Initial revision

From-SVN: r102074

libjava/classpath/gnu/xml/transform/ElementAvailableFunction.java

@@ -0,0 +1,183 @@
+/* ElementAvailableFunction.java -- 
+   Copyright (C) 2004 Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU Classpath is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+02110-1301 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version. */
+
+package gnu.xml.transform;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.Iterator;
+import java.util.List;
+import java.util.TreeSet;
+import javax.xml.namespace.QName;
+import javax.xml.namespace.NamespaceContext;
+import javax.xml.xpath.XPathFunction;
+import javax.xml.xpath.XPathFunctionException;
+import org.w3c.dom.Node;
+import gnu.xml.xpath.Expr;
+import gnu.xml.xpath.Function;
+
+/**
+ * The XSLT <code>element-available</code> function.
+ *
+ * @author <a href='mailto:dog@gnu.org'>Chris Burdess</a>
+ */
+class ElementAvailableFunction
+  extends Expr
+  implements Function, XPathFunction
+{
+
+  static final Collection elements;
+  static
+  {
+    TreeSet acc = new TreeSet();
+    acc.add("stylesheet");
+    acc.add("template");
+    acc.add("param");
+    acc.add("variable");
+    acc.add("include");
+    acc.add("import");
+    acc.add("output");
+    acc.add("preserve-space");
+    acc.add("strip-space");
+    acc.add("key");
+    acc.add("decimal-format");
+    acc.add("namespace-alias");
+    acc.add("attribute-set");
+    acc.add("apply-templates");
+    acc.add("call-template");
+    acc.add("value-of");
+    acc.add("for-each");
+    acc.add("if");
+    acc.add("choose");
+    acc.add("when");
+    acc.add("otherwise");
+    acc.add("element");
+    acc.add("attribute");
+    acc.add("text");
+    acc.add("copy");
+    acc.add("processing-instruction");
+    acc.add("comment");
+    acc.add("number");
+    acc.add("copy-of");
+    acc.add("message");
+    acc.add("sort");
+    acc.add("with-param");
+    acc.add("fallback");
+    acc.add("apply-imports");
+    elements = Collections.unmodifiableSet(acc);
+  }
+
+  final NamespaceContext nsctx;
+  List args;
+
+  ElementAvailableFunction(NamespaceContext nsctx)
+  {
+    this.nsctx = nsctx;
+  }
+
+  public Object evaluate(List args)
+    throws XPathFunctionException
+  {
+    // Useless...
+    return Collections.EMPTY_SET;
+  }
+
+  public void setArguments(List args)
+  {
+    this.args = args;
+  }
+
+  public Object evaluate(Node context, int pos, int len)
+  {
+    Expr arg = (Expr) args.get(0);
+    Object val = arg.evaluate(context, pos, len);
+    String name = _string(context, val);
+    String prefix, localName, uri;
+    int ci = name.indexOf(':');
+    if (ci == -1)
+      {
+        prefix = null;
+        localName = name;
+      }
+    else
+      {
+        prefix = name.substring(0, ci);
+        localName = name.substring(ci + 1);
+      }
+    uri = nsctx.getNamespaceURI(prefix);
+    if (Stylesheet.XSL_NS.equals(uri))
+      {
+        return elements.contains(localName) ?
+          Boolean.TRUE : Boolean.FALSE;
+        // TODO extension elements
+      }
+    return Boolean.FALSE;
+  }
+  
+  public Expr clone(Object context)
+  {
+    NamespaceContext n = nsctx;
+    if (context instanceof NamespaceContext)
+      {
+        n = (NamespaceContext) context;
+      }
+    ElementAvailableFunction f = new ElementAvailableFunction(n);
+    int len = args.size();
+    List args2 = new ArrayList(len);
+    for (int i = 0; i < len; i++)
+      {
+        args2.add(((Expr) args.get(i)).clone(context));
+      }
+    f.setArguments(args2);
+    return f;
+  }
+
+  public boolean references(QName var)
+  {
+    for (Iterator i = args.iterator(); i.hasNext(); )
+      {
+        if (((Expr) i.next()).references(var))
+          {
+            return true;
+          }
+      }
+    return false;
+  }
+
+}
+