QGraphicsItem subclass access to QGraphicsView size

[rubenvb]

Hi,

I would like to draw an arrow inside a QGraphicsScene linked to a QGraphicsview, but the arrow needs to reach from the left-bottom of the view to the right-bottom of the view. It also needs to move and stay +/- 10 pixels above the bottom. It should always be in view, but resize only one line (no transformation).
Something like this:
|-------------------->|
resized:
|---------------------------------------->|
note the arrow pointer thing (>) has not changed size.
It almost seems like I need to make a QPainterPath with three lineTo's and one moveTo, where one lineTo is subject to normal transformation, but the rest isn't.
My conclusion would be QPainterPath isn't what I'm looking for; maybe a QList<QGrapicsLineItem> is what I need. What do you think?

Thanks

[ecanela]

if only need to draw a arrow in the top of the view is more simple subclass a view and draw the arrow in the drawForeground() function

class CustomView : public QGraphicsView
{
public:
   explicit CustomView ( QWidget * parent = 0 )
        : QGraphicsView (parent){};
 
protected:
void drawForeground ( QPainter * painter, const QRectF & rect )
    {
        painter->setPen(QPen(Qt::red,3));
        painter->drawLine( rect.topLeft(), rect.bottomRight() );
        painter->drawLine( rect.topRight(), rect.bottomLeft() );
     }
};

class CustomView : public QGraphicsView
{
public:
   explicit CustomView ( QWidget * parent = 0 )
        : QGraphicsView (parent){};
    
protected:
void drawForeground ( QPainter * painter, const QRectF & rect )
    {
        painter->setPen(QPen(Qt::red,3));
        painter->drawLine( rect.topLeft(), rect.bottomRight() );
        painter->drawLine( rect.topRight(), rect.bottomLeft() );
     }
};

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this draw a big X in the view.
convert the code to draw a arrow must be trivial. but is late and i want to sleep

[rubenvb]

That looks like a good idea, that way I won't have to worry about getting parent widget coordinates.

One question though: will it be possible to "print" the whole scene (including the arrows) to an image, or will the arrow not be included because it's not part of the scene?

Thanks!

[rubenvb]

Note to self, must read docs:
http://doc.trolltech.com/4.2/qgraphicsview.html#render

It is the view that is rendered to the printer, not the scene, so drawing on the foreground it is!

thanks again

[wysota]

There is also QGraphicsScene::render().