I want to paint selection grips on a QGraphicsRectItem. Currently, I do this by overriding the paint event.



Qt Code: 
  1. void GraphicNode::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget) {
  2.     drawShape(painter);
  3.  
  4.     if (this->isSelected())
  5.         drawSelectionGrips(painter);
  6.  
  7.     if (this->associatedNode)
  8.         drawLabel(painter);
  9. }
  10.  
  11. void GraphicNode::drawSelectionGrips(QPainter *painter) {
  12.     painter->setPen(Qt::SolidLine);
  13.     painter->setPen(Qt::black);
  14.     painter->setBrush(Qt::black);
  15.  
  16.     painter->drawRect(this->boundingRect().x(), this->boundingRect().y(), GRIPSIZE, GRIPSIZE);
  17.  
  18.     int topRightX = this->boundingRect().x() + this->boundingRect().width() - GRIPSIZE - SHADOWSIZE;
  19.     painter->drawRect(topRightX, this->boundingRect().y(), GRIPSIZE, GRIPSIZE);
  20.  
  21.     int bottomLeftY = this->boundingRect().y() + this->boundingRect().height() - GRIPSIZE - SHADOWSIZE;
  22.     painter->drawRect(this->boundingRect().x(), bottomLeftY, GRIPSIZE, GRIPSIZE);
  23.  
  24.     int bottomRightX = this->boundingRect().x() + this->boundingRect().width() - SHADOWSIZE;
  25.     int bottomRightY = this->boundingRect().y() + this->boundingRect().height() - SHADOWSIZE;
  26.     painter->drawRect(bottomRightX - GRIPSIZE, bottomRightY - GRIPSIZE, GRIPSIZE, GRIPSIZE);
  27.  
  28.     painter->setPen(Qt::DotLine);
  29.     painter->setBrush(Qt::transparent);
  30.     painter->drawRect(this->boundingRect().x(), this->boundingRect().y(), this->boundingRect().width() - SHADOWSIZE, this->boundingRect().height() - SHADOWSIZE);
  31. }
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I want the cursor to change when the user hovers over the selection grips, so I was thinking I'd convert them into four QGraphicsRectItems and use setCursor to modify the cursor.

In the constructor:
Qt Code: 
  1. this->topLeftGrip = new QGraphicsRectItem();
  2.     this->topLeftGrip->setCursor(Qt::SizeFDiagCursor);
  3.     this->topLeftGrip->setPen(QPen(Qt::black));
  4.     this->topLeftGrip->setBrush(QBrush(Qt::black));
  5.     this->topRightGrip = new QGraphicsRectItem();
  6.     this->topRightGrip->setCursor(Qt::SizeBDiagCursor);
  7.     this->topRightGrip->setPen(QPen(Qt::black));
  8.     this->topRightGrip->setBrush(QBrush(Qt::black));
  9.     this->bottomLeftGrip = new QGraphicsRectItem();
  10.     this->bottomLeftGrip->setCursor(Qt::SizeFDiagCursor);
  11.     this->bottomLeftGrip->setPen(QPen(Qt::black));
  12.     this->bottomLeftGrip->setBrush(QBrush(Qt::black));
  13.     this->bottomRightGrip = new QGraphicsRectItem();
  14.     this->bottomRightGrip->setCursor(Qt::SizeBDiagCursor);
  15.     this->bottomRightGrip->setPen(QPen(Qt::black));
  16.     this->bottomRightGrip->setBrush(QBrush(Qt::black));
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In the selection drawing function:
Qt Code: 
  1. this->topLeftGrip->setRect(this->boundingRect().x(), this->boundingRect().y(), GRIPSIZE, GRIPSIZE);
  2.     this->topLeftGrip->setVisible(true);
  3.  
  4.     int topRightX = this->boundingRect().x() + this->boundingRect().width();
  5.     this->topRightGrip->setRect(topRightX, this->boundingRect().y(), GRIPSIZE, GRIPSIZE);
  6.     this->topRightGrip->setVisible(true);
  7.  
  8.     int bottomLeftY = this->boundingRect().y() + this->boundingRect().height() - GRIPSIZE - SHADOWSIZE;
  9.     this->bottomLeftGrip->setRect(this->boundingRect().x(), bottomLeftY, GRIPSIZE, GRIPSIZE);
  10.     this->bottomLeftGrip->setVisible(true);
  11.  
  12.     int bottomRightX = this->boundingRect().x() + this->boundingRect().width() - SHADOWSIZE;
  13.     int bottomRightY = this->boundingRect().y() + this->boundingRect().height() - SHADOWSIZE;
  14.     this->bottomRightGrip->setRect(bottomRightX - GRIPSIZE, bottomRightY - GRIPSIZE, GRIPSIZE, GRIPSIZE);
  15.     this->bottomRightGrip->setVisible(true);
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I don't see any selection grips when I use the QGraphicsRectItem approach. Did I forget something important? Is there a better way to draw the selection grips? (Keep in mind that my object also uses drop shadow, so I may not be able to use Qt's built-in selection features.)