- /*
- * 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: BoolStack.java,v 1.10 2004/02/17 04:21:14 minchau Exp $
- */
- package com.sun.org.apache.xml.internal.utils;
-
-
- /**
- * Simple stack for boolean values.
- * @xsl.usage internal
- */
- public final class BoolStack implements Cloneable
- {
-
- /** Array of boolean values */
- private boolean m_values[];
-
- /** Array size allocated */
- private int m_allocatedSize;
-
- /** Index into the array of booleans */
- private int m_index;
-
- /**
- * Default constructor. Note that the default
- * block size is very small, for small lists.
- */
- public BoolStack()
- {
- this(32);
- }
-
- /**
- * Construct a IntVector, using the given block size.
- *
- * @param size array size to allocate
- */
- public BoolStack(int size)
- {
-
- m_allocatedSize = size;
- m_values = new boolean[size];
- m_index = -1;
- }
-
- /**
- * Get the length of the list.
- *
- * @return Current length of the list
- */
- public final int size()
- {
- return m_index + 1;
- }
-
- /**
- * Clears the stack.
- *
- */
- public final void clear()
- {
- m_index = -1;
- }
-
- /**
- * Pushes an item onto the top of this stack.
- *
- *
- * @param val the boolean to be pushed onto this stack.
- * @return the <code>item</code> argument.
- */
- public final boolean push(boolean val)
- {
-
- if (m_index == m_allocatedSize - 1)
- grow();
-
- return (m_values[++m_index] = val);
- }
-
- /**
- * Removes the object at the top of this stack and returns that
- * object as the value of this function.
- *
- * @return The object at the top of this stack.
- * @throws EmptyStackException if this stack is empty.
- */
- public final boolean pop()
- {
- return m_values[m_index--];
- }
-
- /**
- * Removes the object at the top of this stack and returns the
- * next object at the top as the value of this function.
- *
- *
- * @return Next object to the top or false if none there
- */
- public final boolean popAndTop()
- {
-
- m_index--;
-
- return (m_index >= 0) ? m_values[m_index] : false;
- }
-
- /**
- * Set the item at the top of this stack
- *
- *
- * @param b Object to set at the top of this stack
- */
- public final void setTop(boolean b)
- {
- m_values[m_index] = b;
- }
-
- /**
- * Looks at the object at the top of this stack without removing it
- * from the stack.
- *
- * @return the object at the top of this stack.
- * @throws EmptyStackException if this stack is empty.
- */
- public final boolean peek()
- {
- return m_values[m_index];
- }
-
- /**
- * Looks at the object at the top of this stack without removing it
- * from the stack. If the stack is empty, it returns false.
- *
- * @return the object at the top of this stack.
- */
- public final boolean peekOrFalse()
- {
- return (m_index > -1) ? m_values[m_index] : false;
- }
-
- /**
- * Looks at the object at the top of this stack without removing it
- * from the stack. If the stack is empty, it returns true.
- *
- * @return the object at the top of this stack.
- */
- public final boolean peekOrTrue()
- {
- return (m_index > -1) ? m_values[m_index] : true;
- }
-
- /**
- * Tests if this stack is empty.
- *
- * @return <code>true</code> if this stack is empty;
- * <code>false</code> otherwise.
- */
- public boolean isEmpty()
- {
- return (m_index == -1);
- }
-
- /**
- * Grows the size of the stack
- *
- */
- private void grow()
- {
-
- m_allocatedSize *= 2;
-
- boolean newVector[] = new boolean[m_allocatedSize];
-
- System.arraycopy(m_values, 0, newVector, 0, m_index + 1);
-
- m_values = newVector;
- }
-
- public Object clone()
- throws CloneNotSupportedException
- {
- return super.clone();
- }
-
- }