Monitoring signal strength with CTelephony

Comments

09 Sep
2009

Article Review by User:FireSwarog (20090909)

This article demonstrates how to obtain signal strenght with the help of CTelephony. The implementation is based on the active object paradigm and observer pattern. Such approach for implementation of asyncronous requests is very popular in Symbian C++. The code example is fully self-sufficient. You can simply copy this class into your project.

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10 Sep
2009

Article Review by skumar_rao (20090910)

This article have a nice code snippet that can directly be used in any GUI / Non-UI applications by just copying to .h and .cpp files and adding to project. works even in v5.x. This article need to be re-formatted with headers. But that does not reduce the importance or usability of this article.

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Article Metadata

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Code Example

Source file: Media:SignalStrengthReader.zip

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Platform Security

Signing Required: Self-Signed

Capabilities: NetworkServices

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Article

Keywords: CTelephony

Created: symbianyucca (27 Mar 2007)

Last edited: hamishwillee (12 Jan 2012)

See Also

TSS000881 - Measuring signal strength using CTelephony

CNwSignalCheck implementation illustrates how to check and monitor the signal strength of S60 3rd Edition devices with CTelephony API.

The implementation is pretty simple, and when using this one only thing to do in calling class is to implement the callback interface and then to construct an instance of the CNwSignalCheck.

When constructing CNwSignalCheck, the initial signal strength is checked with GetSignalStrength() -function and after this function returns and calls back the RunL(), all changes in the signal strength are monitored by calling NotifyChange() for the signal strength status.

Link against:

LIBRARY etel3rdparty.lib

SignalStrenght.cpp

#include "SignalStrenght.h"
 
CNwSignalCheck* CNwSignalCheck::NewLC(MNwSignalObserver& aObserver)
{
    CNwSignalCheck* self = new (ELeave) CNwSignalCheck(aObserver);
    CleanupStack::PushL(self);
    self->ConstructL();
    return self;
}
 
CNwSignalCheck* CNwSignalCheck::NewL(MNwSignalObserver& aObserver)
{
    CNwSignalCheck* self = CNwSignalCheck::NewLC(aObserver);
    CleanupStack::Pop(); // self;
    return self;
}
 
void CNwSignalCheck::ConstructL(void)
{
    iTelephony = CTelephony::NewL();
    GetSignalInfo();
}
 
 
CNwSignalCheck::~CNwSignalCheck()
{
    Cancel();
    delete iTelephony;
}
 
 
CNwSignalCheck::CNwSignalCheck(MNwSignalObserver& aObserver)
: CActive(EPriorityStandard),iObserver(aObserver),iSigStrengthV1Pckg(iSigStrengthV1)
{
    CActiveScheduler::Add(this);
}
 
void CNwSignalCheck::GetSignalInfo()
{
    if(iTelephony && !IsActive())
    {
        iGettingSignal = ETrue;
        iTelephony->GetSignalStrength(iStatus, iSigStrengthV1Pckg);
        SetActive();
    }
}
 
void CNwSignalCheck::RunL()
{
    iObserver.SignalStatus(iSigStrengthV1.iSignalStrength,iSigStrengthV1.iBar);
 
    if(iStatus != KErrCancel)
    {
        iTelephony->NotifyChange(iStatus,CTelephony::ESignalStrengthChange,iSigStrengthV1Pckg);
        SetActive();
    }
 
    iGettingSignal = EFalse;
}
 
void CNwSignalCheck::DoCancel()
{
    if(iGettingSignal)
        iTelephony->CancelAsync(CTelephony::EGetSignalStrengthCancel);
    else
        iTelephony->CancelAsync(CTelephony::ESignalStrengthChangeCancel);
}

SignalStrenght.h

#include <Etel3rdParty.h>
 
class MNwSignalObserver
{
    public:
        virtual void SignalStatus(TInt32 aStrength,TInt8 aBars) = 0;
};
 
 
class CNwSignalCheck : public CActive
{
    public:
        ~CNwSignalCheck();
        static CNwSignalCheck* NewLC(MNwSignalObserver& aObserver);
        static CNwSignalCheck* NewL(MNwSignalObserver& aObserver);
 
    private:
        CNwSignalCheck(MNwSignalObserver& aObserver);
        void ConstructL(void);
 
    private:
        void GetSignalInfo();
        void RunL();
        void DoCancel();
 
    private:
        MNwSignalObserver& iObserver;
        CTelephony* iTelephony;
        CTelephony::TSignalStrengthV1 iSigStrengthV1;
        CTelephony::TSignalStrengthV1Pckg iSigStrengthV1Pckg;
        TBool iGettingSignal;
};

Example Code

• Example code