Module form_fields 

PDF interactive form fields (AcroForm).

AcroForm declares interactive fields — text inputs, checkboxes, radio buttons, choice lists, signatures — at the document level. Each terminal field has a fully-qualified name (parent names joined with .) and one or more widget annotations that give it a visible presence on a page.

FormCatalog is the top-level container; FormField is a single field (terminal or non-terminal container) with type-tagged data in FieldKind.

Cross-linking with annotations

Each terminal field carries a list of widget object numbers (FormField::widget_obj_nums). Consumers that want the corresponding Annotation data look up matching annotations on each page via PdfDocument::page_annotations; the annotation whose source object number equals the widget’s is the one to use.

Structs

ButtonField

/FT /Btn — pushbutton, checkbox, or radio button.

ChoiceField

/FT /Ch — list box or combo box.

ChoiceOption

One entry in /Opt.

FieldFlags

/Ff flags shared by all field types.

FormCatalog

Top-level AcroForm dictionary.

FormField

One form field — terminal (has a value) or non-terminal (container).

SigFlags

/SigFlags bit field.

SignatureField

/FT /Sig — digital signature.

TextField

/FT /Tx — text input.

Enums

ButtonType

Resolved button kind (pre-classified for caller convenience).

FieldKind

Field type plus subtype-specific data.

FieldValue

Field value. PDF stores values type-erased; the form-walker maps each /V (or /DV) to one of these variants based on the field type and the value’s PDF type.

Functions

parse_acroform

Parse the document’s /AcroForm if present.