Hi Martin,
I implemented my own canvas item for SVG markers like you told me. But
When
I created a object of custom canvas item in main, it broke down. The error
says 'This may be due to a corruption of the heap...', see more in
error.jpg. I looked up for answers in exchange, which I found a similar
topic here
<http://gis.stackexchange.com/questions/81465/how-to-refresh-layers-independently/81470#81470>
, in the topic Nathan did exactly what I did. I don't know why.
<http://osgeo-org.1560.x6.nabble.com/file/n5161805/error.jpg>
Here is my code:
//main.cpp
int main(int argc, char ** argv)
{
// Start the Application
QgsApplication app(argc, argv, true);
QgsMapCanvas * mypMapCanvas = new QgsMapCanvas();
mypMapCanvas->setVisible(true);
mypMapCanvas->refresh();
QString fileName =
"D:\\qgis\\svg\\symbol\\poi_tower_communications.svg";
TFMapCanvasSvgItem mTFSvgItem(mypMapCanvas, fileName);
mTFSvgItem.setPos(0, 0);
return app.exec();
}
// Custom canvas item class -TFMapCanvasSvgItem.h
class TFMapCanvasSvgItem: public QgsMapCanvasItem
{
public:
TFMapCanvasSvgItem(QgsMapCanvas* canvas, QString
fileName = "");
~TFMapCanvasSvgItem();
void paint(QPainter* painter);
QRectF boundingRect() const;
void setFilePath(const QString& file);
QString filePath() const {return mFilePath;}
private:
QSvgRenderer mSvgRenderer;
QString mFilePath;
};
//TFMapCanvasSvgItem.cpp
TFMapCanvasSvgItem::TFMapCanvasSvgItem(QgsMapCanvas*
canvas, QString
fileName): QgsMapCanvasItem(canvas), mSvgRenderer(fileName)
{
}
TFMapCanvasSvgItem::~TFMapCanvasSvgItem()
{
}
void TFMapCanvasSvgItem::paint(QPainter* painter)
{
if (!painter)
{
return;
}
QRectF viewBox = mSvgRenderer.viewBoxF();
if (viewBox.isValid())
{
setPos(this->toCanvasCoordinates(QgsPoint(0.0,
0.0)));
mSvgRenderer.render(painter, viewBox);
}
}
QRectF TFMapCanvasSvgItem::boundingRect() const
{
QRectF viewBox = mSvgRenderer.viewBoxF();
qreal halfWeight = viewBox.width() / 2;
qreal halfHeight = viewBox.height() / 2;
return QRectF(-halfWeight, -halfHeight, viewBox.width(),
viewBox.height());
}
void TFMapCanvasSvgItem::setFilePath(const QString& file)
{
mFilePath = file;
mSvgRenderer.load(mFilePath);
}
--
View this message in context:
http://osgeo-org.1560.x6.nabble.com/Is-QGIS-supports-dynamic-display-tp5155726p5161805.html
Sent from the Quantum GIS - Developer mailing list archive at Nabble.com.
_______________________________________________
Qgis-developer mailing list
Qgis-developer@lists.osgeo.org
http://lists.osgeo.org/mailman/listinfo/qgis-developer
