QGraphicsView vs QOpenGLWidget?

jdlyga

I'm working on a way to switch between two different view implementations at runtime, which currently works statically. On one hand, we have a QsmGraphicsView, which is a derived class of QGraphicsView. On the other, we have QsmOpenGLWidget, which is a derived class of QOpenGLWidget.

QsmOpenGLWidget is basically a re-implementation of the QsmGraphicsView that supports adding a QGraphicsScene as well as OpenGL effects.

In order to transition over to the new QsmOpenGLWidget, we need to have a parent class that we can use to replace all of our QsmGraphicsView pointers. This works very well at compile time. Based on a #define set up in the main pro file, we either inherit from one class or another.

#ifdef OPENGL_WIDGET
#define VIEWWIDGET QsmOpenGLWidget
#else
#define VIEWWIDGET QsmGraphicsView
#endif

class QsmNewGraphicsView : public VIEWWIDGET
{
    Q_OBJECT

    public:

        explicit QsmNewGraphicsView(QWidget * parent = 0);
};

My question is if this is possible to do at runtime. So far the best solution I can come up with, to prevent a ton of duplicated code, is to write a container class like this. All functions we used a pointer to the QsmGraphicsView for, we now re-implement by using one pointer or another depending on a runtime config option.

class QsmNewGraphicsView
{
    Q_OBJECT

    public:

        QsmNewGraphicsView(QWidget * view);

        //all used functions go here

    private:

        bool m_opengl = false;

        QsmGraphicsView * graphicsView = nullptr;
        QsmOpenGLWidget * openglWidget = nullptr;
};

But I have a feeling that there's something missing, like I'm overlooking a really good design pattern or Qt feature. Since there has to be a better way than adding a thousand lines of stub functions. Thanks!

SGaist

Hi,

What kind of function do you have in common ? Can you show an example ?