| /******************************************************************************* |
| * 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 org.w3c.dom.Element; |
| |
| import org.eclipse.core.runtime.CoreException; |
| import org.eclipse.core.runtime.IConfigurationElement; |
| |
| import org.eclipse.core.expressions.EvaluationResult; |
| import org.eclipse.core.expressions.Expression; |
| import org.eclipse.core.expressions.ExpressionInfo; |
| import org.eclipse.core.expressions.ICountable; |
| import org.eclipse.core.expressions.IEvaluationContext; |
| |
| |
| public class CountExpression extends Expression { |
| |
| private static final int ANY_NUMBER= 5; |
| private static final int EXACT= 4; |
| private static final int ONE_OR_MORE= 3; |
| private static final int NONE_OR_ONE= 2; |
| private static final int NONE= 1; |
| private static final int UNKNOWN= 0; |
| |
| /** |
| * The seed for the hash code for all count expressions. |
| */ |
| private static final int HASH_INITIAL= CountExpression.class.getName().hashCode(); |
| |
| private int fMode; |
| private int fSize; |
| |
| public CountExpression(IConfigurationElement configElement) { |
| String size = configElement.getAttribute(ATT_VALUE); |
| initializeSize(size); |
| } |
| |
| public CountExpression(Element element) { |
| String size = element.getAttribute(ATT_VALUE); |
| initializeSize(size.length() > 0 ? size : null); |
| } |
| |
| public CountExpression(String size) { |
| initializeSize(size); |
| } |
| |
| private void initializeSize(String size) { |
| if (size == null) |
| size= "*"; //$NON-NLS-1$ |
| if (size.equals("*")) //$NON-NLS-1$ |
| fMode= ANY_NUMBER; |
| else if (size.equals("?")) //$NON-NLS-1$ |
| fMode= NONE_OR_ONE; |
| else if (size.equals("!")) //$NON-NLS-1$ |
| fMode= NONE; |
| else if (size.equals("+")) //$NON-NLS-1$ |
| fMode= ONE_OR_MORE; |
| else { |
| try { |
| fSize= Integer.parseInt(size); |
| fMode= EXACT; |
| } catch (NumberFormatException e) { |
| fMode= UNKNOWN; |
| } |
| } |
| } |
| |
| public EvaluationResult evaluate(IEvaluationContext context) throws CoreException { |
| Object var= context.getDefaultVariable(); |
| int size; |
| if (var instanceof Collection) { |
| size= ((Collection)var).size(); |
| } else { |
| ICountable countable= Expressions.getAsICountable(var, this); |
| if (countable == null) |
| return EvaluationResult.NOT_LOADED; |
| size= countable.count(); |
| } |
| switch (fMode) { |
| case UNKNOWN: |
| return EvaluationResult.FALSE; |
| case NONE: |
| return EvaluationResult.valueOf(size == 0); |
| case NONE_OR_ONE: |
| return EvaluationResult.valueOf(size == 0 || size == 1); |
| case ONE_OR_MORE: |
| return EvaluationResult.valueOf(size >= 1); |
| case EXACT: |
| return EvaluationResult.valueOf(fSize == size); |
| case ANY_NUMBER: |
| return EvaluationResult.TRUE; |
| } |
| return EvaluationResult.FALSE; |
| } |
| |
| public void collectExpressionInfo(ExpressionInfo info) { |
| info.markDefaultVariableAccessed(); |
| } |
| |
| public boolean equals(final Object object) { |
| if (!(object instanceof CountExpression)) |
| return false; |
| |
| final CountExpression that= (CountExpression)object; |
| return (this.fMode == that.fMode) && (this.fSize == that.fSize); |
| } |
| |
| protected int computeHashCode() { |
| return HASH_INITIAL * HASH_FACTOR + fMode |
| * HASH_FACTOR + fSize; |
| } |
| } |