--- /dev/null
+/*******************************************************************************
+ * Copyright (c) 2010, 2014 Sonatype, Inc.
+ * 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:
+ * Sonatype, Inc. - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.aether;
+
+/**
+ * A listener being notified of events from the repository system. In general, the system sends events upon termination
+ * of an operation like {@link #artifactResolved(RepositoryEvent)} regardless whether it succeeded or failed so
+ * listeners need to inspect the event details carefully. Also, the listener may be called from an arbitrary thread.
+ * <em>Note:</em> Implementors are strongly advised to inherit from {@link AbstractRepositoryListener} instead of
+ * directly implementing this interface.
+ *
+ * @see org.eclipse.aether.RepositorySystemSession#getRepositoryListener()
+ * @see org.eclipse.aether.transfer.TransferListener
+ * @noimplement This interface is not intended to be implemented by clients.
+ * @noextend This interface is not intended to be extended by clients.
+ */
+public interface RepositoryListener
+{
+
+ /**
+ * Notifies the listener of a syntactically or semantically invalid artifact descriptor.
+ * {@link RepositoryEvent#getArtifact()} indicates the artifact whose descriptor is invalid and
+ * {@link RepositoryEvent#getExceptions()} carries the encountered errors. Depending on the session's
+ * {@link org.eclipse.aether.resolution.ArtifactDescriptorPolicy}, the underlying repository operation might abort
+ * with an exception or ignore the invalid descriptor.
+ *
+ * @param event The event details, must not be {@code null}.
+ */
+ void artifactDescriptorInvalid( RepositoryEvent event );
+
+ /**
+ * Notifies the listener of a missing artifact descriptor. {@link RepositoryEvent#getArtifact()} indicates the
+ * artifact whose descriptor is missing. Depending on the session's
+ * {@link org.eclipse.aether.resolution.ArtifactDescriptorPolicy}, the underlying repository operation might abort
+ * with an exception or ignore the missing descriptor.
+ *
+ * @param event The event details, must not be {@code null}.
+ */
+ void artifactDescriptorMissing( RepositoryEvent event );
+
+ /**
+ * Notifies the listener of syntactically or semantically invalid metadata. {@link RepositoryEvent#getMetadata()}
+ * indicates the invalid metadata and {@link RepositoryEvent#getExceptions()} carries the encountered errors. The
+ * underlying repository operation might still succeed, depending on whether the metadata in question is actually
+ * needed to carry out the resolution process.
+ *
+ * @param event The event details, must not be {@code null}.
+ */
+ void metadataInvalid( RepositoryEvent event );
+
+ /**
+ * Notifies the listener of an artifact that is about to be resolved. {@link RepositoryEvent#getArtifact()} denotes
+ * the artifact in question. Unlike the {@link #artifactDownloading(RepositoryEvent)} event, this event is fired
+ * regardless whether the artifact already exists locally or not.
+ *
+ * @param event The event details, must not be {@code null}.
+ */
+ void artifactResolving( RepositoryEvent event );
+
+ /**
+ * Notifies the listener of an artifact whose resolution has been completed, either successfully or not.
+ * {@link RepositoryEvent#getArtifact()} denotes the artifact in question and
+ * {@link RepositoryEvent#getExceptions()} indicates whether the resolution succeeded or failed. Unlike the
+ * {@link #artifactDownloaded(RepositoryEvent)} event, this event is fired regardless whether the artifact already
+ * exists locally or not.
+ *
+ * @param event The event details, must not be {@code null}.
+ */
+ void artifactResolved( RepositoryEvent event );
+
+ /**
+ * Notifies the listener of some metadata that is about to be resolved. {@link RepositoryEvent#getMetadata()}
+ * denotes the metadata in question. Unlike the {@link #metadataDownloading(RepositoryEvent)} event, this event is
+ * fired regardless whether the metadata already exists locally or not.
+ *
+ * @param event The event details, must not be {@code null}.
+ */
+ void metadataResolving( RepositoryEvent event );
+
+ /**
+ * Notifies the listener of some metadata whose resolution has been completed, either successfully or not.
+ * {@link RepositoryEvent#getMetadata()} denotes the metadata in question and
+ * {@link RepositoryEvent#getExceptions()} indicates whether the resolution succeeded or failed. Unlike the
+ * {@link #metadataDownloaded(RepositoryEvent)} event, this event is fired regardless whether the metadata already
+ * exists locally or not.
+ *
+ * @param event The event details, must not be {@code null}.
+ */
+ void metadataResolved( RepositoryEvent event );
+
+ /**
+ * Notifies the listener of an artifact that is about to be downloaded from a remote repository.
+ * {@link RepositoryEvent#getArtifact()} denotes the artifact in question and
+ * {@link RepositoryEvent#getRepository()} the source repository. Unlike the
+ * {@link #artifactResolving(RepositoryEvent)} event, this event is only fired when the artifact does not already
+ * exist locally.
