Add U8NUMFN and U32NUMFN

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points to a callback procedure instead of address of variable

uint32_t u32fn(uint8_t msg, uint32_t arg);
uint8_t u8fn(uint8_t msg, uint8_t arg);

msg = M2_NUM_MSG_GET   /* returns value from procedure */
msg = M2_NUM_MSG_SET   /* provides value in "arg" */

Original issue reported on code.google.com by olikr...@gmail.com on 26 Jan 2012 at 11:25

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This is badly needed!

Original comment by sammyl...@gmail.com on 26 Jan 2012 at 2:04

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implementation started:

uint8_t u8_x = 2;

uint8_t u8_cb(m2_el_fnarg_p fnarg, uint8_t msg, uint8_t val)
{
  if ( msg == M2_U8_MSG_SET_VALUE )
    u8_x = val;
  return u8_x;
}

#define M2_U8_MSG_GET_VALUE 0
#define M2_U8_MSG_SET_VALUE 1

M2_U8NUMFN(el,fmt,min,max,fn)

documentation: SET_VALUE is only called, if value has really changed

Original comment by olikr...@gmail.com on 26 Jan 2012 at 10:34

• Changed state: Started

[GoogleCodeExporter]

changed first arg to the element pointer (to be consistent between u8 and u32)
started with u32 (testing needed)

Original comment by olikr...@gmail.com on 27 Jan 2012 at 5:53

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- write u32 test case, check the code 
- rewrite u8 procedure, remove el_data, use runtime object type identification 
as in u32 code

Original comment by olikr...@gmail.com on 27 Jan 2012 at 8:16

[GoogleCodeExporter]

implemented, documentation needs to be done

Original comment by olikr...@gmail.com on 27 Jan 2012 at 9:33

[GoogleCodeExporter]

done

Original comment by olikr...@gmail.com on 28 Jan 2012 at 8:26

• Changed state: Verified

[GoogleCodeExporter]

Seem to make problems with classes - get error: "a pointer to a bound function 
my only be used to call the function"

This works:

uint8_t u8_cb(m2_rom_void_p element, uint8_t msg, uint8_t val)
{
  if ( msg == M2_U8_MSG_SET_VALUE )
    global_value = val;
  return global_value;
}
M2_U8NUMFN(el_Frost_aktiv_num,"c2", 1, 20, u8_cb );

This does not work:

class testclass {

public:
    uint8_t u8_cb(m2_rom_void_p element, uint8_t msg, uint8_t val);
};

uint8_t testclass::u8_cb(m2_rom_void_p element, uint8_t msg, uint8_t val)
{
  if ( msg == M2_U8_MSG_SET_VALUE )
    global_value = val;
  return global_value;
}

testclass test;

M2_U8NUMFN(el_Frost_aktiv_num,"c2", 1, 20, test.u8_cb );

Any ideas?

Original comment by sammyl...@gmail.com on 30 Jan 2012 at 2:14

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This is not possible:
http://www.parashift.com/c++-faq-lite/pointers-to-members.html

Original comment by olikr...@gmail.com on 30 Jan 2012 at 3:54

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This will not work. Member functions be not be passed directly (see also the 
C++ FAQ)

Original comment by olikr...@gmail.com on 30 Jan 2012 at 4:02

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OK I got it - Thanks

Original comment by sammyl...@gmail.com on 30 Jan 2012 at 4:18