Listening for Symbian Window Server events in Qt

Overview

This code snippets shows how a Qt application listens for native Symbian 76ytuiytuityutyutututyutyutyu window server events.

Preconditions

• Install Qt SDK

Send a message

A native Symbian application sends a message to the Qt application.

1. include <apgtask.h> // Symbian header

TApaTaskList tasklist(iCoeEnv->WsSession());

// A task is a running application TUid id = TUid::Uid(0x12345678); //Qt app UID TApaTask task(tasklist.FindApp(id));

TUid messageid = TUid::Uid(0x000001); //Custom message uid

TBuf8<20> param; param.Append(_L("hello world")); task.SendMessage(messageid, param)); TApaTask::SendMessage() does not need SwEvent capability.

Listen for the message

The Qt application listens for 76ytuiytuityutyutututyutyutyu window server events. Derive 76ytuiytuityutyutututyutyutyu and implement the base class 76ytuiytuityutyutututyutyutyu method to listen for window server events. In this case we listen for 76ytuiytuityutyutututyutyutyu type of events with the custom message UID.

1. include <QApplication>
2. include <apgtask.h> // Symbian header

class S60QApplication: public QApplication

   {
   Q_OBJECT

public:

   S60QApplication(int &argc, char **argv, int = QT_VERSION);
   S60QApplication(int &argc, char **argv, bool GUIenabled, int = QT_VERSION);
   S60QApplication(int &argc, char **argv, Type, int = QT_VERSION);
   bool s60EventFilter(TWsEvent *);
   };

S60QApplication::S60QApplication(int &argc, char **argv, int version)

QApplication(argc,argv,version)

   {
   }

S60QApplication::S60QApplication(int &argc, char **argv, bool GUIenabled, int version)

QApplication(argc, argv, GUIenabled, version)

   {
   }

S60QApplication::S60QApplication(int &argc, char **argv, Type type, int version)

QApplication(argc, argv, type, version)

   {
   }

bool S60QApplication::s60EventFilter(TWsEvent *aEvent)

   {
   bool handled = false;
   const TInt KCustomMessageId=0x000001; // Custom message uid
   
   switch(aEvent->Type())
       {       
       case EEventMessageReady:    
             {
             RWsSession iWsSession;
             TInt err = iWsSession.Connect();
             
             TUid messageUid;
             TPtr8 messageParameters(NULL, 0, 0);
             // Fetch message
             User::LeaveIfError(iWsSession.FetchMessage(messageUid,
             messageParameters, *aEvent));
             // Was it our custom message?
             switch(messageUid.iUid)
               {
               case KCustomMessageId:
                   {
                   HBufC *p = HBufC::NewL(messageParameters.Length());
                   p->Des().Copy(messageParameters);
                   
                   // Converting message from HBufC to QString
                   QString message((QChar*)p->Des().Ptr(),p->Length());

                   handled = true;
                   delete p;
                   break;
                   }
               default:
                   {
                   break;
                   }
               }
             iWsSession.Close();
             break;
             }
       default:
           break;
       };
       
   return handled;
   }

Postconditions

The events have been sent and received.