plClientWindow.h

class plClientWindow
{
protected:
    pcSmallRect fWindowSize;

public:
    plClientWindow() : fWindowSize(0, 0, 800, 600) { }
    virtual ~plClientWindow() = default;

    /**
     * Does any necessary pre-initialization work to set up/configure the
     * environment before trying to create a window.
     *
     * Returns false on failure, which will stop the client launch.
     */
    virtual bool PreInit() { return true; }

    /**
     * Creates the client window, but does not display it on the screen.
     *
     * Returns false on failure, which will stop the client launch.
     */
    virtual bool CreateClientWindow() = 0;

    /**
     * Makes the client window visible on the screen.
     */
    virtual void ShowClientWindow() = 0;

    /**
     * Process any OS/Window events that are in the queue.
     *
     * This essentially runs the event loop until there are no more messages,
     * then returns to allow the plClient MainLoop to continue.
     *
     * Returns false on an exit message, which will cause plClient to quit.
     */
    virtual bool ProcessEvents(plClient* client) = 0;

    /**
     * Does any necessary cleanup work to deinitialize the window.
     */
    virtual void DeInit() = 0;

    virtual hsWindowHndl GetWindowHandle() const = 0;
    virtual hsWindowHndl GetDisplayHandle() const = 0;
};