Qt Reference Documentation

# weatherinfo.cpp Example File

demos/embedded/weatherinfo/weatherinfo.cpp

     /****************************************************************************
     **
     ** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies).
     ** All rights reserved.
     ** Contact: Nokia Corporation (qt-info@nokia.com)
     **
     ** This file is part of the demonstration applications of the Qt Toolkit.
     **
     ** $QT_BEGIN_LICENSE:LGPL$
     ** GNU Lesser General Public License Usage
     ** This file may be used under the terms of the GNU Lesser General Public
     ** License version 2.1 as published by the Free Software Foundation and
     ** appearing in the file LICENSE.LGPL included in the packaging of this
     ** file. Please review the following information to ensure the GNU Lesser
     ** General Public License version 2.1 requirements will be met:
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     ** rights. These rights are described in the Nokia Qt LGPL Exception
     ** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
     **
     ** GNU General Public License Usage
     ** Alternatively, this file may be used under the terms of the GNU General
     ** Public License version 3.0 as published by the Free Software Foundation
     ** and appearing in the file LICENSE.GPL included in the packaging of this
     ** file. Please review the following information to ensure the GNU General
     ** Public License version 3.0 requirements will be met:
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     ** conditions contained in a signed written agreement between you and Nokia.
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     ** $QT_END_LICENSE$
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     ****************************************************************************/

     #include <QtCore>
     #include <QtGui>
     #include <QtNetwork>
     #include <QtSvg>

     class WeatherInfo: public QMainWindow
     {
         Q_OBJECT

     private:

         QGraphicsView *m_view;
         QGraphicsScene m_scene;
         QString city;
         QGraphicsRectItem *m_statusItem;
         QGraphicsTextItem *m_temperatureItem;
         QGraphicsTextItem *m_conditionItem;
         QGraphicsSvgItem *m_iconItem;
         QList<QGraphicsRectItem*> m_forecastItems;
         QList<QGraphicsTextItem*> m_dayItems;
         QList<QGraphicsSvgItem*> m_conditionItems;
         QList<QGraphicsTextItem*> m_rangeItems;
         QTimeLine m_timeLine;
         QHash<QString, QString> m_icons;
         QNetworkAccessManager m_manager;

     public:
         WeatherInfo(QWidget *parent = 0): QMainWindow(parent) {

             m_view = new QGraphicsView(this);
             setCentralWidget(m_view);

             setupScene();
             m_view->setScene(&m_scene);
             m_view->setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
             m_view->setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);

             m_view->setFrameShape(QFrame::NoFrame);
             setWindowTitle("Weather Info");

             QStringList cities;
             cities << "Oslo";
             cities << "Berlin";
             cities << "Brisbane";
             cities << "Helsinki";
             cities << "San Diego";
             for (int i = 0; i < cities.count(); ++i) {
                 QAction *action = new QAction(cities[i], this);
                 connect(action, SIGNAL(triggered()), SLOT(chooseCity()));
                 addAction(action);
     #if defined(Q_OS_SYMBIAN)
                 menuBar()->addAction(action);
     #endif
             }
             setContextMenuPolicy(Qt::ActionsContextMenu);

             connect(&m_manager, SIGNAL(finished(QNetworkReply*)),
                     this, SLOT(handleNetworkData(QNetworkReply*)));

             QTimer::singleShot(0, this, SLOT(delayedInit()));
         }

     private slots:
         void delayedInit() {
             request("Oslo");
         }

     private slots:

         void chooseCity() {
             QAction *action = qobject_cast<QAction*>(sender());
             if (action)
                 request(action->text());
         }

         void handleNetworkData(QNetworkReply *networkReply) {
             QUrl url = networkReply->url();
             if (!networkReply->error())
                 digest(QString::fromUtf8(networkReply->readAll()));
             networkReply->deleteLater();
         }

         void animate(int frame) {
             qreal progress = static_cast<qreal>(frame) / 100;
     #if QT_VERSION >= 0x040500
             m_iconItem->setOpacity(progress);
     #endif
             qreal hw = width() / 2.0;
             m_statusItem->setPos(-hw + hw * progress, 0);
             for (int i = 0; i < m_forecastItems.count(); ++i) {
                 qreal ofs = i * 0.5 / m_forecastItems.count();
                 qreal alpha = qBound(qreal(0), 2 * (progress - ofs), qreal(1));
     #if QT_VERSION >= 0x040500
                 m_conditionItems[i]->setOpacity(alpha);
     #endif
                 QPointF pos = m_forecastItems[i]->pos();
                 if (width() > height()) {
                     qreal fx = width() - width() * 0.4 * alpha;
                     m_forecastItems[i]->setPos(fx, pos.y());
                 } else {
                     qreal fx = height() - height() * 0.5 * alpha;
                     m_forecastItems[i]->setPos(pos.x(), fx);
                 }
             }
         }

