Handling new touch-related MEikListBoxObserver events

ID		Creation date	September 30, 2008
Platform	S60 5th Edition	Tested on devices	Nokia 5800 XpressMusic
Category	Symbian C++	Subcategory	Touch UI

Keywords (APIs, classes, methods, functions): MEikListBoxObserver::HandleListBoxEventL()

Overview

S60 5th Edition supports touch events. All AVKON ui controls handles touch ui events and you do not need to implement nothing new.

If your ui control has the listbox and it's listening listbox events by MEikListBoxObserver you have to handle few new touch ui related events:

* 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 handles already its touch ui poiter 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

We have CAknSingleStyleListBox inside our control and it's 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();
    }

Here is listbox event listening, see new EEventItemDoubleClicked touch ui related event. EEventEnterKeyPressed event is 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

Application handles listbox pointer events.

See also

[S60 5th Calendar Example]