svgviewer.cpp

   1 #include "svgviewer.h"
   2
   3 SVGViewer::SVGViewer(QWidget *parent) : QGraphicsView(parent) {
   4     /* Init scene */
   5     setScene(new QGraphicsScene(this));
   6     setTransformationAnchor(AnchorUnderMouse);
   7     setViewportUpdateMode(FullViewportUpdate);
   8 }
   9
  10 void SVGViewer::paintEvent(QPaintEvent *event) {
  11     QGraphicsView::paintEvent(event);
  12 }
  13
  14 bool SVGViewer::openFile(QString fileName) {
  15     svgItem = new QGraphicsSvgItem(fileName);
  16
  17     /* Reject invalid SVG documents */
  18     if (!svgItem->renderer()->isValid()) {
  19         /* TODO: Also show details in error message */
  20         QMessageBox::critical(this, "Invalid SVG document",
  21                               "The selected file is not a valid SVG document and could not be opened.");
  22         return false;
  23     }
  24
  25     /* Set up scene */
  26     setDragMode(ScrollHandDrag);
  27
  28     scene()->clear();
  29     resetTransform();
  30
  31     svgItem->setFlags(QGraphicsItem::ItemClipsToShape);
  32     svgItem->setCacheMode(QGraphicsItem::NoCache);
  33
  34     /* Show image */
  35     scene()->addItem(svgItem);
  36     return true;
  37 }
  38
  39 void SVGViewer::closeFile() {
  40     delete svgItem;
  41     svgItem = NULL;
  42     /* Reset view parameters */
  43     scene()->clear();
  44     resetTransform();
  45     setDragMode(NoDrag);
  46 }
  47
  48 void SVGViewer::zoomIn() {
  49     zoomChange(2);
  50 }
  51 void SVGViewer::zoomOut() {
  52     zoomChange(0.5);
  53 }
  54 void SVGViewer::zoomReset() {
  55     if(svgItem != NULL) {
  56         resetTransform();
  57     }
  58 }
  59
  60 void SVGViewer::zoomChange(qreal factor) {
  61     if(svgItem != NULL) {
  62         scale(factor, factor);
  63     }
  64 }
  65
  66 void SVGViewer::wheelEvent(QWheelEvent *event) {
  67     /* Change zoom on using the mouse wheel */
  68     qreal factor = qPow(1.2, event->delta() / 240.0);
  69     zoomChange(factor);
  70     event->accept();
  71 }