Layout

ILayout is a recursive splitter. Each node is either a leaf (wrapping an IRenderable) or an internal node split by rows or columns. Named regions let you reach into the tree later and swap content via Update.

When to use

• Dashboards with header / sidebar / main / footer regions.
• Any layout where multiple panels need fixed sizes or ratios.
• Anywhere you'd reach for a TUI window manager.

For simpler horizontal/vertical stacks without sized regions, use Columns / Rows. For aligned columnar data, use Grid.

Basic usage

var
  root, hdr, body, side, main, foot : ILayout;
begin
  root := Widgets.Layout('root');
  hdr  := Widgets.Layout('header').WithSize(3);
  side := Widgets.Layout('side').WithRatio(1);
  main := Widgets.Layout('main').WithRatio(2);
  body := Widgets.Layout('body');
  body.SplitColumns([side, main]);
  foot := Widgets.Layout('footer').WithSize(1);
  root.SplitRows([hdr, body, foot]);

  hdr.Update(Widgets.Markup('[bold yellow]Dashboard[/]'));
  side.Update(Widgets.Markup('sidebar'));
  main.Update(Widgets.Markup('main content'));
  foot.Update(Widgets.Markup('[grey]press q to quit[/]'));

  root.WithHeight(24);
  AnsiConsole.Write(root);
end;

Size strategies

A node can be fixed, ratio'd, or default:

Method	Effect
WithSize(value)	Exactly value cells (in the splitting axis).
WithRatio(value)	Take value/total-ratio of the leftover space.
WithMinimumSize(value)	Floor on the size — the node won't shrink below this.
WithVisible(value)	When False the region collapses to zero size.
WithHeight(value)	Used at the root to set the overall layout height.

If a child has neither a fixed size nor a ratio, it's treated as ratio 1.

Splits

Method	Effect
SplitRows(children)	Split this node vertically into the given children.
SplitColumns(children)	Split this node horizontally.
Update(renderable)	Set the leaf content. Replaces previous content.
FindByName(name) : ILayout	Locate a descendant by its name string.

Updating a region

Once built, you can change a region's content with Update:

side := root.FindByName('side');
side.Update(Widgets.Panel(newContent));
AnsiConsole.Write(root);

This is the typical pattern when combined with Live display to redraw a dashboard in place.

Configuration recap

hdr  := Widgets.Layout('header').WithSize(3).WithMinimumSize(3);
side := Widgets.Layout('side').WithRatio(1).WithMinimumSize(20);
main := Widgets.Layout('main').WithRatio(2);
foot := Widgets.Layout('footer').WithSize(1).WithVisible(showFooter);

API reference

• Widgets.Layout() — anonymous root.
• Widgets.Layout(name) — named layout node.
• ILayout — interface.

See also

• Live display — refresh a layout in place.
• Panel — the typical leaf content for a layout region.
• Rows / Columns — simpler alternatives.