Groups

Group places children in the same local region under one shared alignment policy. Unlike a stack it does not lay children out in sequence, and unlike an overlay it does not snap them to anchors: every child gets the same box and the same alignment.

use Atelier\Layout\Alignment;
use Atelier\Layout\Element\Group;
use Atelier\Layout\Geometry\Rect;
use Atelier\Layout\LayoutContext;
use Atelier\Layout\Value\InsetSpec;

$group = Group::of('badges')
    ->padding(InsetSpec::px(8))
    ->align(Alignment::End, Alignment::Start)
    ->add($primary)
    ->add($secondary);

$solved = $group->solve(new LayoutContext(), Rect::fromSize(160, 96));

Use it for badges, grouped labels, and overlays that are not anchor-specific.

Reading Solved Frames

Every solved tree returns a PlacedNode. Ids are the bridge between layout and renderers: you name a node when you build it, and you ask for it by that name afterwards.

$solved->frameOf('primary');   // the Rect, or null
$solved->find('primary');      // the PlacedNode, or null

Nothing downstream needs to know how the frame was computed. A renderer that receives frameOf('primary') draws a rectangle; whether it came from a grid slot, a stack child, or a group is not its concern.

Bounds Around Solved Children

Bounds computes the rectangle that contains a set of rectangles. It is a pure value helper, not a node: give it frames you already solved.

use Atelier\Layout\Geometry\Bounds;
use Atelier\Layout\Geometry\Insets;

$box = Bounds::of($a, $b, $c);
$padded = Bounds::expand($box, Insets::all(12));

Bounds::fromRects(iterable $rects) takes any iterable and returns null for an empty one, which is the form to use when the set is built at runtime and may be empty.

Use it to frame a cluster, to compute a background plate behind a group of nodes, or to size a viewBox around everything that was solved.