qgraphicsview

问题 I want to implement arc in QGraphicsScene. I want that on clicking of three points my arc should be drawn such that on clicking of three points arc is drawn where first point will be starting of arc, second will be any point on arc and third will be end point of arc. I have tried studing drawArc function but got confused with startangle and spanangle. I was unable to set them dynamically. Please suggest me some way to proceed. I tried the solution to embend it in my project but got the

问题 I have an application with a QGraphicsView window in the middle of the screen. I want to be able to zoom in and out using a mouse wheel scroll. Currently I have re-implemented QGraphicsView and overriden the mouse scroll function so that it doesn\'t scroll the image (like it does by default). void MyQGraphicsView::wheelEvent(QWheelEvent *event) { if(event->delta() > 0) { emit mouseWheelZoom(true); } else { emit mouseWheelZoom(false); } } so when I scroll, I\'m emitting a signal true if mouse

问题 I am using python and Qt Designer to implement loading tiff images and to enable Pan and Zoom on some mouse event (wheel - zoom, press wheel - pan). I was looking into some options and classes that can work with images etc, and so far I have found: QGraphicsScene, QImage, QGraphicsView I have three classes (just testing) ViewerDemo which have QGraphicsView element: \"\"\"description of class\"\"\" # Form implementation generated from reading ui file \'GraphicsViewdemo.ui\' try: _fromUtf8 =