Module card 

Anchored info cards — measured, placed, and clamped by the library.

A recurring overlay shape: a small rounded card with a title and a few detail lines, floated next to an anchor point (a tapped body, a hovered element, a reticle). Every app that hand-rolls one repeats the same three mistakes:

1. Guessed text width (chars × size × k) — wrong for anything non-monospace or non-ASCII, so the card is too tight or too wide.
2. Clamping against its own widget bounds only — the card lands underneath sibling edge chrome (button rails, trays, the on-screen keyboard) and looks cut off.
3. No side-flipping — when the anchor nears an edge the card gets pushed over the anchor or off-screen instead of flipping sides.

This module owns all three: measure uses the draw context’s real text metrics, and anchored_rect places the card against the viewport-wide safe area (crate::overlay_insets) with symmetric margins, flipping below/above the anchor as space demands. The convenience wrapper paint_anchored does measure → place → paint in one call — the pit of success for tap-info overlays.

All coordinates are logical, Y-up, relative to the widget doing the painting — pass that widget’s size as container. When the widget fills the viewport (the common overlay-host case) the safe-area insets line up 1:1; a non-fullscreen host can still use anchored_rect_with_insets with its own insets.

Structs

CardStyle

Visual + spacing parameters for an anchored card. The defaults give a dark tooltip-style card; override the colors to match app chrome.

Functions

anchored_rect

Place a card of size near anchor inside container, avoiding the frame’s crate::overlay_insets. See anchored_rect_with_insets.

anchored_rect_with_insets

Pure placement: prefer sitting fully below the anchor (Y-up: spanning downward from anchor.y - clearance), flip fully above when the bottom lacks room, and otherwise clamp into the safe area on the side with more space. Horizontally the card centres on the anchor and clamps; if it is wider than the safe area it centres so any overflow is symmetric. The result never leaves container − insets − margin on any side the card fits.

measure

Measure the card needed for title + details using the context’s real text metrics (falls back to a monospace estimate only if the backend can’t measure).

paint

Paint the card chrome + text into rect (as produced by anchored_rect).

paint_anchored

Measure → wrap → place → paint in one call; returns the rect painted so the caller can hit-test or decorate it. This is the intended entry point: detail lines wrap to the safe width, so even a narrow phone viewport with a wide reserved rail produces a taller card instead of one that pokes underneath the chrome. A clipped or edge-hugging card now requires deliberate effort rather than being the accidental default.