svgview.cpp Example File

svgviewer/svgview.cpp
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#include "svgview.h" #include <QSvgRenderer> #include <QWheelEvent> #include <QMouseEvent> #include <QGraphicsRectItem> #include <QGraphicsSvgItem> #include <QPaintEvent> #include <qmath.h> #ifndef QT_NO_OPENGL #include <QGLWidget> #endif SvgView::SvgView(QWidget *parent) : QGraphicsView(parent) , m_renderer(Native) , m_svgItem(nullptr) , m_backgroundItem(nullptr) , m_outlineItem(nullptr) { setScene(new QGraphicsScene(this)); setTransformationAnchor(AnchorUnderMouse); setDragMode(ScrollHandDrag); setViewportUpdateMode(FullViewportUpdate); // Prepare background check-board pattern QPixmap tilePixmap(64, 64); tilePixmap.fill(Qt::white); QPainter tilePainter(&tilePixmap); QColor color(220, 220, 220); tilePainter.fillRect(0, 0, 32, 32, color); tilePainter.fillRect(32, 32, 32, 32, color); tilePainter.end(); setBackgroundBrush(tilePixmap); } void SvgView::drawBackground(QPainter *p, const QRectF &) { p->save(); p->resetTransform(); p->drawTiledPixmap(viewport()->rect(), backgroundBrush().texture()); p->restore(); } QSize SvgView::svgSize() const { return m_svgItem ? m_svgItem->boundingRect().size().toSize() : QSize(); } bool SvgView::openFile(const QString &fileName) { QGraphicsScene *s = scene(); const bool drawBackground = (m_backgroundItem ? m_backgroundItem->isVisible() : false); const bool drawOutline = (m_outlineItem ? m_outlineItem->isVisible() : true); QScopedPointer<QGraphicsSvgItem> svgItem(new QGraphicsSvgItem(fileName)); if (!svgItem->renderer()->isValid()) return false; s->clear(); resetTransform(); m_svgItem = svgItem.take(); m_svgItem->setFlags(QGraphicsItem::ItemClipsToShape); m_svgItem->setCacheMode(QGraphicsItem::NoCache); m_svgItem->setZValue(0); m_backgroundItem = new QGraphicsRectItem(m_svgItem->boundingRect()); m_backgroundItem->setBrush(Qt::white); m_backgroundItem->setPen(Qt::NoPen); m_backgroundItem->setVisible(drawBackground); m_backgroundItem->setZValue(-1); m_outlineItem = new QGraphicsRectItem(m_svgItem->boundingRect()); QPen outline(Qt::black, 2, Qt::DashLine); outline.setCosmetic(true); m_outlineItem->setPen(outline); m_outlineItem->setBrush(Qt::NoBrush); m_outlineItem->setVisible(drawOutline); m_outlineItem->setZValue(1); s->addItem(m_backgroundItem); s->addItem(m_svgItem); s->addItem(m_outlineItem); s->setSceneRect(m_outlineItem->boundingRect().adjusted(-10, -10, 10, 10)); return true; } void SvgView::setRenderer(RendererType type) { m_renderer = type; if (m_renderer == OpenGL) { #ifndef QT_NO_OPENGL setViewport(new QGLWidget(QGLFormat(QGL::SampleBuffers))); #endif } else { setViewport(new QWidget); } } void SvgView::setHighQualityAntialiasing(bool highQualityAntialiasing) { #ifndef QT_NO_OPENGL setRenderHint(QPainter::HighQualityAntialiasing, highQualityAntialiasing); #else Q_UNUSED(highQualityAntialiasing); #endif } void SvgView::setViewBackground(bool enable) { if (!m_backgroundItem) return; m_backgroundItem->setVisible(enable); } void SvgView::setViewOutline(bool enable) { if (!m_outlineItem) return; m_outlineItem->setVisible(enable); } void SvgView::paintEvent(QPaintEvent *event) { if (m_renderer == Image) { if (m_image.size() != viewport()->size()) { m_image = QImage(viewport()->size(), QImage::Format_ARGB32_Premultiplied); } QPainter imagePainter(&m_image); QGraphicsView::render(&imagePainter); imagePainter.end(); QPainter p(viewport()); p.drawImage(0, 0, m_image); } else { QGraphicsView::paintEvent(event); } } void SvgView::wheelEvent(QWheelEvent *event) { qreal factor = qPow(1.2, event->delta() / 240.0); scale(factor, factor); event->accept(); } QSvgRenderer *SvgView::renderer() const { if (m_svgItem) return m_svgItem->renderer(); return nullptr; }