- /*
- * Copyright 1999-2004 The Apache Software Foundation.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
- /*
- * $Id: BasicTestIterator.java,v 1.6 2004/02/17 04:32:08 minchau Exp $
- */
- package com.sun.org.apache.xpath.internal.axes;
-
- import com.sun.org.apache.xml.internal.dtm.DTM;
- import com.sun.org.apache.xml.internal.dtm.DTMFilter;
- import com.sun.org.apache.xml.internal.dtm.DTMIterator;
- import com.sun.org.apache.xml.internal.utils.PrefixResolver;
- import com.sun.org.apache.xpath.internal.compiler.Compiler;
-
- /**
- * Base for iterators that handle predicates. Does the basic next
- * node logic, so all the derived iterator has to do is get the
- * next node.
- */
- public abstract class BasicTestIterator extends LocPathIterator
- {
- /**
- * Create a LocPathIterator object.
- *
- * @param nscontext The namespace context for this iterator,
- * should be OK if null.
- */
- protected BasicTestIterator()
- {
- }
-
-
- /**
- * Create a LocPathIterator object.
- *
- * @param nscontext The namespace context for this iterator,
- * should be OK if null.
- */
- protected BasicTestIterator(PrefixResolver nscontext)
- {
-
- super(nscontext);
- }
-
- /**
- * Create a LocPathIterator object, including creation
- * of step walkers from the opcode list, and call back
- * into the Compiler to create predicate expressions.
- *
- * @param compiler The Compiler which is creating
- * this expression.
- * @param opPos The position of this iterator in the
- * opcode list from the compiler.
- *
- * @throws javax.xml.transform.TransformerException
- */
- protected BasicTestIterator(Compiler compiler, int opPos, int analysis)
- throws javax.xml.transform.TransformerException
- {
- super(compiler, opPos, analysis, false);
-
- int firstStepPos = compiler.getFirstChildPos(opPos);
- int whatToShow = compiler.getWhatToShow(firstStepPos);
-
- if ((0 == (whatToShow
- & (DTMFilter.SHOW_ATTRIBUTE
- | DTMFilter.SHOW_NAMESPACE
- | DTMFilter.SHOW_ELEMENT
- | DTMFilter.SHOW_PROCESSING_INSTRUCTION)))
- || (whatToShow == DTMFilter.SHOW_ALL))
- initNodeTest(whatToShow);
- else
- {
- initNodeTest(whatToShow, compiler.getStepNS(firstStepPos),
- compiler.getStepLocalName(firstStepPos));
- }
- initPredicateInfo(compiler, firstStepPos);
- }
-
- /**
- * Create a LocPathIterator object, including creation
- * of step walkers from the opcode list, and call back
- * into the Compiler to create predicate expressions.
- *
- * @param compiler The Compiler which is creating
- * this expression.
- * @param opPos The position of this iterator in the
- * opcode list from the compiler.
- * @param shouldLoadWalkers True if walkers should be
- * loaded, or false if this is a derived iterator and
- * it doesn't wish to load child walkers.
- *
- * @throws javax.xml.transform.TransformerException
- */
- protected BasicTestIterator(
- Compiler compiler, int opPos, int analysis, boolean shouldLoadWalkers)
- throws javax.xml.transform.TransformerException
- {
- super(compiler, opPos, analysis, shouldLoadWalkers);
- }
-
-
- /**
- * Get the next node via getNextXXX. Bottlenecked for derived class override.
- * @return The next node on the axis, or DTM.NULL.
- */
- protected abstract int getNextNode();
-
- /**
- * Returns the next node in the set and advances the position of the
- * iterator in the set. After a NodeIterator is created, the first call
- * to nextNode() returns the first node in the set.
- *
- * @return The next <code>Node</code> in the set being iterated over, or
- * <code>null</code> if there are no more members in that set.
- */
- public int nextNode()
- {
- if(m_foundLast)
- {
- m_lastFetched = DTM.NULL;
- return DTM.NULL;
- }
-
- if(DTM.NULL == m_lastFetched)
- {
- resetProximityPositions();
- }
-
- int next;
-
- com.sun.org.apache.xpath.internal.VariableStack vars;
- int savedStart;
- if (-1 != m_stackFrame)
- {
- vars = m_execContext.getVarStack();
-
- // These three statements need to be combined into one operation.
- savedStart = vars.getStackFrame();
-
- vars.setStackFrame(m_stackFrame);
- }
- else
- {
- // Yuck. Just to shut up the compiler!
- vars = null;
- savedStart = 0;
- }
-
- try
- {
- do
- {
- next = getNextNode();
-
- if (DTM.NULL != next)
- {
- if(DTMIterator.FILTER_ACCEPT == acceptNode(next))
- break;
- else
- continue;
- }
- else
- break;
- }
- while (next != DTM.NULL);
-
- if (DTM.NULL != next)
- {
- m_pos++;
- return next;
- }
- else
- {
- m_foundLast = true;
-
- return DTM.NULL;
- }
- }
- finally
- {
- if (-1 != m_stackFrame)
- {
- // These two statements need to be combined into one operation.
- vars.setStackFrame(savedStart);
- }
- }
- }
-
- /**
- * Get a cloned Iterator that is reset to the beginning
- * of the query.
- *
- * @return A cloned NodeIterator set of the start of the query.
- *
- * @throws CloneNotSupportedException
- */
- public DTMIterator cloneWithReset() throws CloneNotSupportedException
- {
-
- ChildTestIterator clone = (ChildTestIterator) super.cloneWithReset();
-
- clone.resetProximityPositions();
-
- return clone;
- }
-
-
- }
-