[Bf-python] event ID questions - partly solved

[Thomas Bleicher]

After rereading the sources again I found something and can
answer this myself:


On Wed, Aug 03, 2005 at 15:31:23 +0200, Thomas Bleicher wrote:
> Now the questions:
> 
> 
> 1) I have up to 80 buttons to create at one time. This is no problem
>    but I don't know where to find a large enough range of IDs for
>    these buttons that's not already used for other signals (ie.
>    event 8 was generated when a menu button was left _without_ changing
>    its value).

I have to appologize for this report. I fear I've tested my script
accidentally with version 2.35. I tried it again right now and could
not reproduce this behaviour with 2.37.

I think the solution is this (I don't have the 2.35 source to
compare with so I can't say when it was introduced):

In source/blender/python/api2_2x/Draw.c the following constants
are defined for this purpose:

    #define EXPP_BUTTON_EVENTS_OFFSET 1001
    #define EXPP_BUTTON_EVENTS_MIN 0
    #define EXPP_BUTTON_EVENTS_MAX 15382 /* 16384 - 1 - OFFSET */

If someone gets it wrong, an error message is generated as well:

    "button event argument must be in the range [0, 16382]"

This message is partly wrong, though, as the check_button_event
checks against EXPP_BUTTON_EVENTS_MAX, which is 15382. In Python
I'd use 
    
    "button event ... in the range [0, %d]" % EXPP_BUTTON_EVENTS_MAX

but I don't know if this is that easy in C. 

>    If there is no continuous range where can I find events which are
>    already assigned to something? Other toolkits offer a way to
>    generate/access the next usable ID; for example wxWindows:
>    
>         id = newId() # iirc; haven't used it for some time
>     
>    Would this be possible/a good idea for BPY?

Still might be a good idea.


Thomas