src/com/android/documentsui/services/Job.java - LeafOS-Project/android_packages_apps_DocumentsUI - Gitiles

 /*
  * Copyright (C) 2016 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 package com.android.documentsui.services;

 import static android.content.ContentResolver.wrap;

 import static com.android.documentsui.DocumentsApplication.acquireUnstableProviderOrThrow;
 import static com.android.documentsui.services.FileOperationService.EXTRA_CANCEL;
 import static com.android.documentsui.services.FileOperationService.EXTRA_DIALOG_TYPE;
 import static com.android.documentsui.services.FileOperationService.EXTRA_FAILED_DOCS;
 import static com.android.documentsui.services.FileOperationService.EXTRA_FAILED_URIS;
 import static com.android.documentsui.services.FileOperationService.EXTRA_JOB_ID;
 import static com.android.documentsui.services.FileOperationService.EXTRA_OPERATION_TYPE;
 import static com.android.documentsui.services.FileOperationService.OPERATION_UNKNOWN;

 import android.app.Notification;
 import android.app.Notification.Builder;
 import android.app.PendingIntent;
 import android.content.ContentProviderClient;
 import android.content.ContentResolver;
 import android.content.Context;
 import android.content.Intent;
 import android.net.Uri;
 import android.os.CancellationSignal;
 import android.os.DeadObjectException;
 import android.os.FileUtils;
 import android.os.Parcelable;
 import android.os.RemoteException;
 import android.provider.DocumentsContract;
 import android.util.Log;

 import androidx.annotation.DrawableRes;
 import androidx.annotation.IntDef;
 import androidx.annotation.PluralsRes;

 import com.android.documentsui.Metrics;
 import com.android.documentsui.OperationDialogFragment;
 import com.android.documentsui.R;
 import com.android.documentsui.base.DocumentInfo;
 import com.android.documentsui.base.DocumentStack;
 import com.android.documentsui.base.Features;
 import com.android.documentsui.base.Shared;
 import com.android.documentsui.clipping.UrisSupplier;
 import com.android.documentsui.files.FilesActivity;
 import com.android.documentsui.services.FileOperationService.OpType;

 import java.io.FileNotFoundException;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.Map;

 import javax.annotation.Nullable;

 /**
  * A mashup of work item and ui progress update factory. Used by {@link FileOperationService}
  * to do work and show progress relating to this work.
  */
 abstract public class Job implements Runnable {
     private static final String TAG = "Job";

     @Retention(RetentionPolicy.SOURCE)
     @IntDef({STATE_CREATED, STATE_STARTED, STATE_SET_UP, STATE_COMPLETED, STATE_CANCELED})
     @interface State {}
     static final int STATE_CREATED = 0;
     static final int STATE_STARTED = 1;
     static final int STATE_SET_UP = 2;
     static final int STATE_COMPLETED = 3;
     /**
      * A job is in canceled state as long as {@link #cancel()} is called on it, even after it is
      * completed.
      */
     static final int STATE_CANCELED = 4;

     static final String INTENT_TAG_WARNING = "warning";
     static final String INTENT_TAG_FAILURE = "failure";
     static final String INTENT_TAG_PROGRESS = "progress";
     static final String INTENT_TAG_CANCEL = "cancel";

     final Context service;
     final Context appContext;
     final Listener listener;

     final @OpType int operationType;
     final String id;
     final DocumentStack stack;

     final UrisSupplier mResourceUris;

     int failureCount = 0;
     final ArrayList<DocumentInfo> failedDocs = new ArrayList<>();
     final ArrayList<Uri> failedUris = new ArrayList<>();

     final Notification.Builder mProgressBuilder;

     final CancellationSignal mSignal = new CancellationSignal();

     private final Map<String, ContentProviderClient> mClients = new HashMap<>();
     private final Features mFeatures;

     private volatile @State int mState = STATE_CREATED;