     private:

         void setupScene() {

             QColor textColor = palette().color(QPalette::WindowText);
             QFont textFont = font();
             textFont.setBold(true);
             textFont.setPointSize(textFont.pointSize() * 2);

             m_temperatureItem = m_scene.addText(QString(), textFont);
             m_temperatureItem->setDefaultTextColor(textColor);

             m_conditionItem = m_scene.addText(QString(), textFont);
             m_conditionItem->setDefaultTextColor(textColor);

             m_iconItem = new QGraphicsSvgItem;
             m_scene.addItem(m_iconItem);

             m_statusItem = m_scene.addRect(0, 0, 10, 10);
             m_statusItem->setPen(Qt::NoPen);
             m_statusItem->setBrush(Qt::NoBrush);
             m_temperatureItem->setParentItem(m_statusItem);
             m_conditionItem->setParentItem(m_statusItem);
             m_iconItem->setParentItem(m_statusItem);

             connect(&m_timeLine, SIGNAL(frameChanged(int)), SLOT(animate(int)));
             m_timeLine.setDuration(1100);
             m_timeLine.setFrameRange(0, 100);
             m_timeLine.setCurveShape(QTimeLine::EaseInCurve);
         }

         void request(const QString &location) {
             QUrl url("http://www.google.com/ig/api");
             url.addEncodedQueryItem("hl", "en");
             url.addEncodedQueryItem("weather", QUrl::toPercentEncoding(location));

             m_manager.get(QNetworkRequest(url));

             city = QString();
             setWindowTitle("Loading...");
         }

         QString extractIcon(const QString &data) {
             if (m_icons.isEmpty()) {
                 m_icons["mostly_cloudy"]    = "weather-few-clouds";
                 m_icons["cloudy"]           = "weather-overcast";
                 m_icons["mostly_sunny"]     = "weather-sunny-very-few-clouds";
                 m_icons["partly_cloudy"]    = "weather-sunny-very-few-clouds";
                 m_icons["sunny"]            = "weather-sunny";
                 m_icons["flurries"]         = "weather-snow";
                 m_icons["fog"]              = "weather-fog";
                 m_icons["haze"]             = "weather-haze";
                 m_icons["icy"]              = "weather-icy";
                 m_icons["sleet"]            = "weather-sleet";
                 m_icons["chance_of_sleet"]  = "weather-sleet";
                 m_icons["snow"]             = "weather-snow";
                 m_icons["chance_of_snow"]   = "weather-snow";
                 m_icons["mist"]             = "weather-showers";
                 m_icons["rain"]             = "weather-showers";
                 m_icons["chance_of_rain"]   = "weather-showers";
                 m_icons["storm"]            = "weather-storm";
                 m_icons["chance_of_storm"]  = "weather-storm";
                 m_icons["thunderstorm"]     = "weather-thundershower";
                 m_icons["chance_of_tstorm"] = "weather-thundershower";
             }
             QRegExp regex("([\\w]+).gif$");
             if (regex.indexIn(data) != -1) {
                 QString i = regex.cap();
                 i = i.left(i.length() - 4);
                 QString name = m_icons.value(i);
                 if (!name.isEmpty()) {
                     name.prepend(":/icons/");
                     name.append(".svg");
                     return name;
                 }
             }
             return QString();
         }

         static QString toCelcius(QString t, QString unit) {
             bool ok = false;
             int degree = t.toInt(&ok);
             if (!ok)
                 return QString();
             if (unit != "SI")
                 degree = ((degree - 32) * 5 + 8)/ 9;
             return QString::number(degree) + QChar(176);
         }

     #define GET_DATA_ATTR xml.attributes().value("data").toString()

         void digest(const QString &data) {

             QColor textColor = palette().color(QPalette::WindowText);
             QString unitSystem;

             delete m_iconItem;
             m_iconItem = new QGraphicsSvgItem();
             m_scene.addItem(m_iconItem);
             m_iconItem->setParentItem(m_statusItem);
             qDeleteAll(m_dayItems);
             qDeleteAll(m_conditionItems);
             qDeleteAll(m_rangeItems);
             qDeleteAll(m_forecastItems);
             m_dayItems.clear();
             m_conditionItems.clear();
             m_rangeItems.clear();
             m_forecastItems.clear();

