soundmixercontainer.cpp

A sound mixer example in Symbian OS, see readme.txt for details

   /*
    *
============================================================================
    *  Name     : SoundMixerContainer.cpp
    *  Part of  : SoundMixer
    *  Created  : 03/01/2003 by Forum Nokia
    *  Description:
    *     This is the project specification file for SoundMixer.
    *
    *  Version  : 1.0.0
    *  Copyright: Forum Nokia
    *
============================================================================
    */


#include "SoundMixerContainer.h"
#include <eikenv.h>
#include "CSndMixer.h"
#include "CWavLoader.h"

void CSoundMixerContainer::ConstructL(const TRect& aRect)
    {

	// load sound samples
	CWavLoader* wavLoader = CWavLoader::NewLC();

	iMusicSample = wavLoader->LoadL(_L("music2.wav") );
	iEffectSample = wavLoader->LoadL( _L("effect.wav") );
	iEffectSample2 = wavLoader->LoadL( _L("effect2.wav") );

	CleanupStack::PopAndDestroy( wavLoader );

	// create sound mixer
	iSndMixer = CSndMixer::NewL();

	// make iMusicSample repeat itself
	iMusicSample.iRepEnd = iMusicSample.iLength;

	// and play music on channel 0 at 16KHz with volume 256 ( max )
	iSndMixer->Play( iMusicSample, 0, 16000, 256 );

    CreateWindowL();

	// create periodic timer to move blocks
    iTimer = CPeriodic::NewL( EPriorityNormal );

	// initial positions and speeds for blocks
	TInt i;
	for( i=0; i<8; i++ )
		{
		iSpeed[ i ] = TPoint( ( i & 3 ) -1, ( ( i+2 ) & 3 ) -1 );
		iPosition[ i ] = TPoint( 10 + i * 10, 100 );
		}

    SetRect( aRect );
    ActivateL();

	// make this class observe changes is foreground events
	// to stop blocks and sound when application is inactive
	CEikonEnv::Static()->AddForegroundObserverL( *this );
    }

CSoundMixerContainer::~CSoundMixerContainer()
    {
	iTimer->Cancel();
	delete iTimer;

	delete iSndMixer;
	delete iMusicSample.iData;
	delete iEffectSample.iData;
	delete iEffectSample2.iData;
    }

TKeyResponse CSoundMixerContainer::OfferKeyEventL( const TKeyEvent& aKeyEvent, TEventCode aType )
	{
	// here's the place for getting key events

	// set volume control to joystick's left / right
	if( aType == EEventKeyDown )
		{
		if( aKeyEvent.iScanCode == EStdKeyLeftArrow )
			{
			VolumeDown();
			}
		if( aKeyEvent.iScanCode == EStdKeyRightArrow )
			{
			VolumeUp();
			}
		}
	return EKeyWasConsumed;
	}


TInt CSoundMixerContainer::TimerCallBack( TAny* aPtr )
	{
	return ((CSoundMixerContainer*)aPtr)->DoTimer();
	}

TInt CSoundMixerContainer::DoTimer()
	{
	// here's everything moving and sounding

	// get gc to draw with
	CWindowGc& gc = SystemGc();

	gc.Activate( Window() );
	gc.Clear();
	gc.SetPenStyle(CGraphicsContext::ENullPen);
    gc.SetBrushColor( TRgb( 255,0,0 ) );
    gc.SetBrushStyle( CGraphicsContext::ESolidBrush );


	for( TInt i=0; i<8; i++ )
		{
		TBool edgeCollide = EFalse;	// flag for boxes colliding against walls
		TBool boxCollide = EFalse;	// flag for boxes colliding each other

		TPoint& pos = iPosition[ i ];
		TPoint& spd = iSpeed[ i ];

		// move blocks
		pos += spd;

		TRect rect = Rect();

		// check box collide against walls
		if( ( pos.iX+8 >= rect.iBr.iX ) || ( pos.iX <= rect.iTl.iX ) )
			{
			spd.iX = -spd.iX;
			pos += spd;
			edgeCollide = ETrue;
			}

		if( ( pos.iY+8 >= rect.iBr.iY ) || ( pos.iY <= rect.iTl.iY ) )
			{
			spd.iY = -spd.iY;
			pos += spd;
			edgeCollide = ETrue;
			}


		// check box collide against each other
		TRect boxRect( pos, TSize( 8,8 ) );
		for( TInt j=0; j<8; j++ )
			{
			TRect boxRect2( iPosition[ j ], TSize( 8,8 ) );
			if( ( i != j ) && ( boxRect.Intersects( boxRect2 ) ) )
				{
				spd.iY = -spd.iY;
				spd.iX = -spd.iX;
				boxCollide = ETrue;
				}
			}

		// play sounds if collide
		if( edgeCollide )
			{
			iSndMixer->Play( iEffectSample, 1 + i, 8000 + i * 1000, 32 );
			}

		if( boxCollide )
			{
			iSndMixer->Play( iEffectSample2, 1 + i, 8000 + i * 1000, 32 );
			}


		// draw current box
		gc.DrawRect( boxRect );

		}

	gc.Deactivate();
	return ETrue;
	}


void CSoundMixerContainer::HandleGainingForeground()
	{
	// application gets focused
	// this function is called first time when application starts
	// that's why there's no need to start timer and sound in constructor

	iTimer->Start( 10000, 10000, TCallBack( TimerCallBack, this ) );
	iSndMixer->Resume();
	}

void CSoundMixerContainer::HandleLosingForeground()
	{
	// application loses focus
	// so stop moving blocks and playing sound

	iTimer->Cancel();
	iSndMixer->Pause();
	}


void CSoundMixerContainer::StartMixer()
	{
	iSndMixer->Resume();
	}

void CSoundMixerContainer::StopMixer()
	{
	iSndMixer->Pause();
	}

void CSoundMixerContainer::VolumeUp()
	{
	TInt volume = iSndMixer->Volume();
	volume += 20;
	if( volume > 255 ) volume = 255;
	iSndMixer->SetVolume( volume );
	}

void CSoundMixerContainer::VolumeDown()
	{
	TInt volume = iSndMixer->Volume();
	volume -= 20;
	if( volume < 0 ) volume = 0;
	iSndMixer->SetVolume( volume );
	}