     /**
      * A simple progressable job, much like an AsyncTask, but with support
      * for providing various related notification, progress and navigation information.
      * @param service The service context in which this job is running.
      * @param listener
      * @param id Arbitrary string ID
      * @param stack The documents stack context relating to this request. This is the
      *     destination in the Files app where the user will be take when the
      *     navigation intent is invoked (presumably from notification).
      * @param srcs the list of docs to operate on
      */
     Job(Context service, Listener listener, String id,
             @OpType int opType, DocumentStack stack, UrisSupplier srcs, Features features) {

         assert(opType != OPERATION_UNKNOWN);

         this.service = service;
         this.appContext = service.getApplicationContext();
         this.listener = listener;
         this.operationType = opType;

         this.id = id;
         this.stack = stack;
         this.mResourceUris = srcs;

         mFeatures = features;

         mProgressBuilder = createProgressBuilder();
     }

     @Override
     public final void run() {
         if (isCanceled()) {
             // Canceled before running
             return;
         }

         mState = STATE_STARTED;
         listener.onStart(this);

         try {
             boolean result = setUp();
             if (result && !isCanceled()) {
                 mState = STATE_SET_UP;
                 start();
             }
         } catch (RuntimeException e) {
             // No exceptions should be thrown here, as all calls to the provider must be
             // handled within Job implementations. However, just in case catch them here.
             Log.e(TAG, "Operation failed due to an unhandled runtime exception.", e);
             Metrics.logFileOperationErrors(operationType, failedDocs, failedUris);
         } finally {
             mState = (mState == STATE_STARTED || mState == STATE_SET_UP) ? STATE_COMPLETED : mState;
             finish();
             listener.onFinished(this);

             // NOTE: If this details is a JumboClipDetails, and it's still referred in primary clip
             // at this point, user won't be able to paste it to anywhere else because the underlying
             mResourceUris.dispose();
         }
     }

     boolean setUp() {
         return true;
     }

     abstract void finish();

     abstract void start();
     abstract Notification getSetupNotification();
     abstract Notification getProgressNotification();
     abstract Notification getFailureNotification();

     abstract Notification getWarningNotification();

     Uri getDataUriForIntent(String tag) {
         return Uri.parse(String.format("data,%s-%s", tag, id));
     }

     ContentProviderClient getClient(Uri uri) throws RemoteException {
         ContentProviderClient client = mClients.get(uri.getAuthority());
         if (client == null) {
             // Acquire content providers.
             client = acquireUnstableProviderOrThrow(
                     getContentResolver(),
                     uri.getAuthority());

             mClients.put(uri.getAuthority(), client);
         }

         assert(client != null);
         return client;
     }

     ContentProviderClient getClient(DocumentInfo doc) throws RemoteException {
         return getClient(doc.derivedUri);
     }

     void releaseClient(Uri uri) {
         ContentProviderClient client = mClients.get(uri.getAuthority());
         if (client != null) {
             client.close();
             mClients.remove(uri.getAuthority());
         }
     }

     void releaseClient(DocumentInfo doc) {
         releaseClient(doc.derivedUri);
     }

     final void cleanup() {
         for (ContentProviderClient client : mClients.values()) {
             FileUtils.closeQuietly(client);
         }
     }

     final @State int getState() {
         return mState;
     }

     final void cancel() {
         mState = STATE_CANCELED;
         mSignal.cancel();
         Metrics.logFileOperationCancelled(operationType);
     }

     final boolean isCanceled() {
         return mState == STATE_CANCELED;
     }

     final boolean isFinished() {
         return mState == STATE_CANCELED || mState == STATE_COMPLETED;
     }

     final ContentResolver getContentResolver() {
         return service.getContentResolver();
     }

     void onFileFailed(DocumentInfo file) {
         failureCount++;
         failedDocs.add(file);
     }

     void onResolveFailed(Uri uri) {
         failureCount++;
         failedUris.add(uri);
     }

     final boolean hasFailures() {
         return failureCount > 0;
     }

     boolean hasWarnings() {
         return false;
     }

     final void deleteDocument(DocumentInfo doc, @Nullable DocumentInfo parent)
             throws ResourceException {
         try {
             if (parent != null && doc.isRemoveSupported()) {
                 DocumentsContract.removeDocument(wrap(getClient(doc)), doc.derivedUri,
                         parent.derivedUri);
             } else if (doc.isDeleteSupported()) {
                 DocumentsContract.deleteDocument(wrap(getClient(doc)), doc.derivedUri);
             } else {
                 throw new ResourceException("Unable to delete source document. "
                         + "File is not deletable or removable: %s.", doc.derivedUri);
             }
         } catch (FileNotFoundException | RemoteException | RuntimeException e) {
             if (e instanceof DeadObjectException) {
                 releaseClient(doc);
             }
             throw new ResourceException("Failed to delete file %s due to an exception.",
                     doc.derivedUri, e);
         }
     }

