/*******************************************************************************
* Copyright (c) 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.ui.internal.expressions;
import org.eclipse.core.expressions.EvaluationResult;
import org.eclipse.core.expressions.ExpressionInfo;
import org.eclipse.core.expressions.IEvaluationContext;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.ui.ISources;
import org.eclipse.ui.IWorkbenchWindow;
import org.eclipse.ui.internal.registry.IActionSetDescriptor;
/**
* <p>
* An expression that evaluates whether a particular action set is active.
* </p>
* <p>
* This class is not intended for use outside of the
* <code>org.eclipse.ui.workbench</code> plug-in.
* </p>
*
* @since 3.2
*/
public final class LegacyActionSetExpression extends WorkbenchWindowExpression {
/**
* The seed for the hash code for all schemes.
*/
private static final int HASH_INITIAL = LegacyActionSetExpression.class
.getName().hashCode();
/**
* The identifier of the action set that must be active for this expression
* to evaluate to <code>true</code>. This value is never
* <code>null</code>.
*/
private final String actionSetId;
/**
* Constructs a new instance of {@link LegacyActionSetExpression}.
*
* @param actionSetId
* The identifier of the action set that must be active for this
* expression to evaluate to <code>true</code>; must not be
* <code>null</code>.
* @param window
* The workbench window in which this handler should be active.
* This avoids conflicts between handlers from different windows.
* This should not be <code>null</code>.
*/
public LegacyActionSetExpression(final String actionSetId,
final IWorkbenchWindow window) {
super(window);
if (actionSetId == null) {
throw new NullPointerException(
"The action set identifier cannot be null"); //$NON-NLS-1$
}
this.actionSetId = actionSetId;
}
public final void collectExpressionInfo(final ExpressionInfo info) {
super.collectExpressionInfo(info);
info.addVariableNameAccess(ISources.ACTIVE_ACTION_SETS_NAME);
}
protected final int computeHhashCode() {
int hashCode = HASH_INITIAL * HASH_FACTOR + hashCode(getWindow());
hashCode = hashCode * HASH_FACTOR + hashCode(actionSetId);
return hashCode;
}
public final boolean equals(final Object object) {
if (object instanceof LegacyActionSetExpression) {
final LegacyActionSetExpression that = (LegacyActionSetExpression) object;
return equals(this.actionSetId, that.actionSetId)
&& equals(this.getWindow(), that.getWindow());
}
return false;
}
public final EvaluationResult evaluate(final IEvaluationContext context)
throws CoreException {
final EvaluationResult result = super.evaluate(context);
if (result == EvaluationResult.FALSE) {
return result;
}
// Check the action sets.
final Object variable = context
.getVariable(ISources.ACTIVE_ACTION_SETS_NAME);
if (variable instanceof IActionSetDescriptor[]) {
final IActionSetDescriptor[] descriptors = (IActionSetDescriptor[]) variable;
for (int i = 0; i < descriptors.length; i++) {
final IActionSetDescriptor descriptor = descriptors[i];
final String currentId = descriptor.getId();
if (actionSetId.equals(currentId)) {
return EvaluationResult.TRUE;
}
}
}
return EvaluationResult.FALSE;
}
public final String toString() {
final StringBuffer buffer = new StringBuffer();
buffer.append("ActionSetExpression("); //$NON-NLS-1$
buffer.append(actionSetId);
buffer.append(',');
buffer.append(getWindow());
buffer.append(')');
return buffer.toString();
}
}