| /******************************************************************************* |
| * Copyright (c) 2000, 2006 IBM Corporation and others. |
| * All rights reserved. This program and the accompanying materials |
| * are made available under the terms of the Eclipse Public License v1.0 |
| * which accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/epl-v10.html |
| * |
| * Contributors: |
| * IBM Corporation - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.core.internal.expressions; |
| |
| import java.util.Collection; |
| import java.util.Iterator; |
| import java.util.List; |
| |
| import org.w3c.dom.Element; |
| |
| import org.eclipse.core.runtime.Assert; |
| import org.eclipse.core.runtime.CoreException; |
| import org.eclipse.core.runtime.IConfigurationElement; |
| |
| import org.eclipse.core.expressions.EvaluationResult; |
| import org.eclipse.core.expressions.ExpressionInfo; |
| import org.eclipse.core.expressions.IEvaluationContext; |
| import org.eclipse.core.expressions.IIterable; |
| |
| public class IterateExpression extends CompositeExpression { |
| |
| private static class IteratePool implements IEvaluationContext { |
| |
| private Iterator fIterator; |
| private Object fDefaultVariable; |
| private IEvaluationContext fParent; |
| |
| public IteratePool(IEvaluationContext parent, Iterator iterator) { |
| Assert.isNotNull(parent); |
| Assert.isNotNull(iterator); |
| fParent= parent; |
| fIterator= iterator; |
| } |
| public IEvaluationContext getParent() { |
| return fParent; |
| } |
| public IEvaluationContext getRoot() { |
| return fParent.getRoot(); |
| } |
| public Object getDefaultVariable() { |
| return fDefaultVariable; |
| } |
| public boolean getAllowPluginActivation() { |
| return fParent.getAllowPluginActivation(); |
| } |
| public void setAllowPluginActivation(boolean value) { |
| fParent.setAllowPluginActivation(value); |
| } |
| public void addVariable(String name, Object value) { |
| fParent.addVariable(name, value); |
| } |
| public Object removeVariable(String name) { |
| return fParent.removeVariable(name); |
| } |
| public Object getVariable(String name) { |
| return fParent.getVariable(name); |
| } |
| public Object resolveVariable(String name, Object[] args) throws CoreException { |
| return fParent.resolveVariable(name, args); |
| } |
| public Object next() { |
| fDefaultVariable= fIterator.next(); |
| return fDefaultVariable; |
| } |
| public boolean hasNext() { |
| return fIterator.hasNext(); |
| } |
| } |
| |
| private static final String ATT_OPERATOR= "operator"; //$NON-NLS-1$ |
| private static final String ATT_IF_EMPTY= "ifEmpty"; //$NON-NLS-1$ |
| private static final int OR= 1; |
| private static final int AND= 2; |
| |
| /** |
| * The seed for the hash code for all iterate expressions. |
| */ |
| private static final int HASH_INITIAL= IterateExpression.class.getName().hashCode(); |
| |
| private int fOperator; |
| private Boolean fEmptyResult; |
| |
| public IterateExpression(IConfigurationElement configElement) throws CoreException { |
| String opValue= configElement.getAttribute(ATT_OPERATOR); |
| initializeOperatorValue(opValue); |
| initializeEmptyResultValue(configElement.getAttribute(ATT_IF_EMPTY)); |
| } |
| |
| public IterateExpression(Element element) throws CoreException { |
| String opValue= element.getAttribute(ATT_OPERATOR); |
| initializeOperatorValue(opValue.length() > 0 ? opValue : null); |
| String ifEmpty= element.getAttribute(ATT_IF_EMPTY); |
| initializeEmptyResultValue(ifEmpty.length() > 0 ? ifEmpty : null); |
| } |
| |
| public IterateExpression(String opValue) throws CoreException { |
| initializeOperatorValue(opValue); |