     Notification getSetupNotification(String content) {
         mProgressBuilder.setProgress(0, 0, true)
                 .setContentText(content);
         return mProgressBuilder.build();
     }

     Notification getFailureNotification(@PluralsRes int titleId, @DrawableRes int icon) {
         final Intent navigateIntent = buildNavigateIntent(INTENT_TAG_FAILURE);
         navigateIntent.putExtra(EXTRA_DIALOG_TYPE, OperationDialogFragment.DIALOG_TYPE_FAILURE);
         navigateIntent.putExtra(EXTRA_OPERATION_TYPE, operationType);
         navigateIntent.putParcelableArrayListExtra(EXTRA_FAILED_DOCS, failedDocs);
         navigateIntent.putParcelableArrayListExtra(EXTRA_FAILED_URIS, failedUris);

         final Notification.Builder errorBuilder = createNotificationBuilder()
                 .setContentTitle(service.getResources().getQuantityString(titleId,
                         failureCount, failureCount))
                 .setContentText(service.getString(R.string.notification_touch_for_details))
                 .setContentIntent(PendingIntent.getActivity(appContext, 0, navigateIntent,
                         PendingIntent.FLAG_UPDATE_CURRENT | PendingIntent.FLAG_ONE_SHOT
                         | PendingIntent.FLAG_MUTABLE))
                 .setCategory(Notification.CATEGORY_ERROR)
                 .setSmallIcon(icon)
                 .setAutoCancel(true);

         return errorBuilder.build();
     }

     abstract Builder createProgressBuilder();

     final Builder createProgressBuilder(
             String title, @DrawableRes int icon,
             String actionTitle, @DrawableRes int actionIcon) {
         Notification.Builder progressBuilder = createNotificationBuilder()
                 .setContentTitle(title)
                 .setContentIntent(
                         PendingIntent.getActivity(appContext, 0,
                                 buildNavigateIntent(INTENT_TAG_PROGRESS),
                                 PendingIntent.FLAG_IMMUTABLE))
                 .setCategory(Notification.CATEGORY_PROGRESS)
                 .setSmallIcon(icon)
                 .setOngoing(true);

         final Intent cancelIntent = createCancelIntent();

         progressBuilder.addAction(
                 actionIcon,
                 actionTitle,
                 PendingIntent.getService(
                         service,
                         0,
                         cancelIntent,
                         PendingIntent.FLAG_ONE_SHOT | PendingIntent.FLAG_CANCEL_CURRENT
                         | PendingIntent.FLAG_MUTABLE));

         return progressBuilder;
     }

     Notification.Builder createNotificationBuilder() {
         return mFeatures.isNotificationChannelEnabled()
                 ? new Notification.Builder(service, FileOperationService.NOTIFICATION_CHANNEL_ID)
                 : new Notification.Builder(service);
     }

     /**
      * Creates an intent for navigating back to the destination directory.
      */
     Intent buildNavigateIntent(String tag) {
         // TODO (b/35721285): Reuse an existing task rather than creating a new one every time.
         Intent intent = new Intent(service, FilesActivity.class);
         intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
         intent.setData(getDataUriForIntent(tag));
         intent.putExtra(Shared.EXTRA_STACK, (Parcelable) stack);
         return intent;
     }

     Intent createCancelIntent() {
         final Intent cancelIntent = new Intent(service, FileOperationService.class);
         cancelIntent.setData(getDataUriForIntent(INTENT_TAG_CANCEL));
         cancelIntent.putExtra(EXTRA_CANCEL, true);
         cancelIntent.putExtra(EXTRA_JOB_ID, id);
         return cancelIntent;
     }

     @Override
     public String toString() {
         return new StringBuilder()
                 .append("Job")
                 .append("{")
                 .append("id=" + id)
                 .append("}")
                 .toString();
     }

     /**
      * Listener interface employed by the service that owns us as well as tests.
      */
     interface Listener {
         void onStart(Job job);
         void onFinished(Job job);
     }

