This class contains methods used to format a table's columns. It is limited by the support cross-browser HTML support for column formatting.

class ColumnFormatter {
 dart_html.Element columnGroup;
 HtmlTable _table;

 /**
  * Adds a style to the specified column.
  *
  * @param col the col to which the style will be added
  * @param styleName the style name to be added
  * @see UiObject#addStyleName(String)
  * @throws IndexOutOfBoundsException
  */
 void addStyleName(int col, String styleName) {
   UiObject.manageElementStyleName(ensureColumn(col), styleName, true);
 }

 /**
  * Get the col element for the column.
  *
  * @param column the column index
  * @return the col element
  */
 dart_html.Element getElement(int column) {
   return ensureColumn(column);
 }

 /**
  * Gets the style of the specified column.
  *
  * @param column the column to be queried
  * @return the style name
  * @see UiObject#getStyleName()
  * @throws IndexOutOfBoundsException
  */
 String getStyleName(int column) {
   return UiObject.getElementStyleName(ensureColumn(column));
 }

 /**
  * Gets the primary style of the specified column.
  *
  * @param column the column to be queried
  * @return the style name
  * @see UiObject#getStylePrimaryName()
  * @throws IndexOutOfBoundsException
  */
 String getStylePrimaryName(int column) {
   return UiObject.getElementStylePrimaryName(ensureColumn(column));
 }

 /**
  * Removes a style from the specified column.
  *
  * @param column the column from which the style will be removed
  * @param styleName the style name to be removed
  * @see UiObject#removeStyleName(String)
  * @throws IndexOutOfBoundsException
  */
 void removeStyleName(int column, String styleName) {
   UiObject.manageElementStyleName(ensureColumn(column), styleName, false);
 }

 /**
  * Sets the style name associated with the specified column.
  *
  * @param column the column whose style name is to be set
  * @param styleName the new style name
  * @see UiObject#setStyleName(String)
  * @throws IndexOutOfBoundsException
  */
 void setStyleName(int column, String styleName) {
   UiObject.setElementStyleName(ensureColumn(column), styleName);
 }

 /**
  * Sets the primary style name associated with the specified column.
  *
  * @param column the column whose style name is to be set
  * @param styleName the new style name
  * @see UiObject#setStylePrimaryName(String)
  * @throws IndexOutOfBoundsException
  */
 void setStylePrimaryName(int column, String styleName) {
   UiObject.setElementStylePrimaryName(ensureColumn(column), styleName);
 }

 /**
  * Sets the width of the specified column.
  *
  * @param column the column of the cell whose width is to be set
  * @param width the cell's new width, in percentage or pixel units
  * @throws IndexOutOfBoundsException
  */
 void setWidth(int column, String width) {
   Dom.setElementProperty(ensureColumn(column), "width", width);
 }

 /**
  * Resize the column group element.
  *
  * @param columns the number of columns
  * @param growOnly true to only grow, false to shrink if needed
  */
 void resizeColumnGroup(int columns, bool growOnly) {
   // The colgroup should always have at least one element.  See
   // prepareColumnGroup() for more details.
   columns = dart_math.max(columns, 1);

   int num = columnGroup.children.length;
   if (num < columns) {
     for (int i = num; i < columns; i++) {
       columnGroup.append(new dart_html.TableColElement());
     }
   } else if (!growOnly && num > columns) {
     for (int i = num; i > columns; i--) {
       columnGroup.lastChild.remove();
     }
   }
 }

 dart_html.Element ensureColumn(int col) {
   _table.prepareColumn(col);
   prepareColumnGroup();
   resizeColumnGroup(col + 1, true);
   return columnGroup.children[col];
 }

 /**
  * Prepare the colgroup tag for the first time, guaranteeing that it exists
  * and has at least one col tag in it. This method corrects a Mozilla issue
  * where the col tag will affect the wrong column if a col tag doesn't exist
  * when the element is attached to the page.
  */
 void prepareColumnGroup() {
   if (columnGroup == null) {
     columnGroup = new dart_html.Element.tag("colgroup");
     Dom.insertChild(_table.tableElem, columnGroup, 0);
     columnGroup.append(new dart_html.TableColElement());
   }
 }
}