/**
* create a new identifier that is one larger than the given
* identifier, with the first element set to front.
*/
public AreaIdentifier(int front, AreaIdentifier back)
{
if (front < 0)
{
throw new ArgumentException("value must not be negative", "front");
}
path = new int[back.path.Length + 1];
path[0] = front;
Array.Copy(back.path, 0, path, 1, back.path.Length);
}
/**
* if the id id empty (at a terminal node), return 0,
* otherwise throw an invalid id exception
* TODO figure out why we do this
*/
public override Scaled Origin(AreaIdentifier id)
{
if (id.End)
{
return(0);
}
else
{
throw new InvalidIdentifier();
}
}
/**
* simple areas are terminsl nodes, so make sure the identifer
* is empty at this point, and return this node, otherwise
* throw an invalid id exception
*/
public override Area GetArea(AreaIdentifier identifier)
{
if (identifier.End)
{
return(this);
}
else
{
throw new InvalidIdentifier();
}
}
/**
* create a new identifier that is next identifier relative
* to the given identifier. this takes the given identifier and
* makes a new identifier that has a path length one less than
* the given identier, and copies the all items except the first
* one. So if the given identifier is [k1,k2,k3,...,kn], the
* new identifier will be [k2,k3,...,kn].
* If the previous identifer is allready empty, an
* InvalidArgument exception is thrown.
*/
public AreaIdentifier(AreaIdentifier previous)
{
if (previous.path.Length > 0)
{
path = new int[previous.path.Length - 1];
previous.path.CopyTo(path, 1);
}
else
{
throw new ArgumentException(
"the previous identifier must not be empty", "previous");
}
}
/**
* if the id is for this node, return 0. otherwise if the id is for
* a child node, return that node's left side.
*/
public override Scaled RightSide(AreaIdentifier id)
{
if (id.End)
{
return(0);
}
else if (id.Current < content.Length)
{
return(content[id.Current].RightSide(id++));
}
else
{
throw new InvalidIdentifier();
}
}
/**
* get the right side value.
* the identier is only valid if it is for the child
* node, or one of the child node's descendants. a
* bin container can not have a right side value.
*/
public override Scaled RightSide(AreaIdentifier id)
{
if (id.End)
{
throw new InvalidOperation();
}
else if (id.Current == 0)
{
id.MoveNext();
return(child.RightSide(id));
}
else
{
throw new InvalidIdentifier();
}
}
/**
* create an identifier for a descendant area.
* as a BinContainerArea can only have one direct child area,
* the only valie identifiers are ones that are at the end of
* thier path, indicating that it identifies this this node,
* or an identifier with its' current element being zero, indicating
* that the current leg of its's path identifies the zero'th and
* only child node.
*/
public override Area GetArea(AreaIdentifier id)
{
if (id.End)
{
return(this);
}
else if (id.Current == 0)
{
id.MoveNext();
return(child.GetArea(id));
}
else
{
throw new InvalidIdentifier();
}
}
/**
* get a child area that has a path to this node
* if the identifier is at its's last item, this final step
* in the path, so return this node, otherwise, if the current step
* is valid (less than the size of the child node list, the child
* area at the current position will get the path moved to the next
* position. If the id is not at it's end, and the current item is
* out of range, an invalid id exception is thrown.
*/
public override Area GetArea(AreaIdentifier id)
{
if (id.End)
{
return(this);
}
else if (id.Current < content.Length)
{
Area current = content[id.Current];
id.MoveNext();
return(current.GetArea(id));
}
else
{
throw new InvalidIdentifier();
}
}
/**
* TODO write this up
*/
public override Scaled Origin(AreaIdentifier id)
{
if (id.End)
{
// get the origin for this node.
return(0);
}
else if (id.Current == 0)
{
// get the origin for the child node
id.MoveNext();
return(child.Origin(id));
}
else
{
// bad monkey
throw new InvalidIdentifier();
}
}
/**
* get the width of all nodes up to the identified nodes,
* plus the the origin of the identifed node.
* This is the relative distance from the identified node's origin
* to this node's origin.
*/
public override Scaled Origin(AreaIdentifier id)
{
if (id.End)
{
return(0);
}
else if (id.Current < content.Length)
{
Scaled width = 0;
// all nodes up to, but not including the identified node
for (int i = 0; i < id.Current; i++)
{
width += content[i].BoundingBox.Width;
}
return(content[id.Current].Origin(id++) + width);
}
else
{
throw new InvalidIdentifier();
}
}
/**
* not supported on simple nodes
* TODO find out why
*/
public override Scaled RightSide(AreaIdentifier id)
{
throw new InvalidOperation();
}
public virtual float LeftSide(AreaIdentifier id)
{
return(0);
}
/**
* compute the horizontal component of the identified node's
* origin with respect to this node's origin, e.g. the identified
* node's reference point with respect to this node's refernce point.
* The following recursive relation holds:
*
* 1: a node with no child nodes returns 0:
* a.Origin([]) = 0
*
* 2: a horizontal array returns the width of all previous nodes
* plus the origin of the identified node:
* HorizontalArray.Origin([k1,k2,k3,...kn] = sum(0.width -> k1.width) +
* k1.Origin([k2,k3,...kn])
*
* 3: a node with child nodes that is not a horizontal array
* returns the identified node's origin:
* a.Origin([k1,k2,k3...kn]) = k1.Origin([k2,k3,...,kn])
*/
public virtual float Origin(AreaIdentifier id)
{
return(0);
}
/**
* get an area with an identifier that is a relative path
* to this node.
*/
public virtual Area GetArea(AreaIdentifier id)
{
return(null);
}