How to renew a request from the active scheduler

This document describes how to maintain an outstanding request from an active scheduler.

It is possible to maintain an outstanding request from the active scheduler, by overriding the CActiveScheduler::WaitForAnyRequest() function.

In this case, it is useful for the active scheduler to have a data member which points to the active object for which it will maintain an outstanding request. Implement the active scheduler as follows:

      
       
      
      class CExampleScheduler : public CActiveScheduler
    {
public:
    void Error (TInt aError) const;
    void WaitForAnyRequest();
    void SetActiveObject(CActiveConsole* aActiveConsole);
private:
    CActiveConsole* iActiveConsole;
    };
     

      
       
      
      void CExampleScheduler::SetActiveObject(CActiveConsole* aActiveConsole)
    {
    iActiveConsole = aActiveConsole;
    }
     

where iActiveConsole is a pointer to an active object, initialized by call to SetActiveObject() during the construction of the controlling active object:

      
       
      
      void CMessageKeyProcessor::ConstructL()
    {
    CActiveScheduler::Add(this);
    (CExampleScheduler*)(CActiveScheduler::Current())->SetActiveObject(this);
    }
     

Now override CActiveScheduler::WaitForAnyRequest() :

      
       
      
      void CExampleScheduler::WaitForAnyRequest()
    {
    if (!(iActiveConsole->IsActive()))
        {
        iActiveConsole->RequestCharacter();
        }
    CActiveScheduler::WaitForAnyRequest();
    }