S60 3rd Edition SDK for Symbian OS Example Applications Guide

SnowContainer.h

/*
* ==============================================================================
*  Name        : SnowContainer.h
*  Part of     : OpenGLEx / Snow
*  Interface   : 
*  Description : 
*  Version     : 
*
*  Copyright (c) 2004-2006 Nokia Corporation.
*  This material, including documentation and any related 
*  computer programs, is protected by copyright controlled by 
*  Nokia Corporation.
* ==============================================================================
*/

#ifndef SNOWCONTAINER_H
#define SNOWCONTAINER_H

// INCLUDES
#include <coecntrl.h>
#include <GLES\egl.h>
#include "snow.h"
#include <akndef.h>
   
// CLASS DECLARATION

/**
 * Container control class that handles the OpenGL ES initialization and deinitializations.
 * Also uses the CSnow class to do the actual OpenGL ES rendering.
 */
class CSnowContainer : public CCoeControl, MCoeControlObserver
    {
    public: // Constructors and destructor
        
        /**
         * EPOC default constructor. Initializes the OpenGL ES for rendering to the window surface.
         * @param aRect Screen rectangle for container.
         */
        void ConstructL(const TRect& aRect);

        /**
         * Destructor. Destroys the CPeriodic, CSnow and uninitializes OpenGL ES.
         */
        virtual ~CSnowContainer();

    public: // New functions

        /**
         * Callback function for the CPeriodic. Calculates the current frame, keeps the background
         * light from turning off and orders the CSnow to do the rendering for each frame.
         *@param aInstance Pointer to this instance of CSnowContainer.
         */
        static TInt DrawCallBack( TAny* aInstance );

    private: // Functions from base classes

        /**
         * Method from CoeControl that gets called when the display size changes.
         * If OpenGL has been initialized, notifies the renderer class that the screen
         * size has changed.
         */
        void SizeChanged();

         /**
          * Handles a change to the control's resources. This method
          * reacts to the KEikDynamicLayoutVariantSwitch event (that notifies of
          * screen size change) by calling the SetExtentToWholeScreen() again so that
          * this control fills the new screen size. This will then trigger a call to the
          * SizeChanged() method.
          * @param aType Message UID value, only KEikDynamicLayoutVariantSwitch is handled by this method.
          */
        void HandleResourceChange(TInt aType); 

        /**
         * Method from CoeControl. Does nothing in this implementation.
         */
        TInt CountComponentControls() const;

        /**
         * Method from CCoeControl. Does nothing in this implementation.
         */
        CCoeControl* ComponentControl(TInt aIndex) const;

        /**
         * Method from CCoeControl. Does nothing in this implementation.
         * All rendering is done in the DrawCallBack() method.
         */
        void Draw(const TRect& aRect) const;

        /**
         * Method from MCoeControlObserver that handles an event from the observed control.
         * Does nothing in this implementation.
                 * @param aControl   Control changing its state.
                 * @param aEventType Type of the control event.
         */
        void HandleControlEventL(CCoeControl* aControl,TCoeEvent aEventType);
        
    private: //data
        
        /** Display where the OpenGL ES window surface resides. */
        EGLDisplay  iEglDisplay;
        /** Window surface where the OpenGL ES rendering is blitted to. */
        EGLSurface  iEglSurface;
        /** OpenGL ES rendering context. */
        EGLContext  iEglContext;
        
        /** Active object that is the timing source for the animation. */
        CPeriodic*  iPeriodic;

        /**
         * Flag that indicates if OpenGL ES has been initialized or not.
         * Used to check if SizeChanged() can react to incoming notifications.
         */
        TBool iOpenGlInitialized;

    public:  //data
        
        /** Frame counter variable, used in the animation. */
        TInt iFrame;
        /** Used in DrawCallBack() method to do the actual OpenGL ES rendering.  */
        CSnow* iSnow;
    };

#endif

// End of File

---

© Nokia 2006