demoitem.py 文件源码

def _validateImage(self):
        if (self._sharedImage.transform != DemoItem._transform and not Colors.noRescale) or (self._sharedImage.image is None and self._sharedImage.pixmap is None):
            # (Re)create image according to new transform.
            self._sharedImage.image = None
            self._sharedImage.pixmap = None
            self._sharedImage.transform = DemoItem._transform

            # Let subclass create and draw a new image according to the new
            # transform.
            if Colors.noRescale:
                transform = QTransform()
            else:
                transform = DemoItem._transform
            image = self.createImage(transform)
            if image is not None:
                if Colors.showBoundingRect:
                    # Draw red transparent rect.
                    painter = QPainter(image)
                    painter.fillRect(image.rect(), QColor(255, 0, 0, 50))
                    painter.end()

                self._sharedImage.unscaledBoundingRect = self._sharedImage.transform.inverted()[0].mapRect(QRectF(image.rect()))

                if Colors.usePixmaps:
                    if image.isNull():
                        self._sharedImage.pixmap = QPixmap(1, 1)
                    else:
                        self._sharedImage.pixmap = QPixmap(image.size())

                    self._sharedImage.pixmap.fill(QColor(0, 0, 0, 0))
                    painter = QPainter(self._sharedImage.pixmap)
                    painter.drawImage(0, 0, image)
                else:
                    self._sharedImage.image = image

                return True
            else:
                return False

        return True