qgraphicsitem

Aim is to connect a signal of the top class TicTacToe with the QMainWindow class. It throws an error: TicTacToe cannot be converted to PyQt5.QtCore.QObject in this context #!/usr/bin/env python from PyQt5.QtCore import (QLineF, QPointF, QRectF, pyqtSignal) from PyQt5.QtGui import (QIcon, QBrush, QColor, QPainter, QPixmap) from PyQt5.QtWidgets import (QAction, QMainWindow, QApplication, QGraphicsView, QGraphicsScene, QGraphicsItem, QGridLayout, QVBoxLayout, QHBoxLayout, QLabel, QLineEdit, QPushButton) class TicTacToe(QGraphicsItem): def __init__(self): super(TicTacToe, self).__init__() def

Is there a way to restrict the area where a QGraphicsItem like QRect can be moved when setFlag(ItemIsMovable) is set? I'm new to pyqt and trying to find a way to move an item with the mouse, and the restrict it to only vertically/horizontally. If you want to keep a limited area you can reimplement the ItemChanged() Declare: #ifndef GRAPHIC_H #define GRAPHIC_H #include <QGraphicsRectItem> class Graphic : public QGraphicsRectItem { public: Graphic(const QRectF & rect, QGraphicsItem * parent = 0); protected: virtual QVariant itemChange ( GraphicsItemChange change, const QVariant & value ); };

I have custom ellipse QGraphicsItem class and custom line class. On scene I have let's say two ellipses and connection made between them by a line. Ellipse has a pointer to this line and is movable. My problem is that I dont know how to use itemChange() from QGraphicsItem . I want to make connection which will be changing with ellipse movement. So I want to use itemChange() method to change line coordinates in a way that it always will be in center of ellipse. I read documentation from QGraphicsItem::itemChange() but I don't know how to use it in my case. As others have already noted, you need

Use case: This should be a fairly common problem. In a normal QMainWindow with QMdiArea lives an mdiChild with a QGraphicsView. This view displays a QGraphicsScene with QGraphicsItems inside. A right-click at one of these items selects (focusses) the item and opens a context menu, which is conveniently placed at the screen coordinates QGraphicsSceneMouseEvent::screenPos() . This is working as expected. Now I'd like to show the same context menu when the user presses a key (e.g. Qt::Key_Menu). I know the selected (focussed) item, I know the view which displays the scene. So my question is: What