The Symbian notifier framework allow system or custom event to be handled quite easily by your application. It's an easy way for a server with no UI to display some events on the phone screen.
The behaviour of notifiers is supplied by providing an implementation of the MEikSrvNotifierBase interface . A notifier is associated with a channel and a priority. Priority is used to determine the order of activation if more than one notifier is activated at any time. Priority only affects notifiers on the same channel (e.g. a screen or LED). This means that two notifiers can be active at the same time provided that they are on different channels.
Here is how you can define your own custom notifier:
1. Implement a class which inherits from both CEikDialog and MEikSrvNotifierBase.
#include "CknNtfy.h"
#include <eikdialg.h>
/**
* class CCknMmcNotifier
*
* a sleeping dialog used to request a password when a protected MMC is inserted
*/
class CCknMmcNotifier : public CEikDialog, public MEikSrvNotifierBase
{
public:
static CCknMmcNotifier* NewL();
~CCknMmcNotifier();
public:
CCknMmcNotifier();
void ConstructL();
TInt DisplayNotifier();
// from CEikDialog
void PreLayoutDynInitL();
TBool OkToExitL(TInt aButtonId);
// from MEikSrvNotifierBase
void Release();
TNotifierInfo RegisterL();
TNotifierInfo Info() const;
TPtrC8 StartL(const TDesC8& aBuffer);
void StartL(const TDesC8& aBuffer, const TAny* aReturnVal, RMessage aMessage);
void Cancel();
TPtrC8 UpdateL(const TDesC8& aBuffer);
private:
TNotifierInfo iInfo;
RMessage iMessage;
const TAny* iReturnVal;
};
2. Example cpp implementation:
//
// CknMmc.cpp
//
#include "CknMmc.h"
#include <EikSecEd.h>
#include <EikEnv.h>
#include <EikBtGpc.h>
#include <BaUtils.h>
#include <notifiertest.rsg>
//#include "CknNtfy.hrh"
// local copy for now...will be defined in a header
const TUid KScreenOutputChannel={0x100065aa};
void CCknMmcNotifier::Release()
{
delete this;
}
CCknMmcNotifier::TNotifierInfo CCknMmcNotifier::RegisterL()
{
iInfo.iUid=KCkonMmcNotifierUid;
iInfo.iChannel=KScreenOutputChannel;
iInfo.iPriority=ENotifierPriorityVHigh;
return iInfo;
}
CCknMmcNotifier::TNotifierInfo CCknMmcNotifier::Info() const
{ // return notifier info
return iInfo;
}
TInt CCknMmcNotifier::DisplayNotifier()
{
RouseSleepingDialog();
return KErrNone;
}
TPtrC8 CCknMmcNotifier::StartL(const TDesC8& /*aBuffer*/)
{ // will not get called as this is a get response notifier
RouseSleepingDialog();
return TPtrC8();
}
void CCknMmcNotifier::StartL(const TDesC8& /*aBuffer*/, const TAny* aReturnVal, RMessage aMessage)
{ // display the notifier
const TAny* rdes=aMessage.Ptr2();
TInt desLength=aMessage.Client().GetDesLength(rdes);
if(desLength!=(TInt)sizeof(TMediaPswdReplyNotifyInfoV1))
User::Leave(KErrGeneral);
// non waiting dialog
iMessage=aMessage;
iReturnVal=aReturnVal;
RouseSleepingDialog();
}
void CCknMmcNotifier::Cancel()
{
ExitSleepingDialog();
//static_cast<CEikSecretEditor*>(Control(ECkonMmcNotifyLabel))->Reset();
//if (iMessage.MessagePtr()!=RMessagePtr())
//{
//iMessage.Complete(KErrCancel);
//}
}
TPtrC8 CCknMmcNotifier::UpdateL(const TDesC8& /*aBuffer*/)
{ // ??
