/// <summary>
/// If name is null or invalid, throws an InvalidNameException.
///
/// Otherwise, returns the contents (as opposed to the value) of the named cell. The return
/// value should be either a string, a double, or a Formula.
/// </summary>
public override object GetCellContents(string name)
{
if (Cell.IsValidName(name) && cells.ContainsKey(name))
{
return(cells[name].content);
}
else
{
throw new InvalidNameException();
}
}
/// <summary>
/// If the parameter is null, throws an ArgumentNullException.
///
/// Otherwise, if name is null or invalid, throws an InvalidNameException.
///
/// Otherwise, if changing the contents of the named cell to be the formula would cause a
/// circular dependency, throws a CircularException. (No change is made to the spreadsheet.)
///
/// Otherwise, the contents of the named cell becomes formula. The method returns a
/// Set consisting of name plus the names of all other cells whose value depends,
/// directly or indirectly, on the named cell.
///
/// For example, if name is A1, B1 contains A1*2, and C1 contains B1+A1, the
/// set {A1, B1, C1} is returned.
/// </summary>
private ISet <string> SetContents(string name, object content)
{
// Make sure the content is not null
if (content == null)
{
throw new ArgumentNullException("Make sure the formula is not null.");
}
if (name == null || !Cell.IsValidName(name))
{
throw new InvalidNameException();
}
// Every time we set the contents, remove all of the dependents and dependees for this name.
cellRelations.ReplaceDependents(name, new List <string>());
// Set the value to the content. Value will change if content is a formula.
object value = content;
// Now, handle formula-specific actions
if (content is Formula)
{
// First make sure that adding this new content would not create a circular dependency.
Formula contentAsFormula = (Formula)content;
checkForCircularDependency(name, contentAsFormula);
// Add in all of the dependencies for this cell
List <string> variablesInFormula = contentAsFormula.GetVariables().ToList();
foreach (string v in variablesInFormula)
{
cellRelations.AddDependency(name, v);
}
// Get the value and content prepped for cell creation
value = contentAsFormula.Evaluate(lookup);
content = contentAsFormula.ToString();
}
// If the cell already exists, just change the content and value.
if (cells.ContainsKey(name))
{
// If they are setting the content to "", remove the cell.
if (value.ToString().Equals(""))
{
cells.Remove(name);
}
else
{
cells[name].content = content;
cells[name].value = value;
}
}
// Otherwise, create a new cell object with the proper name, content, and value
// This will also check that the name of the cell is valid or not.
else
{
Cell cellForName = new Cell(name, content, value);
cells.Add(name, cellForName);
}
// Get all of the dependees for the named cell and return them.
HashSet <string> dependsOnNamedCell = new HashSet <string>()
{
name
};
List <string> namedCellDependees = GetCellsToRecalculate(name).ToList();
foreach (string dep in namedCellDependees)
{
dependsOnNamedCell.Add(dep);
}
return(dependsOnNamedCell);
}
