| /******************************************************************************* |
| * Copyright (c) 2009, 2010 IBM 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 - initial API and implementation |
| ******************************************************************************/ |
| package org.eclipse.equinox.p2.metadata; |
| |
| import org.eclipse.equinox.p2.metadata.expression.IMatchExpression; |
| |
| /** |
| * A requirement represents some external constraint on an {@link IInstallableUnit}. |
| * Each requirement represents something an {@link IInstallableUnit} needs that |
| * it expects to be provided by another {@link IInstallableUnit}. Requirements are |
| * entirely generic, and are intended to be capable of representing anything that |
| * an {@link IInstallableUnit} may need either at install time, or at runtime. |
| * |
| * @noimplement This interface is not intended to be implemented by clients. |
| * @noextend This interface is not intended to be extended by clients. |
| * @since 2.0 |
| */ |
| public interface IRequirement { |
| |
| /** |
| * Returns the minimum cardinality of the requirement. That is, the minimum |
| * number of capabilities that must be provided that match this requirement before |
| * this requirement is considered fully satisfied. A minimum cardinality of 0 indicates |
| * that the requirement is optional. |
| * |
| * @return the minimum cardinality of this requirement |
| */ |
| int getMin(); |
| |
| /** |
| * Returns the maximum cardinality of the requirement. That is, the maximum |
| * number of capabilities that are permitted to be present that satisfy this requirement. |
| * A maximum cardinality of 0 indicates that there must <em>not</em> be |
| * any installable unit in the system that satisfies this requirement. |
| * |
| * @return the maximum cardinality of this requirement |
| */ |
| int getMax(); |
| |
| /** |
| * @noreference This method is not intended to be referenced by clients. |
| */ |
| IMatchExpression<IInstallableUnit> getFilter(); |
| |
| /** |
| * Returns a boolean match expression that will return true for any |
| * {@link IInstallableUnit} that matches the requirement. |
| * @return A boolean match expression for installable unit matching. |
| */ |
| IMatchExpression<IInstallableUnit> getMatches(); |
| |
| /** |
| * Returns whether the provided capabilities of the given installable unit satisfy |
| * this requirement. |
| * |
| * @param iu the installable unit to check for matching capabilities |
| * @return <code>true</code> if the given installable unit satisfies this |
| * requirement, and <code>false</code> otherwise. |
| */ |
| boolean isMatch(IInstallableUnit iu); |
| |
| /** |
| * Returns whether this requirement should cause extra installable units |
| * to be installed in order to satisfy it. |
| * @return <code>true</code> if additional installable units should be installed |
| * to satisfy this requirement, and <code>false</code> otherwise |
| */ |
| boolean isGreedy(); |
| |
| /** |
| * Returns a textual description of this requirement. |
| * |
| * @return a textual description of this requirement |
| */ |
| String getDescription(); |
| |
| } |