QGraphicsView::centerOn not working propery in 4.6

[deca5423]

Nope, default is center according to the api. The alignment also isn't associated with QGraphicsScene, it's with QGraphicsView:

"For example, if the alignment is Qt::AlignCenter, which is default, the scene will be centered in the view", but this apparently only holds true "If the whole scene is visible in the view", which it is not when the offset lines are drawn.

If you look at the code with the commented section... I draw a picture (QImage) and I display two lines that show x and y offsets associated with the picture. If I don't draw those lines centerOn works fine. Otherwise the picture gets crammed in the top left corner. I'll try specifically setting the alignment to center, even though both the 4.5 and 4.6 state the default is Qt::AlignCenter and I'm using default. I'll try it when I get home but I can't imagine this being the problem.

[wysota]

The alignment also isn't associated with QGraphicsScene, it's with QGraphicsView:

I never said it was associated with the scene.

If you look at the code with the commented section... I draw a picture (QImage) and I display two lines that show x and y offsets associated with the picture. If I don't draw those lines centerOn works fine. Otherwise the picture gets crammed in the top left corner. I'll try specifically setting the alignment to center, even though both the 4.5 and 4.6 state the default is Qt::AlignCenter and I'm using default. I'll try it when I get home but I can't imagine this being the problem.

Could you provide a minimal compilable example reproducing the problem?

[dchow]

I too was having some problems with QGraphicsView::centerOn... so I tried using QGraphicsView::fitInView. This turned out to work really great for my needs. Although, to use it you have specify the exact rectangle that you'd like to see in the View (or the QGraphicsItem), so if you want to see more than just the QGraphicsItem then you need to make sure the rectangle you specify is larger than that item.

Another thing you could do, if your graphical item is always the same size, is to use fitInView to set the View on the graphical item, then use scale to zoom out some amount.

Lastly, if you don't want to change the scale of your view, then don't use fitInView, since it will adjust the transformation matrix (and zoom in/out accordingly).

Good Luck!