/// <summary>
/// Will read a text's formula and then subscribe to all the referenced cell's in the formula.
/// </summary>
/// <param name="cell">Cell that uses other cells.</param>
private void SubscribeCellDependency(SpreadsheetCellValue cell)
{
if (cell.Text == string.Empty || !cell.Text.StartsWith("=") ||
cell.Value == "!(bad reference)" || cell.Value == "!(self reference)" ||
cell.Value == "!(circular reference)")
{
return; // Subscribe to nothing if the cell text is empty.
}
string cellText = cell.Text.Substring(1, cell.Text.Length - 1);
string[] words = cellText.Split('+', '-', '/', '*', '(', ')'); // Splits all the variables and constants.
int lengthLoop = words.Length;
for (int i = 0; i < lengthLoop; i++)
{
if (CheckIfLetter(words[i]))
{
string cellCoordinate = words[i].ToUpper(); // Set the A1,B1... to a string variable
char letter = cellCoordinate[0];
int rowIndex = Convert.ToInt32(letter) - 65;
string numCol = cellCoordinate.Substring(1, cellCoordinate.Length - 1);
int colIndex = Convert.ToInt32(numCol) - 1;
cell.SubscribeToCell(ref this.cellGrid[colIndex, rowIndex]); // Subscribe to Dependency Changed Event.
}
}
}
/// <summary>
/// Initializes a new instance of the <see cref="Spreadsheet"/> class.
/// </summary>
/// <param name="numRows">Set number of rows in spreadsheet.</param>
/// <param name="numColumns">Set number of columns in spreadsheet.</param>
public Spreadsheet(int numRows, int numColumns)
{
this.rowCount = numRows;
this.columnCount = numColumns;
this.cellGrid = new SpreadsheetCellValue[numRows, numColumns];
for (int i = 0; i < numRows; i++)
{
for (int j = 0; j < numColumns; j++)
{
SpreadsheetCellValue newCell = SpreadsheetCellValue.CreateCell(i, j);
this.cellGrid[i, j] = newCell;
this.cellGrid[i, j].PropertyChanged += this.SpreadsheetCellValue_PropertyChanged;
}
}
}
/// <summary>
/// This will identify the text of a cell and depending if the text string starts with "=" will update the value of the cell.
/// If the string starts with "=" this will set the value of the cell to equal another cell's value. Otherwise, the value
/// will be set equal to the text.
/// </summary>
/// <param name="sender.">Spreadsheet.</param>
/// <param name="e">Cell argument.</param>
private void SpreadsheetCellValue_PropertyChanged(object sender, System.ComponentModel.PropertyChangedEventArgs e)
{
SpreadsheetCellValue cell = (SpreadsheetCellValue)sender;
string evalutedText = cell.Text.ToUpper();
char columnCharacter = Convert.ToChar(cell.ColumnIndex + 65);
string cellName = columnCharacter.ToString().ToUpper() + (cell.RowIndex + 1).ToString(); // Converts cell location to a cellName
try
{
this.cellDependencies[cellName] = CreateCellVariableList(evalutedText); // Add cell variables to cellName list.
}
catch
{
}
if (e.PropertyName == "Text")
{
if (CheckText(evalutedText))
{
if (CheckBadReference(evalutedText))
{
cell.Value = "!(bad reference)";
}
else if (CheckSelfReference(evalutedText, cellName))
{
cell.Value = "!(self reference)";
}
else if (this.CheckCircleReference(cellName, cellName))
{
cell.Value = "!(circular reference)";
}
else
{
string newValue = this.EvaluateText(evalutedText);
this.expressionTree.SetVariable(cellName, Convert.ToDouble(newValue)); // This is assuming that the user inputs the formula without errors and adds the cell value to the dictionary
cell.Value = newValue; // Evaluates the cell text if it starts with "=" and returns the double as a string
}
}
else
{
string cellValue = cell.Text;
double number;
if (double.TryParse(cellValue, out number))
{
this.expressionTree.SetVariable(cellName, number); // If cell value can be parsed to double, set cellName, double
}
else
{
this.expressionTree.SetVariable(cellName, 0); // If cell value cannot be parsed to double, set cellName, 0 (default)
}
cell.Value = cell.Text; // If the string does not start with "=" then the string value will be set to the text of the cell.
}
this.SubscribeCellDependency(cell);
this.PropertyChangedValue(sender, new PropertyChangedEventArgs("Value"));
}
else if (e.PropertyName == "BGColor")
{
this.PropertyChangedValue(sender, new PropertyChangedEventArgs("BGColor")); // Fire off property changed event for color.
}
}
/// <summary>
/// This function will allow the cell to subscribe to a referenced cell dependency.
/// </summary>
/// <param name="cell">Refereneced cell that this.cell will subscribe to.</param>
public void SubscribeToCell(ref SpreadsheetCellValue cell)
{
cell.DependencyChanged += this.SpreadsheetCellValue_DependencyChanged;
}