Qt Reference Documentation

- Qt 4.8
- ALL VERSIONS

- A
- A
- A
- Print

# slideshow.cpp Example File

demos/embedded/fluidlauncher/slideshow.cpp

     /****************************************************************************
     **
     ** Copyright (C) 2015 The Qt Company Ltd.
     ** Contact: http://www.qt.io/licensing/
     **
     ** This file is part of the demonstration applications of the Qt Toolkit.
     **
     ** $QT_BEGIN_LICENSE:LGPL$
     ** Commercial License Usage
     ** Licensees holding valid commercial Qt licenses may use this file in
     ** accordance with the commercial license agreement provided with the
     ** Software or, alternatively, in accordance with the terms contained in
     ** a written agreement between you and The Qt Company. For licensing terms
     ** and conditions see http://www.qt.io/terms-conditions. For further
     ** information use the contact form at http://www.qt.io/contact-us.
     **
     ** GNU Lesser General Public License Usage
     ** Alternatively, this file may be used under the terms of the GNU Lesser
     ** General Public License version 2.1 or version 3 as published by the Free
     ** Software Foundation and appearing in the file LICENSE.LGPLv21 and
     ** LICENSE.LGPLv3 included in the packaging of this file. Please review the
     ** following information to ensure the GNU Lesser General Public License
     ** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
     ** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
     **
     ** As a special exception, The Qt Company gives you certain additional
     ** rights. These rights are described in The Qt Company 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: http://www.gnu.org/copyleft/gpl.html.
     **
     ** $QT_END_LICENSE$
     **
     ****************************************************************************/

     #include <QBasicTimer>
     #include <QList>
     #include <QImage>
     #include <QDir>
     #include <QPainter>
     #include <QPaintEvent>

     #include <QDebug>

     #include "slideshow.h"

     class SlideShowPrivate
     {
     public:
         SlideShowPrivate();

         int currentSlide;
         int slideInterval;
         QBasicTimer interSlideTimer;
         QStringList imagePaths;

         void showNextSlide();
     };

     SlideShowPrivate::SlideShowPrivate()
     {
         currentSlide = 0;
         slideInterval = 10000; // Default to 10 sec interval
     }

     void SlideShowPrivate::showNextSlide()
     {
         currentSlide++;
         if (currentSlide >= imagePaths.size())
           currentSlide = 0;
     }

     SlideShow::SlideShow(QWidget* parent) :
         QWidget(parent)
     {
         d = new SlideShowPrivate;

         setAttribute(Qt::WA_StaticContents, true);
         setAttribute(Qt::WA_OpaquePaintEvent, true);
         setAttribute(Qt::WA_NoSystemBackground, true);

         setMouseTracking(true);
     }

     SlideShow::~SlideShow()
     {
         delete d;
     }

     void SlideShow::addImageDir(QString dirName)
     {
         QDir dir(dirName);

         QStringList fileNames = dir.entryList(QDir::Files | QDir::Readable, QDir::Name);

         for (int i=0; i<fileNames.count(); i++)
             d->imagePaths << dir.absoluteFilePath(fileNames[i]);
     }

     void SlideShow::addImage(QString filename)
     {
         d->imagePaths << filename;
     }

     void SlideShow::clearImages()
     {
         d->imagePaths.clear();
     }

     void SlideShow::startShow()
     {
         d->interSlideTimer.start(d->slideInterval, this);
         d->showNextSlide();
         update();
     }

     void SlideShow::stopShow()
     {
         d->interSlideTimer.stop();
     }

     int SlideShow::slideInterval()
     {
         return d->slideInterval;
     }

     void SlideShow::setSlideInterval(int val)
     {
         d->slideInterval = val;
     }

     void SlideShow::timerEvent(QTimerEvent* event)
     {
         Q_UNUSED(event);
         d->showNextSlide();
         update();
     }

     void SlideShow::paintEvent(QPaintEvent *event)
     {
         QPainter painter(this);
         painter.setRenderHint(QPainter::Antialiasing, false);

         if (d->imagePaths.size() > 0) {
             QPixmap slide = QPixmap(d->imagePaths[d->currentSlide]);
             QSize slideSize = slide.size();
             QSize scaledSize = QSize(qMin(slideSize.width(), size().width()),
                 qMin(slideSize.height(), size().height()));
             if (slideSize != scaledSize)
                 slide = slide.scaled(scaledSize, Qt::KeepAspectRatio);

             QRect pixmapRect(qMax( (size().width() - slide.width())/2, 0),
                              qMax( (size().height() - slide.height())/2, 0),
                              slide.width(),
                              slide.height());

             if (pixmapRect.top() > 0) {
                 // Fill in top & bottom rectangles:
                 painter.fillRect(0, 0, size().width(), pixmapRect.top(), Qt::black);
                 painter.fillRect(0, pixmapRect.bottom(), size().width(), size().height(), Qt::black);
             }

             if (pixmapRect.left() > 0) {
                 // Fill in left & right rectangles:
                 painter.fillRect(0, 0, pixmapRect.left(), size().height(), Qt::black);
                 painter.fillRect(pixmapRect.right(), 0, size().width(), size().height(), Qt::black);
             }

             painter.drawPixmap(pixmapRect, slide);

         } else
             painter.fillRect(event->rect(), Qt::black);
     }

     void SlideShow::keyPressEvent(QKeyEvent* event)
     {
         Q_UNUSED(event);
         emit inputReceived();
     }

     void SlideShow::mouseMoveEvent(QMouseEvent* event)
     {
         Q_UNUSED(event);
         emit inputReceived();
     }

     void SlideShow::mousePressEvent(QMouseEvent* event)
     {
         Q_UNUSED(event);
         emit inputReceived();
     }

     void SlideShow::mouseReleaseEvent(QMouseEvent* event)
     {
         Q_UNUSED(event);
         emit inputReceived();
     }

     void SlideShow::showEvent(QShowEvent * event )
     {
         Q_UNUSED(event);
     #ifndef QT_NO_CURSOR
         setCursor(Qt::BlankCursor);
     #endif
     }