[FIXED] Subclassing QGraphicsLayoutItem to display a pixmap

Issue

I was trying to have a QGraphicsPixmapItem into a QGraphicsLinearLayout. Since that is not possible, because QGraphicsPixmapItem is not a QGraphicsLayoutItem, I am trying to subclass the latter, and make it work like a pixmap item.

Here's my failing attempt:

from PySide import QtGui, QtCore
import sys

class MyItem(QtGui.QGraphicsLayoutItem):
  def __init__(self, image, parent=None):
    super().__init__(parent)
    self.gitem = QtGui.QGraphicsPixmapItem()
    self.gitem.setPixmap(QtGui.QPixmap(image))

  def sizeHint(which, constraint, other):
    return QtCore.QSizeF(200, 200)

  def setGeometry(self, rect):
    self.gitem.setPos(rect.topLeft())

  def graphicsItem(self):
    #does not get called
    return self.gitem

def setGraphicsItem(self, item):
    self.gitem = item

class Application(QtGui.QGraphicsView):
  def __init__(self, parent=None):
    super().__init__(parent)
    gwidget = QtGui.QGraphicsWidget()
    layout = QtGui.QGraphicsLinearLayout()
    layout.addItem(MyItem(r'C:\image1.jpg'))
    layout.addItem(MyItem(r'C:\image2.jpg'))
    gwidget.setLayout(layout)
    scene = QtGui.QGraphicsScene()
    scene.addItem(gwidget)
    self.setScene(scene)

app = QtGui.QApplication(sys.argv)
main = Application()
main.show()
sys.exit(app.exec_())

And as evident from the comment, the graphicsItem() method does not get called, and I end up with a super-white milky graphics view.

How do I achieve this, dear Qt scientists.

Solution

graphicsItem is not virtual. That's why Qt doesn't call it. It seems you need to call setGraphicsItem in your constructor and remove graphicsItem and setGraphicsItem methods from your class. Reimplementing non-virtual functions doesn't make any sense.

Answered By - Pavel Strakhov