PrintFileDocumentAdapter.java revision 798bed6cc7d273e72b0253288605db9cd2b57740 
1/*
2 * Copyright (C) 2013 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package android.print;
18
19import android.content.Context;
20import android.os.AsyncTask;
21import android.os.Bundle;
22import android.os.CancellationSignal;
23import android.os.CancellationSignal.OnCancelListener;
24import android.util.Log;
25
26import com.android.internal.R;
27
28import libcore.io.IoUtils;
29
30import java.io.File;
31import java.io.FileDescriptor;
32import java.io.FileInputStream;
33import java.io.FileOutputStream;
34import java.io.IOException;
35import java.io.InputStream;
36import java.io.OutputStream;
37
38/**
39 * Adapter for printing files. This class could be useful if you
40 * want to print a file and intercept when the system is ready
41 * spooling the data, so you can deleted the file if it is a
42 * temporary one.
43 */
44public final class PrintFileDocumentAdapter extends PrintDocumentAdapter {
45
46    private static final String LOG_TAG = "PrintedFileDocumentAdapter";
47
48    private final Context mContext;
49
50    private final File mFile;
51
52    private final PrintDocumentInfo mDocumentInfo;
53
54    private WriteFileAsyncTask mWriteFileAsyncTask;
55
56    /**
57     * Constructor.
58     *
59     * @param context Context for accessing resources.
60     * @param file The file to print.
61     * @param documentInfo The information about the printed file.
62     */
63    public PrintFileDocumentAdapter(Context context, File file,
64            PrintDocumentInfo documentInfo) {
65        if (file == null) {
66            throw new IllegalArgumentException("File cannot be null!");
67        }
68        if (documentInfo == null) {
69            throw new IllegalArgumentException("documentInfo cannot be null!");
70        }
71        mContext = context;
72        mFile = file;
73        mDocumentInfo = documentInfo;
74    }
75
76    @Override
77    public void onLayout(PrintAttributes oldAttributes, PrintAttributes newAttributes,
78            CancellationSignal cancellationSignal, LayoutResultCallback callback,
79            Bundle metadata) {
80        callback.onLayoutFinished(mDocumentInfo, false);
81    }
82
83    @Override
84    public void onWrite(PageRange[] pages, FileDescriptor destination,
85            CancellationSignal cancellationSignal, WriteResultCallback callback) {
86        mWriteFileAsyncTask = new WriteFileAsyncTask(destination, cancellationSignal, callback);
87        mWriteFileAsyncTask.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR,
88                (Void[]) null);
89    }
90
91    private final class WriteFileAsyncTask extends AsyncTask<Void, Void, Void> {
92
93        private final FileDescriptor mDestination;
94
95        private final WriteResultCallback mResultCallback;
96
97        private final CancellationSignal mCancellationSignal;
98
99        public WriteFileAsyncTask(FileDescriptor destination,
100                CancellationSignal cancellationSignal, WriteResultCallback callback) {
101            mDestination = destination;
102            mResultCallback = callback;
103            mCancellationSignal = cancellationSignal;
104            mCancellationSignal.setOnCancelListener(new OnCancelListener() {
105                @Override
106                public void onCancel() {
107                    cancel(true);
108                }
109            });
110        }
111
112        @Override
113        protected Void doInBackground(Void... params) {
114            InputStream in = null;
115            OutputStream out = new FileOutputStream(mDestination);
116            final byte[] buffer = new byte[8192];
117            try {
118                in = new FileInputStream(mFile);
119                while (true) {
120                    if (isCancelled()) {
121                        break;
122                    }
123                    final int readByteCount = in.read(buffer);
124                    if (readByteCount < 0) {
125                        break;
126                    }
127                    out.write(buffer, 0, readByteCount);
128                }
129             } catch (IOException ioe) {
130                 Log.e(LOG_TAG, "Error writing data!", ioe);
131                 mResultCallback.onWriteFailed(mContext.getString(
132                         R.string.write_fail_reason_cannot_write));
133             } finally {
134                IoUtils.closeQuietly(in);
135                IoUtils.closeQuietly(out);
136            }
137            return null;
138        }
139
140        @Override
141        protected void onPostExecute(Void result) {
142            mResultCallback.onWriteFinished(new PageRange[] {PageRange.ALL_PAGES});
143        }
144
145        @Override
146        protected void onCancelled(Void result) {
147            mResultCallback.onWriteFailed(mContext.getString(
148                    R.string.write_fail_reason_cancelled));
149        }
150    }
151}
152
153