/// <summary>
/// A private Event Handler that is called whenever the ChangeContents event is fired.
/// </summary>
private void HandleChangeContents()
{
// Obtain the name of the currently selected cell and its desired contents.
window.GetSelection(out int col, out int row);
string cellName = toCellName(col, row);
string contents = window.GetDesiredContents();
ISet <string> dependents = new HashSet <string>();
// Try and change the contents of the spreadsheet to the new contents.
try
{
dependents = spreadsheet.SetContentsOfCell(cellName, contents);
}
catch (Exception e)
{
// Show the appropriate error message if the passed in contents aren't allowed.
if (e is FormulaFormatException)
{
window.InvalidFormula();
}
else if (e is CircularException)
{
window.CircularFormula();
}
return;
}
// Update all of the cells so they show the correct value
foreach (string s in dependents)
{
object value = spreadsheet.GetCellValue(s);
toCoordinates(s, out int currentCol, out int currentRow);
if (value is FormulaError)
{
value = "#ERROR";
}
window.SetValue(currentCol, currentRow, value.ToString());
}
// Update the text box to show the correct contents.
HandleNewCellSelected();
}