Module floating_layer 

Where the floating layer’s cards stand, as plain arithmetic.

The session hosts one floating layer: every activity the person keeps over the windows is a card in it. This module is the layer’s placement as a pure function, so what a frame draws can be proven from numbers alone: cards never overlap each other, never sit under the bar, inside the notification column while a banner shows, or in the band the hardware readout stands in, and always keep a reachable strip inside the work area.

Apps describe, the session places: nothing here knows what an activity is beyond its Summary.

Structs

Card

One activity the layer holds, and where the person left it when they dragged it loose.

Folded

A card the layer leaves in the pill.

Layer

What the layer shows.

Named

An activity the bar’s pill names: the app that shows it and its summary. An activity’s id is its own app’s, so the app is part of what names it.

Parts

Where the parts of a card stand on it, as the frame draws them.

Pill

What the bar’s pill shows: the activity that stands first, and how many others are waiting behind it (one dot each).

Placed

A card as the layer draws it.

Placement

The screen the cards stand on, in the layer’s own coordinates: the work area under the bar, the bar itself, the notification column while a banner shows, and the band the readout stands in while it does.

Enums

Corner

Which corner of the work area the cards dock in. It is the person’s choice on this device, never shared.

FoldReason

Why a card is not on the screen.

Constants

CARD_GAP

The space between two docked cards.

EDGE_INSET

How far a card rests from the work area’s edges.

MAX_CARDS

The most cards expanded at once; the least recently touched folds into the pill when another arrives.

NARROW_PX

Below this width a display is phone-width: the pill is the only resting form and a card only drops when the person expands it.

REACHABLE

The least a card keeps inside the work area, whatever the person dragged it to: enough to grab it again.

Functions

card_extent

How big card stands on work: every card in a column is as wide as the layer’s one column, so the cards share a width and an edge, and the layer’s place wins over what its app asked for. A card its app draws keeps the height its app asked for; every other card the height its summary’s rows take. The app lays its body out at the width the layer’s place gives it.

card_parts

Where each of summary’s parts stands on a card in card: the rows card_size reserves, laid out whatever the card’s real height.

card_size

How big an activity’s card is on work: one token’s width (a hero picture takes its own), never wider than the display, and the height of the rows the summary has, so a card is as tall as what it says and no taller.

keep_inside

A card the size of size dragged to at, kept inside work and inset from its edges but for a strip reachable long the person can grab: a card that fits stays wholly inside, a card larger than the work area keeps that strip. Every place a card is dropped ends here, so a settled card and a remembered one land the same way.

narrow

Whether work is a phone-width display.

pill

The bar’s pill: the most urgent activity, and how many others wait behind it. A call stands before directions, directions before a timer that is due within a minute, that timer before any other timer, timers before music.

place

Where the cards stand: corner’s column, in priority order from the corner, or — phone-width and expanded — one full-width card under the bar.