Creating +a Privacy Notification Notifier

This topic describes how to implement a Privacy Notification Notifier, +which is used to handle privacy notification requests.

The implementation of a Privacy Notification Notifier is similar to that +of a Privacy Verification Notifier. In particular, the same TLbsExternalRequestInfo object +is passed for privacy notification as for privacy verification. The most notable +difference for privacy notification is that the synchronous method MEikSrvNotifierBase::StartL() is +implemented. This is because the notifier is used only for privacy notification +and it is not possible to respond to it. This makes implementation of the +notifier easier.

Defining the Privacy Notification Notifier +

The code below shows a definition of a Privacy Notification Notifier +class.

The notifier owns a CMyLBSPrivacyNotifierDialog dialog +class to show details of the privacy request to the end user and to obtain +the response.

/* +============================================================================ + Name : MyLBSPrivacyNotifier.h + Description : This file defines a LBS Privacy Notification Notifier +============================================================================ +*/ + +#ifndef __MYLBSPRIVACYNOTIFIER_H__ +#define __MYLBSPRIVACYNOTIFIER_H__ + +#define NOTIFY_RESOURCE_PATH "\\private\\10003a4a\\" // Default location for dialog GUI resources +#define NOTIFY_RESOURCE "MyLBSPrivacyDialogs.rsc" // Compiled dialog resource file name + +// This value is defined in MyLBSPrivacyVerifier.h +//const TUid KScreenOutputChannel={0x1000ABEF}; + +// Include Files +#include <e32base.h> +#include <eiknotapi.h> +#include <eikdialg.h> +#include "lbsprivacyextnotifiers.h" // Defines privacy data types +#include "MyLBSNotifiersChannel.h" // Channel for notifier display + +// Dialog forward declaration for notifier +class CMyLBSPrivacyNotifierDialog; + +// Privacy verification notifier class definintion +class CMyLBSPrivacyNotifier : public CBase, public MEikSrvNotifierBase2 + { +public: + static CMyLBSPrivacyNotifier* NewL(); + ~CMyLBSPrivacyNotifier(); + + // Called when the dialog is hidden + void DialogDismissed(); + +private: // From MEikSrvNotifierBase2 + + // Not used for location notification - no response is required + void StartL(const TDesC8& aBuffer, TInt aReplySlot, const RMessagePtr2& aMessage); + + // Synchronous StartL is used for location notification + TPtrC8 StartL(const TDesC8& aBuffer); + + // Not implemented for LBS privacy notifiers + TPtrC8 UpdateL(const TDesC8& aBuffer); + + TNotifierInfo RegisterL(); + TNotifierInfo Info() const; + void Cancel(); + void Release(); + +private: + CMyLBSPrivacyNotifier(); + void ConstructL(); + +private: + // Data members + TNotifierInfo iInfo; + + // From lbsprivacyextnotifiers.h - request parameters + TLbsPrivacyNotifierParams iRequestParams; + + // Verification Dialog + CMyLBSPrivacyNotifierDialog* iDlg; + + }; + +#endif // __MYLBSPRIVACYNOTIFIER_H__

Defining the Privacy Notification Dialog

The following +is the definition of the dialog used by the example Privacy Notification Notifier:

