Coordinates for QGraphicsView

leinad

I placed a QGraphicsView inside a tab widget using QTCreator. In QtCreator the dimensions of the graphicsView is 6, 6, 687, 319.
When I try to get the coordinates and size of the view via these commands:

int sceneStartCornerX = ui->testGridGraphicsView->x(); //X coordinate of the left to corner of the QGraphicsView (6)
int sceneStartCornerY = ui->testGridGraphicsView->y(); //Y coordinate of the left to corner of the QGraphicsView (6)
int sceneEndCornerX = ui->testGridGraphicsView->width(); //Width of the QGraphicsScene (687)
int sceneEndCornerY = ui->testGridGraphicsView->height(); //height of the QGraphicsScene (319)

the returned results are 0, 0, 100, 30

When I try to map the scene to the view and place rectItems, the items are skewed within the scene. Is there something else I need to do to make sure the ui->testGridGraphicsView values match the coordinates in QTCreator?

I know I must be missing something. The view is inside a frame if that makes a difference.

Thanks!

SGaist

Hi,

When are you requesting these values ?

leinad

In the constructor

SGaist

Until the widgets are shown they have no "physical" dimensions.

Also note that the size of the scene and the view do not necessarily match unless you made it so.

leinad

This is what I did when I created the scene.
//create the scene
scene_ = new QGraphicsScene(sceneStartCornerX_,
sceneStartCornerY_,
sceneEndCornerX,
sceneEndCornerY,
ui->testGridGraphicsView);

ui->testGridGraphicsView->setScene(scene_); //attach the scene to the view (QGraphicsView)

//smooth graphics
ui->testGridGraphicsView->setRenderHints(QPainter::SmoothPixmapTransform | QPainter::Antialiasing | QPainter::TextAntialiasing);

leinad

What do you mean until the widgets are shown? I assume the user must click on the tab. Is there a way to force it to see the dimensions without clicking on the tab?

SGaist

Why not just build a "size less" scene ?

leinad

You mean don't set the dimensions when setting up the scene?
scene = new QGraphicsScene(ui->testGridGraphicsView);

I did that with the same results.

SGaist

How are you placing the items on your scene ?

leinad

Programmatically using dimensions. It looks fine but skewed because the original sizes are incorrect.

SGaist

Please provide a minimal compilable example that reproduces that issue.

leinad

Thanks, you actually helped me resolve the issue. I created a signal/slot when the tab is selected which now shows the view. At that point I get the coordinates and they show properly.