a very basic example showing ofEvent - sorry its so boring.

gistfile1.cpp

#include "testApp.h"

//--------------------------------------------------------------
void testApp::setup(){
  displayString = "press mouse to fire an event";
	 
	ofAddListener(timeStampEvent, this, &testApp::eventsIn);
}

//--------------------------------------------------------------
void testApp::eventsIn(string & eventStr){
	cout << "we got an event!" << endl;
	cout << "timestamp is:" <<endl; 
	cout << eventStr << endl; 
	
	displayString = "last timestamp received: \n" + eventStr;
}

//--------------------------------------------------------------
void testApp::update(){
	if( ofGetMousePressed(0) ){
		string str = ofGetTimestampString();
		ofNotifyEvent(timeStampEvent, str, this);
	}
}

//--------------------------------------------------------------
void testApp::draw(){
	ofSetColor(30);
	ofDrawBitmapString(displayString, 10, 20);
}

//--------------------------------------------------------------
void testApp::keyPressed(int key){

}

//--------------------------------------------------------------
void testApp::keyReleased(int key){

}

//--------------------------------------------------------------
void testApp::mouseMoved(int x, int y){

}

//--------------------------------------------------------------
void testApp::mouseDragged(int x, int y, int button){

}

//--------------------------------------------------------------
void testApp::mousePressed(int x, int y, int button){

}

//--------------------------------------------------------------
void testApp::mouseReleased(int x, int y, int button){

}

//--------------------------------------------------------------
void testApp::windowResized(int w, int h){

}

//--------------------------------------------------------------
void testApp::gotMessage(ofMessage msg){

}

//--------------------------------------------------------------
void testApp::dragEvent(ofDragInfo dragInfo){ 

}

gistfile2.cpp

#pragma once

#include "ofMain.h"

class testApp : public ofBaseApp{
  public:
		void setup();
		void update();
		void draw();
		
		//note the type of the argument has to be the same as the type of ofEvent - in this case a string
		//also note the & - without it the notification will not happen 
		void eventsIn( string & eventStr );
		
		void keyPressed(int key);
		void keyReleased(int key);
		void mouseMoved(int x, int y);
		void mouseDragged(int x, int y, int button);
		void mousePressed(int x, int y, int button);
		void mouseReleased(int x, int y, int button);
		void windowResized(int w, int h);
		void dragEvent(ofDragInfo dragInfo);
		void gotMessage(ofMessage msg);
		
		//this object 'timeStampEvent' allows anyone that adds a listener to it, to get notfication of that event.
		//sometimes it makes sense to have the event be a global variable so muliple classes can register for notification. 
		ofEvent <string> timeStampEvent;
		
		
		string displayString;
};