/// <summary>
/// Initializes a new instance of the <see cref="CalculatorControl"/> class.
/// </summary>
public CalculatorControl()
{
this.InitializeComponent();
this.InputCommand = new RelayCommand(this.OnInputCommandRequested);
this.CopyCommand = new RelayCommand(this.OnCopyResultRequested);
this.lastButton = new CalculatorButton()
{
FunctionType = FunctionType.Clear
};
}
/// <summary>
/// Finds a calculator button of a given item in the visual tree.
/// </summary>
/// <param name="parent">The dependency object parent.</param>
/// <param name="content">The buttons' content.</param>
/// <returns>Null if nothing found.</returns>
public static CalculatorButton FindButton(DependencyObject parent, string content)
{
// Confirm parent and childName are valid.
if (parent == null)
{
return(null);
}
CalculatorButton foundChild = null;
int childrenCount = VisualTreeHelper.GetChildrenCount(parent);
for (int i = 0; i < childrenCount; i++)
{
var child = VisualTreeHelper.GetChild(parent, i);
// If the child is not of the request child type child
CalculatorButton childType = child as CalculatorButton;
if (childType == null)
{
// Recursively drill down the tree
foundChild = FindButton(child, content);
// If the child is found, break so we do not overwrite the found child.
if (foundChild != null)
{
break;
}
}
else if (!string.IsNullOrEmpty(content))
{
var button = child as CalculatorButton;
// If the button text is set for search
if (button != null && button.Text == content)
{
// If the child's name is of the request name
foundChild = (CalculatorButton)child;
break;
}
}
else
{
// Child element found.
foundChild = (CalculatorButton)child;
break;
}
}
return(foundChild);
}
private static void buttonValuePropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
CalculatorButton CB = (CalculatorButton)d;
CB.Text.Content = CB.buttonValue;
}
/// <summary>
/// Performs the needed operations after the user input.
/// </summary>
/// <param name="button">The button, which has been pressed.</param>
private void ProcessUserInput(CalculatorButton button)
{
if (button == null)
{
throw new ArgumentNullException("button");
}
if (button.FunctionType == FunctionType.Clear)
{
this.Result = "0";
this.Expression = string.Empty;
this.lastButton = button;
return;
}
else if (button.FunctionType == FunctionType.ClearEntry)
{
this.Result = "0";
}
if (button.FunctionType == FunctionType.LeftBracket)
{
if (this.lastButton.FunctionType == FunctionType.LeftBracket || this.lastButton.IsOperatorButton || this.lastButton.FunctionType == FunctionType.Clear)
{
this.Expression += button.Text;
this.Result = "0";
this.lastButton = button;
}
return;
}
else if (button.FunctionType == FunctionType.RightBracket)
{
int leftBracketsCount = 0;
int rightBracketsCount = 0;
foreach (var ch in this.Expression)
{
if (ch == '(')
{
leftBracketsCount++;
}
else if (ch == ')')
{
rightBracketsCount++;
}
}
if (leftBracketsCount - rightBracketsCount < 1)
{
this.lastButton = button;
return;
}
this.Expression += this.Result + button.Text;
this.Result = string.Empty;
this.lastButton = button;
return;
}
// Checking if the result is not a text (i.e we have an error).
double resultNumber;
bool isParseOK = double.TryParse(
this.Result,
NumberStyles.AllowDecimalPoint | NumberStyles.AllowExponent | NumberStyles.AllowLeadingSign,
CultureInfo.CurrentCulture,
out resultNumber);
if (this.Result.Length != 0 && (!isParseOK || double.IsInfinity(resultNumber) || double.IsNaN(resultNumber)))
{
// The user can only use the 'C' (clear all) button.
return;
}
if (button.IsDigitButton)
{
if (this.Result == "0")
{
this.Result = string.Empty;
}
if (this.lastButton.IsOperatorButton)
{
this.Result = button.Text;
}
else
{
this.Result += button.Text;
}
this.lastButton = button;
return;
}
if (button.IsOperatorButton)
{
if (this.lastButton.IsOperatorButton)
{
// Changing the last operator
var oldExpression = this.Expression;
var index = oldExpression.LastIndexOf(" " + this.lastButton.Text[0] + " ");
var newExpression = oldExpression.Remove(index, 3);
newExpression += " " + button.Text[0] + " ";
this.Expression = newExpression;
}
else if (this.lastButton.IsBracket)
{
this.Expression += " " + button.Text + " ";
}
else
{
this.Expression += this.Result + " " + button.Text + " ";
}
this.lastButton = button;
return;
}
if (button.FunctionType == FunctionType.Equals)
{
this.Expression += this.Result;
try
{
this.Result = CalculatorCore.Operations.Compute(this.Expression).ToString();
}
catch (Exception ex)
{
this.Result = ex.Message;
}
this.Expression = string.Empty;
}
else if (button.FunctionType == FunctionType.Back)
{
if (this.Result.Length > 0 && this.lastButton.IsErasableButton)
{
this.Result = this.Result.Substring(0, this.Result.Length - 1);
if (this.Result.Length == 0)
{
this.Result = "0";
}
}
}
else if (button.FunctionType == FunctionType.Comma)
{
if (!this.lastButton.IsErasableButton)
{
this.Result = "0" + button.Text;
this.lastButton = button;
return;
}
if (!this.Result.Contains(button.Text))
{
this.Result += button.Text;
}
}
else if (button.IsCustomFunction)
{
string fname = button.FunctionType.ToString().ToLower();
if (this.Result == string.Empty)
{
this.Expression = string.Format("{0}({1})", fname, this.Expression);
}
else
{
this.Expression += string.Format("{0}({1})", fname, this.Result);
}
this.Result = string.Empty;
}
else if (button.FunctionType == FunctionType.Pi)
{
this.Result = Math.PI.ToString();
}
else if (button.FunctionType == FunctionType.E)
{
this.Result = Math.E.ToString();
}
this.lastButton = button;
}