return TPtrC8();
}
CCknMmcNotifier* CCknMmcNotifier::NewL()
{ // construct the notifier
CCknMmcNotifier* self=new (ELeave) CCknMmcNotifier();
CleanupStack::PushL(self);
self->ConstructL();
CleanupStack::Pop();
return self;
}
CCknMmcNotifier::~CCknMmcNotifier()
{ // remove sleeping dialog from the stack
iEikonEnv->RemoveFromStack(this);
}
CCknMmcNotifier::CCknMmcNotifier()
{
}
void CCknMmcNotifier::ConstructL()
{
//#pragma message ("A problem with wins emulatator. CBA can not be used if SetGloballyCapturing(ETrue) is called")
//SetGloballyCapturing(ETrue);
_LIT(KResFileName,"\\System\\Data\\notifiertest.rsc");
_LIT(KDrive,"z:");
// hack as Dll::Filename appears to not return the drive for notifiers
TBuf<2> drive;
drive=KDrive;
TFileName fileName;
Dll::FileName(fileName);
TParse parse;
parse.Set(KResFileName, &fileName, &drive);
fileName=parse.FullName();
BaflUtils::NearestLanguageFile(iEikonEnv->FsSession(),fileName);
//
TInt offset=iEikonEnv->AddResourceFileL(fileName);
TRAPD(err,ConstructSleepingAlertDialogL(R_CHECKBOX_DEMO_DIALOG));
iEikonEnv->DeleteResourceFile(offset);
User::LeaveIfError(err);
}
void CCknMmcNotifier::PreLayoutDynInitL()
{ // must not fail in anyway
}
TBool CCknMmcNotifier::OkToExitL(TInt aButtonId)
{
return ETrue;
}
3. Create dll entry implementation file.
/*
============================================================================
Name : Try_00Dll.cpp
Author : HanyMT & basedj
Version :
Copyright : Your copyright notice
Description : Try_00Dll.cpp - main DLL source
============================================================================
*/
// Include Files
#include <e32std.h> // GLDEF_C
#include "Try_00.pan" // panic codes
// Global Functions
GLDEF_C void Panic(TTry_00Panic aPanic)
// Panics the thread with given panic code
{
User::Panic(_L("TRY_00"), aPanic);
}
// Exported Functions
EXPORT_C TInt E32Dll(TDllReason /*aReason*/)
// Called when the DLL is loaded and unloaded. Note: have to define
// epoccalldllentrypoints in MMP file to get this called in THUMB.
{
return KErrNone;
}
4. Create a MMP file
Use a custom - and registered - UID3 to identify your notifier. Note the UID2 value which must match the KUidNotifierPlugIn value (0x10005522):
/*
============================================================================
Name : Try_00.mmp
Author : HanyMT & Basedj
Version :
Copyright : Your copyright notice
Description : This is the project specification file for Try_00.
============================================================================
*/
TARGET Try_00.dll
TARGETTYPE dll
TARGETPATH \system\Notifiers
UID 0x10005522 0x101f5ac4
USERINCLUDE ..\inc
SYSTEMINCLUDE \epoc32\include
DOCUMENT bld.inf
DOCUMENT Try_00.pkg
SOURCEPATH ..\data
RESOURCE NotifierTest.rss
SOURCEPATH ..\src
SOURCE cknmmc.cpp
SOURCE cknntfy.cpp
LIBRARY eiksrv.lib
LIBRARY eikcore.lib
LIBRARY efsrv.lib
LIBRARY eikdlg.lib
LIBRARY cone.lib
LIBRARY eikcoctl.lib
LIBRARY bafl.lib
LIBRARY euser.lib
EXPORTUNFROZEN
5. Call notifier from client app.
Rnotifier r;
r.Connect();
r.StartNotifier(NotifierUID,buf1,buf2);
You'll find a nice example of NotifierArray in the SDK. Search for NotifierArray.
With respect to order of exports, I think you're wondering how to ensure that NotifierArray is the first ordinal. This is doen't via the mmp file. TARGETTYPE can be set to notifier.
jk