slideshow.cpp Example File

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 #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
 }