* js> defineClass("Matrix")
* js> m = new Matrix(2); A constructor call, see Matrix below.
* [object Matrix] The "Matrix" here comes from getClassName.
* js> version(120); switch to JavaScript1.2 to see arrays better
* 0
* js> m[0][0] = 3;
* 3
* js> m[0]; an array was created automatically!
* [3]
* js> m[1]; array is created even if we don't set a value
* []
* js> m.dim; we can access the "dim" property
* 2
* js> m.dim = 3;
* 3
* js> m.dim; but not modify it
* 2
*
*
* @see org.mozilla.javascript.Context
* @see org.mozilla.javascript.Scriptable
*
* @author Norris Boyd
*/
public class Matrix implements Scriptable {
/**
* The zero-parameter constructor.
*
* When Context.defineClass is called with this class, it will
* construct Matrix.prototype using this constructor.
*/
public Matrix() {
}
/**
* The Java constructor, also used to define the JavaScript constructor.
*/
public Matrix(int dimension) {
if (dimension <= 0) {
throw Context.reportRuntimeError(
"Dimension of Matrix must be greater than zero");
}
dim = dimension;
v = new Vector();
}
/**
* Returns the name of this JavaScript class, "Matrix".
*/
public String getClassName() {
return "Matrix";
}
/**
* Defines the "dim" property by returning true if name is
* equal to "dim".
* * Defines no other properties, i.e., returns false for * all other names. * * @param name the name of the property * @param start the object where lookup began */ public boolean has(String name, Scriptable start) { return name.equals("dim"); } /** * Defines all numeric properties by returning true. * * @param index the index of the property * @param start the object where lookup began */ public boolean has(int index, Scriptable start) { return true; } /** * Get the named property. *
* Handles the "dim" property and returns NOT_FOUND for all * other names. * @param name the property name * @param start the object where the lookup began */ public Object get(String name, Scriptable start) { if (name.equals("dim")) return new Integer(dim); return NOT_FOUND; } /** * Get the indexed property. *
* Look up the element in the associated vector and return * it if it exists. If it doesn't exist, create it.
* @param index the index of the integral property
* @param start the object where the lookup began
*/
public Object get(int index, Scriptable start) {
if (index >= v.size())
v.setSize(index+1);
Object result = v.elementAt(index);
if (result != null)
return result;
if (dim > 2) {
Matrix m = new Matrix(dim-1);
m.setParentScope(getParentScope());
m.setPrototype(getPrototype());
result = m;
} else {
Context cx = Context.getCurrentContext();
Scriptable scope = ScriptableObject.getTopLevelScope(start);
result = cx.newArray(scope, 0);
}
v.setElementAt(result, index);
return result;
}
/**
* Set a named property.
*
* We do nothing here, so all properties are effectively read-only.
*/
public void put(String name, Scriptable start, Object value) {
}
/**
* Set an indexed property.
*
* We do nothing here, so all properties are effectively read-only.
*/
public void put(int index, Scriptable start, Object value) {
}
/**
* Remove a named property.
*
* This method shouldn't even be called since we define all properties
* as PERMANENT.
*/
public void delete(String id) {
}
/**
* Remove an indexed property.
*
* This method shouldn't even be called since we define all properties
* as PERMANENT.
*/
public void delete(int index) {
}
/**
* Get prototype.
*/
public Scriptable getPrototype() {
return prototype;
}
/**
* Set prototype.
*/
public void setPrototype(Scriptable prototype) {
this.prototype = prototype;
}
/**
* Get parent.
*/
public Scriptable getParentScope() {
return parent;
}
/**
* Set parent.
*/
public void setParentScope(Scriptable parent) {
this.parent = parent;
}
/**
* Get properties.
*
* We return an empty array since we define all properties to be DONTENUM.
*/
public Object[] getIds() {
return new Object[0];
}
/**
* Default value.
*
* Use the convenience method from Context that takes care of calling
* toString, etc.
*/
public Object getDefaultValue(Class typeHint) {
return "[object Matrix]";
}
/**
* instanceof operator.
*
* We mimick the normal JavaScript instanceof semantics, returning
* true if this appears in value's prototype
* chain.
*/
public boolean hasInstance(Scriptable value) {
Scriptable proto = value.getPrototype();
while (proto != null) {
if (proto.equals(this)) return true;
}
return false;
}
/**
* Some private data for this class.
*/
private int dim;
private Vector v;
private Scriptable prototype, parent;
}