why do I get panic EIKON-EDWIN 8 when trying to use an AVKON_INTEGER_EDWIN control?

[leisti]

Ok, so I've given up on the two-control dialog and gone with two separate dialogs. (See the post "frustrations in using dialogs and controls" (http://discussion.forum.nokia.com/fo...d.php?t=124421) I just posted on this same discussion board.)

The first dialog is defined by the following resource:

RESOURCE DIALOG r_authorisation_extension_query_dialog
    {
    flags   = EGeneralQueryFlags; 
    buttons = R_AVKON_SOFTKEYS_OK_CANCEL;
    items   =
        {
        DLG_LINE
            {
            type      = EAknCtQuery;
            id        = EAuthQueryDlgExtensionEntryId;
            itemflags = EAknEditorFlagNoT9;
            control   = AVKON_DATA_QUERY
                {
                layout = ENumberLayout;
                // class CAknIntegerEdwin can be instantiated based on a
                // AVKON_INTEGER_EDWIN control:
                control = AVKON_INTEGER_EDWIN
                    {
                    min         = 0;
                    unset_value = 0;
                    maxlength   = KMaxExtensionDigits;
                    };
                };

            }
        };
    }

KMaxExtensionDigits is defined as 8 in the app's .hrh file.

The following code is from the view container class that instantiates the dialog:

TBool CMobUiAuthorisationViewContainer::HandleAuthorisation()
    {
    HBufC* iExtensionDigits( NULL );
    HBufC* headerText = StringLoader::LoadLC( R_STRING_EXTENSION_PROMPT );
    iAuthQueryDlg = new ( ELeave ) CMobUiAuthorisationQueryDialog( *headerText,
                                                                   EFalse,
                                                                   iExtensionDigits );
    CleanupStack::PopAndDestroy( headerText );

    iAuthQueryDlg->SetMopParent( this );
    iAuthQueryDlg->ExecuteLD( R_AUTHORISATION_EXTENSION_QUERY_DIALOG );
    //!!! continue...
    }

The resource R_STRING_EXTENSION_PROMPT contains the instruction to the user to enter an extension number, since the DLG_LINE's prompt field is useless (see my post "frustrations in using dialogs and controls" just posted before this one). The resource R_AUTHORISATION_EXTENSION_QUERY_DIALOG is the dialog resource whose definition I gave above. (The idea here is to use the same CMobUiAuthorisationQueryDialog class for entering both the extension number, and, later, the PIN, just instantiated with a different resource ID. But that's beside the point here.)

When the line iAuthQueryDlg->ExecuteLD is executed, the dialog comes up on the emulator screen, showing the instruction text and an edit box (= the control). I can enter digits into the edit box, and after the eighth one, no more are accepted, because of the maxlength definition in the dialog resource, as expected. When I press the OK softkey, the program execution moves to the following function:

TBool CMobUiAuthorisationQueryDialog::OkToExitL( TInt aKeycode )
    {
    switch ( aKeycode )
        {
        case EAknSoftkeyOk:
            {
            if ( !iExtensionOrPin ) // I'm reusing the same code for the PIN dialog.
                                    // EFalse here just means we're executing the
                                    // dialog for entering an extension number.
                {
                // We're getting the extension number.  Get the editor control:
                CAknIntegerEdwin* extensionEditor =
                    static_cast< CAknIntegerEdwin* >(
                        ControlOrNull( EAuthQueryDlgExtensionEntryId ) );
                if ( extensionEditor == NULL )
                    {
                    // something is very wrong if the control can't be accessed
                    User::Leave( EMobilityUi );
                    }
                TInt enteredExtension;

/* CRASH HERE: */
                CAknNumericEdwin::TValidationStatus validationStatus =
                    extensionEditor->GetTextAsInteger( enteredExtension );

                if (   ( validationStatus != CAknNumericEdwin::EValueValid )
                    || ( enteredExtension == 0 ) )
                    {
                    // Can't exit the dialog if nothing was entered, or if an
                    // invalid set of digits were entered.
                    return EFalse;
                    }
                // discard any previous content of iEnteredDigits:
                delete iEnteredDigits;
                iEnteredDigits = NULL;
                iEnteredDigits = HBufC16::NewLC( 0 );
                // convert the read integer to a string, while assigning the
                // result to the descriptor object owned by the caller:
                iEnteredDigits->Des().Format( KSingleIntegerFormatString,
                                              enteredExtension );
                }
            else
                {
                // We're getting the PIN.  Get the editor control:
                CAknNumericSecretEditor* passwordEditor =
                    static_cast< CAknNumericSecretEditor* >(
                        Control( EAuthQueryDlgPasswordEntryId ) );
                //!! continue....
                }

            return ETrue; // yes, dialog can exit if softkey OK pressed
            }
        case EAknSoftkeyCancel:
            {
            return ETrue; // yes, dialog can exit if softkey Cancel pressed
            }
        default:
            {
            return EFalse; // no, dialog can't exit otherwise
            }
        }
    }

Everything goes fine until the line I've marked with /* CRASH HERE: */. The function call ControlOrNull gives me a non-null pointer, which I presume is to the control identified by EAuthQueryDlgExtensionEntryId, which was used in the resource definition to identify the dialog line.

What happens is that on the emulator screen, the error App. closed: Application Name EIKON-EDWIN 8 is displayed. EIKON-EDWIN 8 is apparently the ninth code (first one is 0) in enum TEikEdwinPanic in file epoc32\include\eikedwin.pan, namely EEikPanicEdwinNoText.

This is strange, as I most definitely did enter text into the control, and even if I hadn't, that should not be communicated by a panic, but rather by a value of EEmpty (of type CAknNumericEdwin::TValidationStatus) returned by the function GetTextAsInteger.

I googled for other mentions of people getting a panic of type EIKON-EDWIN 8, but found nothing useful. Someone mentioned that when an EDWIN control has been defined with a flag EEikEdwinUserSuppliedText, this problem might occur, but (a) this is an AVKON_INTEGER_EDWIN control, and (b) the flag I used was EGeneralQueryFlags, which is defined as EAknDialogGenericQueryFlags in avkon.hrh, which is defined as (EEikDialogFlagWait | EEikDialogFlagNoDrag | EEikDialogFlagNoTitleBar | EEikDialogFlagCbaButtons) in the same file; i.e., no EEikEdwinUserSuppliedText.

I thought that I was doing something wrong with the AVKON_INTEGER_EDWIN control, so tried, instead, an EDWIN control, and changed the code accordingly. Instead of calling extensionEditor->GetTextAsInteger, which is not available for the CEikEdwin class that goes with an EDWIN control, I called extensionEditor->GetTextInHBufL, which should simply return an HBufC* containing the entered text. Instead, when I tried to step over that line in the debugger, I got, again, a panic of type EIKON-EDWIN 8.

So, I'm stumped. What the hell am I doing wrong now? What undocumented or underdocumented little programming detail or details have I overlooked now? Please, anybody?!?