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Columns

Most FDC grid columns are field-bound declarations. The fieldName must resolve to a compatible field in the dataset schema.

const FdcTextColumn<dynamic>(
  id: 'companyColumn',
  fieldName: 'company',
  label: 'Company',
  width: 240,
  minWidth: 140,
  maxWidth: 420,
)

Stable column identity​

Use id when a column must preserve runtime layout state across rebuilds or be targeted by FdcGridController commands.

final controller = FdcGridController();

FdcGrid(
  controller: controller,
  dataSet: customers,
  columns: const [
    FdcTextColumn<dynamic>(
      id: 'cityColumn',
      fieldName: 'city',
    ),
  ],
)

Later:

controller.focusColumn('cityColumn');
controller.hideColumn('cityColumn');
controller.showColumn('cityColumn');

Common column controls​

All standard field-bound columns share common configuration such as:

  • label, hint, visible, and enabled
  • readOnly, tabStop, and focusOrder
  • width, minWidth, maxWidth, and autoSizeMode
  • allowSort, filterConfig, and allowResize
  • horizontalAlignment
  • pin
  • summary
  • onValueChanging, onValueChanged, and onLookup

Column sizing and resizing​

Column width is constrained by minWidth and maxWidth, while width provides the configured width:

const FdcTextColumn<dynamic>(
  fieldName: 'company',
  width: 240,
  minWidth: 140,
  maxWidth: 420,
  allowResize: true,
)

Interactive resize is controlled at both grid and column level. The grid must allow column resize and the target column must not disable it:

FdcGrid(
  dataSet: customers,
  options: const FdcGridOptions(
    allowColumnResize: true,
  ),
  columns: const [
    FdcTextColumn<dynamic>(
      fieldName: 'company',
      allowResize: true,
    ),
  ],
)

autoSizeMode controls whether a column participates in viewport width distribution. It is a layout behavior, not content measurement:

ModeBehavior
FdcGridColumnAutoSizeMode.noneKeeps the configured width except for explicit or manual resize.
FdcGridColumnAutoSizeMode.viewportLets the column absorb scrollable viewport width deltas.

Pinned columns do not participate in the scrollable viewport auto-size pass. Use stable minWidth and maxWidth constraints when a viewport-sized column must remain within a practical range.

Column pinning​

const FdcTextColumn<dynamic>(
  fieldName: 'company',
  pin: FdcGridColumnPin.start,
)

Interactive pinning is opt-in. Enable it globally when users should be able to pin and unpin columns from grid menus:

FdcGrid(
  dataSet: customers,
  pinning: const FdcGridColumnPinning(enabled: true),
)

Programmatic initial pinning through FdcGridColumn.pin remains available independently of interactive pinning.

Duplicate field bindings​

Multiple columns may bind to the same field. Give them distinct id values when each column needs independent layout state.