Moving QGraphicsItem with mouse

[BrainFreeze]

I've starting experimenting with QGraphicsScene, QGraphicsView, and have a problem I don't understand. I can move a QGraphicsItem with the mouse, but it can be moved outside of the scene (sceneRect?). I noticed this when I zoom out to see the whole scene. Is there a way to keep the item inside the scene?

[tbscope]

Yes, check the coordinates of the item and prevent them to get outside the scene.

[totem]

to monitor graphicsItem position change, take a look at QGraphicsItem::itemChange()

[BrainFreeze]

to monitor graphicsItem position change, take a look at QGraphicsItem::itemChange()

Being a beginner, I haven't ever written a custom item, no idea how. Can you direct me to a tutorial for that? As for my beginning experiments, I'm using a QGraphicsItem rather than a custom item. Does your suggestion apply to that, too? This is all new to me, so any tutorials you can suggest would be helpful. Thanks in advance.

[wysota]

Just follow the link you were given.

[BrainFreeze]

Just follow the link you were given.

That's not a tutorial, it's just a code snippet

[wysota]

So... you expect to have a tutorial about what? Using a single method? How would such a tutorial be different from the documentation of this method showing an example of use?

[BrainFreeze]

So... you expect to have a tutorial about what? Using a single method? How would such a tutorial be different from the documentation of this method showing an example of use?

I requested a tutorial on how to create a custom item. I've never done that, and have no idea how. Sorry if I wasn't clear on that.

[wysota]

QGraphicsItem

[JohannesMunk]

Try that link! Suspense rises until you hit:

"To write your own graphics item, you first create a subclass of QGraphicsItem, and then start by implementing its two pure virtual public functions: boundingRect(), which returns an estimate of the area painted by the item, and paint(), which implements the actual painting. For example: "

Don't take this the wrong way! Good luck with your first custom item!

Johannes