize size(scaled.width(), scaled.height() * 2 + 2);
              return QRectF(QPointF(0, 0), size);
          }

      private:
          QPixmap original;
          QPixmap scaled;
      };

      int main(int argc, char *argv[])
      {
          Q_INIT_RESOURCE(weatheranchorlayout);

          QApplication app(argc, argv);

          QGraphicsScene scene;
          scene.setSceneRect(0, 0, 800, 480);

          // pixmaps widgets
          PixmapWidget *title = new PixmapWidget(QPixmap(":/images/title.jpg"));
          PlaceWidget *place = new PlaceWidget(QPixmap(":/images/place.jpg"));
          PixmapWidget *details = new PixmapWidget(QPixmap(":/images/5days.jpg"));
          PixmapWidget *sunnyWeather = new PixmapWidget(QPixmap(":/images/weather-few-clouds.png"));
          PixmapWidget *tabbar = new PixmapWidget(QPixmap(":/images/tabbar.jpg"));

          // setup sizes
          title->setPreferredSize(QSizeF(348, 45));
          title->setSizePolicy(QSizePolicy::Minimum, QSizePolicy::Minimum);

          place->setPreferredSize(QSizeF(96, 72));
          place->setSizePolicy(QSizePolicy::Minimum, QSizePolicy::Minimum);

          details->setMinimumSize(QSizeF(200, 112));
          details->setPreferredSize(QSizeF(200, 112));
          details->setSizePolicy(QSizePolicy::Minimum, QSizePolicy::Minimum);

          tabbar->setPreferredSize(QSizeF(70, 24));
          tabbar->setSizePolicy(QSizePolicy::Minimum, QSizePolicy::Minimum);

          sunnyWeather->setPreferredSize(QSizeF(128, 97));
          sunnyWeather->setSizePolicy(QSizePolicy::Minimum, QSizePolicy::Minimum);
          sunnyWeather->setZValue(9999);

          // start anchor layout
          QGraphicsAnchorLayout *layout = new QGraphicsAnchorLayout;
          layout->setSpacing(0);

          // setup the main widget
          QGraphicsWidget *widget = new QGraphicsWidget(0, Qt::Window);
          QPalette p;
          p.setColor(QPalette::Window, Qt::black);
          widget->setPalette(p);
          widget->setPos(20, 20);
          widget->setLayout(layout);

          // vertical anchors
          QGraphicsAnchor *anchor = layout->addAnchor(title, Qt::AnchorTop, layout, Qt::AnchorTop);
          anchor = layout->addAnchor(place, Qt::AnchorTop, title, Qt::AnchorBottom);
          anchor->setSpacing(12);
          anchor = layout->addAnchor(place, Qt::AnchorBottom, layout, Qt::AnchorBottom);
          anchor->setSpacing(12);

          anchor = layout->addAnchor(sunnyWeather, Qt::AnchorTop, title, Qt::AnchorTop);
          anchor = layout->addAnchor(sunnyWeather, Qt::AnchorBottom, layout, Qt::AnchorVerticalCenter);

          anchor = layout->addAnchor(tabbar, Qt::AnchorTop, title, Qt::AnchorBottom);
          anchor->setSpacing(5);
          anchor = layout->addAnchor(details, Qt::AnchorTop, tabbar, Qt::AnchorBottom);
          anchor->setSpacing(2);
          anchor = layout->addAnchor(details, Qt::AnchorBottom, layout, Qt::AnchorBottom);
          anchor->setSpacing(12);

          // horizontal anchors
          anchor = layout->addAnchor(layout, Qt::AnchorLeft, title, Qt::AnchorLeft);
          anchor = layout->addAnchor(title, Qt::AnchorRight, layout, Qt::AnchorRight);

          anchor = layout->addAnchor(place, Qt::AnchorLeft, layout, Qt::AnchorLeft);
          anchor->setSpacing(15);
          anchor = layout->addAnchor(place, Qt::AnchorRight, details, Qt::AnchorLeft);
          anchor->setSpacing(35);

          anchor = layout->addAnchor(sunnyWeather, Qt::AnchorLeft, place, Qt::AnchorHorizontalCenter);
          anchor = layout->addAnchor(sunnyWeather, Qt::AnchorRight, layout, Qt::AnchorHorizontalCenter);

          anchor = layout->addAnchor(tabbar, Qt::AnchorHorizontalCenter, details, Qt::AnchorHorizontalCenter);
          anchor = layout->addAnchor(details, Qt::AnchorRight, layout, Qt::AnchorRight);

          // QGV setup
          scene.addItem(widget);
          scene.setBackgroundBrush(Qt::white);
          QGraphicsView *view = new QGraphicsView(&scene);
          view->show();

          return app.exec();
      }

      #include "main.moc"