SVG file in QGraphicsView

Sucharek

Hi, I'm wondering if I can put an SVG file into a QGraphicsView widget. I've seen something about QSvgRenderer, but I don't know if that would work.
I was using QPixmap when I was displaying jpg files, but svg files don't work.

SGaist

Hi,

QGraphicsSvgItem is what you are looking for.

Sucharek

Hi @SGaist, ok, but I don't know how to properly use it. I did this:

QGraphicsSvgItem svg(":/hands/handLeftDark.svg");

But I don't know how to add in in QGraphicsView now. I tried:

ui->graphicsView_LeftHand->scene()->addItem(svg);

But I don't know how to convert QGraphicsSvgItem to QGraphicsItem.

SGaist

QGraphicsSvgItem *svgItem = new QGraphicsSvgItem(":/hands/handLeftDark.svg");
ui->graphicsView_LeftHand->scene()->addItem(svgItem);

Sucharek

@SGaist I'm getting an error:

undefined reference to `QGraphicsSvgItem::QGraphicsSvgItem(QString const&, QGraphicsItem*)'

SGaist

Are you linking the svg module ?

JoeCFD

in pro
QT += svg
in cmake
find_package(Qt5 REQUIRED ... Svg ... )

Sucharek

Hi @JoeCFD, I added svg in .pro file, but I don't know is in cmake

JoeCFD

@Sucharek that may be good enough for you after you put it into pro file. I use both.

Sucharek

Hi @JoeCFD, ok I just realised that I put it in a wrong thing in my .pro file, and when I put it right, it works. I don't know where the cmake file is, but it doesn't matter not because it works.
But I have another problem, you see, I have a dark and light mode in my app, and when I switch, QGraphicsView makes 2 lines on the edges of the image. I tried "ui->graphicsview->scene()->clear", but that just crashes the application. This is how the lines look:

JoeCFD

override this one and define the size of your pic
QRectF boundingRect() const

Sucharek

@JoeCFD, ok I tried that, but it doesn't seem to be working...
It doesn't display anything. Here's what it displays:
My code:

QPixmap left(":/hands/handLeftDark.svg");
QRectF size(150, 150, 150, 150);
ui->graphicsView_LeftHand->scene()->addPixmap(left);
ui->graphicsView_LeftHand->setSceneRect(size);

Sucharek

Hi, so I solved it by doing "ui->graphicsView_LeftHand->scene()->removeItem(svgLeftDark);" and then adding the other svg.
So it's like this:

QGraphicsScene *sceneLeft = new QGraphicsScene(this);
ui->graphicsView_LeftHand->setScene(sceneLeft);

QGraphicsSvgItem *add = new QGraphicsSvgItem("path/to/svg.svg");
QGraphicsSvgItem *remove = new QGraphicsSvgItem("path/to/svg.svg");

ui->graphicsView_LeftHand->scene()->removeItem(remove); //remove the svg that you don't want
ui->graphicsView_LeftHand->scene()->addItem(add); //add the svg that you want

If you want to have it across different voids, just add this at the top of the .cpp file (where you declare cross void variables, ...):

QGraphicsSvgItem *add = new QGraphicsSvgItem("path/to/svg.svg");
QGraphicsSvgItem *remove = new QGraphicsSvgItem("path/to/svg.svg");