Example

The following is an example of how to construct and use an ECLKeyNotify object.

// ECLKeyNotify class
//
// This sample demonstrates the use of:
//
// ECLKeyNotify::NotifyEvent
// ECLKeyNotify::NotifyError
// ECLKeyNotify::NotifyStop
// ECLPS::RegisterKeyEvent
// ECLPS::UnregisterKeyEvent
//-------------------------------------------------------------------
 
//...................................................................
// Define a class derived from ECLKeyNotify
//...................................................................
class MyKeyNotify: public ECLKeyNotify
{
public:
  // Define my own constructor to store instance data
  MyKeyNotify(HANDLE DataHandle);
 
  // We have to implement this function
  virtual int NotifyEvent(ECLPS *PSObj, char const KeyType[2],
                          const char * const KeyString);
 
  // We choose to implement this function
  void NotifyStop (ECLPS *PSObj, int Reason);
 
  // We will take the default behaviour for this so we
  // don't implement it in our class:
  // void NotifyError (ECLPS *PSObj, ECLErr ErrObject);
 
private:
  // We will store our application data handle here
  HANDLE MyDataH;
};
 
 //..................................................................
MyKeyNotify::MyKeyNotify(HANDLE DataHandle)   // Constructor
//...................................................................
{
  MyDataH = DataHandle;  // Save data handle for later use
}
 
//...................................................................
int MyKeyNotify::NotifyEvent(ECLPS *PSObj,
                             char const KeyType[2],
                             const char * const KeyString)

//...................................................................
 
{
  // This function is called whenever a keystroke occurs.  We will
  // just do something simple: when the user presses PF1 we will
  // send a PF2 to the host instead.  All other keys will be unchanged.
 
  if (KeyType[0] == 'M') {             // Is this a mnemonic keyword?
    if (!strcmp(KeyString, "[pf1]")) { // Is it a PF1 key?
      PSObj->SendKeys("[pf2]");        // Send PF2 instead
      printf("Changed PF1 to PF2 on connection %c.\n",
             PSObj->GetName());
      return 1;                        // Discard this PF1 key
    }
  }
 
  return 0;                            // Process key normally
}
 
 

//..................................................................
void MyKeyNotify::NotifyStop (ECLPS *PSObj, int Reason)
//...................................................................
{
  // When notification ends, display message
  printf("Keystroke intercept for connection %c stopped.\n", PSObj->GetName());
}
 
//...................................................................
// Create the class and start keystroke processing on A and B.
//...................................................................
void Sample44() {
 
ECLPS *PSA, *PSB;       // PS objects
MyKeyNotify *Event;     // Ptr to my event handling object
HANDLE InstData;	    	// Handle to application data block (for example)
 
try {
 
  PSA = new ECLPS('A');               // Create PS objects
  PSB = new ECLPS('B');
  Event = new MyKeyNotify(InstData);  // Create event handler
 
  PSA->RegisterKeyEvent(Event);       // Register for keystroke events
  PSB->RegisterKeyEvent(Event);       // Register for keystroke events
 

  // At this point, any keystrokes on A or B will cause the
  // MyKeyEvent::NotifyEvent() function to execute.  For
  // this sample, we put this thread to sleep during this
  // time.
 
  printf("Processing keystrokes for 60 seconds on A and B...\n");
  Sleep(60000);
 
  // Now stop event generation.  This will cause the NotifyStop
  // member to be called.
  PSA->UnregisterKeyEvent(Event);
  PSB->UnregisterKeyEvent(Event);
 
  delete Event;  // Don't delete until after unregister!
  delete PSA;
  delete PSB;
}
catch (ECLErr Err) {
  printf("ECL Error: %s\n", Err.GetMsgText());
}
 
} // end sample
 
//-------------------------------------------------------------------