Re: How to do "events"

From:
"mlimber" <mlimber@gmail.com>
Newsgroups:
comp.lang.c++
Date:
12 Apr 2007 08:16:28 -0700
Message-ID:
<1176390988.910968.315850@o5g2000hsb.googlegroups.com>
On Apr 12, 9:55 am, "Erik Wikstr=F6m" <eri...@student.chalmers.se>
wrote:

On 12 Apr, 15:12, timor.su...@gmail.com wrote:

Hi group,

I would like to simulate something that can be quite similar to
"Events".
I would like that a member function of a class can be "setted" as an
Event and that this method can be called after something special.
Consider the following example :
I'm setting a function with a pointor function, then in a while-true
block, I ask for an input, if input is "abc", i'm firing an event
(that prints "abc").

#include <iostream>
#include <string>

using namespace std;

typedef void (*fPtrEvent)();

class Event
{
private:
        static fPtrEvent fEvent;
public:
        Event() {};
        static void Set(fPtrEvent f)
        {
                fEvent = f;
        }
        void WhileTrue()
        {
                while(1)
                {
                        string s;
                        cin >> s;
                        if (s == "abc" && fEvent != 0)
                                fEvent();
                        if (s == "q")
                                break;
                }
        }

};

fPtrEvent Event::fEvent = 0;

class Test
{
public:
        static void DoPrint()
        {
                cout << "print abc" << endl;
        }

};

int main (void)
{
        Event *c = new Event();
        c->Set(&Test::DoPrint);
        c->WhileTrue();
        delete c;
        return 0;

}

What I would like from you is :
- to tell me if it's a good way to achieve what I want.
- if there are better way to do that.
- tell me how I can avoid to use static methods (because that means
can only access to static attributes)
- everything you want :)


Google for delegates, I think boos::funtion can be of use.


Or better, std::tr1::bind (aka boost::bind). Then you needn't use
static functions.

Cheers! --M

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