Add curses window attribute get/set methods and WA_* constants

[serhiy-storchaka]

Feature or enhancement

Feature or enhancement

The curses module wraps the legacy attron()/attroff()/attrset() functions, which take a chtype (where the color pair is packed into the value via COLOR_PAIR()), but it does not expose the X/Open attr_t-based family that passes the color pair as a separate argument:

• wattr_get() / wattr_set()
• wattr_on() / wattr_off()
• wcolor_set()

These are the modern, recommended forms: they keep the attribute bits (A_* / WA_*) and the color pair separate, which is what cchar_t-based wide-character output (add_wch() etc.) already uses internally. The legacy functions also can't address color pairs above 255 without the pair number colliding with the attribute bits.

This issue proposes adding the corresponding window methods:

• window.attr_get() → (attributes, pair) — current attribute bits and color pair
• window.attr_set(attr, pair=0) — set attribute bits and color pair
• window.attr_on(attr) — turn attribute bits on
• window.attr_off(attr) — turn attribute bits off
• window.color_set(pair) — set just the color pair

and the associated WA_* attribute constants (WA_NORMAL, WA_BOLD, WA_UNDERLINE, WA_REVERSE, WA_BLINK, WA_DIM, WA_STANDOUT, WA_ALTCHARSET, WA_INVIS, WA_PROTECT, WA_ITALIC, WA_HORIZONTAL, WA_LEFT, WA_LOW, WA_RIGHT, WA_TOP, WA_VERTICAL, WA_ATTRIBUTES), each guarded by #ifdef for portability. On ncurses the WA_* values are bit-identical to the matching A_* values.

The color_set part overlaps with the long-standing gh-49618 (which also asks for the unrelated addchstr family); this issue scopes the attribute get/set surface specifically.

Linked PRs

Linked PRs

• gh-152219: Add curses window attribute get/set methods and WA_* constants #152221