qgraphicsscene

I would like to write a simple program in Python with PyQt. I have a QGraphicsScene and I would like to do the following: There are 2 options using two RadioButtons: For generating points. This way if someone clicks on the scene an ellipse will appear. For selecting points. This way if someone clicks on a point the selected point will be returned. I'm kinda new at PyQt and also at GUI programming. My main problem is that I don't really understand how mouse events work in Qt. If someone was so kind and patient to explain me the basics of mouse events and gave me some tipps for the problem

How can I toggle the QPen color for the selected graphicsview items? Ideally I would like to handle this color change in the graphicsview or graphics scene objects rather than directly handling it in the main windows selection event. Any help is appreciated. Currently it will turn the pen color white when the object is selected. I'm not sure how to turn it back avoiding looping through all objects. Is there a way i could add a function in the MyGraphicsView class itself that would handle the color change of the pen for any and all selected items in the graph? Update: More detailed information

Ok so I've got a QGraphicsScene in a class called eye. I call a function: void eye::playSequence(int sequenceNum) { for (int i=0; i<sequences[sequenceNum].numberOfSlides(); i++) { presentSlide(sequenceNum, i); time_t start; time(&start); bool cont=false; while (!cont) { time_t now; time(&now); double dif; dif=difftime(now, start); if (dif>5.0) cont=true; } } } which for each slide calls: void eye::presentSlide(int sequenceNum, int slideNum) { Slide * slide=sequences[sequenceNum].getSlide(slideNum); QGraphicsPixmapItem * pic0=scene.addPixmap(slide->getStimulus(0)->getImage()); pic0->setPos(0,0)

I have a QGraphicsScene which contains custom objects (with QGraphicsItem as base class). I can retrieve these objects with: foreach (QGraphicsItem* item, items()) { if (item->type() == CustomItem::Type) qgraphicsitem_cast<CustomItem*>(item).doStuff(...); } Is it possible to write a custom iterator for just this type of objects? I want to be able to use range-based for-loops and algorithms from the STL. for(CustomItem& a : custom_items()) a.doStuff(...); I want to avoid storing pointers to these objects manually (for example in a vector) since this involves additional book-keeping when objects

I've got an application where you can watch replays for a given 2D game : Basically, a vehicle is moving on a map. The view is centered on vehicle so the map is scrolling as replay is playing, something Micro Machines -like (it's just to give an idea, the actual game is not Micro Machines ). (source: randomracket.com ) In my scene, the map is static while the vehicle is moving around. The view is scrolling for each frame of the replay, so that vehicle is centered. For performance reason, the map is tiled in several QGraphicsPixmapItem s. Viewport update mode is set to QGraphicsView:

I'm messing around with QGraphicsView and QGraphicsScene to create a Tic Tac Toe clone. I add some QGraphicsLineItem s to my scene and override the resizeEvent method of the Widget that contains the view, so that when the window is resized, the view and its contents are scaled appropriately. This works fine, except for the first time that I run the program: Once I resize the window by any amount, the scene is scaled correctly: Here's the code: main.cpp: #include <QtGui> #include "TestApp.h" int main(int argv, char **args) { QApplication app(argv, args); TestApp window; window.show(); return