     /**
      * Interface for tracking job progress.
      */
     interface ProgressTracker {
         default double getProgress() {  return -1; }
         default long getRemainingTimeEstimate() {
             return -1;
         }
     }
 }
	/*
	* Copyright (C) 2016 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	package com.android.documentsui.services;

	import static android.content.ContentResolver.wrap;

	import static com.android.documentsui.DocumentsApplication.acquireUnstableProviderOrThrow;
	import static com.android.documentsui.services.FileOperationService.EXTRA_CANCEL;
	import static com.android.documentsui.services.FileOperationService.EXTRA_DIALOG_TYPE;
	import static com.android.documentsui.services.FileOperationService.EXTRA_FAILED_DOCS;
	import static com.android.documentsui.services.FileOperationService.EXTRA_FAILED_URIS;
	import static com.android.documentsui.services.FileOperationService.EXTRA_JOB_ID;
	import static com.android.documentsui.services.FileOperationService.EXTRA_OPERATION_TYPE;
	import static com.android.documentsui.services.FileOperationService.OPERATION_UNKNOWN;

	import android.app.Notification;
	import android.app.Notification.Builder;
	import android.app.PendingIntent;
	import android.content.ContentProviderClient;
	import android.content.ContentResolver;
	import android.content.Context;
	import android.content.Intent;
	import android.net.Uri;
	import android.os.CancellationSignal;
	import android.os.DeadObjectException;
	import android.os.FileUtils;
	import android.os.Parcelable;
	import android.os.RemoteException;
	import android.provider.DocumentsContract;
	import android.util.Log;

	import androidx.annotation.DrawableRes;
	import androidx.annotation.IntDef;
	import androidx.annotation.PluralsRes;

	import com.android.documentsui.Metrics;
	import com.android.documentsui.OperationDialogFragment;
	import com.android.documentsui.R;
	import com.android.documentsui.base.DocumentInfo;
	import com.android.documentsui.base.DocumentStack;
	import com.android.documentsui.base.Features;
	import com.android.documentsui.base.Shared;
	import com.android.documentsui.clipping.UrisSupplier;
	import com.android.documentsui.files.FilesActivity;
	import com.android.documentsui.services.FileOperationService.OpType;

	import java.io.FileNotFoundException;
	import java.lang.annotation.Retention;
	import java.lang.annotation.RetentionPolicy;
	import java.util.ArrayList;
	import java.util.HashMap;
	import java.util.Map;

	import javax.annotation.Nullable;

	/**
	* A mashup of work item and ui progress update factory. Used by {@link FileOperationService}
	* to do work and show progress relating to this work.
	*/
	abstract public class Job implements Runnable {
	private static final String TAG = "Job";

	@Retention(RetentionPolicy.SOURCE)
	@IntDef({STATE_CREATED, STATE_STARTED, STATE_SET_UP, STATE_COMPLETED, STATE_CANCELED})
	@interface State {}
	static final int STATE_CREATED = 0;
	static final int STATE_STARTED = 1;
	static final int STATE_SET_UP = 2;
	static final int STATE_COMPLETED = 3;
	/**
	* A job is in canceled state as long as {@link #cancel()} is called on it, even after it is
	* completed.
	*/
	static final int STATE_CANCELED = 4;

	static final String INTENT_TAG_WARNING = "warning";
	static final String INTENT_TAG_FAILURE = "failure";
	static final String INTENT_TAG_PROGRESS = "progress";
	static final String INTENT_TAG_CANCEL = "cancel";

	final Context service;
	final Context appContext;
	final Listener listener;

	final @OpType int operationType;
	final String id;
	final DocumentStack stack;

	final UrisSupplier mResourceUris;

	int failureCount = 0;
	final ArrayList<DocumentInfo> failedDocs = new ArrayList<>();
	final ArrayList<Uri> failedUris = new ArrayList<>();

	final Notification.Builder mProgressBuilder;

	final CancellationSignal mSignal = new CancellationSignal();

	private final Map<String, ContentProviderClient> mClients = new HashMap<>();
	private final Features mFeatures;

	private volatile @State int mState = STATE_CREATED;

