wavegen_view.cpp

symbian学习音乐播放的源代码

//
// wavegen_view.cpp
//
// Copyright (C) 2005 Nokia Corporation. All rights reserved.
//
///////////////////////////////////////////////////////////////////////////////

// INCLUDE FILES
#include <avkon.hrh>
#include <avkon.rsg>
#include <akntitle.h>
#include <aknviewappui.h>
#include <wavegen.rsg>
#include "wavegen_view.h"
#include "wavegen_listbox.h"

#include "wavegen_engine.h"

// CONSTANTS
// Possible UIDs of view.
const TUid KViewId1 = { EGenerator };
const TUid KViewId2 = { EFilePlayer };

// max length of a status pane title text
const TInt KWaveGenTitleBufLength = 32;


//
// CWaveGenView class
//
/*
-------------------------------------------------------------------------------
    NewL

    Description: Standard Symbian NewL constructor

    Return Value: Pointer to a newly-created CWaveGenView object.
-------------------------------------------------------------------------------
*/
CWaveGenView* CWaveGenView::NewL(CStreamAudioEngine* aEng, TPlaybackMode aMode)
    {
    CWaveGenView* self = NewLC(aEng, aMode);
    CleanupStack::Pop(); // self
    return self;
    }


/*
-------------------------------------------------------------------------------
    NewLC

    Description: Standard Symbian NewLC constructor

    Return Value: Pointer to a newly-created CWaveGenView object, which is also
                  left in the cleanup stack
-------------------------------------------------------------------------------
*/
CWaveGenView* CWaveGenView::NewLC(CStreamAudioEngine* aEng, TPlaybackMode aMode)
    {
    CWaveGenView* self = new (ELeave) CWaveGenView(aEng, aMode);
    CleanupStack::PushL(self);
    self->ConstructL();
    return self;
    }


/*
-------------------------------------------------------------------------------
    ConstructL

    Description: Standard 2nd phase constructor (called by NewLC)

    Return Value: N/A
-------------------------------------------------------------------------------
*/
void CWaveGenView::ConstructL()
    {
    BaseConstructL();
    }


/*
-------------------------------------------------------------------------------
    CWaveGenView

    Description: Constructor
-------------------------------------------------------------------------------
*/
CWaveGenView::CWaveGenView(CStreamAudioEngine* aEng, TPlaybackMode aMode)
:   iEng(aEng),
    iListBox(NULL),
    iMode(aMode)
    {
    }

/*
-------------------------------------------------------------------------------
    ~CWaveGenView

    Description: Destructor
-------------------------------------------------------------------------------
*/
CWaveGenView::~CWaveGenView()
    {
    if (iListBox)
        {
        AppUi()->RemoveFromStack(iListBox);
        }

    delete iListBox;    
    }

/*
-------------------------------------------------------------------------------
    Id
    
    Description: Returns ID of this view

    Return Value: TUid
-------------------------------------------------------------------------------
*/
TUid CWaveGenView::Id() const
    {
    return (iMode == EGenerator) ? KViewId1 : KViewId2;
    }

/*
-------------------------------------------------------------------------------
    HandleCommandL

    Description: Menu command handler

    Return Value: N/A
-------------------------------------------------------------------------------
*/
void CWaveGenView::HandleCommandL(TInt aCommand)
    {	
    switch (aCommand) 
        {        
        case EWaveGenCmdPlay:
            iEng->PlayL();
            break;
        
        case EWaveGenCmdStop:
            iEng->StopL();
            break;    
            
        default:
            break;
        }
    }

/*
-------------------------------------------------------------------------------
    CreateListBoxL

    Description: constructs and activates a new listbox from a specified 
                 resource

    Return Value: N/A
-------------------------------------------------------------------------------
*/
void CWaveGenView::CreateListBoxL(TInt aResourceId)
    {
    DeleteListBox();

    iListBox = new (ELeave) CWaveGenListbox(iEng);      
    
    iListBox->SetMopParent(this);
    iListBox->ConstructFromResourceL(aResourceId);
    AppUi()->AddToStackL(*this, iListBox);
    iListBox->MakeVisible(ETrue);
    iListBox->SetRect(ClientRect());
    iListBox->ActivateL();
    iListBox->DrawNow();    
    }


/*
-------------------------------------------------------------------------------
    DeleteListBoxL

    Description: deletes and the listbox and removes it from control stack

    Return Value: N/A
-------------------------------------------------------------------------------
*/
void CWaveGenView::DeleteListBox()
    {
    if (iListBox)
        {
        AppUi()->RemoveFromStack(iListBox);
        }

    delete iListBox;
    iListBox = 0;
    }

/*
-------------------------------------------------------------------------------
    SetTitlePaneTextL

    Description: Sets the title pane text from resource

    Return Value: N/A
-------------------------------------------------------------------------------
*/
void CWaveGenView::SetTitlePaneTextL(const TInt aResourceId)
    {    
    CAknTitlePane* titlePane = static_cast<CAknTitlePane*>
        (StatusPane()->ControlL(TUid::Uid(EEikStatusPaneUidTitle)));

    TBuf<KWaveGenTitleBufLength> titleText(NULL);
    iEikonEnv->ReadResource(titleText, aResourceId);
    titlePane->SetTextL(titleText);
    titlePane->DrawNow();    
    }

/*
-------------------------------------------------------------------------------
    ActivateGeneratorViewL

    Description: Creates the setting listbox for generator view and sets the
                 correct text for title pane

    Return Value: N/A
-------------------------------------------------------------------------------
*/
void CWaveGenView::ActivateGeneratorViewL()
    {
    // stop the audio engine and switch to the generator buffer
    iEng->StopL();
    iEng->SwitchBuffer(EFalse); 
    CreateListBoxL(R_WAVEGEN_SETTING_LIST_SETTING_GENERATOR);
    SetTitlePaneTextL(R_WAVEGEN_TITLE_TEXT_GENERATOR);            
    }

/*
-------------------------------------------------------------------------------
    ActivatePlayerViewL

    Description: Creates the setting listbox for player view and sets the
                 correct text for title pane

    Return Value: N/A
-------------------------------------------------------------------------------
*/
void CWaveGenView::ActivatePlayerViewL()
    {
    // stop the audio engine and switch to the player buffer    
    iEng->StopL();
    if(iEng->SwitchBuffer(ETrue))
        {
        CreateListBoxL(R_WAVEGEN_SETTING_LIST_SETTING_PCMPLAYER);
        SetTitlePaneTextL(R_WAVEGEN_TITLE_TEXT_PCMPLAYER);                
        }
    else
        {
        // display error message in the title pane if it fails
        SetTitlePaneTextL(R_WAVEGEN_ERROR_PCM_FILE);
        }
    }


/*
-------------------------------------------------------------------------------
    DoActivateL

    Description: Activates this view by creating the correct listbox
                 according to view type (generator/file player)

    Return Value: N/A
-------------------------------------------------------------------------------
*/
void CWaveGenView::DoActivateL(const TVwsViewId& /*aPrevViewId*/,
    TUid /*aCustomMessageId*/, const TDesC8& /*aCustomMessage*/ )
    {
    if(iMode == EGenerator)
        ActivateGeneratorViewL();
    else
        ActivatePlayerViewL();
    }


/*
-------------------------------------------------------------------------------
    DoDeactivate

    Description: Deactivates this view by deleting the listbox object

    Return Value: N/A
-------------------------------------------------------------------------------
*/
void CWaveGenView::DoDeactivate()
    {
    DeleteListBox();
    }

// eof