How to open SVG using QT c++ - c++

Question

I'm trying to create and save QGraphicsScene to .svg file and my code works properly. Which creates rectangle,circle and save it into .svg But problem is which can only open rectangles only,how can I implement this to open circle(ellipse too) Please help me.
here are my codes.
readsvg.h
#ifndef READSVG_H
#define READSVG_H
#include <QList>
#include <QGraphicsRectItem>
class ReadSVG
{
public:
ReadSVG();
static QList<QGraphicsRectItem *> getElements(const QString filename);
static QRectF getSizes(const QString filename);
//static QList<QGraphicsEllipseItem *> getElements(const QString filename);
//static QRectF getSizes(const QString filename);
};
#endif // READSVG_H
readsvg.cpp
#include "readsvg.h"
#include <QPen>
#include <QFile>
#include <QMessageBox>
#include <QDomDocument>
#include <QStringList>
ReadSVG::ReadSVG()
{
}
QList<QGraphicsRectItem *> ReadSVG::getElements(const QString filename)
{
QList<QGraphicsRectItem *> rectList; // We declare in the stack a list of rectangles
QDomDocument doc; // document object
QFile file(filename); // Open our SVG file
// If it did not open or could not transfer content to QDocDocument
if (!file.open(QIODevice::ReadOnly) || !doc.setContent(&file))
return rectList; // then return the list, but empty
// Look in the document for all objects with the tag g
QDomNodeList gList = doc.elementsByTagName("g");
// We start to sort them out
for (int i = 0; i < gList.size(); i++) {
QDomNode gNode = gList.item(i); // Select the node from the list
QDomElement rectangle = gNode.firstChildElement("rect"); // And we search in it for an element with the tag rect
// If the resulting elements are not zero, then
if (rectangle.isNull()){
continue;
} else {
// begin to form a rectangle
QGraphicsRectItem *rect = new QGraphicsRectItem();
// This flag makes the object moveable, it will be required for verification
rect->setFlag(QGraphicsItem::ItemIsMovable);
// We take sizes from the rect tag
QDomElement gElement = gNode.toElement();
rect->setRect(rectangle.attribute("x").toInt(),
rectangle.attribute("y").toInt(),
rectangle.attribute("width").toInt(),
rectangle.attribute("height").toInt());
/*
We take the parameters of the colors gNode from the node element
yes yes yes ... it's from gNode, not from rectangle. These parameters are stored in the tag g
* */
QColor fillColor(gElement.attribute("fill", "#ffffff")); // fill color
fillColor.setAlphaF(gElement.attribute("fill-opacity","0").toFloat());
rect->setBrush(QBrush(fillColor));
// as well as the color and thickness of the outline
QColor strokeColor(gElement.attribute("stroke", "#000000"));
strokeColor.setAlphaF(gElement.attribute("stroke-opacity").toFloat());
rect->setPen(QPen(strokeColor,gElement.attribute("stroke-width", "0").toInt()));
rectList.append(rect); // add a rectangle to the list
}
}
file.close();
return rectList;
}
QRectF ReadSVG::getSizes(const QString filename)
{
QDomDocument doc; // initialize the QDomDocument object on the stack
QFile file(filename); // Open our SVG file
// If it did not open or could not transfer content to QDocDocument
if (!file.open(QIODevice::ReadOnly) || !doc.setContent(&file))
return QRectF(0,0,200,200); // then return the values ​​for the default scene
/* Next, we take the list of elements with the tag svg.
* In case the list of elements is not empty,
* then we will take the dimensions of the graphic scene.
* */
QDomNodeList list = doc.elementsByTagName("svg");
if(list.length() > 0) {
QDomElement svgElement = list.item(0).toElement();
QStringList parameters = svgElement.attribute("viewBox").split(" ");
return QRectF(parameters.at(0).toInt(),
parameters.at(1).toInt(),
parameters.at(2).toInt(),
parameters.at(3).toInt());
}
return QRectF(0,0,200,200);
}
widget.h
#ifndef WIDGET_H
#define WIDGET_H
#include <QGraphicsScene>
#include <QGraphicsRectItem>
#include <QWidget>
#include <QtCore>
#include <QtGui>
#include <QSvgGenerator>
namespace Ui {
class Widget;
}
class Widget : public QWidget
{
Q_OBJECT
public:
explicit Widget(QWidget *parent = 0);
~Widget();
private slots:
void on_pushButton_clicked();
void on_btnSave_clicked();
void on_btnOpen_clicked();
private:
Ui::Widget *ui;
QGraphicsScene *scene;
QGraphicsEllipseItem *elipse;
QGraphicsRectItem *rect;
QString path;
};
#endif // WIDGET_H
widget.cpp
#include "widget.h"
#include "ui_widget.h"
#include "readsvg.h"
#include <QCursor>
#include <QFileDialog>
Widget::Widget(QWidget *parent) :
QWidget(parent),
ui(new Ui::Widget)
{
ui->setupUi(this);
scene = new QGraphicsScene(this);
ui->graphicsView->setScene(scene);
QBrush redBrush(Qt::red);
QBrush blueBrush(Qt::blue);
QPen blackPen(Qt::black);
blackPen.setWidth(6);
elipse = scene->addEllipse(10,10,100,100,blackPen,redBrush);
rect = scene->addRect(-10,-10,100,100,blackPen,blueBrush);
rect->setFlag(QGraphicsItem::ItemIsMovable, true);
}
Widget::~Widget()
{
delete ui;
}
void Widget::on_pushButton_clicked()
{
QString fileName= QFileDialog::getSaveFileName(this, "Save image", QCoreApplication::applicationDirPath(), "BMP Files (*.bmp);;JPEG (*.JPEG);;PNG (*.png)" );
if (!fileName.isNull())
{
QPixmap pixMap = this->ui->graphicsView->grab();
pixMap.save(fileName);
}
}
void Widget::on_btnSave_clicked()
{
// Заберём путь к файлу и его имененем, который будем создавать
QString newPath = QFileDialog::getSaveFileName(this, trUtf8("Save SVG"),
path, tr("SVG files (*.svg)"));
if (newPath.isEmpty())
return;
path = newPath;
QSvgGenerator generator;
generator.setFileName(path);
generator.setSize(QSize(scene->width(), scene->height()));
generator.setViewBox(QRect(0, 0, scene->width(), scene->height()));
generator.setTitle(trUtf8("SVG Example"));
generator.setDescription(trUtf8("File created by SVG Example"));
QPainter painter;
painter.begin(&generator);
scene->render(&painter);
painter.end();
}
void Widget::on_btnOpen_clicked()
{
QString newPath = QFileDialog::getOpenFileName(this, trUtf8("Open SVG"),
path, tr("SVG files (*.svg)"));
if (newPath.isEmpty())
return;
path = newPath;
scene->clear();
scene->setSceneRect(ReadSVG::getSizes(path)); // Set the size of the graphic scene
// Install the objects on the graphical scene, get them using the getElements
foreach (QGraphicsRectItem *item, ReadSVG::getElements(path)) {
QGraphicsRectItem *rect = item;
scene->addItem(rect);
}
}

Answer 1

You can continue with the approach that you have started. Look for elements with the tag names that you want. Start with the "circle" tag. Here's what a ciricle tag might look like;
<circle cx="5" cy="5" r="3" fill="#0f0"/>