+ *
+ * @param event The event details, must not be {@code null}.
+ */
+ void artifactDownloading( RepositoryEvent event );
+
+ /**
+ * Notifies the listener of an artifact whose download has been completed, either successfully or not.
+ * {@link RepositoryEvent#getArtifact()} denotes the artifact in question and
+ * {@link RepositoryEvent#getExceptions()} indicates whether the download succeeded or failed. Unlike the
+ * {@link #artifactResolved(RepositoryEvent)} event, this event is only fired when the artifact does not already
+ * exist locally.
+ *
+ * @param event The event details, must not be {@code null}.
+ */
+ void artifactDownloaded( RepositoryEvent event );
+
+ /**
+ * Notifies the listener of some metadata that is about to be downloaded from a remote repository.
+ * {@link RepositoryEvent#getMetadata()} denotes the metadata in question and
+ * {@link RepositoryEvent#getRepository()} the source repository. Unlike the
+ * {@link #metadataResolving(RepositoryEvent)} event, this event is only fired when the metadata does not already
+ * exist locally.
+ *
+ * @param event The event details, must not be {@code null}.
+ */
+ void metadataDownloading( RepositoryEvent event );
+
+ /**
+ * Notifies the listener of some metadata whose download has been completed, either successfully or not.
+ * {@link RepositoryEvent#getMetadata()} denotes the metadata in question and
+ * {@link RepositoryEvent#getExceptions()} indicates whether the download succeeded or failed. Unlike the
+ * {@link #metadataResolved(RepositoryEvent)} event, this event is only fired when the metadata does not already
+ * exist locally.
+ *
+ * @param event The event details, must not be {@code null}.
+ */
+ void metadataDownloaded( RepositoryEvent event );
+
+ /**
+ * Notifies the listener of an artifact that is about to be installed to the local repository.
+ * {@link RepositoryEvent#getArtifact()} denotes the artifact in question.
+ *
+ * @param event The event details, must not be {@code null}.
+ */
+ void artifactInstalling( RepositoryEvent event );
+
+ /**
+ * Notifies the listener of an artifact whose installation to the local repository has been completed, either
+ * successfully or not. {@link RepositoryEvent#getArtifact()} denotes the artifact in question and
+ * {@link RepositoryEvent#getExceptions()} indicates whether the installation succeeded or failed.
+ *
+ * @param event The event details, must not be {@code null}.
+ */
+ void artifactInstalled( RepositoryEvent event );
+
+ /**
+ * Notifies the listener of some metadata that is about to be installed to the local repository.
+ * {@link RepositoryEvent#getMetadata()} denotes the metadata in question.
+ *
+ * @param event The event details, must not be {@code null}.
+ */
+ void metadataInstalling( RepositoryEvent event );
+
+ /**
+ * Notifies the listener of some metadata whose installation to the local repository has been completed, either
+ * successfully or not. {@link RepositoryEvent#getMetadata()} denotes the metadata in question and
+ * {@link RepositoryEvent#getExceptions()} indicates whether the installation succeeded or failed.
+ *
+ * @param event The event details, must not be {@code null}.
+ */
+ void metadataInstalled( RepositoryEvent event );
+
+ /**
+ * Notifies the listener of an artifact that is about to be uploaded to a remote repository.
+ * {@link RepositoryEvent#getArtifact()} denotes the artifact in question and
+ * {@link RepositoryEvent#getRepository()} the destination repository.
+ *
+ * @param event The event details, must not be {@code null}.
+ */
+ void artifactDeploying( RepositoryEvent event );
+
+ /**
+ * Notifies the listener of an artifact whose upload to a remote repository has been completed, either successfully
+ * or not. {@link RepositoryEvent#getArtifact()} denotes the artifact in question and
+ * {@link RepositoryEvent#getExceptions()} indicates whether the upload succeeded or failed.
+ *
+ * @param event The event details, must not be {@code null}.
+ */
+ void artifactDeployed( RepositoryEvent event );
+
+ /**
+ * Notifies the listener of some metadata that is about to be uploaded to a remote repository.
+ * {@link RepositoryEvent#getMetadata()} denotes the metadata in question and
+ * {@link RepositoryEvent#getRepository()} the destination repository.
+ *
+ * @param event The event details, must not be {@code null}.
+ */
+ void metadataDeploying( RepositoryEvent event );
+
+ /**
+ * Notifies the listener of some metadata whose upload to a remote repository has been completed, either
+ * successfully or not. {@link RepositoryEvent#getMetadata()} denotes the metadata in question and
+ * {@link RepositoryEvent#getExceptions()} indicates whether the upload succeeded or failed.
+ *
+ * @param event The event details, must not be {@code null}.
+ */
+ void metadataDeployed( RepositoryEvent event );
+
+}