Handling new touch-related MEikListBoxObserver events

Article Metadata

---

Tested with

Devices(s): Nokia 5800 XpressMusic

---

Compatibility

Platform(s): S60 5th Edition

---

Article

Keywords: MEikListBoxObserver::HandleListBoxEventL()

Created: tepaa (03 Oct 2008)

Last edited: hamishwillee (14 Jun 2012)

Overview

S60 5th Edition supports touch events. All AVKON UI controls handle touch UI events and you do not need to implement anything new.

If your UI control has a listbox and it is listening for listbox events using MEikListBoxObserver, you need to handle a few new events related to touch UI:

* EEventItemClicked            // Item single-tap event
* EEventItemDoubleClicked      // Item two-taps event
* EEventPenDownOnItem          // Pen is down and over an item
* EEventItemDraggingActioned   // Pen is dragged from item to another

Note that CAknSingleStyleListBox already handles its touch UI pointer events in its AVKON base class CAknColumnListBox::HandlePointerEventL(). Do not override this implementation.

MMP file

The following libraries are required:

LIBRARY avkon.lib
LIBRARY eikcoctl.lib
LIBRARY eikctl.lib

Header file

#include <aknlists.h> // CAknSingleStyleListBox
#include <eiklbo.h> // MEikListBoxObserver

Source file

CAknSingleStyleListBox is inside the control and it is created in ConstructL().

void CMyContainer::ConstructL(const TRect& aRect)
    {
    CreateWindowL();    
 
    // Initialize component array
    InitComponentArrayL();
 
    // Create listbox    
    iSearchListBox = new (ELeave) CAknSingleStyleListBox;
    iSearchListBox->SetContainerWindowL(*this); 
    TResourceReader reader; 
    CEikonEnv::Static()->CreateResourceReaderLC(reader, R_MY_LISTBOX); 
    iSearchListBox->ConstructFromResourceL(reader); 
    CleanupStack::PopAndDestroy(); //reader
 
    // --> Start event listening
    iSearchListBox->SetListBoxObserver(this);
 
    // Enable scrollbars
    iSearchListBox->CreateScrollBarFrameL(ETrue);
    iSearchListBox->ScrollBarFrame()
    ->SetScrollBarVisibilityL(  CEikScrollBarFrame::EOff,
    CEikScrollBarFrame::EAuto);
 
    Components().AppendLC(iSearchListBox,1);
    CleanupStack::Pop( iSearchListBox );
 
    SetRect(aRect);
    ActivateL();
    }

Listbox event listening is implemented below. Note the new EEventItemDoubleClicked event related to touch UI. The EEventEnterKeyPressed event is the old selection key event (from S60 3rd Edition).

void CMyContainer::HandleListBoxEventL(CEikListBox* aListBox, TListBoxEvent aEventType)
    {
    if (aEventType == EEventEnterKeyPressed || aEventType == EEventItemDoubleClicked)
        {
        // TODO: Listbox got double click, what to do?
        // From CEikListBox::CurrentItemIndex() you could get the selected row...
        }
    }

Postconditions

The application handles listbox pointer events.

See also

S60 Platform: Calendar Interim API Example