将函数参数保存在结构数组中

Question

I'm new to this forum. Very litlle programing experices. And english is not my primary language :)

I'm writing C code for microcontroller and for now I have created Graphic menu with array of structures. In this array I have defined jumps in case of pressed buttons (UP, DOWN, ENTER), menu texts and called functions in case of pressed buttons (if you are on correct submenu you can call functions).

Structure definition:

typedef const struct Menu_structure
{
    const char *text;
    unsigned char Menu_points;
    unsigned char Menu_button_UP;
    unsigned char Menu_button_DOWN;
    unsigned char Menu_button_ENTER;
    Menu_Waveform_parameter_t Waveform_parameter_value;
    void (*Menu_function_UP) ();
    void (*Menu_function_DOWN) ();
    void (*Menu_function_ENTER) ();
} MenuEntry;

1:menu tekst, 2:size of current submenu(for refresh purposes), 3:jump in case of UP, 4: jump in case of down, 5: jump in case of enter, 6: parameter enum, 7: function that are called in case of presses buttons.

Example of array:

MenuEntry menu[] =
{
    {menu_01,   5,  0,  0,  0,  0,              0,  0,  0},         
    {menu_02,   5,  1,  2,  1,  0,              0,  0,  funtion_0}, 
    {menu_03,   5,  1,  3,  6,  0,              0,  0,  0},             
    {menu_04,   5,  2,  4,  11, 0,              0,  0,  0},             
    {menu_05,   5,  3,  4,  1,  0,              0,  0,  funtion_1},
 }

Code for calling function (enter button pressed)

        case Button_ENTER:      if (menu[Menu_selected].Menu_function_ENTER != 0)
                                {
                                    menu[Menu_selected].Menu_function_ENTER();
                                }
                                break;

Everything works perfectly. The problem is that my menu is very long. Which means that I would need a lot of different functions (some of them can be combined with use of arguments).

Here comes my question. How can I save constant arguments in a array of structures. Any suggestions. Thank you.

Answer 1

In order to accomplish what you are asking for, I would first recommend moving on from C to some higher level language, at least for your User Interface. (The rest of your low-level stuff can remain in C.) Nowadays you can find high level languages even in embedded systems, complete with features for interfacing with C.

But let me guess, this is not an option for you.

So, the second thing I would recommend in order to accomplish what you are asking for is to use that wonderfully terrible hack of C known as preprocessor macros.

In C you can define a macro like this:

#define MYMACRO(a,b,c,d,e,i) { a, b, c, d, e, 0, 0, 0, i }

So then your table looks as follows:

{
    MYMACRO( menu_01,   5,  0,  0,  0,  0},         
    MYMACRO( menu_02,   5,  1,  2,  1,  funtion_0}, 
    MYMACRO( menu_03,   5,  1,  3,  6,  0},             
    MYMACRO( menu_04,   5,  2,  4,  11, 0},             
    MYMACRO( menu_05,   5,  3,  4,  1,  funtion_1},
}

Of course, you can define various different versions of MYMACRO with different arguments, expanding to use different constants, etc. Knock yourself out!