Use CAknEnumeratedTextPopupSettingItem dynamically at runtime(转)

Use CAknEnumeratedTextPopupSettingItem dynamically at runtime

In an article -- "Create Dynamic Settings Pages", there is a section describing how to "Adding Enumerated Text Item". See it for details.

In this article, I will introduce another way -- creating a CAknEnumeratedTextPopupSettingItem-derived class to use dynamic data at runtime.

An important note: "Setting Item Lis 6" panic will occur when no match found in the EnumeratedTextArray, not zero-based. To demonstrate this, I will use 1,2,10 for the enumeration values, different from those(0,1,10) in the above article. We will see how to fix it also.

Contents

 [hide]

• 1 Create test data
• 2 Check target value
• 3 constructor, etc
• 4 The header file
• 5 Use CMyTextPopupSettingItem
• 6 See also

Create test data

First we need some test data, and then load the test data when calling CompleteConstructionL() function.

void CMyTextPopupSettingItem::LoadTestDataL()
    {
    _LIT(KFirst, "first (1)");
    _LIT(KSecond, "second (2)");
    _LIT(KThird, "third (10)");
 
    // Get the value array
    CArrayPtr<CAknEnumeratedText>* texts = this->EnumeratedTextArray();
    CArrayPtr<HBufC>* popTextArr = this->PoppedUpTextArray();
    // Empty it
    if (texts && popTextArr)
        {
        texts->ResetAndDestroy();
        texts->AppendL(new CAknEnumeratedText(1, KFirst().AllocL()));
        texts->AppendL(new CAknEnumeratedText(2, KSecond().AllocL()));
        texts->AppendL(new CAknEnumeratedText(10, KThird().AllocL()));
        popTextArr->ResetAndDestroy();
        popTextArr->AppendL(KFirst().AllocL());
        popTextArr->AppendL(KSecond().AllocL());
        popTextArr->AppendL(KThird().AllocL());
        }
    }
 
void CMyTextPopupSettingItem::CompleteConstructionL()
    {
    CAknEnumeratedTextPopupSettingItem::CompleteConstructionL();
    LoadTestDataL(); // overwrite the resource definitions.
    }

Check target value

We must check whether the target value, iValue, is in the loaded array or not. If not, it definitely causes a panic -- "Setting Item Lis 6". In that case, we will choose the first item as the default one. See below:

void CMyTextPopupSettingItem::LoadL()
    {
    CArrayPtr<CAknEnumeratedText>* texts = this->EnumeratedTextArray();
    TInt selectedIndex = this->IndexFromValue(iValue);
    if (selectedIndex < 0)  // no match found.
        {
        if (texts->Count() > 0)  
            {
            // choose the first item as default one.
            CAknEnumeratedText* item = texts->At(0);
            // reset external value to the default one.
            this->SetExternalValue(item->EnumerationValue());
            }
        }
    CAknEnumeratedTextPopupSettingItem::LoadL();
    }

constructor, etc

The constructor of CMyTextPopupSettingItem:

CMyTextPopupSettingItem::CMyTextPopupSettingItem( TInt aIdentifier, TInt& aValue )
    : CAknEnumeratedTextPopupSettingItem(aIdentifier, aValue), iValue(aValue)
    {
    }

The implementation of CreateAndExecuteSettingPageL:

void CMyTextPopupSettingItem::CreateAndExecuteSettingPageL()
    {
    CAknSettingPage* dlg = CreateSettingPageL();
 
    SetSettingPage( dlg );
    SettingPage()->SetSettingPageObserver(this);
 
    SettingPage()->SetSettingTextL(SettingName());
 
    SettingPage()->ExecuteLD(CAknSettingPage::EUpdateWhenChanged);
    SetSettingPage(0);
    }

The header file

class CMyTextPopupSettingItem : public CAknEnumeratedTextPopupSettingItem
    {
    public: // Constructor
        CMyTextPopupSettingItem( TInt aIdentifier, TInt& aValue );
        void LoadL();
 
    protected: // Functions from base classes
        void CreateAndExecuteSettingPageL();
        void CompleteConstructionL();
 
    private: // custom methods
        void LoadTestDataL();
 
    private:
        TInt iValue;
    };

Use CMyTextPopupSettingItem

In the CreateSettingItemL method of your Setting List container, add some code like this:

case EMyAppItemTest:
        {
//      iData = 1; // here you can specify the default value to test the class we have just created.
//      iData = 0; // This will cause a panic if no fixes in LoadL function.
        settingItem = new (ELeave) CMyTextPopupSettingItem(aIdentifier, iData);
        break;
        }

See also

• Setting Item List panics
• Create Dynamic Settings Pages