GridSpecification.fromRegularTiles({double tileWidth, double tileHeight, int columnCount, int rowCount, double columnSpacing: 0.0, double rowSpacing: 0.0, EdgeInsets padding: EdgeInsets.zero })

Creates a grid specification containing a certain number of equally sized tiles.

The tileWidth and tileHeight is the horizontal and vertical (respectively) extent that each child will be allocated in the grid. The tiles will have columnSpacing space between them horizontally and rowSpacing space between them vertically.

If the tiles are to completely fill the grid, then their size should be based on the grid's padded interior and the column and row spacing.

Source 

GridSpecification.fromRegularTiles({
  double tileWidth,
  double tileHeight,
  int columnCount,
  int rowCount,
  double columnSpacing: 0.0,
  double rowSpacing: 0.0,
  this.padding: EdgeInsets.zero
}) : columnOffsets = _generateRegularOffsets(columnCount, tileWidth + columnSpacing),
     rowOffsets = _generateRegularOffsets(rowCount, tileHeight + rowSpacing),
     columnSpacing = columnSpacing,
     rowSpacing = rowSpacing {
  assert(_debugIsMonotonic(columnOffsets));
  assert(_debugIsMonotonic(rowOffsets));
  assert(columnSpacing != null && columnSpacing >= 0.0);
  assert(rowSpacing != null && rowSpacing >= 0.0);
  assert(padding != null && padding.isNonNegative);
}