layout top-level property Null safety

Implementation

Map<String, dynamic> layout = {
  "constraints": {"transformer": getConstraints},
  "width": {
    "property": "width",
    "scale": "sizes",
  },
  "w": {"property": "width", "scale": "sizes"},
  "height": {"property": "height", "scale": "sizes"},
  "h": {"property": "height", "scale": "sizes"},
  "minWidth": {
    "property": "constraints",
    "scale": "sizes",
    "transformer": getConstraints
  },
  "minW": {
    "property": "constraints",
    "scale": "sizes",
    "transformer": getConstraints
  },
  "minHeight": {
    "property": "constraints",
    "scale": "sizes",
    "transformer": getConstraints
  },
  "minH": {
    "property": "constraints",
    "scale": "sizes",
    "transformer": getConstraints
  },
  "maxWidth": {
    "property": "constraints",
    "scale": "sizes",
    "transformer": getConstraints
  },
  "maxW": {
    "property": "constraints",
    "scale": "sizes",
    "transformer": getConstraints
  },
  "maxHeight": {
    "property": "constraints",
    "scale": "sizes",
    "transformer": getConstraints
  },
  "maxH": {
    "property": "constraints",
    "scale": "sizes",
    "transformer": getConstraints
  },
  "size": {
    "property": "constraints",
    "scale": "sizes",
    "transformer": getConstraints
  },
  "boxSize": {
    "property": "constraints",
    "scale": "sizes",
    "transformer": getConstraints
  },
};