public void CellPropertyChanged(object sender, PropertyChangedEventArgs e)
{
if (e.PropertyName == "Text")
{
// Create new cell instance and have it as a sender
m_Cell m_c = sender as m_Cell;
// free the cell of dependents
FreeCell(m_c.Name);
if ((m_c.Text.Length > 1) && (m_c.Text != "") && (m_c.Text[0] == '='))
{
ExpTree exp = new ExpTree(m_c.Text.Substring(1));
trackDependents(m_c.Name, exp.GetVarNames());
}
EvalCell(sender as Cell);
}
else if (e.PropertyName == "BGColor")
{
// pass the sender to get the currrent cell in the sheetchanged function in form1
// fire property changed event for the spreadsheet to color
SSPropertyChanged(sender, new PropertyChangedEventArgs("BGColor"));
}
}
public void EvalCell(Cell CellArg)
{
m_Cell m_c = CellArg as m_Cell;
if (string.IsNullOrEmpty(m_c.Text))
{
m_c.setValue("");
SSPropertyChanged(CellArg, new PropertyChangedEventArgs("Value"));
}
else if (m_c.Text[0] == '=' && m_c.Text.Length > 1)
{
bool flag = false;
string expStr = m_c.Text.Substring(1);
// set the expression string and create the tree
ExpTree exp = new ExpTree(expStr);
// gets expression variables
string[] expVars = exp.GetVarNames();
// sets each variable in the expression
foreach (string varName in expVars)
{
// check if the cell is valid
if (GetCell(varName) == null)
{
// set value to the error and fire property changed event for the value
m_c.setValue("!(Bad Reference)");
SSPropertyChanged(m_c, new PropertyChangedEventArgs("Value"));
flag = true;
break;
}
// check to see if its a self reference
if (varName == m_c.Name)
{
// set value to the error and fire property changed event for the value
m_c.setValue("!(Self Reference)");
SSPropertyChanged(m_c, new PropertyChangedEventArgs("Value"));
flag = true;
break;
}
// valid variable
SetExpVariable(exp, varName);
// check for circular reference after we've determined its a valid reference
if (CheckCircularRef(varName, m_c.Name))
{
// set value to the error and fire property changed event for the value
m_c.setValue("!(Circular Reference)");
SSPropertyChanged(m_c, new PropertyChangedEventArgs("Value"));
updateCells(m_c.Name);
flag = true;
break;
}
}
if (flag)
{
return;
}
// Sets the expression evaluation to the current cells value and fires the property changed event
m_c.setValue(exp.Eval().ToString());
SSPropertyChanged(CellArg, new PropertyChangedEventArgs("Value"));
}
else // no equals sign present so change the text
{
m_c.setValue(m_c.Text);
SSPropertyChanged(CellArg, new PropertyChangedEventArgs("Value"));
}
if (dependencies.ContainsKey(m_c.Name))
{
foreach (string name in dependencies[m_c.Name])
{
EvalCell(name);
}
}
}
