How do I construct the right field_flags using the Enumerations table?

[ag-gaphp]

Enumerations for Widgets: https://pymupdf.readthedocs.io/en/latest/vars.html#widget-flags-field-flags

I'm a tiny bit confused on how to properly set the flags when I need a combination of things to happen. I'm not entirely sure what 1 << 1 means, but since there's no description I'm guessing it's a pretty common documentation thing that I just don't know how to read.

Seems like in some cases the values just need to be added together. So if I need a field to be required then I set the flag value to 2 (i.e., 1+1).

What if I need a field to be both required and multi-line, though? I tried adding all the values (in this case it would be 15), but when I set that flag it seems to break the field. When viewed in Acrobat it's like there isn't a field there at all.

I also get somewhat confused by the initial readout of the field_flags for a multi-line text field. It reports the flag value is 4096 (coming from a LibreOffice Draw doc).

Any clarification on how to parse the flag values would be greatly appreciated.

[ag-gaphp]

Ahhh, I realize now what the docs mean. Completely didn't register with me that 1 << 1 is referencing shifting zeros in python (d'oh). My idiocy strikes again.

That explains the initial flag value, 1 << 12 = 4096. I'm still not sure how to combine two flags, though. Maybe it isn't possible and I have to choose between required or multi-line?

[ag-gaphp]

Ok! Turns out it's just as simple as adding together the two shifted values. So for this case 4096 + 2, and that gets me a multi-line field that is required. I was getting turned around due to not realizing << was a python operator.

Amazing what you can do when you understand what you're reading!