QGraphicsTextItem Paint()

[goldhappywang]

hello, I overrided the paint() in the class QGraphicsTextItem
the Code


void Tag::paint(QPainter *item,const QStyleOptionGraphicsItem *option,QWidget *widget)
{
QRectF rect = boundingRect();
item->drawRect(rect);
}


but the rect only display the top and left frame lines
the bottom and right frame lines disappear

thanks

[wysota]

That's perfectly normal. Read QRect docs about the right() and bottom() members.

[scascio]

Why is it perfeclty normal? The painter cannot draw it correctly?

Isn't it a question of antialiasing?

[goldhappywang]

That's OK


rect.setBottomRight(QPointF(rect.x() +100, rect.y()+100));


thanks a lot!

I have another problem, how to change the line space?

[wysota]

Why is it perfeclty normal? The painter cannot draw it correctly?

Isn't it a question of antialiasing?

It's a question of interpreting QRect. For historical reasons its bottom and right values are decreased by 1. Antialiasing is another thing but GV should compensate for it automatically.

[Scorp2us]

A box of height and width of 40 at 0,0 takes pixels 0-39 to draw. Now, if you draw a box that fits in that, and you measure, you'll get pixels 1-38 as the difference between the lines. This creates a problem, because your drawn with is no where near the 40 width your rect indicated. What you have to do is pic the next-highest pixel. So you end up drawing on 0 and 40. But the 40th pixel is clipped. I've seen this done in many different packages and it is "right".