QGraphicsView: Images doesn't fit view frame

[janck]

It seems that there is no solution for QGraphicsView. I'm looking at QLabel which also provides support for QPixmap and looks it's easier to show image in here. What would be the command for fitting image into QLabel, because scaledContents only scale image, so it doesn't keep ratio?

[wysota]

There is no equivalent. You can implement a custom widget that does what you want or use QGraphicsView. I assure you the latter works, I've used in many times like that. However implementing a custom widget is very easy.

[janck]

I found another code on web and adjusted it to my project, but it's same as before. I really don't know what could be wrong and as well I don't understand you last tips - probably because I'm into Qt only few weeks. Here is my current code:

image = new QImage(filePath);
scn = new QGraphicsScene(this);
ui->graphicsView->setScene(scn);
scn->addPixmap(QPixmap::fromImage(*image));
scn->setSceneRect(0,0,image->width(),image->height());
ui->graphicsView->fitInView(scn->sceneRect(),Qt::KeepAspectRatioByExpanding);

image = new QImage(filePath);
scn = new QGraphicsScene(this);
ui->graphicsView->setScene(scn);
scn->addPixmap(QPixmap::fromImage(*image));
scn->setSceneRect(0,0,image->width(),image->height());
ui->graphicsView->fitInView(scn->sceneRect(),Qt::KeepAspectRatioByExpanding);

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What can I do to fit image into this frame?

Thank you very much!

[wysota]

I already told you -- you cannot call fitInView() before the view is first shown because it has no size yet. You can find as many "codes on web" but they will all fail because of the same reason. You need to do as I told you -- call fitInView() when the view is already visible.

[janck]

Ok, I see what's the problem. But how can I do that image would fit the frame on setup of dialog?

[wysota]

Am I wasting my time here? Did you read post #11? You have two possible solutions there. And in #13 there is a suggestion to implement a custom widget that draws a resized pixmap. It's as easy as subclassing QWidget, reimplementing its paintEvent() and calling QPainter::drawPixmap().

[janck]

Sorry, I didn't know that showEvent() also exists for Dialogs. This solved my problem, so thank you!