main.cpp Example File | Qt Widgets 5.12.8

- Qt 5.12
- Qt Widgets
- Weather Anchor Layout Example
- main.cpp Example File
- Qt 5.12.8 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"