PNode FindNode(PNode p, int x, int y)
{
PNode result = null;
if (p == null)
{
return(result);
}
if (((p.x - x) * (p.x - x) + (p.y - y) * (p.y - y)) <= 10 * R)
{
result = p;
}
else
{
if ((p is NodeOperation) && ((p as NodeOperation).left != null))
{
result = FindNode((p as NodeOperation).left, x, y);
}
if ((result == null) && (p is NodeOperation) && ((p as NodeOperation).right != null))
{
result = FindNode((p as NodeOperation).right, x, y);
}
}
return(result);
}
public Parser(int width, int height, ref string s)
{
top = null;
bitmap = new Bitmap(width, height);
Expression(ref s, out top);
SetCoordinates();
}
public bool FindCoordinates(int x, int y)
{
if (top != null)
{
selected = FindNode(top, x, y);
}
return(selected != null);
}
void Digit(ref string s, out PNode P)
{
string st = "";
while (s.Length != 0 && Test(s[0], digits))
{
st += Pop(ref s, 1);
}
P = new NodeConst(Convert.ToInt32(st));
}
void DrawNode(PNode p)
{
if ((p is NodeOperation) && ((p as NodeOperation).left != null))
{
g.DrawLine(Pens.Black, p.x, p.y, (p as NodeOperation).left.x, (p as NodeOperation).left.y);
}
if ((p is NodeOperation) && ((p as NodeOperation).right != null))
{
g.DrawLine(Pens.Black, p.x, p.y, (p as NodeOperation).right.x, (p as NodeOperation).right.y);
}
if (p.visit == false)
{
g.FillEllipse(Brushes.LightBlue, p.x - R, p.y - R, 2 * R, 2 * R);
}
else
{
g.FillEllipse(Brushes.CornflowerBlue, p.x - R, p.y - R, 2 * R, 2 * R);
}
g.DrawEllipse(Pens.Black, p.x - R, p.y - R, 2 * R, 2 * R);
string s = "";
if (p is NodeOperation)
{
switch ((p as NodeOperation).type)
{
case Operation.multiply: s = "*"; break;
case Operation.divide: s = "/"; break;
case Operation.plus: s = "+"; break;
case Operation.minus: s = "-"; break;
}
}
else
{
s = Convert.ToString(p.Value);
}
SizeF size = g.MeasureString(s, myFont);
g.DrawString(s, myFont, Brushes.Black,
p.x - size.Width / 2,
p.y - size.Height / 2);
if ((p is NodeOperation) && ((p as NodeOperation).left != null))
{
DrawNode((p as NodeOperation).left);
}
if ((p is NodeOperation) && ((p as NodeOperation).right != null))
{
DrawNode((p as NodeOperation).right);
}
}
void Set(PNode p, int x, int y, int i)
{
p.x = x; p.y = y;
if ((p is NodeOperation) && ((p as NodeOperation).left != null))
{
Set((p as NodeOperation).left, x - (int)Math.Pow(2, i) * step, y + dh * step, i - 1);
}
if ((p is NodeOperation) && ((p as NodeOperation).right != null))
{
Set((p as NodeOperation).right, x + (int)Math.Pow(2, i) * step, y + dh * step, i - 1);
}
}
void ShiftNode(PNode p, int dx, int dy)
{
p.x -= dx; p.y -= dy;
if ((p is NodeOperation) && ((p as NodeOperation).left != null))
{
ShiftNode((p as NodeOperation).left, dx, dy);
}
if ((p is NodeOperation) && ((p as NodeOperation).right != null))
{
ShiftNode((p as NodeOperation).right, dx, dy);
}
}
void DeSelectNode(PNode p)
{
if (p != null)
{
if (p is NodeOperation)
{
DeSelectNode((p as NodeOperation).left);
}
p.visit = false;
if (p is NodeOperation)
{
DeSelectNode((p as NodeOperation).right);
}
}
}
public Parser(int width, int height)
{
top = null;
bitmap = new Bitmap(width, height);
}
public NodeOperation(Operation op, PNode left, PNode right)
{
this.left = left;
this.right = right;
this.type = op;
}
public void Clear()
{
n = 0;
top = null;
selected = null;
}
void Expression(ref string s, out PNode P)
{
if (s.Length != 0)
{
if (Test(s[0], digits))
{
Digit(ref s, out P);
}
else
if (s[0] == '(')
{
Pop(ref s, 1);
Expression(ref s, out P);
if (s.Length == 0 || s.Length > 0 && s[0] != ')')
{
throw new ParserException(2);
}
Pop(ref s, 1);
}
else
{
switch (s[0])
{
case '*': throw new ParserException(3);
case '/': throw new ParserException(4);
default: throw new ParserException(8);
}
}
if (s.Length > 0 && !(Test(s[0], symbols) || s[0] == ')'))
{
throw new ParserException(8);
}
while (s.Length > 0 && Test(s[0], symbols))
{
string symbol = Pop(ref s, 1);
if (s.Length == 0)
{
switch (symbol)
{
case "*": throw new ParserException(3);
case "/": throw new ParserException(5);
case "+": throw new ParserException(6);
case "-": throw new ParserException(7);
}
}
PNode P2;
Expression(ref s, out P2);
PNode P1 = P;
Operation op = Operation.none;
switch (symbol)
{
case "*": op = Operation.multiply; break;
case "/": op = Operation.divide; break;
case "+": op = Operation.plus; break;
case "-": op = Operation.minus; break;
}
P = new NodeOperation(op, P1, P2);
n++;
}
}
else
{
throw new ParserException(1);
}
}