| } |
| |
| public IterateExpression(String opValue, String ifEmpty) throws CoreException { |
| initializeOperatorValue(opValue); |
| initializeEmptyResultValue(ifEmpty); |
| } |
| |
| private void initializeOperatorValue(String opValue) throws CoreException { |
| if (opValue == null) { |
| fOperator= AND; |
| } else { |
| Expressions.checkAttribute(ATT_OPERATOR, opValue, new String[] {"and", "or"}); //$NON-NLS-1$//$NON-NLS-2$ |
| if ("and".equals(opValue)) { //$NON-NLS-1$ |
| fOperator= AND; |
| } else { |
| fOperator= OR; |
| } |
| } |
| } |
| |
| private void initializeEmptyResultValue(String value) { |
| if (value == null) { |
| fEmptyResult= null; |
| } else { |
| fEmptyResult= Boolean.valueOf(value); |
| } |
| } |
| |
| /* (non-Javadoc) |
| * @see Expression#evaluate(IVariablePool) |
| */ |
| public EvaluationResult evaluate(IEvaluationContext context) throws CoreException { |
| Object var= context.getDefaultVariable(); |
| if (var instanceof Collection) { |
| Collection col= (Collection)var; |
| switch (col.size()) { |
| case 0: |
| if (fEmptyResult == null) { |
| return fOperator == AND ? EvaluationResult.TRUE : EvaluationResult.FALSE; |
| } else { |
| return fEmptyResult.booleanValue() ? EvaluationResult.TRUE : EvaluationResult.FALSE; |
| } |
| case 1: |
| if (col instanceof List) |
| return evaluateAnd(new DefaultVariable(context, ((List)col).get(0))); |
| // fall through |
| default: |
| IteratePool iter= new IteratePool(context, col.iterator()); |
| EvaluationResult result= fOperator == AND ? EvaluationResult.TRUE : EvaluationResult.FALSE; |
| while (iter.hasNext()) { |
| iter.next(); |
| switch(fOperator) { |
| case OR: |
| result= result.or(evaluateAnd(iter)); |
| if (result == EvaluationResult.TRUE) |
| return result; |
| break; |
| case AND: |
| result= result.and(evaluateAnd(iter)); |
| if (result != EvaluationResult.TRUE) |
| return result; |
| break; |
| } |
| } |
| return result; |
| } |
| } else { |
| IIterable iterable= Expressions.getAsIIterable(var, this); |
| if (iterable == null) |
| return EvaluationResult.NOT_LOADED; |
| int count= 0; |
| IteratePool iter= new IteratePool(context, iterable.iterator()); |
| EvaluationResult result= fOperator == AND ? EvaluationResult.TRUE : EvaluationResult.FALSE; |
| while (iter.hasNext()) { |
| iter.next(); |
| count++; |
| switch(fOperator) { |
| case OR: |
| result= result.or(evaluateAnd(iter)); |
| if (result == EvaluationResult.TRUE) |
| return result; |
| break; |
| case AND: |
| result= result.and(evaluateAnd(iter)); |
| if (result != EvaluationResult.TRUE) |
| return result; |
| break; |
| } |
| } |
| if (count > 0) { |
| return result; |
| } else { |
| if (fEmptyResult == null) { |
| return fOperator == AND ? EvaluationResult.TRUE : EvaluationResult.FALSE; |
| } else { |
| return fEmptyResult.booleanValue() ? EvaluationResult.TRUE : EvaluationResult.FALSE; |
| } |
| } |
| } |
| } |
| |
| public void collectExpressionInfo(ExpressionInfo info) { |
| // Although we access every single variable we only mark the default |
| // variable as accessed since we don't have single variables for the |
| // elements. |
| info.markDefaultVariableAccessed(); |
| super.collectExpressionInfo(info); |
| } |
| |
| public boolean equals(final Object object) { |
| if (!(object instanceof IterateExpression)) |
| return false; |
| |
| final IterateExpression that= (IterateExpression)object; |
| return (this.fOperator == that.fOperator) && equals(this.fExpressions, that.fExpressions); |
| } |
| |
| protected int computeHashCode() { |
| return HASH_INITIAL * HASH_FACTOR + hashCode(fExpressions) |
| * HASH_FACTOR + fOperator; |
| } |
| } |