	/**
	* A simple progressable job, much like an AsyncTask, but with support
	* for providing various related notification, progress and navigation information.
	* @param service The service context in which this job is running.
	* @param listener
	* @param id Arbitrary string ID
	* @param stack The documents stack context relating to this request. This is the
	* destination in the Files app where the user will be take when the
	* navigation intent is invoked (presumably from notification).
	* @param srcs the list of docs to operate on
	*/
	Job(Context service, Listener listener, String id,
	@OpType int opType, DocumentStack stack, UrisSupplier srcs, Features features) {

	assert(opType != OPERATION_UNKNOWN);

	this.service = service;
	this.appContext = service.getApplicationContext();
	this.listener = listener;
	this.operationType = opType;

	this.id = id;
	this.stack = stack;
	this.mResourceUris = srcs;

	mFeatures = features;

	mProgressBuilder = createProgressBuilder();
	}

	@Override
	public final void run() {
	if (isCanceled()) {
	// Canceled before running
	return;
	}

	mState = STATE_STARTED;
	listener.onStart(this);

	try {
	boolean result = setUp();
	if (result && !isCanceled()) {
	mState = STATE_SET_UP;
	start();
	}
	} catch (RuntimeException e) {
	// No exceptions should be thrown here, as all calls to the provider must be
	// handled within Job implementations. However, just in case catch them here.
	Log.e(TAG, "Operation failed due to an unhandled runtime exception.", e);
	Metrics.logFileOperationErrors(operationType, failedDocs, failedUris);
	} finally {
	mState = (mState == STATE_STARTED \|\| mState == STATE_SET_UP) ? STATE_COMPLETED : mState;
	finish();
	listener.onFinished(this);

	// NOTE: If this details is a JumboClipDetails, and it's still referred in primary clip
	// at this point, user won't be able to paste it to anywhere else because the underlying
	mResourceUris.dispose();
	}
	}

	boolean setUp() {
	return true;
	}

	abstract void finish();

	abstract void start();
	abstract Notification getSetupNotification();
	abstract Notification getProgressNotification();
	abstract Notification getFailureNotification();

	abstract Notification getWarningNotification();

	Uri getDataUriForIntent(String tag) {
	return Uri.parse(String.format("data,%s-%s", tag, id));
	}

	ContentProviderClient getClient(Uri uri) throws RemoteException {
	ContentProviderClient client = mClients.get(uri.getAuthority());
	if (client == null) {
	// Acquire content providers.
	client = acquireUnstableProviderOrThrow(
	getContentResolver(),
	uri.getAuthority());

	mClients.put(uri.getAuthority(), client);
	}

	assert(client != null);
	return client;
	}

	ContentProviderClient getClient(DocumentInfo doc) throws RemoteException {
	return getClient(doc.derivedUri);
	}

	void releaseClient(Uri uri) {
	ContentProviderClient client = mClients.get(uri.getAuthority());
	if (client != null) {
	client.close();
	mClients.remove(uri.getAuthority());
	}
	}

	void releaseClient(DocumentInfo doc) {
	releaseClient(doc.derivedUri);
	}

	final void cleanup() {
	for (ContentProviderClient client : mClients.values()) {
	FileUtils.closeQuietly(client);
	}
	}

	final @State int getState() {
	return mState;
	}

	final void cancel() {
	mState = STATE_CANCELED;
	mSignal.cancel();
	Metrics.logFileOperationCancelled(operationType);
	}

	final boolean isCanceled() {
	return mState == STATE_CANCELED;
	}

	final boolean isFinished() {
	return mState == STATE_CANCELED \|\| mState == STATE_COMPLETED;
	}

	final ContentResolver getContentResolver() {
	return service.getContentResolver();
	}

	void onFileFailed(DocumentInfo file) {
	failureCount++;
	failedDocs.add(file);
	}

	void onResolveFailed(Uri uri) {
	failureCount++;
	failedUris.add(uri);
	}

	final boolean hasFailures() {
	return failureCount > 0;
	}

	boolean hasWarnings() {
	return false;
	}

	final void deleteDocument(DocumentInfo doc, @Nullable DocumentInfo parent)
	throws ResourceException {
	try {
	if (parent != null && doc.isRemoveSupported()) {
	DocumentsContract.removeDocument(wrap(getClient(doc)), doc.derivedUri,
	parent.derivedUri);
	} else if (doc.isDeleteSupported()) {
	DocumentsContract.deleteDocument(wrap(getClient(doc)), doc.derivedUri);
	} else {
	throw new ResourceException("Unable to delete source document. "
	+ "File is not deletable or removable: %s.", doc.derivedUri);
	}
	} catch (FileNotFoundException \| RemoteException \| RuntimeException e) {
	if (e instanceof DeadObjectException) {
	releaseClient(doc);
	}
	throw new ResourceException("Failed to delete file %s due to an exception.",
	doc.derivedUri, e);
	}
	}

