#Events: a little surprise from UCCNC

[dezsoe]

Over the development of UCCNC, first came the #Events tag in macros. This was made for putting special code in macros to handle forms events or other functions/subroutines. An other development was about the macro compilation. In the past every time a macro was called, it was first compiled. It was very slow. Now if Precompile switch is on the macros are compiled on program startup, or if not, they are compiled on first run. Of course, if a macro is changed, it will be compiled again.

These two developments have a little but very useful side-effect: we can use static variables after the #Events tag. These variables store their values until the macro is recompiled or UCCNC exits. A small example:

Code: Select all

AS3.Additemtolistbeginning("Value: " + value, 2);
++value;

#Events

static int value = 0;

Running this macro more times you can see in the status window the increasing value.

Now we have unlimited possibilities. Let's make a tri-state button: every press executes the next function in cycle:

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switch (state)
{
  case 1:
    AS3.Additemtolistbeginning("First state", 2);
    ++state;
    break;
  case 2:
    AS3.Additemtolistbeginning("Second state", 2);
    ++state;
    break;
  case 3:
    AS3.Additemtolistbeginning("Third state", 2);
    state = 1;
    break;
}

#Events

static int state = 1;

In the past you had to use #variables or - as the worst way - you could write values to the profile and read back. The first was only for numeric values and could interfere with the running g-code, the second is slow and messes up the profile file.

[Battwell]

This looks like a great method to use for a hot swap tool changer.
Where full list of tools can be read in from the start of the file. Then the changer can have the next tool ready for instant swap.