             QXmlStreamReader xml(data);
             while (!xml.atEnd()) {
                 xml.readNext();
                 if (xml.tokenType() == QXmlStreamReader::StartElement) {
                     if (xml.name() == "city") {
                         city = GET_DATA_ATTR;
                         setWindowTitle(city);
                     }
                     if (xml.name() == "unit_system")
                         unitSystem = xml.attributes().value("data").toString();
                     // Parse current weather conditions
                     if (xml.name() == "current_conditions") {
                         while (!xml.atEnd()) {
                             xml.readNext();
                             if (xml.name() == "current_conditions")
                                 break;
                             if (xml.tokenType() == QXmlStreamReader::StartElement) {
                                 if (xml.name() == "condition") {
                                     m_conditionItem->setPlainText(GET_DATA_ATTR);
                                 }
                                 if (xml.name() == "icon") {
                                     QString name = extractIcon(GET_DATA_ATTR);
                                     if (!name.isEmpty()) {
                                         delete m_iconItem;
                                         m_iconItem = new QGraphicsSvgItem(name);
                                         m_scene.addItem(m_iconItem);
                                         m_iconItem->setParentItem(m_statusItem);
                                     }
                                 }
                                 if (xml.name() == "temp_c") {
                                     QString s = GET_DATA_ATTR + QChar(176);
                                     m_temperatureItem->setPlainText(s);
                                 }
                             }
                         }
                     }
                     // Parse and collect the forecast conditions
                     if (xml.name() == "forecast_conditions") {
                         QGraphicsTextItem *dayItem  = 0;
                         QGraphicsSvgItem *statusItem = 0;
                         QString lowT, highT;
                         while (!xml.atEnd()) {
                             xml.readNext();
                             if (xml.name() == "forecast_conditions") {
                                 if (dayItem && statusItem &&
                                     !lowT.isEmpty() && !highT.isEmpty()) {
                                     m_dayItems << dayItem;
                                     m_conditionItems << statusItem;
                                     QString txt = highT + '/' + lowT;
                                     QGraphicsTextItem* rangeItem;
                                     rangeItem = m_scene.addText(txt);
                                     rangeItem->setDefaultTextColor(textColor);
                                     m_rangeItems << rangeItem;
                                     QGraphicsRectItem *box;
                                     box = m_scene.addRect(0, 0, 10, 10);
                                     box->setPen(Qt::NoPen);
                                     box->setBrush(Qt::NoBrush);
                                     m_forecastItems << box;
                                     dayItem->setParentItem(box);
                                     statusItem->setParentItem(box);
                                     rangeItem->setParentItem(box);
                                 } else {
                                     delete dayItem;
                                     delete statusItem;
                                 }
                                 break;
                             }
                             if (xml.tokenType() == QXmlStreamReader::StartElement) {
                                 if (xml.name() == "day_of_week") {
                                     QString s = GET_DATA_ATTR;
                                     dayItem = m_scene.addText(s.left(3));
                                     dayItem->setDefaultTextColor(textColor);
                                 }
                                 if (xml.name() == "icon") {
                                     QString name = extractIcon(GET_DATA_ATTR);
                                     if (!name.isEmpty()) {
                                         statusItem = new QGraphicsSvgItem(name);
                                         m_scene.addItem(statusItem);
                                     }
                                 }
                                 if (xml.name() == "low")
                                     lowT = toCelcius(GET_DATA_ATTR, unitSystem);
                                 if (xml.name() == "high")
                                     highT = toCelcius(GET_DATA_ATTR, unitSystem);
                             }
                         }
                     }

                 }
             }

             m_timeLine.stop();
             layoutItems();
             animate(0);
             m_timeLine.start();
         }

         void layoutItems() {
             m_scene.setSceneRect(0, 0, width() - 1, height() - 1);
             m_view->centerOn(width() / 2, height() / 2);
             if (width() > height())
                 layoutItemsLandscape();
             else
                 layoutItemsPortrait();
         }

         void layoutItemsLandscape() {
             m_statusItem->setRect(0, 0, width() / 2 - 1, height() - 1);

             if (!m_iconItem->boundingRect().isEmpty()) {
                 qreal dim = qMin(width() * 0.6, height() * 0.8);
                 qreal pad = (height()  - dim) / 2;
                 qreal sw = dim / m_iconItem->boundingRect().width();
                 qreal sh = dim / m_iconItem->boundingRect().height();
                 m_iconItem->setTransform(QTransform().scale(sw, sh));
                 m_iconItem->setPos(1, pad);
             }

             m_temperatureItem->setPos(2, 2);
             qreal h = m_conditionItem->boundingRect().height();
             m_conditionItem->setPos(10, height() - h);

