Cfrgtkky

I want to call a method that will accept as an argument a pointer to a list of class:method pointers:

void dispatch ( int cmdCount, methodFunction *pointer  ) {

...

}

This typedef creates methodFunction:

typedef void ( ClassName::*methodFunction )( char, char );

But I cannot see how to make ClassName something that gets passed to dispatch. I think this needs some form of template, but I am not clear on templates yet.

Here is my entire code (drop code into TemplateTest.ino and code.h:

    //  Template Test

    #include "code.h"



    Dispatcher *dispatcher;

    Example1 ex1;

    Example2 ex2;



    void setup() {

        Serial.begin ( 115200 );



        ex1.execute ( 'a', '+' );

        ex1.execute ( 'b', '-' );

        ex2.execute ( 'y', '?' );

    }



    void loop() {}



    <<<<<<<<<< NEW FILE: code.h >>>>>>>>>>>>



#pragma once



class Dispatcher {

public:

    template<class T>



    void dispatch ( T& instance, void(T::*func)(char sel, char act), char def [2], int cmdCount ) {

        //  Walk through the array containing sel,act pairs.

        //  When we find a match, launch the function from

        //  tPointer with the same index value.

        for (int i = 0; i < cmdCount; i++) {

            char _sel = def [i] [0];

            char _act = def [i] [1];

            if (( sel == _sel ) && ( act == _act )) {

                ( *T [i] )( sel, act );

                return;

            }

        }

    }

};



//  Example 1 Code

char ex1Array  [2] = {

    {'a','+'},

    {'a','-'},

    {'b','+'},

    {'b','-'},

};



class Example1 {

public:



    char *_name = "Template Example 1";



    Dispatcher disp;



    static const int cmdCount = sizeof ( ex1Array ) / sizeof ( ex1Array [0] );



    typedef void ( Example1::*FunctionPointer )( char sel, char act );



    //  Function dispatch table

    FunctionPointer cmdMethods [cmdCount] = {

        &Example1::alphaPlus,

        &Example1::alphaMinus,

        &Example1::betaPlus,

        &Example1::betaMinus,

    };



    Example1 () {

    }



    void alphaPlus ( char sel, char act ) {

        Serial.println ( F ( "Alpha +" ) );

    }

    void alphaMinus ( char sel, char act ) {

        Serial.println ( F ( "Alpha -" ) );

    }

    void betaPlus ( char sel, char act ) {

        Serial.println ( F ( "Beta +" ) );

    }

    void betaMinus ( char sel, char act ) {

        Serial.println ( F ( "Beta -" ) );

    }



    void execute ( char sel, char act ) {

        disp.dispatch ( *this, cmdMethods [0], 'a', 'b', ex1Array[0], cmdCount );

    }



};



//  Example 2 

char ex2Array  [2] = {

    {'x','?'},

    {'y','?'},

    {'z','?'},

};



class Example2 {

public:



    char *_name = "Template Example 2";



    Dispatcher disp;



    static const int cmdCount = sizeof ( ex2Array ) / sizeof ( ex2Array [0] );



    typedef void ( Example2::*FunctionPointer )( char sel, char act );



    //  Function dispatch table

    FunctionPointer cmdMethods [cmdCount] = {

        &Example2::x,

        &Example2::y,

        &Example2::z,

    };



    Example2 () {

    }



    void x ( char sel, char act ) {

        Serial.println ( F ( "X" ) );

    }

    void y ( char sel, char act ) {

        Serial.println ( F ( "Y" ) );

    }

    void z ( char sel, char act ) {

        Serial.println ( F ( "Z" ) );

    }



    void execute ( char sel, char act ) {

        disp.dispatch ( *this, cmdMethods [0], 'a', 'b', ex2Array [0], cmdCount );

    }

};

dispatch should called with an instance.

template<class T>

void dispatch(T& instance, void(T::*func)(char, char), char param1, char param2  )

{

  instance.*func(param1, param2);

}

call dispatch:

dispatch(*this, cmdMethods[0], 'a', 'b');