/* +============================================================================ + Name : MyLBSPrivacyNotifier.cpp + Description : Source for LBS location notification notifier and dialog +============================================================================ +*/ + +// System headers +#include <eikdialg.h> +#include <eikmfne.h> +#include <eikenv.h> +#include <bautils.h> +#include <eikappui.h> +#include <e32cmn.h> + +// LBS headers +#include <lbsprivacyextnotifiers.h> + +// project headers +#include <MyLBSPrivacyDialogs.rsg> +#include "MyLBSPrivacyNotifier.h" +#include "MyLBSDialogs.hrh" + +/* CMyLBSPrivacyNotifierDialog + The resource for this dialog defines it as a sleeping dialog + Resources are allocated for it when the owning notifier is loaded by ECom + This is a good idea for situations where emergency requests notify the user + so that a confirmation dialog is shown even in low memory conditions +*/ + +class CMyLBSPrivacyNotifierDialog : public CEikDialog + { +public: + static CMyLBSPrivacyNotifierDialog* NewLD(CMyLBSPrivacyNotifier* aNotifier); + ~CMyLBSPrivacyNotifierDialog(); + + void ShowDialog(TLbsExternalRequestInfo& aInfo); + void HideDialog(); + +public: // from CEikDialog + TBool OkToExitL(TInt aButtonId); + void PreLayoutDynInitL(); + +private: + CMyLBSPrivacyNotifierDialog(CMyLBSPrivacyNotifier* aNotifier); + void LoadResourceL(); + void FreeResource(); + void ConstructL(); + +private: + + // The notifier that calls this dialog + CMyLBSPrivacyNotifier* iNotifier; + + // Library resource containing dialog resources + TInt iResourceFile; + + // The privacy requester info - contains requester id and name + TLbsExternalRequestInfo iInfo; + };

The dialog requires a resource definition. In this case +the dialog has only a continue button because no response +can be made to the notification.

RESOURCE DIALOG r_lbs_notify_dialog + { + title = "Privacy Notification Dialog"; + flags=EEikDialogFlagNotifyEsc; + buttons = R_EIK_BUTTONS_CONTINUE; + items = + { + DLG_LINE + { + type = EEikCtLabel; + control = LABEL + { + standard_font = EEikLabelFontAnnotation; + txt = "Sending your location to :"; + }; + }, + DLG_LINE + { + type = EEikCtEdwin; + id = EPrivacyClientName; + control = EDWIN + { + width = 10; + maxlength = 25; + }; + } + }; + }

Notifier and dialog method implementations

Much +of the implementation of a Privacy Notification Notifier is similar to that +for a Privacy Verification Notifier. The most relevant differences are in +the implementation of MEikSrvNotifierBase2::RegisterL(), MEikSrvNotifierBase2::StartL() and CEikDialog::OkToExitL().

The value KLbsExtLocationRequestNotifyUid as defined in lbsextprivacynotifiers.h +must be used for the notifier registration. The choice of notifier priority +is a licensee decision, but a high priority is recommended because a location +notification can be sent as part of an emergency services request and the +user may want to know that their location was successfully sent.

// Called by notifier framework once to register the notifier with ECOM +MEikSrvNotifierBase2::TNotifierInfo CMyLBSPrivacyNotifier::RegisterL() + { + iInfo.iUid = KLbsExtLocationRequestNotifyUid; + iInfo.iChannel = KScreenOutputChannel; + + // High priority privacy request + iInfo.iPriority = ENotifierPriorityVHigh; + return iInfo; + }

The notifier implements only the synchronous version of StartL().

// Synchronous StartL is used for location +// notification because no response is required +TPtrC8 CMyLBSPrivacyNotifier::StartL(const TDesC8& aBuffer) + { + TBuf8<KLbsMaxClientNameSize> clientName; + TBuf8<KLbsMaxRequesterIdSize> requesterId; + + TLbsPrivacyNotifierParamsPckg pckg; + pckg.Copy(aBuffer); + TLbsPrivacyNotifierParams params = pckg(); + TLbsExternalRequestInfo info; + params.GetRequesterInfo(info); + + // Show the dialog with the requester details + iDlg->ShowDialog(info); + + return TPtrC8(); + }

OkToExit() does not write any notifier +response parameters.

// From CEikDialog - called when a dialog button is pressed +TBool CMyLBSPrivacyNotifierDialog::OkToExitL(TInt aButtonId) + { + // No response parameters to set for location notification + + // Inform the notifier that this dialog + // is exiting so that it can inform the notifier manager + iNotifier->DialogDismissed(); + return ETrue; + }