             if (m_dayItems.count()) {
                 qreal left = width() * 0.6;
                 qreal h = height() / m_dayItems.count();
                 QFont textFont = font();
                 textFont.setPixelSize(static_cast<int>(h * 0.3));
                 qreal statusWidth = 0;
                 qreal rangeWidth = 0;
                 for (int i = 0; i < m_dayItems.count(); ++i) {
                     m_dayItems[i]->setFont(textFont);
                     QRectF brect = m_dayItems[i]->boundingRect();
                     statusWidth = qMax(statusWidth, brect.width());
                     brect = m_rangeItems[i]->boundingRect();
                     rangeWidth = qMax(rangeWidth, brect.width());
                 }
                 qreal space = width() - left - statusWidth - rangeWidth;
                 qreal dim = qMin(h, space);
                 qreal pad = statusWidth + (space  - dim) / 2;
                 for (int i = 0; i < m_dayItems.count(); ++i) {
                     qreal base = h * i;
                     m_forecastItems[i]->setPos(left, base);
                     m_forecastItems[i]->setRect(0, 0, width() - left, h);
                     QRectF brect = m_dayItems[i]->boundingRect();
                     qreal ofs = (h - brect.height()) / 2;
                     m_dayItems[i]->setPos(0, ofs);
                     brect = m_rangeItems[i]->boundingRect();
                     ofs = (h - brect.height()) / 2;
                     m_rangeItems[i]->setPos(width() - rangeWidth - left, ofs);
                     brect = m_conditionItems[i]->boundingRect();
                     ofs = (h - dim) / 2;
                     m_conditionItems[i]->setPos(pad, ofs);
                     if (brect.isEmpty())
                         continue;
                     qreal sw = dim / brect.width();
                     qreal sh = dim / brect.height();
                     m_conditionItems[i]->setTransform(QTransform().scale(sw, sh));
                 }
             }
         }

         void layoutItemsPortrait() {

             m_statusItem->setRect(0, 0, width() - 1, height() / 2 - 1);

             if (!m_iconItem->boundingRect().isEmpty()) {
                 qreal dim = qMin(width() * 0.8, height() * 0.4);
                 qreal ofsy = (height() / 2  - dim) / 2;
                 qreal ofsx = (width() - dim) / 3;
                 qreal sw = dim / m_iconItem->boundingRect().width();
                 qreal sh = dim / m_iconItem->boundingRect().height();
                 m_iconItem->setTransform(QTransform().scale(sw, sh));
                 m_iconItem->setPos(ofsx, ofsy);
             }

             m_temperatureItem->setPos(2, 2);
             qreal ch = m_conditionItem->boundingRect().height();
             qreal cw = m_conditionItem->boundingRect().width();
             m_conditionItem->setPos(width() - cw , height() / 2 - ch - 20);

             if (m_dayItems.count()) {
                 qreal top = height() * 0.5;
                 qreal w = width() / m_dayItems.count();
                 qreal statusHeight = 0;
                 qreal rangeHeight = 0;
                 for (int i = 0; i < m_dayItems.count(); ++i) {
                     m_dayItems[i]->setFont(font());
                     QRectF brect = m_dayItems[i]->boundingRect();
                     statusHeight = qMax(statusHeight, brect.height());
                     brect = m_rangeItems[i]->boundingRect();
                     rangeHeight = qMax(rangeHeight, brect.height());
                 }
                 qreal space = height() - top - statusHeight - rangeHeight;
                 qreal dim = qMin(w, space);

                 qreal boxh = statusHeight + rangeHeight + dim;
                 qreal pad = (height() - top - boxh) / 2;

                 for (int i = 0; i < m_dayItems.count(); ++i) {
                     qreal base = w * i;
                     m_forecastItems[i]->setPos(base, top);
                     m_forecastItems[i]->setRect(0, 0, w, boxh);
                     QRectF brect = m_dayItems[i]->boundingRect();
                     qreal ofs = (w - brect.width()) / 2;
                     m_dayItems[i]->setPos(ofs, pad);

                     brect = m_rangeItems[i]->boundingRect();
                     ofs = (w - brect.width()) / 2;
                     m_rangeItems[i]->setPos(ofs, pad + statusHeight + dim);

                     brect = m_conditionItems[i]->boundingRect();
                     ofs = (w - dim) / 2;
                     m_conditionItems[i]->setPos(ofs, pad + statusHeight);
                     if (brect.isEmpty())
                         continue;
                     qreal sw = dim / brect.width();
                     qreal sh = dim / brect.height();
                     m_conditionItems[i]->setTransform(QTransform().scale(sw, sh));
                 }
             }
         }

         void resizeEvent(QResizeEvent *event) {
             Q_UNUSED(event);
             layoutItems();
         }

     };

     #include "weatherinfo.moc"

     int main(int argc, char *argv[])
     {
         QApplication app(argc, argv);

         WeatherInfo w;
     #if defined(Q_OS_SYMBIAN)
         w.showMaximized();
     #else
         w.resize(520, 288);
         w.show();
     #endif

         return app.exec();
     }