How to run a function everytime a value is changed on MUI?

[dolence]

Hi!

On M2TK lib I could do something like this:
M2_U8NUMFN(el_val_conf_velocidade,"c2f1",1,25,muda_velocidade);
And as result everytime a new value was entered the function "muda_velocidade" was called and I knew I had to recalculate my parameters using the new entered values.

How to do something similar to this in MUI? I have a global variable holding my motor speed value and I would like to calculate a new PWM duty everytime a change occurs.

Also, how to get which form is active as in m2_GetRoot()?

Edit: typo

[dolence]

I could just user variables to track these changes, but I think probably this isn't the best way to do this, but after reading the MUI help I didn't found it. Please, any help would be greatly appreciated 👍

[olikraus]

You could extend an existing MUIF. Lets take this list of functions:

u8g2/sys/arduino/u8g2_page_buffer/MUICountDown/MUICountDown.ino

Lines 347 to 359 in d987608

	muif_t muif_list[] = {
	/* normal text style */
	MUIF_U8G2_FONT_STYLE(0, u8g2_font_helvR08_tr),
	/* Leave the menu system */
	MUIF_VARIABLE("LV",&exit_code,mui_u8g2_btn_exit_wm_fi),
	/* input for a number between 0 to 9 */
	MUIF_U8G2_U8_MIN_MAX("IN", &number_input, 0, 9, mui_u8g2_u8_min_max_wm_mse_pi),
	/* MUI_LABEL is used to place fixed text on the screeen */
	MUIF_LABEL(mui_u8g2_draw_text)
	};

More specific, lets get change events from "mui_u8g2_u8_min_max_wm_mse_pi", which is defined here:

u8g2/csrc/mui_u8g2.c

Line 727 in d987608

uint8_t mui_u8g2_u8_min_max_wm_mse_pi(mui_t *ui, uint8_t msg)

In this case we will first call the original function and then listen and react on the events which modify the value.

uint8_t my_mui_u8g2_u8_min_max_wm_mse_pi(mui_t *ui, uint8_t msg)
{
  uint8_t result = mui_u8g2_u8_min_max_wm_mse_pi(ui, msg);  // call original function
  if ( msg == MUIF_MSG_CURSOR_SELECT || msg == MUIF_MSG_VALUE_INCREMENT || msg == MUIF_MSG_VALUE_DECREMENT )
  {
    ...   // value has changed, do something special
  }
  return result;
}

Then of course, in the MUIF list you have to use your own function:

muif_t muif_list[] = {
  /* normal text style */
  MUIF_U8G2_FONT_STYLE(0, u8g2_font_helvR08_tr),
  
  /* Leave the menu system */
  MUIF_VARIABLE("LV",&exit_code,mui_u8g2_btn_exit_wm_fi),
  
  /* input for a number between 0 to 9 */
  MUIF_U8G2_U8_MIN_MAX("IN", &number_input, 0, 9, my_mui_u8g2_u8_min_max_wm_mse_pi),  // call modified function
  
  /* MUI_LABEL is used to place fixed text on the screeen */
  MUIF_LABEL(mui_u8g2_draw_text)
};