	Notification getSetupNotification(String content) {
	mProgressBuilder.setProgress(0, 0, true)
	.setContentText(content);
	return mProgressBuilder.build();
	}

	Notification getFailureNotification(@PluralsRes int titleId, @DrawableRes int icon) {
	final Intent navigateIntent = buildNavigateIntent(INTENT_TAG_FAILURE);
	navigateIntent.putExtra(EXTRA_DIALOG_TYPE, OperationDialogFragment.DIALOG_TYPE_FAILURE);
	navigateIntent.putExtra(EXTRA_OPERATION_TYPE, operationType);
	navigateIntent.putParcelableArrayListExtra(EXTRA_FAILED_DOCS, failedDocs);
	navigateIntent.putParcelableArrayListExtra(EXTRA_FAILED_URIS, failedUris);

	final Notification.Builder errorBuilder = createNotificationBuilder()
	.setContentTitle(service.getResources().getQuantityString(titleId,
	failureCount, failureCount))
	.setContentText(service.getString(R.string.notification_touch_for_details))
	.setContentIntent(PendingIntent.getActivity(appContext, 0, navigateIntent,
	PendingIntent.FLAG_UPDATE_CURRENT \| PendingIntent.FLAG_ONE_SHOT
	\| PendingIntent.FLAG_MUTABLE))
	.setCategory(Notification.CATEGORY_ERROR)
	.setSmallIcon(icon)
	.setAutoCancel(true);

	return errorBuilder.build();
	}

	abstract Builder createProgressBuilder();

	final Builder createProgressBuilder(
	String title, @DrawableRes int icon,
	String actionTitle, @DrawableRes int actionIcon) {
	Notification.Builder progressBuilder = createNotificationBuilder()
	.setContentTitle(title)
	.setContentIntent(
	PendingIntent.getActivity(appContext, 0,
	buildNavigateIntent(INTENT_TAG_PROGRESS),
	PendingIntent.FLAG_IMMUTABLE))
	.setCategory(Notification.CATEGORY_PROGRESS)
	.setSmallIcon(icon)
	.setOngoing(true);

	final Intent cancelIntent = createCancelIntent();

	progressBuilder.addAction(
	actionIcon,
	actionTitle,
	PendingIntent.getService(
	service,
	0,
	cancelIntent,
	PendingIntent.FLAG_ONE_SHOT \| PendingIntent.FLAG_CANCEL_CURRENT
	\| PendingIntent.FLAG_MUTABLE));

	return progressBuilder;
	}

	Notification.Builder createNotificationBuilder() {
	return mFeatures.isNotificationChannelEnabled()
	? new Notification.Builder(service, FileOperationService.NOTIFICATION_CHANNEL_ID)
	: new Notification.Builder(service);
	}

	/**
	* Creates an intent for navigating back to the destination directory.
	*/
	Intent buildNavigateIntent(String tag) {
	// TODO (b/35721285): Reuse an existing task rather than creating a new one every time.
	Intent intent = new Intent(service, FilesActivity.class);
	intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
	intent.setData(getDataUriForIntent(tag));
	intent.putExtra(Shared.EXTRA_STACK, (Parcelable) stack);
	return intent;
	}

	Intent createCancelIntent() {
	final Intent cancelIntent = new Intent(service, FileOperationService.class);
	cancelIntent.setData(getDataUriForIntent(INTENT_TAG_CANCEL));
	cancelIntent.putExtra(EXTRA_CANCEL, true);
	cancelIntent.putExtra(EXTRA_JOB_ID, id);
	return cancelIntent;
	}

	@Override
	public String toString() {
	return new StringBuilder()
	.append("Job")
	.append("{")
	.append("id=" + id)
	.append("}")
	.toString();
	}

	/**
	* Listener interface employed by the service that owns us as well as tests.
	*/
	interface Listener {
	void onStart(Job job);
	void onFinished(Job job);
	}

	/**
	* Interface for tracking job progress.
	*/
	interface ProgressTracker {
	default double getProgress() { return -1; }
	default long getRemainingTimeEstimate() {
	return -1;
	}
	}
	}