SpecDefinition referenceView source

Composition

Automatic slide and content-group arrangement. Nested content groups arrange their children independently, inheriting only minFontSize and overflow. Explicit promoted regions retain their positions. A layout defines its grid as one ordered list of regions; its composition supports gap, padding, minFontSize and overflow rather than mode, columns or weights.

Metadata

Definition: #/$defs/Composition
Form: object
Source: spec/schemas/opf.schema.json

Field index

Field	Type	Req.	Description
mode	enum	—	auto chooses a grid from available space and content; grid uses columns; row and column use one horizontal or vertical track. `mode` · Allowed values `"auto""grid""row""column"`
columns	integer	—	Column count for grid. In auto mode this caps the number of columns.
gap	number	—	Space between cells as a fraction of the container short edge (canvas at slide root). Default 0.03333333333333333.
padding	number	—	Inset as a fraction of the container short edge. Default 0.08 on a slide, 0 inside a group.
weights	array<number>	—	Relative track sizes: columns for row/grid/auto, rows for column. Omitted tracks have weight 1; extra weights are ignored.
minFontSize	number	—	Minimum readable text size in reference pixels at a 720-pixel canvas short edge. Default 16. Overflow is diagnosed when text cannot fit at this size.
overflow	enum	—	warn returns diagnostics for content that does not fit; error rejects layout. Content is never silently removed. Default warn. `overflow` · Allowed values `"warn""error"`

`mode`

typeenumrequirednodefault—

auto chooses a grid from available space and content; grid uses columns; row and column use one horizontal or vertical track.

mode · Allowed values: "auto""grid""row""column"

Field fragment · mode.json

{
  "mode": "auto"
}

`columns`

typeintegerrequirednodefault—

Column count for grid. In auto mode this caps the number of columns.

`gap`

typenumberrequirednodefault—

Space between cells as a fraction of the container short edge (canvas at slide root). Default 0.03333333333333333.

`padding`

typenumberrequirednodefault—

Inset as a fraction of the container short edge. Default 0.08 on a slide, 0 inside a group.

`weights`

typearray<number>requirednodefault—

Relative track sizes: columns for row/grid/auto, rows for column. Omitted tracks have weight 1; extra weights are ignored.

`minFontSize`

typenumberrequirednodefault—

Minimum readable text size in reference pixels at a 720-pixel canvas short edge. Default 16. Overflow is diagnosed when text cannot fit at this size.

`overflow`

typeenumrequirednodefault—

warn returns diagnostics for content that does not fit; error rejects layout. Content is never silently removed. Default warn.

overflow · Allowed values: "warn""error"

Field fragment · overflow.json

{
  "overflow": "warn"
}

Complete definition constraints

Exact schema constraints

{
  "type": "object",
  "additionalProperties": false,
  "description": "Automatic slide and content-group arrangement. Nested content groups arrange their children independently, inheriting only minFontSize and overflow. Explicit promoted regions retain their positions. A layout defines its grid as one ordered list of regions; its composition supports gap, padding, minFontSize and overflow rather than mode, columns or weights.",
  "properties": {
    "mode": {
      "type": "string",
      "enum": [
        "auto",
        "grid",
        "row",
        "column"
      ],
      "description": "auto chooses a grid from available space and content; grid uses columns; row and column use one horizontal or vertical track."
    },
    "columns": {
      "type": "integer",
      "minimum": 1,
      "maximum": 12,
      "description": "Column count for grid. In auto mode this caps the number of columns."
    },
    "gap": {
      "type": "number",
      "minimum": 0,
      "maximum": 0.1,
      "description": "Space between cells as a fraction of the container short edge (canvas at slide root). Default 0.03333333333333333."
    },
    "padding": {
      "type": "number",
      "minimum": 0,
      "maximum": 0.2,
      "description": "Inset as a fraction of the container short edge. Default 0.08 on a slide, 0 inside a group."
    },
    "weights": {
      "type": "array",
      "minItems": 1,
      "maxItems": 12,
      "items": {
        "type": "number",
        "exclusiveMinimum": 0,
        "maximum": 100
      },
      "description": "Relative track sizes: columns for row/grid/auto, rows for column. Omitted tracks have weight 1; extra weights are ignored."
    },
    "minFontSize": {
      "type": "number",
      "minimum": 8,
      "maximum": 32,
      "description": "Minimum readable text size in reference pixels at a 720-pixel canvas short edge. Default 16. Overflow is diagnosed when text cannot fit at this size."
    },
    "overflow": {
      "type": "string",
      "enum": [
        "warn",
        "error"
      ],
      "description": "warn returns diagnostics for content that does not fit; error rejects layout. Content is never silently removed. Default warn."
    }
  }
}