| /******************************************************************************* |
| * Copyright (c) 2005 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; |
| |
| import org.eclipse.core.expressions.EvaluationResult; |
| import org.eclipse.core.expressions.Expression; |
| import org.eclipse.core.expressions.ExpressionInfo; |
| import org.eclipse.core.expressions.IEvaluationContext; |
| import org.eclipse.swt.widgets.Shell; |
| |
| /** |
| * <p> |
| * An expression that checks the active shell variable. The variable names is |
| * <code>ISources.ACTIVE_SHELL_NAME</code> and falls back to |
| * <code>ISources.ACTIVE_WORKBENCH_WINDOW</code>. That is, if the active |
| * shell doesn't match, then it will be allowed to match the active workbench |
| * window. |
| * </p> |
| * |
| * @since 3.1 |
| */ |
| public final class ActiveShellExpression extends Expression { |
| |
| /** |
| * The sources value to use with this expression. |
| */ |
| public static final int SOURCES = ISources.ACTIVE_SHELL |
| | ISources.ACTIVE_WORKBENCH_WINDOW; |
| |
| /** |
| * The shell that must be active for this expression to evaluate to |
| * <code>true</code>. If this value is <code>null</code>, then any |
| * shell may be active. |
| */ |
| private final Shell activeShell; |
| |
| /** |
| * Constructs a new instance of <code>ActiveShellExpression</code> |
| * |
| * @param activeShell |
| * The shell to match with the active shell; <code>null</code> |
| * if it will match any active shell. |
| */ |
| public ActiveShellExpression(final Shell activeShell) { |
| this.activeShell = activeShell; |
| } |
| |
| /** |
| * Evaluates this expression. If the active shell defined by the context |
| * matches the shell from this expression, then this evaluates to |
| * <code>EvaluationResult.TRUE</code>. Similarly, if the active workbench |
| * window shell defined by the context matches the shell from this |
| * expression, then this evaluates to <code>EvaluationResult.TRUE</code>. |
| * |
| * @param context |
| * The context from which the current state is determined; must |
| * not be <code>null</code>. |
| * @return <code>EvaluationResult.TRUE</code> if the shell is active; |
| * <code>EvaluationResult.FALSE</code> otherwise. |
| */ |
| public final EvaluationResult evaluate(final IEvaluationContext context) { |
| if (activeShell != null) { |
| Object value = context.getVariable(ISources.ACTIVE_SHELL_NAME); |
| if (!activeShell.equals(value)) { |
| value = context |
| .getVariable(ISources.ACTIVE_WORKBENCH_WINDOW_SHELL_NAME); |
| if (!activeShell.equals(value)) { |
| return EvaluationResult.FALSE; |
| } |
| } |
| } |
| |
| return EvaluationResult.TRUE; |
| } |
| |
| public final void collectExpressionInfo(final ExpressionInfo info) { |
| info.addVariableNameAccess(ISources.ACTIVE_SHELL_NAME); |
| info.addVariableNameAccess(ISources.ACTIVE_WORKBENCH_WINDOW_NAME); |
| } |
| |
| public final String toString() { |
| final StringBuffer buffer = new StringBuffer(); |
| buffer.append("ActiveShellExpression("); //$NON-NLS-1$ |
| buffer.append(activeShell); |
| buffer.append(')'); |
| return buffer.toString(); |
| } |
| } |